Imaging

Clinical question: Is MRI safe for patients who have implanted ICD or pacemakers that have not been deemed to be “MRI conditional” by the Food and Drug Administration?

Background: The majority of patients with implantable cardiac devices have a clinical indication for MRI within 10 years. Devices that meet certain criteria specified by the Food and Drug Administration are not felt to pose any safety hazards and are deemed “MRI conditional.” Those that do not meet these criteria are referred to as “legacy” devices and are considered to be a contraindication to MRI by the FDA and device manufacturers. The majority of ICDs and pacemakers currently in use are legacy devices and access to MRI for patients who have these devices has been very limited. This study is the first large prospective study to evaluate the safety of an MRI protocol in patients with legacy ICDs and pacemakers.

Study design: Prospective nonrandomized study.

Setting: Single academic medical center.

Synopsis: During 2003-2015, 1,509 patients with ICDs (629 patients) and pacemakers (880 patients) were enrolled and underwent 2,103 MRI examinations supervised by either an electrophysiologist or a registered nurse with cardiac device programming experience.

Study outcomes included safety and device function immediately after MRI and change in device parameters both immediately after MRI and at long-term follow-up. The most important clinical adverse event that occurred was a reset of device to backup settings referred to as “power on reset” that occurred in nine examinations. Of these nine events, one was associated with mild physical discomfort, one led to device replacement, and one was associated with transient inhibition of pacing. Small changes in P- or R-wave amplitude and atrial or ventricular capture were noted at long-term follow-up. However, none of these were large enough to result in lead revision or device reprogramming. Notable limitations of this study include that it is a single-center study limiting its ability to be generalized and that nearly 20% of patients were lost to long term follow up.

Bottom line: When performed at an institution with an established safety protocol, MRI examinations in patients with legacy devices are not associated with clinically significant adverse safety events or changes in device function that require reprogramming. Multicenter studies are necessary to determine if these results can be generalizable.

Citation: Nazarian S et al. Safety of magnetic resonance imaging in patients with cardiac devices. N Engl J Med. 2017 Dec 28;377(26):2555-64.

Dr. Scaletta is a hospitalist at Denver Health Medical Center and an assistant professor of medicine at the University of Colorado at Denver, Aurora.

Clinical question: Is MRI safe for patients who have implanted ICD or pacemakers that have not been deemed to be “MRI conditional” by the Food and Drug Administration?

Background: The majority of patients with implantable cardiac devices have a clinical indication for MRI within 10 years. Devices that meet certain criteria specified by the Food and Drug Administration are not felt to pose any safety hazards and are deemed “MRI conditional.” Those that do not meet these criteria are referred to as “legacy” devices and are considered to be a contraindication to MRI by the FDA and device manufacturers. The majority of ICDs and pacemakers currently in use are legacy devices and access to MRI for patients who have these devices has been very limited. This study is the first large prospective study to evaluate the safety of an MRI protocol in patients with legacy ICDs and pacemakers.

Study design: Prospective nonrandomized study.

Setting: Single academic medical center.

Synopsis: During 2003-2015, 1,509 patients with ICDs (629 patients) and pacemakers (880 patients) were enrolled and underwent 2,103 MRI examinations supervised by either an electrophysiologist or a registered nurse with cardiac device programming experience.

Study outcomes included safety and device function immediately after MRI and change in device parameters both immediately after MRI and at long-term follow-up. The most important clinical adverse event that occurred was a reset of device to backup settings referred to as “power on reset” that occurred in nine examinations. Of these nine events, one was associated with mild physical discomfort, one led to device replacement, and one was associated with transient inhibition of pacing. Small changes in P- or R-wave amplitude and atrial or ventricular capture were noted at long-term follow-up. However, none of these were large enough to result in lead revision or device reprogramming. Notable limitations of this study include that it is a single-center study limiting its ability to be generalized and that nearly 20% of patients were lost to long term follow up.

Bottom line: When performed at an institution with an established safety protocol, MRI examinations in patients with legacy devices are not associated with clinically significant adverse safety events or changes in device function that require reprogramming. Multicenter studies are necessary to determine if these results can be generalizable.

Citation: Nazarian S et al. Safety of magnetic resonance imaging in patients with cardiac devices. N Engl J Med. 2017 Dec 28;377(26):2555-64.

Dr. Scaletta is a hospitalist at Denver Health Medical Center and an assistant professor of medicine at the University of Colorado at Denver, Aurora.

Clinical question: Is MRI safe for patients who have implanted ICD or pacemakers that have not been deemed to be “MRI conditional” by the Food and Drug Administration?

Background: The majority of patients with implantable cardiac devices have a clinical indication for MRI within 10 years. Devices that meet certain criteria specified by the Food and Drug Administration are not felt to pose any safety hazards and are deemed “MRI conditional.” Those that do not meet these criteria are referred to as “legacy” devices and are considered to be a contraindication to MRI by the FDA and device manufacturers. The majority of ICDs and pacemakers currently in use are legacy devices and access to MRI for patients who have these devices has been very limited. This study is the first large prospective study to evaluate the safety of an MRI protocol in patients with legacy ICDs and pacemakers.

Study design: Prospective nonrandomized study.

Setting: Single academic medical center.

Synopsis: During 2003-2015, 1,509 patients with ICDs (629 patients) and pacemakers (880 patients) were enrolled and underwent 2,103 MRI examinations supervised by either an electrophysiologist or a registered nurse with cardiac device programming experience.

Study outcomes included safety and device function immediately after MRI and change in device parameters both immediately after MRI and at long-term follow-up. The most important clinical adverse event that occurred was a reset of device to backup settings referred to as “power on reset” that occurred in nine examinations. Of these nine events, one was associated with mild physical discomfort, one led to device replacement, and one was associated with transient inhibition of pacing. Small changes in P- or R-wave amplitude and atrial or ventricular capture were noted at long-term follow-up. However, none of these were large enough to result in lead revision or device reprogramming. Notable limitations of this study include that it is a single-center study limiting its ability to be generalized and that nearly 20% of patients were lost to long term follow up.

Bottom line: When performed at an institution with an established safety protocol, MRI examinations in patients with legacy devices are not associated with clinically significant adverse safety events or changes in device function that require reprogramming. Multicenter studies are necessary to determine if these results can be generalizable.

Citation: Nazarian S et al. Safety of magnetic resonance imaging in patients with cardiac devices. N Engl J Med. 2017 Dec 28;377(26):2555-64.

Dr. Scaletta is a hospitalist at Denver Health Medical Center and an assistant professor of medicine at the University of Colorado at Denver, Aurora.

ABSTRACT

Injuries to the distal biceps occur at the tendinous insertion at the radial tuberosity. Distal biceps injuries range from tendinosis to partial tears to non-retracted and retracted complete tears. Acute and chronic complete tears result from a tendinous avulsion at the radial tuberosity. Acute tears result from a strong force exerted on an eccentric biceps contraction, leading to tendon injury.

Distal biceps tendon injuries are uncommon (1.2 per 100,000 patients in one study).¹ An underlying degenerative component is involved in all distal biceps tendon tears and tendinosis.² Partial tears can be caused by the same mechanism or by no particular inciting event.³ Magnetic resonance imaging (MRI) is the optimal imaging modality for distal tendon tears because of its excellent specificity and sensitivity in the detection of complete tears.^4,5 Imaging also accurately diagnoses and characterizes partial tears and tendinosis.⁵ On MRI, fast spin-echo intermediate-weighted and T2-weighted or short tau inversion recovery (STIR) sequences are normally obtained to assess tendon integrity. Along with standard axial and sagittal views, the FABS (flexed elbow, abducted shoulder, supinated forearm) view is an important tool in the diagnosis of distal biceps tendon tears.⁶ The FABS view is obtained with the patient prone with the shoulder abducted 180° (above the head), with the elbow flexed to 90°, and the forearm supinated. This position allows a longitudinal view of along the entire length of the distal tendon.

Complete distal biceps tears can usually be diagnosed by history and physical examinations. However, imaging can be helpful when intact brachialis function can compensate for a completely torn tendon. MRI is also useful in the setting of a complete tear to locate the torn tendon stump, and assess the degree of retraction for tendon retrieval^7,8 and quality of the tendon stump for repair. For associated rupture of the lacertus, the degree of proximal tendon retraction can be significant (Figures 1A, 1B). 

Given that distal biceps tendon rupture occurs as an avulsion at the tendon-bone interface (Figure 2), complete distal biceps tendon tears typically demonstrate no tendon at the insertion on the radial tuberosity with a fluid-filled tendon gap with edema and/or hemorrhage^7,9 or an ill-defined T2-hyperintense mass at the expected site of the tendon.⁷ 

Complete tears without rupture of the lacertus fibrosis (bicipital aponeurosis) will have a small amount of retraction because the intact aponeurosis tethers the torn tendon stump (Figures 3A-3C). 

Chronic complete tears demonstrate heterogeneous signal intensity and fluid signal at the tendon, as well as muscle belly atrophy.⁹ A small percentage of distal biceps brachii tendons are bifid ¹⁰ (Figure 4). 

When injured, 75% have complete rupture of the short head with 17% of these having additional complete rupture of the long head, whereas 50% of those with complete rupture of the short head have partial tear or tendinosis of the long head.

Continue to: Partial distal bicep tears...

 

Partial distal bicep tears are characterized on MRI by focal or partial detachment of the tendon at the radial tuberosity with fluid filling the site of the tear. The degree of partial tearing can be assessed on MRI (Figures 5A, 5B). 

In distal biceps tendinosis, increased signals of thickened tendon fibers at the radial tuberosity are evident without focal discontinuity^7,8 (Figures 6A-6C). Patients may display attenuation of the distal tendon fibers or adjacent fluid distension representing bicipitoradial bursitis (Figures 7A, 7B).

MRI is useful in assessing the distal biceps tendon in the postoperative setting to evaluate the integrity of a repaired tendon. Cortical fixation button technique for repair creates minimal susceptibility artifacts on MRI. Postoperative MRI typically demonstrates a transverse hole drilled through the proximal radius at the site of the tuberosity with a cortical fixation button flush against the posterior radial cortex (Figures 8A-8D). 

The postoperative complication of heterotopic ossification can occasionally be observed on plain radiograph at the site of surgery, but it is less common with the current surgical technique than in the past.¹¹

ABSTRACT

Injuries to the distal biceps occur at the tendinous insertion at the radial tuberosity. Distal biceps injuries range from tendinosis to partial tears to non-retracted and retracted complete tears. Acute and chronic complete tears result from a tendinous avulsion at the radial tuberosity. Acute tears result from a strong force exerted on an eccentric biceps contraction, leading to tendon injury.

Distal biceps tendon injuries are uncommon (1.2 per 100,000 patients in one study).¹ An underlying degenerative component is involved in all distal biceps tendon tears and tendinosis.² Partial tears can be caused by the same mechanism or by no particular inciting event.³ Magnetic resonance imaging (MRI) is the optimal imaging modality for distal tendon tears because of its excellent specificity and sensitivity in the detection of complete tears.^4,5 Imaging also accurately diagnoses and characterizes partial tears and tendinosis.⁵ On MRI, fast spin-echo intermediate-weighted and T2-weighted or short tau inversion recovery (STIR) sequences are normally obtained to assess tendon integrity. Along with standard axial and sagittal views, the FABS (flexed elbow, abducted shoulder, supinated forearm) view is an important tool in the diagnosis of distal biceps tendon tears.⁶ The FABS view is obtained with the patient prone with the shoulder abducted 180° (above the head), with the elbow flexed to 90°, and the forearm supinated. This position allows a longitudinal view of along the entire length of the distal tendon.

Complete distal biceps tears can usually be diagnosed by history and physical examinations. However, imaging can be helpful when intact brachialis function can compensate for a completely torn tendon. MRI is also useful in the setting of a complete tear to locate the torn tendon stump, and assess the degree of retraction for tendon retrieval^7,8 and quality of the tendon stump for repair. For associated rupture of the lacertus, the degree of proximal tendon retraction can be significant (Figures 1A, 1B). 

Given that distal biceps tendon rupture occurs as an avulsion at the tendon-bone interface (Figure 2), complete distal biceps tendon tears typically demonstrate no tendon at the insertion on the radial tuberosity with a fluid-filled tendon gap with edema and/or hemorrhage^7,9 or an ill-defined T2-hyperintense mass at the expected site of the tendon.⁷ 

Complete tears without rupture of the lacertus fibrosis (bicipital aponeurosis) will have a small amount of retraction because the intact aponeurosis tethers the torn tendon stump (Figures 3A-3C). 

Chronic complete tears demonstrate heterogeneous signal intensity and fluid signal at the tendon, as well as muscle belly atrophy.⁹ A small percentage of distal biceps brachii tendons are bifid ¹⁰ (Figure 4). 

When injured, 75% have complete rupture of the short head with 17% of these having additional complete rupture of the long head, whereas 50% of those with complete rupture of the short head have partial tear or tendinosis of the long head.

Continue to: Partial distal bicep tears...

 

Partial distal bicep tears are characterized on MRI by focal or partial detachment of the tendon at the radial tuberosity with fluid filling the site of the tear. The degree of partial tearing can be assessed on MRI (Figures 5A, 5B). 

In distal biceps tendinosis, increased signals of thickened tendon fibers at the radial tuberosity are evident without focal discontinuity^7,8 (Figures 6A-6C). Patients may display attenuation of the distal tendon fibers or adjacent fluid distension representing bicipitoradial bursitis (Figures 7A, 7B).

MRI is useful in assessing the distal biceps tendon in the postoperative setting to evaluate the integrity of a repaired tendon. Cortical fixation button technique for repair creates minimal susceptibility artifacts on MRI. Postoperative MRI typically demonstrates a transverse hole drilled through the proximal radius at the site of the tuberosity with a cortical fixation button flush against the posterior radial cortex (Figures 8A-8D). 

The postoperative complication of heterotopic ossification can occasionally be observed on plain radiograph at the site of surgery, but it is less common with the current surgical technique than in the past.¹¹

ABSTRACT

Injuries to the distal biceps occur at the tendinous insertion at the radial tuberosity. Distal biceps injuries range from tendinosis to partial tears to non-retracted and retracted complete tears. Acute and chronic complete tears result from a tendinous avulsion at the radial tuberosity. Acute tears result from a strong force exerted on an eccentric biceps contraction, leading to tendon injury.

Distal biceps tendon injuries are uncommon (1.2 per 100,000 patients in one study).¹ An underlying degenerative component is involved in all distal biceps tendon tears and tendinosis.² Partial tears can be caused by the same mechanism or by no particular inciting event.³ Magnetic resonance imaging (MRI) is the optimal imaging modality for distal tendon tears because of its excellent specificity and sensitivity in the detection of complete tears.^4,5 Imaging also accurately diagnoses and characterizes partial tears and tendinosis.⁵ On MRI, fast spin-echo intermediate-weighted and T2-weighted or short tau inversion recovery (STIR) sequences are normally obtained to assess tendon integrity. Along with standard axial and sagittal views, the FABS (flexed elbow, abducted shoulder, supinated forearm) view is an important tool in the diagnosis of distal biceps tendon tears.⁶ The FABS view is obtained with the patient prone with the shoulder abducted 180° (above the head), with the elbow flexed to 90°, and the forearm supinated. This position allows a longitudinal view of along the entire length of the distal tendon.

Complete distal biceps tears can usually be diagnosed by history and physical examinations. However, imaging can be helpful when intact brachialis function can compensate for a completely torn tendon. MRI is also useful in the setting of a complete tear to locate the torn tendon stump, and assess the degree of retraction for tendon retrieval^7,8 and quality of the tendon stump for repair. For associated rupture of the lacertus, the degree of proximal tendon retraction can be significant (Figures 1A, 1B). 

Given that distal biceps tendon rupture occurs as an avulsion at the tendon-bone interface (Figure 2), complete distal biceps tendon tears typically demonstrate no tendon at the insertion on the radial tuberosity with a fluid-filled tendon gap with edema and/or hemorrhage^7,9 or an ill-defined T2-hyperintense mass at the expected site of the tendon.⁷ 

Complete tears without rupture of the lacertus fibrosis (bicipital aponeurosis) will have a small amount of retraction because the intact aponeurosis tethers the torn tendon stump (Figures 3A-3C). 

Chronic complete tears demonstrate heterogeneous signal intensity and fluid signal at the tendon, as well as muscle belly atrophy.⁹ A small percentage of distal biceps brachii tendons are bifid ¹⁰ (Figure 4). 

When injured, 75% have complete rupture of the short head with 17% of these having additional complete rupture of the long head, whereas 50% of those with complete rupture of the short head have partial tear or tendinosis of the long head.

Continue to: Partial distal bicep tears...

 

Partial distal bicep tears are characterized on MRI by focal or partial detachment of the tendon at the radial tuberosity with fluid filling the site of the tear. The degree of partial tearing can be assessed on MRI (Figures 5A, 5B). 

In distal biceps tendinosis, increased signals of thickened tendon fibers at the radial tuberosity are evident without focal discontinuity^7,8 (Figures 6A-6C). Patients may display attenuation of the distal tendon fibers or adjacent fluid distension representing bicipitoradial bursitis (Figures 7A, 7B).

MRI is useful in assessing the distal biceps tendon in the postoperative setting to evaluate the integrity of a repaired tendon. Cortical fixation button technique for repair creates minimal susceptibility artifacts on MRI. Postoperative MRI typically demonstrates a transverse hole drilled through the proximal radius at the site of the tuberosity with a cortical fixation button flush against the posterior radial cortex (Figures 8A-8D). 

The postoperative complication of heterotopic ossification can occasionally be observed on plain radiograph at the site of surgery, but it is less common with the current surgical technique than in the past.¹¹

ABSTRACT

Lesser tuberosity osteotomy (LTO) and subscapularis tenotomy (ST) are used for takedown of the subscapularis during shoulder arthroplasty. LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis. However, humeral stem subsidence and loosening may be greater when osteotomy is performed, which may compromise functional outcomes. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique.

During the surgical approach for total shoulder arthroplasty (TSA), the subscapularis is taken down for adequate exposure to the glenohumeral joint. Various methods are available for taking down the subscapularis, including lesser tuberosity osteotomy (LTO) and a subscapularis tenotomy (ST). LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis secondary to bone-to-bone healing. One concern, however, is that humeral stem subsidence may be greater when an osteotomy is performed owing to compromise of metaphyseal cortical bone, which may compromise functional outcomes. The humeral stem design may also influence subsidence when metaphyseal bone proximally is compromised. This is a concern in both metaphyseal and diaphyseal fitting stems. Metaphyseal collars on diaphyseal fitting stems rely on adequate bone stock in the metaphysis to provide the additional support needed. Also, posterior subluxation remains a challenge in shoulder arthroplasty. The integrity of the subscapularis is important in prevention of posterior subluxation.¹ To our knowledge, no study to date has directly compared differences in humeral stem subsidence, loosening, or posterior subluxation between LTO and ST techniques with any humeral stem design. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique. We also hypothesize that no difference in posterior subluxation exists between LTO and ST techniques.

MATERIALS AND METHODS

INCLUSION CRITERIA

Consecutive patients with a minimum of 12 months of radiographic follow-up were selected from 2007 to 2010 after TSA was performed by 1 of the senior authors (Dr. Miller and Dr. Voloshin). Study patients underwent primary TSA for primary osteoarthritis or rheumatoid arthritis.

EXCLUSION CRITERIA

Patients were excluded if they underwent TSA for posttraumatic glenohumeral arthritis, hemiarthroplasty, or osteonecrosis. Patients were also excluded if a rotator cuff tear was discovered intraoperatively or if they had a history of a rotator cuff repair. Additional exclusion criteria included postoperative trauma to the operative shoulder, postoperative infection, extensive documentation of chronic pain, and underlying neurologic disorder (eg, Parkinson disease, dystonia). Patients with a history of diabetes mellitus were not excluded.

SURGICAL TECHNIQUE

All patients underwent TSA via a deltopectoral approach in a modified beach chair position. Biceps tendons were tenodesed at the level of the pectoralis major. All patients received the same proximal collar press-fit implant (Bigliani-Flatow; Zimmer Biomet). These stems provide rotational stability in the metaphyseal segment via fins, vertical stability with the proximal collar, and distal fixation via an interference fit. All parts of the procedure were performed in similar fashion with the exception of ST vs LTO (Figures 1A-1D). 

All patients followed the same postoperative rehabilitation protocol.

Continue to: LTO was performed as the primary...

 

LESSER TUBEROSITY OSTEOTOMY

LTO was performed as the primary or preferred technique of 1 surgeon. After completion of the biceps tenodesis, the lesser tuberosity is reflected off with the subscapularis intact using an osteotome. After placement of the press-fit humeral stem, the LTO is repaired using No. 5 Ethibond Excel sutures (Ethicon) passed through previously created bone tunnels in the greater tuberosity. These sutures are tied over metal buttons over the lateral cortex of the greater tuberosity. Last, the lateral corner of the rotator interval is repaired using a single No. 2 FiberWire (Arthrex).²

SUBSCAPULARIS TENOTOMY

ST is the preferred surgical technique of the second surgeon. After a biceps tenodesis, the subscapularis tendon is released from the lesser tuberosity at the margin of the bicipital groove. Through careful dissection, a single flap including the underlying capsule is created and reflected medially to the level of the coracoid. After placement of the press-fit humeral stem and humeral head, the subscapularis is repaired back in place through previous bone tunnels and with a No. 5 Ethibond Excel suture under the appropriate tension. Then, the lateral corner of the rotator interval is closed using a single No. 2 Ethibond Excel suture in a figure-of-eight fashion.²

RADIOGRAPHIC ANALYSIS

The primary variables analyzed were subsidence and loosening. Additional variables, including humeral-acromial distance (HAD) and subluxation index, were also analyzed to assess for any additional impact caused by subsidence or loosening.³ All radiographic measurements were taken from the Grashey (true anteroposterior) view, except subluxation index, which was calculated using the axillary view. All radiographic measurements were completed by 3 independent reviewers. All radiographs were completed in a consistent manner according to postoperative protocols.

HAD was measured preoperatively, immediately postoperatively, and at final follow-up at a minimum of 1 year. The HAD was measured from the lowest point on the acromion to the humerus using a perpendicular line (Figure 2).

Subsidence of the prosthesis was calculated by determining the difference between immediate postoperative heights of the prosthesis in comparison to the value of the final follow-up films. To calculate the height, 2 lines were drawn, 1 line was drawn perpendicular to the top of the prosthetic head and 1 perpendicular to the top of the greater tuberosity (Figure 3). 

This distance was measured both immediately postoperatively and at final follow-up. The height difference between the 2 time points was used to calculate the subsidence.

Continue to: Posterior subluxation is indicated...

 

Posterior subluxation is indicated by a value >65%, a centered head is between 35% and 65%, and anterior subluxation is indicated by a value <35% (Figure 4).³ 

The subluxation index was calculated using the method outlined by Gerber and colleagues³ using the axillary view radiograph (Figure 4). The midpoint of the glenoid was identified. Then, a perpendicular line (line z) was drawn projecting from the midpoint of the glenoid through the humeral head. Two lines were then drawn in an anterior-to-posterior direction on the humeral head. The first line (measurement A) was drawn from the posterior cortex to the previous perpendicular line (line z). The second line (measurement B) was drawn from the posterior to the anterior cortex. Measurements A and B should be calculated at the same height on the humeral head, roughly at the anatomic neck. The subluxation index is then calculated as A/B × 100. This was calculated both preoperatively and postoperatively.

The humeral stems were evaluated for loosening by assessing for lucency on final radiographic follow-up films. These were evaluated in a zonal fashion as demonstrated by Sanchez-Sotelo and colleagues⁴ and in Figure 5. 

The humeral stem-bone interface was evaluated in 8 radiographic zones. A lucency was not considered significant unless >2 mm. The zone of lucency was then determined for any significant lucencies. Zones 1 and 7 were at the level of the neck component, zones 2 and 6 were at the proximal half of the stem component, and zones 3 and 5 were at the distal half of the stem component. Zone 8 was noted directly inferior to the humeral head prosthesis.⁴

FUNCTIONAL OUTCOME EVALUATION

Before clinical evaluation, each study patient completed the Western Ontario Osteoarthritis of the Shoulder (WOOS) index; the Disabilities of the Hand, Arm and Shoulder (DASH) questionnaire, and the pain and function sections of the Constant score. The functional outcomes scores were captured postoperatively from October to November 2011. The WOOS is a validated outcome measure specific to osteoarthritis of the shoulder and has been used in prior studies evaluating outcomes of TSA.^5-7 Previous studies have determined that the minimal clinically important difference for the WOOS score is 15 on a normalized 0 to 100 scale (100 being the best). The DASH score is a validated outcome measure for disorders of the upper extremity but is not specific to osteoarthritis of the shoulder.⁸ The Constant score is a validated outcome measure for a number of shoulder disorders, including TSA.^9,10

STATISTICAL ANALYSIS

Statistical analyses were completed by a trained biostatistician. A power analysis was calculated using the noninferiority test to determine if adequate data had been obtained for this study. This was calculated by using previously accepted data demonstrating a statistically significant difference for subsidence and HAD. The data from these studies were used to make assumptions regarding accepted standard deviations and noninferiority margins, as calculated from the mean values of the 2 groups analyzed in each respective study.^4,11 This analysis demonstrated power of 0.97 and 0.85 for the subsidence and HAD, respectively, given the current sample sizes. Intraclass coefficients were calculated to evaluate the measurements obtained during the radiographic analysis to determine the interrater agreement. Two samples’ t tests were calculated for the variables analyzed, along with P values and means.

RESULTS

DEMOGRAPHICS

A total of 51 consecutive patients were retrospectively selected for analysis. Of these, 16 patients were excluded from the study because they had <9 months of radiographic follow-up and were unavailable for further follow-up evaluation. Of the remaining 35 patients available for analysis, 4 patients had bilateral TSA, providing 39 shoulders for evaluation. Demographic characteristics of the study cohort are reported in Table 1.

Table 1. Demographic Characteristics
	Tenotomy (n = 24)	Osteotomy (n = 15)	P-value
Age	68.2 [7.4]	70.2 [7.1]	0.46
Follow-up	20.6 [11.5]	18.5 [6.25]	0.94
Females	7 (29%)	6 (40%)	0.58
Dominant shoulder	14 (58%)	8 (53%)	0.81
Primary Diagnosis
Osteoarthritis	22 (92%)	15 (100%)
Rheumatoid arthritis	2 (8%)	0 (0%)

  Fifteen patients underwent LTO, and 24 underwent ST. One patient underwent a tenotomy of the right shoulder and LTO of the left shoulder. Three LTOs were performed by the surgeon who primarily performed ST, owing to potential benefits of LTO. He eventually returned to his preferred technique of ST because of surgeon preference. Three ST procedures were completed by the surgeon who typically performed LTO at the start of the series prior to establishing LTO as his preferred technique. There was no significant difference between the study populations in terms of age, follow-up, male-to-female ratio, hand dominance, and primary diagnosis of osteoarthritis vs rheumatoid arthritis.

Continue to: There was no significant difference...

 

RADIOGRAPHIC DATA

There was no significant difference in preoperative HAD between the LTO and ST groups (9.5 ± 2.4 mm vs 10.9 ± 2.7 mm, P = .11). The immediate postoperative HAD was statistically significant between the LTO and ST groups (11.9 ± 3.7 mm vs 15.9 ± 4.5 mm, P = .005). There was as statistically significant difference noted in the final follow-up films between the LTO and ST groups (11.8 ± 3.2 mm vs 14.5 ± 3.9 mm, P = .025) (Table 2). 

Table 2. Radiographic Data
Humeral Acromial Distance
	LTO		ST		P-Value
Preoperative, mm	9.5	[2.4]	10.9	[2.7]	0.11
Postoperative, mm	11.9	[3.7]	15.9	[4.5]	0.005
Final follow-up, mm	11.8	[3.2]	14.5	[3.9]	0.025
Subsidence
	LTO		ST		P-Value
Subsidence, mm	2.8	[3.1]	2.5	[3.1]	0.72
Subluxation Index
	LTO		ST		P-Value
Preoperative, %	0.55	[0.06]	0.54	[0.07]	0.45
Postoperative, %	0.55	[0.09]	0.48	[0.05]	0.015
Lucent Lines
	LTO		ST		P-Value
Lines >2 mm, %	0.00		0.08		0.51

Abbreviations: LTO, lesser tuberosity osteotomy; ST, subscapularis tenotomy.

There were no statistically significant differences found in subsidence between LTO and ST groups at final follow-up (2.8 mm ± 3.1 mm vs 2.5 mm ± 3.1 mm, P = .72) (Table 2). No statistically significant difference was noted in the subluxation index between the LTO and ST groups (0.55% ± .06% vs 0.54% ± 0.07%, P = .45), but there was a statistically significant difference noted postoperatively between the LTO and ST groups (0.55% ± 0.09% vs .48% ± 0.05%, P = .015) (Table 2).

Two stems were noted to have lucent lines >2 mm, both within the ST cohort. Each had 1 stem zone >2 mm, 1 in zone 7, and 1 in zone 4. No statistically significant difference was identified between the LTO and ST groups (0/15 vs 2/24, P = .51) (Table 2).

FUNCTIONAL OUTCOMES

Study patients were evaluated using functional outcome scores, including the Constant, WOOS, and DASH scores (Table 3). 

Table 3. Functional Data
	LTO		ST		P-Value
WOOS index	93.3	[5.3]	81.5	[20.8]	0.013
DASH score	8.4	[6.6]	13.8	[4.9]	0.13
Constant score	83.3	[9.1]	81.8	[10.1]	0.64

Abbreviations: DASH, disabilities of the arm, shoulder and hand; WOOS, Western Ontario Osteoarthritis of the Shoulder.

No statistically significant differences were noted in the DASH scores (8.4 ± 6.6 vs 13.8 ± 4.9, P = .13) or Constant scores (83.3 ± 9.1 vs 81.8 ± 10.1, P = .64) between the LTO and ST cohorts. There was a statistically significant difference between the WOOS scores (93.3 ± 5.3 vs 81.5 ± 20.8, P = .013). Because separate radiographic reviews were done by 3 independent personnel at 3 different times, it was important to ensure agreement among the reviewers. This was compared using the intraclass correlation coefficients. In the statistical analysis completed, the intraclass coefficients showed the 3 reviewers agreed with each other throughout the radiographic analysis (Table 4).

Table 4. Testing Agreement: ICC
		ICC	CI, 2.5%	CI, 97.5%
HAD	Preoperative	0.4451	0.2202	0.6443
	Postoperative	0.6997	0.4836	0.834
	Final follow-up	0.5575	0.3592	0.7218
Subsidence		0.6863	0.5349	0.807
SI	Preoperative	0.3087	0.1061	0.5213
	Final follow-up	0.5364	0.299	0.7186

Abbreviations: CI, confidence interval; HAD, humeral acromial distance; ICC, intraclass correlation coefficient; SI, subluxation index.

DISCUSSION

At final follow-up, we identified no statistically significant difference between the LTO and ST patients in subsidence, lucent lines >2 mm, or functional outcomes (Constant and DASH scores) in patients who underwent TSA with the same proximal collar press-fit humeral stem. In regard to the functional outcome scores, although the WOOS score was statistically significant (P = .013) between the LTO and ST cohorts, we do not feel that this is clinically relevant because it does not reach the minimal clinically important difference threshold of 15 points.⁸

A statistically significant difference was noted in postoperative subluxation index but was not clinically relevant, because the values between the LTO and ST groups (0.55 vs 0.48) still showed a centered humeral head. Gerber and colleagues³ discussed using a value of 0.65 as a measure of posterior humeral head subluxation, whereas Walch and colleagues¹² defined posterior humeral head subluxation as a value >0.55. On the basis of these numbers, the values obtained in this study demonstrated that the postoperative values were still centered on the glenoid, and therefore were not clinically significant.^3,12

Continue to: In regard to HAD, there...

 

In regard to HAD, there was a statistically significant difference noted postoperatively (P = .005) and at final follow-up (P = .025) between the LTO and ST cohorts. Saupe and colleagues¹³ demonstrated that a HAD <7 mm was considered abnormal and reflected subacromial space narrowing. The values noted in the LTO and ST patients on postoperative and final follow-up radiographs were statistically significant (Table 2), but not clinically relevant because both were >7 mm. A potential source for the variation in HAD may be due to X-ray position and angle.

Studies have shown a concern regarding the integrity of the subscapularis after tenotomy or peel used in TSA with abnormal subscapularis function.^14,15 Miller and colleagues¹⁵ reported 41 patients, nearly two-thirds, of whom described subscapularis dysfunction. Those authors’ response to the poor clinical outcomes was to remove a fleck of bone with the tendon to achieve “bone-to-bone” healing.¹⁴ Gerber and colleagues¹⁶ reported on a series of patients using LTO and repair in TSA with 75% and 89% intact subscapularis function on clinical testing.¹⁶ Studies by Qureshi and colleagues¹⁷ and Scalise and colleagues¹⁸ showed similar results after LTO. Biomechanical studies have shown mixed results. Ponce and colleagues¹⁹ showed biomechanically superior results for LTO in comparison to the various repair techniques for ST. In another study, Giuseffi and colleagues²⁰ showed no difference in LTO vs ST during biomechanical testing. In response to the increased concern regarding subscapularis integrity, Caplan and colleagues²¹ reported on 45 arthroplasties in 43 patients with improved postoperative testing with intact subscapularis testing in 90% to 100% of patients. A level 1 randomized control trial conducted by Lapner and colleagues²² did not demonstrate any clear clinical advantage of LTO vs ST. Controversy still exists regarding which is the preferred technique for TSA.

Sanchez-Sotelo and colleagues⁴ evaluated uncemented humeral components in 72 patients who underwent TSA. They found a humeral component was at risk for loosening if a radiolucent line ≥2 mm was present in at least 3 radiographic zones. They also evaluated tilt or subsidence by measurement and whether the components were observed to have changed. Their measured values correlated with their observed values. That study provided a benchmark for evaluation of loosening and subsidence used during this study.⁴ Although radiographic follow-up is limited in this study, we feel that any potential subsidence secondary to use of the LTO technique would be radiographically apparent at 1 year. There were 16 patients without adequate radiographic follow-up included in the study. However, we feel that this was not a large concern, because the study was adequately powered with the patients available to determine a difference based on subsidence.

CONCLUSION

We found no difference in subsidence, lucent lines >2 mm, posterior subluxation, and the Constant and DASH functional outcome scores when we compared TSA performed by a LTO with an ST technique with proximal collar press-fit humeral stem. These data cannot be extrapolated to metaphyseal fit stems, which may exhibit different settling characteristics in the setting of the LTO technique.

This paper will be judged for the Resident Writer’s Award.

ABSTRACT

Lesser tuberosity osteotomy (LTO) and subscapularis tenotomy (ST) are used for takedown of the subscapularis during shoulder arthroplasty. LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis. However, humeral stem subsidence and loosening may be greater when osteotomy is performed, which may compromise functional outcomes. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique.

During the surgical approach for total shoulder arthroplasty (TSA), the subscapularis is taken down for adequate exposure to the glenohumeral joint. Various methods are available for taking down the subscapularis, including lesser tuberosity osteotomy (LTO) and a subscapularis tenotomy (ST). LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis secondary to bone-to-bone healing. One concern, however, is that humeral stem subsidence may be greater when an osteotomy is performed owing to compromise of metaphyseal cortical bone, which may compromise functional outcomes. The humeral stem design may also influence subsidence when metaphyseal bone proximally is compromised. This is a concern in both metaphyseal and diaphyseal fitting stems. Metaphyseal collars on diaphyseal fitting stems rely on adequate bone stock in the metaphysis to provide the additional support needed. Also, posterior subluxation remains a challenge in shoulder arthroplasty. The integrity of the subscapularis is important in prevention of posterior subluxation.¹ To our knowledge, no study to date has directly compared differences in humeral stem subsidence, loosening, or posterior subluxation between LTO and ST techniques with any humeral stem design. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique. We also hypothesize that no difference in posterior subluxation exists between LTO and ST techniques.

MATERIALS AND METHODS

INCLUSION CRITERIA

Consecutive patients with a minimum of 12 months of radiographic follow-up were selected from 2007 to 2010 after TSA was performed by 1 of the senior authors (Dr. Miller and Dr. Voloshin). Study patients underwent primary TSA for primary osteoarthritis or rheumatoid arthritis.

EXCLUSION CRITERIA

Patients were excluded if they underwent TSA for posttraumatic glenohumeral arthritis, hemiarthroplasty, or osteonecrosis. Patients were also excluded if a rotator cuff tear was discovered intraoperatively or if they had a history of a rotator cuff repair. Additional exclusion criteria included postoperative trauma to the operative shoulder, postoperative infection, extensive documentation of chronic pain, and underlying neurologic disorder (eg, Parkinson disease, dystonia). Patients with a history of diabetes mellitus were not excluded.

SURGICAL TECHNIQUE

All patients underwent TSA via a deltopectoral approach in a modified beach chair position. Biceps tendons were tenodesed at the level of the pectoralis major. All patients received the same proximal collar press-fit implant (Bigliani-Flatow; Zimmer Biomet). These stems provide rotational stability in the metaphyseal segment via fins, vertical stability with the proximal collar, and distal fixation via an interference fit. All parts of the procedure were performed in similar fashion with the exception of ST vs LTO (Figures 1A-1D). 

All patients followed the same postoperative rehabilitation protocol.

Continue to: LTO was performed as the primary...

 

LESSER TUBEROSITY OSTEOTOMY

LTO was performed as the primary or preferred technique of 1 surgeon. After completion of the biceps tenodesis, the lesser tuberosity is reflected off with the subscapularis intact using an osteotome. After placement of the press-fit humeral stem, the LTO is repaired using No. 5 Ethibond Excel sutures (Ethicon) passed through previously created bone tunnels in the greater tuberosity. These sutures are tied over metal buttons over the lateral cortex of the greater tuberosity. Last, the lateral corner of the rotator interval is repaired using a single No. 2 FiberWire (Arthrex).²

SUBSCAPULARIS TENOTOMY

ST is the preferred surgical technique of the second surgeon. After a biceps tenodesis, the subscapularis tendon is released from the lesser tuberosity at the margin of the bicipital groove. Through careful dissection, a single flap including the underlying capsule is created and reflected medially to the level of the coracoid. After placement of the press-fit humeral stem and humeral head, the subscapularis is repaired back in place through previous bone tunnels and with a No. 5 Ethibond Excel suture under the appropriate tension. Then, the lateral corner of the rotator interval is closed using a single No. 2 Ethibond Excel suture in a figure-of-eight fashion.²

RADIOGRAPHIC ANALYSIS

The primary variables analyzed were subsidence and loosening. Additional variables, including humeral-acromial distance (HAD) and subluxation index, were also analyzed to assess for any additional impact caused by subsidence or loosening.³ All radiographic measurements were taken from the Grashey (true anteroposterior) view, except subluxation index, which was calculated using the axillary view. All radiographic measurements were completed by 3 independent reviewers. All radiographs were completed in a consistent manner according to postoperative protocols.

HAD was measured preoperatively, immediately postoperatively, and at final follow-up at a minimum of 1 year. The HAD was measured from the lowest point on the acromion to the humerus using a perpendicular line (Figure 2).

Subsidence of the prosthesis was calculated by determining the difference between immediate postoperative heights of the prosthesis in comparison to the value of the final follow-up films. To calculate the height, 2 lines were drawn, 1 line was drawn perpendicular to the top of the prosthetic head and 1 perpendicular to the top of the greater tuberosity (Figure 3). 

This distance was measured both immediately postoperatively and at final follow-up. The height difference between the 2 time points was used to calculate the subsidence.

Continue to: Posterior subluxation is indicated...

 

Posterior subluxation is indicated by a value >65%, a centered head is between 35% and 65%, and anterior subluxation is indicated by a value <35% (Figure 4).³ 

The subluxation index was calculated using the method outlined by Gerber and colleagues³ using the axillary view radiograph (Figure 4). The midpoint of the glenoid was identified. Then, a perpendicular line (line z) was drawn projecting from the midpoint of the glenoid through the humeral head. Two lines were then drawn in an anterior-to-posterior direction on the humeral head. The first line (measurement A) was drawn from the posterior cortex to the previous perpendicular line (line z). The second line (measurement B) was drawn from the posterior to the anterior cortex. Measurements A and B should be calculated at the same height on the humeral head, roughly at the anatomic neck. The subluxation index is then calculated as A/B × 100. This was calculated both preoperatively and postoperatively.

The humeral stems were evaluated for loosening by assessing for lucency on final radiographic follow-up films. These were evaluated in a zonal fashion as demonstrated by Sanchez-Sotelo and colleagues⁴ and in Figure 5. 

The humeral stem-bone interface was evaluated in 8 radiographic zones. A lucency was not considered significant unless >2 mm. The zone of lucency was then determined for any significant lucencies. Zones 1 and 7 were at the level of the neck component, zones 2 and 6 were at the proximal half of the stem component, and zones 3 and 5 were at the distal half of the stem component. Zone 8 was noted directly inferior to the humeral head prosthesis.⁴

FUNCTIONAL OUTCOME EVALUATION

Before clinical evaluation, each study patient completed the Western Ontario Osteoarthritis of the Shoulder (WOOS) index; the Disabilities of the Hand, Arm and Shoulder (DASH) questionnaire, and the pain and function sections of the Constant score. The functional outcomes scores were captured postoperatively from October to November 2011. The WOOS is a validated outcome measure specific to osteoarthritis of the shoulder and has been used in prior studies evaluating outcomes of TSA.^5-7 Previous studies have determined that the minimal clinically important difference for the WOOS score is 15 on a normalized 0 to 100 scale (100 being the best). The DASH score is a validated outcome measure for disorders of the upper extremity but is not specific to osteoarthritis of the shoulder.⁸ The Constant score is a validated outcome measure for a number of shoulder disorders, including TSA.^9,10

STATISTICAL ANALYSIS

Statistical analyses were completed by a trained biostatistician. A power analysis was calculated using the noninferiority test to determine if adequate data had been obtained for this study. This was calculated by using previously accepted data demonstrating a statistically significant difference for subsidence and HAD. The data from these studies were used to make assumptions regarding accepted standard deviations and noninferiority margins, as calculated from the mean values of the 2 groups analyzed in each respective study.^4,11 This analysis demonstrated power of 0.97 and 0.85 for the subsidence and HAD, respectively, given the current sample sizes. Intraclass coefficients were calculated to evaluate the measurements obtained during the radiographic analysis to determine the interrater agreement. Two samples’ t tests were calculated for the variables analyzed, along with P values and means.

RESULTS

DEMOGRAPHICS

A total of 51 consecutive patients were retrospectively selected for analysis. Of these, 16 patients were excluded from the study because they had <9 months of radiographic follow-up and were unavailable for further follow-up evaluation. Of the remaining 35 patients available for analysis, 4 patients had bilateral TSA, providing 39 shoulders for evaluation. Demographic characteristics of the study cohort are reported in Table 1.

Table 1. Demographic Characteristics
	Tenotomy (n = 24)	Osteotomy (n = 15)	P-value
Age	68.2 [7.4]	70.2 [7.1]	0.46
Follow-up	20.6 [11.5]	18.5 [6.25]	0.94
Females	7 (29%)	6 (40%)	0.58
Dominant shoulder	14 (58%)	8 (53%)	0.81
Primary Diagnosis
Osteoarthritis	22 (92%)	15 (100%)
Rheumatoid arthritis	2 (8%)	0 (0%)

  Fifteen patients underwent LTO, and 24 underwent ST. One patient underwent a tenotomy of the right shoulder and LTO of the left shoulder. Three LTOs were performed by the surgeon who primarily performed ST, owing to potential benefits of LTO. He eventually returned to his preferred technique of ST because of surgeon preference. Three ST procedures were completed by the surgeon who typically performed LTO at the start of the series prior to establishing LTO as his preferred technique. There was no significant difference between the study populations in terms of age, follow-up, male-to-female ratio, hand dominance, and primary diagnosis of osteoarthritis vs rheumatoid arthritis.

Continue to: There was no significant difference...

 

RADIOGRAPHIC DATA

There was no significant difference in preoperative HAD between the LTO and ST groups (9.5 ± 2.4 mm vs 10.9 ± 2.7 mm, P = .11). The immediate postoperative HAD was statistically significant between the LTO and ST groups (11.9 ± 3.7 mm vs 15.9 ± 4.5 mm, P = .005). There was as statistically significant difference noted in the final follow-up films between the LTO and ST groups (11.8 ± 3.2 mm vs 14.5 ± 3.9 mm, P = .025) (Table 2). 

Table 2. Radiographic Data
Humeral Acromial Distance
	LTO		ST		P-Value
Preoperative, mm	9.5	[2.4]	10.9	[2.7]	0.11
Postoperative, mm	11.9	[3.7]	15.9	[4.5]	0.005
Final follow-up, mm	11.8	[3.2]	14.5	[3.9]	0.025
Subsidence
	LTO		ST		P-Value
Subsidence, mm	2.8	[3.1]	2.5	[3.1]	0.72
Subluxation Index
	LTO		ST		P-Value
Preoperative, %	0.55	[0.06]	0.54	[0.07]	0.45
Postoperative, %	0.55	[0.09]	0.48	[0.05]	0.015
Lucent Lines
	LTO		ST		P-Value
Lines >2 mm, %	0.00		0.08		0.51

Abbreviations: LTO, lesser tuberosity osteotomy; ST, subscapularis tenotomy.

There were no statistically significant differences found in subsidence between LTO and ST groups at final follow-up (2.8 mm ± 3.1 mm vs 2.5 mm ± 3.1 mm, P = .72) (Table 2). No statistically significant difference was noted in the subluxation index between the LTO and ST groups (0.55% ± .06% vs 0.54% ± 0.07%, P = .45), but there was a statistically significant difference noted postoperatively between the LTO and ST groups (0.55% ± 0.09% vs .48% ± 0.05%, P = .015) (Table 2).

Two stems were noted to have lucent lines >2 mm, both within the ST cohort. Each had 1 stem zone >2 mm, 1 in zone 7, and 1 in zone 4. No statistically significant difference was identified between the LTO and ST groups (0/15 vs 2/24, P = .51) (Table 2).

FUNCTIONAL OUTCOMES

Study patients were evaluated using functional outcome scores, including the Constant, WOOS, and DASH scores (Table 3). 

Table 3. Functional Data
	LTO		ST		P-Value
WOOS index	93.3	[5.3]	81.5	[20.8]	0.013
DASH score	8.4	[6.6]	13.8	[4.9]	0.13
Constant score	83.3	[9.1]	81.8	[10.1]	0.64

Abbreviations: DASH, disabilities of the arm, shoulder and hand; WOOS, Western Ontario Osteoarthritis of the Shoulder.

No statistically significant differences were noted in the DASH scores (8.4 ± 6.6 vs 13.8 ± 4.9, P = .13) or Constant scores (83.3 ± 9.1 vs 81.8 ± 10.1, P = .64) between the LTO and ST cohorts. There was a statistically significant difference between the WOOS scores (93.3 ± 5.3 vs 81.5 ± 20.8, P = .013). Because separate radiographic reviews were done by 3 independent personnel at 3 different times, it was important to ensure agreement among the reviewers. This was compared using the intraclass correlation coefficients. In the statistical analysis completed, the intraclass coefficients showed the 3 reviewers agreed with each other throughout the radiographic analysis (Table 4).

Table 4. Testing Agreement: ICC
		ICC	CI, 2.5%	CI, 97.5%
HAD	Preoperative	0.4451	0.2202	0.6443
	Postoperative	0.6997	0.4836	0.834
	Final follow-up	0.5575	0.3592	0.7218
Subsidence		0.6863	0.5349	0.807
SI	Preoperative	0.3087	0.1061	0.5213
	Final follow-up	0.5364	0.299	0.7186

Abbreviations: CI, confidence interval; HAD, humeral acromial distance; ICC, intraclass correlation coefficient; SI, subluxation index.

DISCUSSION

At final follow-up, we identified no statistically significant difference between the LTO and ST patients in subsidence, lucent lines >2 mm, or functional outcomes (Constant and DASH scores) in patients who underwent TSA with the same proximal collar press-fit humeral stem. In regard to the functional outcome scores, although the WOOS score was statistically significant (P = .013) between the LTO and ST cohorts, we do not feel that this is clinically relevant because it does not reach the minimal clinically important difference threshold of 15 points.⁸

A statistically significant difference was noted in postoperative subluxation index but was not clinically relevant, because the values between the LTO and ST groups (0.55 vs 0.48) still showed a centered humeral head. Gerber and colleagues³ discussed using a value of 0.65 as a measure of posterior humeral head subluxation, whereas Walch and colleagues¹² defined posterior humeral head subluxation as a value >0.55. On the basis of these numbers, the values obtained in this study demonstrated that the postoperative values were still centered on the glenoid, and therefore were not clinically significant.^3,12

Continue to: In regard to HAD, there...

 

In regard to HAD, there was a statistically significant difference noted postoperatively (P = .005) and at final follow-up (P = .025) between the LTO and ST cohorts. Saupe and colleagues¹³ demonstrated that a HAD <7 mm was considered abnormal and reflected subacromial space narrowing. The values noted in the LTO and ST patients on postoperative and final follow-up radiographs were statistically significant (Table 2), but not clinically relevant because both were >7 mm. A potential source for the variation in HAD may be due to X-ray position and angle.

Studies have shown a concern regarding the integrity of the subscapularis after tenotomy or peel used in TSA with abnormal subscapularis function.^14,15 Miller and colleagues¹⁵ reported 41 patients, nearly two-thirds, of whom described subscapularis dysfunction. Those authors’ response to the poor clinical outcomes was to remove a fleck of bone with the tendon to achieve “bone-to-bone” healing.¹⁴ Gerber and colleagues¹⁶ reported on a series of patients using LTO and repair in TSA with 75% and 89% intact subscapularis function on clinical testing.¹⁶ Studies by Qureshi and colleagues¹⁷ and Scalise and colleagues¹⁸ showed similar results after LTO. Biomechanical studies have shown mixed results. Ponce and colleagues¹⁹ showed biomechanically superior results for LTO in comparison to the various repair techniques for ST. In another study, Giuseffi and colleagues²⁰ showed no difference in LTO vs ST during biomechanical testing. In response to the increased concern regarding subscapularis integrity, Caplan and colleagues²¹ reported on 45 arthroplasties in 43 patients with improved postoperative testing with intact subscapularis testing in 90% to 100% of patients. A level 1 randomized control trial conducted by Lapner and colleagues²² did not demonstrate any clear clinical advantage of LTO vs ST. Controversy still exists regarding which is the preferred technique for TSA.

Sanchez-Sotelo and colleagues⁴ evaluated uncemented humeral components in 72 patients who underwent TSA. They found a humeral component was at risk for loosening if a radiolucent line ≥2 mm was present in at least 3 radiographic zones. They also evaluated tilt or subsidence by measurement and whether the components were observed to have changed. Their measured values correlated with their observed values. That study provided a benchmark for evaluation of loosening and subsidence used during this study.⁴ Although radiographic follow-up is limited in this study, we feel that any potential subsidence secondary to use of the LTO technique would be radiographically apparent at 1 year. There were 16 patients without adequate radiographic follow-up included in the study. However, we feel that this was not a large concern, because the study was adequately powered with the patients available to determine a difference based on subsidence.

CONCLUSION

We found no difference in subsidence, lucent lines >2 mm, posterior subluxation, and the Constant and DASH functional outcome scores when we compared TSA performed by a LTO with an ST technique with proximal collar press-fit humeral stem. These data cannot be extrapolated to metaphyseal fit stems, which may exhibit different settling characteristics in the setting of the LTO technique.

This paper will be judged for the Resident Writer’s Award.

ABSTRACT

Lesser tuberosity osteotomy (LTO) and subscapularis tenotomy (ST) are used for takedown of the subscapularis during shoulder arthroplasty. LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis. However, humeral stem subsidence and loosening may be greater when osteotomy is performed, which may compromise functional outcomes. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique.

During the surgical approach for total shoulder arthroplasty (TSA), the subscapularis is taken down for adequate exposure to the glenohumeral joint. Various methods are available for taking down the subscapularis, including lesser tuberosity osteotomy (LTO) and a subscapularis tenotomy (ST). LTO offers the theoretical but unproven benefit of improved healing and function of the subscapularis secondary to bone-to-bone healing. One concern, however, is that humeral stem subsidence may be greater when an osteotomy is performed owing to compromise of metaphyseal cortical bone, which may compromise functional outcomes. The humeral stem design may also influence subsidence when metaphyseal bone proximally is compromised. This is a concern in both metaphyseal and diaphyseal fitting stems. Metaphyseal collars on diaphyseal fitting stems rely on adequate bone stock in the metaphysis to provide the additional support needed. Also, posterior subluxation remains a challenge in shoulder arthroplasty. The integrity of the subscapularis is important in prevention of posterior subluxation.¹ To our knowledge, no study to date has directly compared differences in humeral stem subsidence, loosening, or posterior subluxation between LTO and ST techniques with any humeral stem design. Our hypothesis is that no difference in proximal collar press-fit humeral stem subsidence or loosening exists, with no impairment of functional outcomes using the LTO technique. We also hypothesize that no difference in posterior subluxation exists between LTO and ST techniques.

MATERIALS AND METHODS

INCLUSION CRITERIA

Consecutive patients with a minimum of 12 months of radiographic follow-up were selected from 2007 to 2010 after TSA was performed by 1 of the senior authors (Dr. Miller and Dr. Voloshin). Study patients underwent primary TSA for primary osteoarthritis or rheumatoid arthritis.

EXCLUSION CRITERIA

Patients were excluded if they underwent TSA for posttraumatic glenohumeral arthritis, hemiarthroplasty, or osteonecrosis. Patients were also excluded if a rotator cuff tear was discovered intraoperatively or if they had a history of a rotator cuff repair. Additional exclusion criteria included postoperative trauma to the operative shoulder, postoperative infection, extensive documentation of chronic pain, and underlying neurologic disorder (eg, Parkinson disease, dystonia). Patients with a history of diabetes mellitus were not excluded.

SURGICAL TECHNIQUE

All patients underwent TSA via a deltopectoral approach in a modified beach chair position. Biceps tendons were tenodesed at the level of the pectoralis major. All patients received the same proximal collar press-fit implant (Bigliani-Flatow; Zimmer Biomet). These stems provide rotational stability in the metaphyseal segment via fins, vertical stability with the proximal collar, and distal fixation via an interference fit. All parts of the procedure were performed in similar fashion with the exception of ST vs LTO (Figures 1A-1D). 

All patients followed the same postoperative rehabilitation protocol.

Continue to: LTO was performed as the primary...

 

LESSER TUBEROSITY OSTEOTOMY

LTO was performed as the primary or preferred technique of 1 surgeon. After completion of the biceps tenodesis, the lesser tuberosity is reflected off with the subscapularis intact using an osteotome. After placement of the press-fit humeral stem, the LTO is repaired using No. 5 Ethibond Excel sutures (Ethicon) passed through previously created bone tunnels in the greater tuberosity. These sutures are tied over metal buttons over the lateral cortex of the greater tuberosity. Last, the lateral corner of the rotator interval is repaired using a single No. 2 FiberWire (Arthrex).²

SUBSCAPULARIS TENOTOMY

ST is the preferred surgical technique of the second surgeon. After a biceps tenodesis, the subscapularis tendon is released from the lesser tuberosity at the margin of the bicipital groove. Through careful dissection, a single flap including the underlying capsule is created and reflected medially to the level of the coracoid. After placement of the press-fit humeral stem and humeral head, the subscapularis is repaired back in place through previous bone tunnels and with a No. 5 Ethibond Excel suture under the appropriate tension. Then, the lateral corner of the rotator interval is closed using a single No. 2 Ethibond Excel suture in a figure-of-eight fashion.²

RADIOGRAPHIC ANALYSIS

The primary variables analyzed were subsidence and loosening. Additional variables, including humeral-acromial distance (HAD) and subluxation index, were also analyzed to assess for any additional impact caused by subsidence or loosening.³ All radiographic measurements were taken from the Grashey (true anteroposterior) view, except subluxation index, which was calculated using the axillary view. All radiographic measurements were completed by 3 independent reviewers. All radiographs were completed in a consistent manner according to postoperative protocols.

HAD was measured preoperatively, immediately postoperatively, and at final follow-up at a minimum of 1 year. The HAD was measured from the lowest point on the acromion to the humerus using a perpendicular line (Figure 2).

Subsidence of the prosthesis was calculated by determining the difference between immediate postoperative heights of the prosthesis in comparison to the value of the final follow-up films. To calculate the height, 2 lines were drawn, 1 line was drawn perpendicular to the top of the prosthetic head and 1 perpendicular to the top of the greater tuberosity (Figure 3). 

This distance was measured both immediately postoperatively and at final follow-up. The height difference between the 2 time points was used to calculate the subsidence.

Continue to: Posterior subluxation is indicated...

 

Posterior subluxation is indicated by a value >65%, a centered head is between 35% and 65%, and anterior subluxation is indicated by a value <35% (Figure 4).³ 

The subluxation index was calculated using the method outlined by Gerber and colleagues³ using the axillary view radiograph (Figure 4). The midpoint of the glenoid was identified. Then, a perpendicular line (line z) was drawn projecting from the midpoint of the glenoid through the humeral head. Two lines were then drawn in an anterior-to-posterior direction on the humeral head. The first line (measurement A) was drawn from the posterior cortex to the previous perpendicular line (line z). The second line (measurement B) was drawn from the posterior to the anterior cortex. Measurements A and B should be calculated at the same height on the humeral head, roughly at the anatomic neck. The subluxation index is then calculated as A/B × 100. This was calculated both preoperatively and postoperatively.

The humeral stems were evaluated for loosening by assessing for lucency on final radiographic follow-up films. These were evaluated in a zonal fashion as demonstrated by Sanchez-Sotelo and colleagues⁴ and in Figure 5. 

The humeral stem-bone interface was evaluated in 8 radiographic zones. A lucency was not considered significant unless >2 mm. The zone of lucency was then determined for any significant lucencies. Zones 1 and 7 were at the level of the neck component, zones 2 and 6 were at the proximal half of the stem component, and zones 3 and 5 were at the distal half of the stem component. Zone 8 was noted directly inferior to the humeral head prosthesis.⁴

FUNCTIONAL OUTCOME EVALUATION

Before clinical evaluation, each study patient completed the Western Ontario Osteoarthritis of the Shoulder (WOOS) index; the Disabilities of the Hand, Arm and Shoulder (DASH) questionnaire, and the pain and function sections of the Constant score. The functional outcomes scores were captured postoperatively from October to November 2011. The WOOS is a validated outcome measure specific to osteoarthritis of the shoulder and has been used in prior studies evaluating outcomes of TSA.^5-7 Previous studies have determined that the minimal clinically important difference for the WOOS score is 15 on a normalized 0 to 100 scale (100 being the best). The DASH score is a validated outcome measure for disorders of the upper extremity but is not specific to osteoarthritis of the shoulder.⁸ The Constant score is a validated outcome measure for a number of shoulder disorders, including TSA.^9,10

STATISTICAL ANALYSIS

Statistical analyses were completed by a trained biostatistician. A power analysis was calculated using the noninferiority test to determine if adequate data had been obtained for this study. This was calculated by using previously accepted data demonstrating a statistically significant difference for subsidence and HAD. The data from these studies were used to make assumptions regarding accepted standard deviations and noninferiority margins, as calculated from the mean values of the 2 groups analyzed in each respective study.^4,11 This analysis demonstrated power of 0.97 and 0.85 for the subsidence and HAD, respectively, given the current sample sizes. Intraclass coefficients were calculated to evaluate the measurements obtained during the radiographic analysis to determine the interrater agreement. Two samples’ t tests were calculated for the variables analyzed, along with P values and means.

RESULTS

DEMOGRAPHICS

A total of 51 consecutive patients were retrospectively selected for analysis. Of these, 16 patients were excluded from the study because they had <9 months of radiographic follow-up and were unavailable for further follow-up evaluation. Of the remaining 35 patients available for analysis, 4 patients had bilateral TSA, providing 39 shoulders for evaluation. Demographic characteristics of the study cohort are reported in Table 1.

Table 1. Demographic Characteristics
	Tenotomy (n = 24)	Osteotomy (n = 15)	P-value
Age	68.2 [7.4]	70.2 [7.1]	0.46
Follow-up	20.6 [11.5]	18.5 [6.25]	0.94
Females	7 (29%)	6 (40%)	0.58
Dominant shoulder	14 (58%)	8 (53%)	0.81
Primary Diagnosis
Osteoarthritis	22 (92%)	15 (100%)
Rheumatoid arthritis	2 (8%)	0 (0%)

  Fifteen patients underwent LTO, and 24 underwent ST. One patient underwent a tenotomy of the right shoulder and LTO of the left shoulder. Three LTOs were performed by the surgeon who primarily performed ST, owing to potential benefits of LTO. He eventually returned to his preferred technique of ST because of surgeon preference. Three ST procedures were completed by the surgeon who typically performed LTO at the start of the series prior to establishing LTO as his preferred technique. There was no significant difference between the study populations in terms of age, follow-up, male-to-female ratio, hand dominance, and primary diagnosis of osteoarthritis vs rheumatoid arthritis.

Continue to: There was no significant difference...

 

RADIOGRAPHIC DATA

There was no significant difference in preoperative HAD between the LTO and ST groups (9.5 ± 2.4 mm vs 10.9 ± 2.7 mm, P = .11). The immediate postoperative HAD was statistically significant between the LTO and ST groups (11.9 ± 3.7 mm vs 15.9 ± 4.5 mm, P = .005). There was as statistically significant difference noted in the final follow-up films between the LTO and ST groups (11.8 ± 3.2 mm vs 14.5 ± 3.9 mm, P = .025) (Table 2). 

Table 2. Radiographic Data
Humeral Acromial Distance
	LTO		ST		P-Value
Preoperative, mm	9.5	[2.4]	10.9	[2.7]	0.11
Postoperative, mm	11.9	[3.7]	15.9	[4.5]	0.005
Final follow-up, mm	11.8	[3.2]	14.5	[3.9]	0.025
Subsidence
	LTO		ST		P-Value
Subsidence, mm	2.8	[3.1]	2.5	[3.1]	0.72
Subluxation Index
	LTO		ST		P-Value
Preoperative, %	0.55	[0.06]	0.54	[0.07]	0.45
Postoperative, %	0.55	[0.09]	0.48	[0.05]	0.015
Lucent Lines
	LTO		ST		P-Value
Lines >2 mm, %	0.00		0.08		0.51

Abbreviations: LTO, lesser tuberosity osteotomy; ST, subscapularis tenotomy.

There were no statistically significant differences found in subsidence between LTO and ST groups at final follow-up (2.8 mm ± 3.1 mm vs 2.5 mm ± 3.1 mm, P = .72) (Table 2). No statistically significant difference was noted in the subluxation index between the LTO and ST groups (0.55% ± .06% vs 0.54% ± 0.07%, P = .45), but there was a statistically significant difference noted postoperatively between the LTO and ST groups (0.55% ± 0.09% vs .48% ± 0.05%, P = .015) (Table 2).

Two stems were noted to have lucent lines >2 mm, both within the ST cohort. Each had 1 stem zone >2 mm, 1 in zone 7, and 1 in zone 4. No statistically significant difference was identified between the LTO and ST groups (0/15 vs 2/24, P = .51) (Table 2).

FUNCTIONAL OUTCOMES

Study patients were evaluated using functional outcome scores, including the Constant, WOOS, and DASH scores (Table 3). 

Table 3. Functional Data
	LTO		ST		P-Value
WOOS index	93.3	[5.3]	81.5	[20.8]	0.013
DASH score	8.4	[6.6]	13.8	[4.9]	0.13
Constant score	83.3	[9.1]	81.8	[10.1]	0.64

Abbreviations: DASH, disabilities of the arm, shoulder and hand; WOOS, Western Ontario Osteoarthritis of the Shoulder.

No statistically significant differences were noted in the DASH scores (8.4 ± 6.6 vs 13.8 ± 4.9, P = .13) or Constant scores (83.3 ± 9.1 vs 81.8 ± 10.1, P = .64) between the LTO and ST cohorts. There was a statistically significant difference between the WOOS scores (93.3 ± 5.3 vs 81.5 ± 20.8, P = .013). Because separate radiographic reviews were done by 3 independent personnel at 3 different times, it was important to ensure agreement among the reviewers. This was compared using the intraclass correlation coefficients. In the statistical analysis completed, the intraclass coefficients showed the 3 reviewers agreed with each other throughout the radiographic analysis (Table 4).

Table 4. Testing Agreement: ICC
		ICC	CI, 2.5%	CI, 97.5%
HAD	Preoperative	0.4451	0.2202	0.6443
	Postoperative	0.6997	0.4836	0.834
	Final follow-up	0.5575	0.3592	0.7218
Subsidence		0.6863	0.5349	0.807
SI	Preoperative	0.3087	0.1061	0.5213
	Final follow-up	0.5364	0.299	0.7186

Abbreviations: CI, confidence interval; HAD, humeral acromial distance; ICC, intraclass correlation coefficient; SI, subluxation index.

DISCUSSION

At final follow-up, we identified no statistically significant difference between the LTO and ST patients in subsidence, lucent lines >2 mm, or functional outcomes (Constant and DASH scores) in patients who underwent TSA with the same proximal collar press-fit humeral stem. In regard to the functional outcome scores, although the WOOS score was statistically significant (P = .013) between the LTO and ST cohorts, we do not feel that this is clinically relevant because it does not reach the minimal clinically important difference threshold of 15 points.⁸

A statistically significant difference was noted in postoperative subluxation index but was not clinically relevant, because the values between the LTO and ST groups (0.55 vs 0.48) still showed a centered humeral head. Gerber and colleagues³ discussed using a value of 0.65 as a measure of posterior humeral head subluxation, whereas Walch and colleagues¹² defined posterior humeral head subluxation as a value >0.55. On the basis of these numbers, the values obtained in this study demonstrated that the postoperative values were still centered on the glenoid, and therefore were not clinically significant.^3,12

Continue to: In regard to HAD, there...

 

In regard to HAD, there was a statistically significant difference noted postoperatively (P = .005) and at final follow-up (P = .025) between the LTO and ST cohorts. Saupe and colleagues¹³ demonstrated that a HAD <7 mm was considered abnormal and reflected subacromial space narrowing. The values noted in the LTO and ST patients on postoperative and final follow-up radiographs were statistically significant (Table 2), but not clinically relevant because both were >7 mm. A potential source for the variation in HAD may be due to X-ray position and angle.

Studies have shown a concern regarding the integrity of the subscapularis after tenotomy or peel used in TSA with abnormal subscapularis function.^14,15 Miller and colleagues¹⁵ reported 41 patients, nearly two-thirds, of whom described subscapularis dysfunction. Those authors’ response to the poor clinical outcomes was to remove a fleck of bone with the tendon to achieve “bone-to-bone” healing.¹⁴ Gerber and colleagues¹⁶ reported on a series of patients using LTO and repair in TSA with 75% and 89% intact subscapularis function on clinical testing.¹⁶ Studies by Qureshi and colleagues¹⁷ and Scalise and colleagues¹⁸ showed similar results after LTO. Biomechanical studies have shown mixed results. Ponce and colleagues¹⁹ showed biomechanically superior results for LTO in comparison to the various repair techniques for ST. In another study, Giuseffi and colleagues²⁰ showed no difference in LTO vs ST during biomechanical testing. In response to the increased concern regarding subscapularis integrity, Caplan and colleagues²¹ reported on 45 arthroplasties in 43 patients with improved postoperative testing with intact subscapularis testing in 90% to 100% of patients. A level 1 randomized control trial conducted by Lapner and colleagues²² did not demonstrate any clear clinical advantage of LTO vs ST. Controversy still exists regarding which is the preferred technique for TSA.

Sanchez-Sotelo and colleagues⁴ evaluated uncemented humeral components in 72 patients who underwent TSA. They found a humeral component was at risk for loosening if a radiolucent line ≥2 mm was present in at least 3 radiographic zones. They also evaluated tilt or subsidence by measurement and whether the components were observed to have changed. Their measured values correlated with their observed values. That study provided a benchmark for evaluation of loosening and subsidence used during this study.⁴ Although radiographic follow-up is limited in this study, we feel that any potential subsidence secondary to use of the LTO technique would be radiographically apparent at 1 year. There were 16 patients without adequate radiographic follow-up included in the study. However, we feel that this was not a large concern, because the study was adequately powered with the patients available to determine a difference based on subsidence.

CONCLUSION

We found no difference in subsidence, lucent lines >2 mm, posterior subluxation, and the Constant and DASH functional outcome scores when we compared TSA performed by a LTO with an ST technique with proximal collar press-fit humeral stem. These data cannot be extrapolated to metaphyseal fit stems, which may exhibit different settling characteristics in the setting of the LTO technique.

This paper will be judged for the Resident Writer’s Award.

ABSTRACT

Dual-energy X-ray absorptiometry (DXA) is a well-established technology with an important and well-known role in measuring bone mineral density (BMD) for the purpose of determining fracture risk, diagnosing osteoporosis, and monitoring treatment efficacy. However, aside from the assessment of bone status, DXA is likely underutilized in the field of orthopedics, and most orthopedists may not be aware of the full capabilities of DXA, particularly with regard to total body scans and body composition assessment. For example, DXA would be a valuable tool for monitoring body composition after surgery where compensatory changes in the affected limb may lead to right-left asymmetry (eg, tracking lean mass change after knee surgery), rehabilitation regimens for athletes, congenital and metabolic disorders that affect the musculoskeletal system, or monitoring sarcopenia and frailty in the elderly. Furthermore, preoperative and postoperative regional scans can track BMD changes during healing or alert surgeons to impending problems such as loss of periprosthetic bone, which could lead to implant failure. This article discusses the capabilities of DXA and how this technology could be better used to the advantage of the attending orthopedist.

Dual-energy X-ray absorptiometry, abbreviated as “DXA,” (although usually abbreviated in older literature as “DEXA”) was first introduced in 1987 (Hologic QDR-1000 system, Hologic, Inc) and immediately made all previous forms of radiation-based bone mineral density (BMD) measurement systems obsolete.¹ Since then, there have been many generations of the technology, with the main US manufacturers in 2017 being Hologic, Inc. and GE Lunar. There are 2 forms of DXA, peripheral systems (which usually measure BMD only in the radius, finger bones, or calcaneus) and central systems (which measure the radius, proximal femur [“hip”], lumbar spine, total body, and custom sites). The general principle of how DXA works is based on the differential attenuation of photons by bone, fat, and lean mass.² The DXA technique uses a low- and high-energy X-ray beam produced by an X-ray tube. With the low-energy beam, attenuation by bone is greater than attenuation by soft tissue. With the high-energy beam, attenuation by bone and soft tissues are similar. The dual X-ray beams are passed through the body regions being scanned (usually posterioanteriorly), and the differential attenuation by bone and soft tissue is analyzed to produce BMD estimates. In addition, a high-quality image is produced to enable the operator of the DXA system to verify that the appropriate body region was scanned. It is important to realize that DXA is 2-dimensional (which is sometimes cited as a weakness of DXA), and the units of BMD are grams of mineral per centimeter squared (g/cm²).

Continue to: When assessing bone status...

 

When assessing bone status for the purpose of determining if a patient is normal, osteopenic, or osteoporotic, the skeletal sites (called regions of interest [ROI]) typically scanned are the proximal femur, lumbar spine, and radius. The BMD of the patient is then compared to a manufacturer-provided normative database of young adults (the logic being that the BMD in the young adult normative population represents maximal peak bone mass). Total body BMD and body composition can also be quantified (grams of lean and fat mass), and custom scans can be designed for other skeletal sites. Specifically, a patient’s BMD is compared to a database of sex- and age-adjusted normal values, and the deviation from normal is expressed as a T-score (the number of standard deviations the patient's BMD is above or below the average BMD of the young adult reference population) and Z-scores (the number of standard deviations a patient's BMD is above or below the average BMD of a sex- and age-matched reference population).³ The International Society for Clinical Densitometry (ISCD) has developed and published well-accepted guidelines used to assist in acquiring high-quality DXA scans and for the diagnosis of osteoporosis using BMD. The accuracy and, especially, the precision of DXA scans can be remarkable when they are performed by trained technologists, and thus, serial scans can be performed to monitor BMD and body composition changes with aging or in response to treatment.

Because of the nature of the scan mechanics and speed, the effective radiation dose with DXA is very low, expressed in microSieverts.^4,5 Generally, the radiation exposure from a series of the lumbar spine, proximal femur, and distal radius is about the same as daily background radiation. Even total body scans present very low exposure due to the scan speed at which any 1 body part is exposed for only a fraction of a second.

BENEFITS OF USING DXA FOR THE ORTHEOPEDIST

At the time of this writing in 2018, the presumption could be made that most physicians in the specialties of internal medicine, rheumatology, endocrinology, radiology, and orthopedics were familiar with the capabilities of DXA to assess BMD for the purpose of diagnosing osteoporosis. However, DXA is likely underused for other purposes, as orthopedists may be unaware of the full capabilities of DXA. Printouts after a scan contain more information than simply BMD, and there are more features and applications of DXA that can potentially be useful to orthopedists.

BONE SIZE

Data from a DXA scan are expressed not only as g/cm² (BMD) but also as total grams in the ROI (known as bone mineral content, abbreviated as BMC), and cm² (area of the ROI). These data may appear on a separate page, being considered ancillary results. The latter 2 variables are rarely included on a report sent to a referring physician; therefore, awareness of their value is probably limited. However, there are instances where such information could be valuable when interpreting results, especially bone size.^6,7 For example, on occasion, patients present with osteopenic lumbar vertebrate but larger than normal vertebral size (area). Many studies have shown that bone size is directly related to bone strength and thus fracture risk.^8,9 Although an understudied phenomenon, large vertebral body size could be protective, counteracting a lower than optimal BMD. Further, because the area of the ROI is measured, it is possible to calculate the bone width (or measure directly with a ruler tool in the software if available) for the area measured. This is especially feasible for tubular bones such as the midshaft of the radius, or more specifically, the classic DXA ROI being the area approximately one third the length of the radius from the distal end, the radius 33% region (actually based on ulna length). Consequently, it is possible to use the width of the radius 33% ROI in addition to BMD and T-score when assessing fracture risk.

CASE STUDY

A 60-year-old man had a DXA series of the lumbar spine, proximal femur, and whole body. His total body T-score was 0.6 (normal), and his total proximal femur T-score was −0.8 (normal), but his lumbar spine vertebrae 2 to 4 T-score was −1.9. As the patient was osteopenic based on the lumbar spine T-score, some physicians may have initiated antiresorptive therapy, especially if other risk factors for fracture were present. Further examination of the ancillary results of the DXA scan revealed that the vertebral body height T-score was a remarkable 1.11 and 1.53 after adjustment for stature (automatic software calculation). These results suggested that the patient had vertebral bodies of above average size, which theoretically would be protective against fracture even though the BMD T-score was below normal. For this patient, this finding mitigated immediate concern about the lumbar spine T-score of −1.9. Although vertebral body size is not typically used in assessing fracture risk, it is useful information that could be factored into the decision to start treatment or watch for further change with aging.

Continue to: Case Series: Distal Radius Fractures...

 

CASE SERIES: DISTAL RADIUS FRACTURES

Table 1 summarizes the data comparing radius 33% ROI T-scores and ROI width in patients who fractured the contralateral radius and normal nonfractured controls.¹⁰  

Table 1. Comparison of Radius Width at the 33% Region of Interest (ROI) and Bone Mineral Density T-Scores in Premenopausal Women With and Without Fractures

	33% ROI T-score	Width of ROI, cm
White women with distal radius fractures
Premenopausal (<49 years), n = 36	-0.2 + 0.9	1.22 + 0.11a
Controls matched for race, age, BMIb
Premenopausal (<49 years), n = 65	-0.1 + 0.8	1.45 + 0.25

For premenopausal women with distal radius fractures, the width of the radius at the radius 33% ROI was significantly smaller than that in controls. However, there was no difference in T-scores between premenopausal women with distal radius fractures and controls. Thus, bone width more accurately identified women with fractures than T-scores based on BMD, and the orthopedist could use bone size in addition to BMD to predict fracture risk in a patient.

PREPARATION FOR SURGERY

For some procedures, there is potential benefit of assessing bone status prior to surgery. That is, determination of low BMD could potentially influence the type of hardware or fixation techniques used in surgery. Various studies have shown that poor bone quality and low BMD can impair purchase with various types of fixation.^11-13 Low preoperative BMD has been shown to be related to high implant migration.¹⁴ Knowledge of BMD could influence the choice of screw type used or the type of implant metal (titanium vs cobalt chrome). Another example is predicting the risk of spine curvature progression in adolescent idiopathic scoliosis.^15-17 It has been reported that low BMD is a risk factor for progression.¹⁵ Knowledge of BMD could potentially help with patient management strategies. For example, a patient with low BMD and vitamin D deficiency could be treated (vitamin D supplementation) prior to planning surgery in an effort to improve the low BMD.

PERIOPROSTHETIC BMD

It is possible to monitor changes in BMD around implants using the periprosthetic software application (this usually needs to be purchased separately from standard software that is installed with a system set-up). Dramatic loss of bone due to stress shielding after total hip arthroplasty (THA) can be a risk factor for implant migration or potentially outright failure of fixation or breakthrough. If bone loss occurs and is observed in the early stages, then antiresorptive treatment can be initiated to limit further loss.^18,19 (Figure 1) shows the image from a periprosthetic scan. 

Standard Gruen zones are the default ROIs.²⁰ It is well established that BMD loss differs from zone to zone, with the greatest loss in zone 7 after THA.

Continue to: A 60-year-old, 215-lb man...

 

CASE REPORT

A 60-year-old, 215-lb man had a total hip replacement using a newly introduced cemented collared cobalt-chromium alloy femoral stem. A baseline periprosthetic DXA scan was performed 6 weeks postoperatively. Compared to baseline, the change in BMD in the Gruen zone 5 was −8.2%, +6.5%, +4.9%, and +9.46% at 3, 6, 12, and 24 months, respectively. In contrast, dramatic BMD loss was seen in Gruen zone 7 (calcar region): −33.2%, −40.8%, −37.1%, and −34.1% at 3, 6, 12, and 24 months, respectively. Similar findings in other patients led to discontinuation of use of this stem in favor of a collarless stem in which less BMD loss was seen in Gruen zone 7. Although additional technologist training is required and scans may not be reimbursable, for research purposes or for evaluating new component prototypes, the periprosthetic DXA scan capability can be useful.

Various other custom scans can be used to detect and quantify vertebral fractures (vertebral fracture assessment application), monitor healing of fractures by scanning through radiolucent cast materials, or for research purposes to assess BMD at unusual locations.^21-23 Other new innovations, such as the ability to perform full-length scans of the femoral shaft and to quantify focal thickening of the lateral cortex to identify beaking, an abnormality associated with atypical femur fracture after long-term bisphosphonate use, continue to expand the utility of DXA. Using standard software, cadaver bones can be scanned prior to biomechanical testing for a variety of purposes, such as ensuring proper matching specimens in test groups. It has been reported that the common practice of using contralateral bone specimens can lead to bias, as the BMD can be significantly different in right and left bones from the same individual.^9,24

TOTAL BODY BMD AND BODY COMPOSITION SCANS

Perhaps the least understood capability of DXA from our experience working with orthopedists is the ability to perform total body scans and to obtain not only total body and regional BMD but also body composition data, namely grams of lean and fat mass.²⁵ Soft tissue (no bone pixels) is partitioned into fat and lean body mass by a calibration procedure (lean mass = total soft tissue –fat mass). DXA has become the standard for body composition assessment given the ease of data acquisition (a total body scan takes only a few minutes), accuracy, and precision of measurements. Compared with other methods (eg, skinfold thickness, bioelectrical impedance, and underwater weighing), it is the only method that gives regional values for fat mass, lean mass, and BMC (this allows the ability to compare left vs right sides).^25-27 The ability to perform regional measurements cannot be overstated, as stable body weight belies potential changes with age and disease that relate to redistribution of fat and lean mass. It is not possible to identify, let alone track, such changes by measuring gross body weight on a scale or with BMI calculations. However, redistribution of fat and lean mass can be monitored in great detail using DXA. Figures 2 and 3 show the typical output from a DXA total body/body composition scan.

 

Total body scans with body composition analyses have many applications. For example, monitoring growth and development or treatment in patients with congenital deformity, metabolic bone disease, osteoporosis, and frailty; patients undergoing rehabilitation; and patients having surgery that could affect the use of a contralateral limb with potential hypertrophy or atrophy. Accurate assessment of percent body fat and fat distribution may help surgeons to improve risk stratification and surgical outcome.^28-30 Fracture risk has been associated with muscle area.²⁸ Simple measurements of quadriceps size underestimates atrophy, and total body composition can quantitate lean mass.³⁰

In sports medicine, body composition assessments could be useful to monitor postoperative recovery and effectiveness of rehabilitation protocols after injury, effectiveness of conditioning and training programs, developmental changes due to sports participation, and for obtaining baseline assessment at the time of preseason physicals.^27,31-34 In athletes, baseline status and morphological adaptations to training have traditionally been measured by anthropometry (eg, skinfold thickness, BMI, limb circumference, etc.), but DXA total body scanning allows for much more detailed assessments with the possibility of subregional quantitation. There is evidence for sports-specific body composition profiles and characteristic adaptations.^27,31-34 Using DXA, adaptive changes as a result of training as well as changes and recovery after surgery or injury can be monitored. For example, quadriceps atrophy usually occurs to some extent after ACL repair, and bone mineral loss and muscle atrophy occur after a limb has been immobilized with a cast. DXA body composition assessment could be used to monitor leg lean mass after surgery for comparison with presurgery values or those of the contralateral noninjured side, or to track recovery of bone mineral and muscle after a cast is removed. Some technical sports, such as tennis and baseball pitching, are known to result in limb asymmetry; DXA body composition could be used to monitor development of right-left arm asymmetry in tennis players or baseball pitchers, and then measures could be taken to balance the asymmetry. Wrestlers and elite dancers are expected to maintain strict weight requirements, but diets are often poor, and as such, DXA body composition could be used to track the effects of dieting and training by comparing serial measurements to baseline to ensure that weight changes include preservation or gain of muscle mass.³¹

Continue to: For older patients...

 

For older patients being followed after orthopedic care, there is a growing concern about age-related loss of muscle mass, or sarcopenia, which can lead to functional impairment (eg, balance, gait, etc.), and physical disability leading to falling and increased risk of fracture.^35-40 Even obese patients can be sarcopenic (a concept known as sarcopenic obesity), and their large body mass can mask the relative deficiency of lean mass.⁴⁰ DXA total body scans can be used to monitor patients at risk for sarcopenia.

Finally, DXA total body composition scans are underused in the pediatric population. Given the low radiation burden, DXA can be used safely in children of all ages. In addition to the same uses as in adults for presurgical assessment, monitoring bone and soft-tissue changes after treatment and rehabilitation, scans can be used to monitor growth and development.⁴¹

CASE STUDY: MONITORING DEVELOPMENT AND TREATMENT

A 12-year-old boy with polyostotic fibrous dysplasia (McCune Albright Syndrome) was started on treatment with cyclic pamidronate to mitigate bone pain and reduce fracture risk. Use of DXA was planned to provide evidence of treatment efficacy by documenting increasing BMD. However, the severe skeletal deformity prevented standard site-specific DXA scans, and consequently, total body scans were effectively used to acquire the BMD data needed to monitor treatment (Figure 4).

CASE STUDY: AGE-RELATED SARCOPENIA

Figure 5 shows images of a 64-year-old woman who was followed after a distal radius fracture. A total body scan and body composition assessment was performed in 2002. At follow-up in 2004, total body weight seemed stable with only a seemingly benign 5.1-lb loss of weight, and the patient’s overall physical appearance was unchanged (Table 2). 

Table 2. Age-Related Changes Potentially Leading to Sarcopenia

	Baseline, 2002	Follow-up, 2004	Change, %
Body weight, kg	57.9 (127.6 lb)	55.6 (122.5 lb)	4
BMI	20.6	19.8
Total body fat, g	13,619	13,390	−1.7
Total body percent fat	23.5	24.1
Total body lean, g	42,038	39,949	−5.0

Dual-energy X-ray absorptiometry scans were performed using a GE Lunar Prodigy system.

However, body composition assessment revealed a disproportionate loss of lean mass, with a resultant total percent body fat increase. This imbalance between the change in fat and lean mass could lead to clinical sarcopenia unless appropriate dietary and exercise measures are taken. Such subtle developing imbalances in body composition could only be quantitated using DXA total body scans.

Continue to: It is not uncommon...

 

CASE STUDY: WEIGHT CHANGE IN A RECREATIONAL ATHLETE

It is not uncommon to encounter patients who have substantial weight changes as a result of lifestyle changes, such as dieting. It is also possible that body weight remains stable, but variable changes occur in the amount and distribution of fat and lean mass. Combining exercise with dieting is more likely to be associated with preservation or gain of lean mass. Such a case is presented. After a knee injury, a club tennis player reported gaining 30 lb in the subsequent 12 months. She enrolled in a DXA study, and serial body composition assessments were performed as she started a diet program and exercised on a treadmill and stationary bike. Table 3 shows body composition changes from baseline. 

Table 3. Body Composition Changes After Dieting and Exercise

			Total Body
	Weight, lb	Body Mass Index	Bone Mineral Density, g/cm2	Fat, g	Lean, g
Baseline	160	27.5	1.245	29,023	39,610
12-month follow-up	148	25.4	1.230	22,581	41,979

Dual-energy X-ray absorptiometry scans were performed using a GE Lunar Prodigy system.

Although gross weight using a scale clearly showed progress in losing weight, it did not provide information about redistribution of fat and lean mass. The DXA body composition assessment showed that at follow up, there was a 22% decrease in total grams of fat and a 6% increase in lean mass (changes were uniform over different body regions). Her BMI still categorized her as being overweight; however, her body composition changes demonstrated that diet and exercise were producing positive results.

CONCLUSION

There are many ways in which DXA technology could provide orthopedists with valuable baseline and postoperative and post-treatment information about their patients. This technology could be used more effectively by orthopedists in both general clinical practice and research.

ABSTRACT

Dual-energy X-ray absorptiometry (DXA) is a well-established technology with an important and well-known role in measuring bone mineral density (BMD) for the purpose of determining fracture risk, diagnosing osteoporosis, and monitoring treatment efficacy. However, aside from the assessment of bone status, DXA is likely underutilized in the field of orthopedics, and most orthopedists may not be aware of the full capabilities of DXA, particularly with regard to total body scans and body composition assessment. For example, DXA would be a valuable tool for monitoring body composition after surgery where compensatory changes in the affected limb may lead to right-left asymmetry (eg, tracking lean mass change after knee surgery), rehabilitation regimens for athletes, congenital and metabolic disorders that affect the musculoskeletal system, or monitoring sarcopenia and frailty in the elderly. Furthermore, preoperative and postoperative regional scans can track BMD changes during healing or alert surgeons to impending problems such as loss of periprosthetic bone, which could lead to implant failure. This article discusses the capabilities of DXA and how this technology could be better used to the advantage of the attending orthopedist.

Dual-energy X-ray absorptiometry, abbreviated as “DXA,” (although usually abbreviated in older literature as “DEXA”) was first introduced in 1987 (Hologic QDR-1000 system, Hologic, Inc) and immediately made all previous forms of radiation-based bone mineral density (BMD) measurement systems obsolete.¹ Since then, there have been many generations of the technology, with the main US manufacturers in 2017 being Hologic, Inc. and GE Lunar. There are 2 forms of DXA, peripheral systems (which usually measure BMD only in the radius, finger bones, or calcaneus) and central systems (which measure the radius, proximal femur [“hip”], lumbar spine, total body, and custom sites). The general principle of how DXA works is based on the differential attenuation of photons by bone, fat, and lean mass.² The DXA technique uses a low- and high-energy X-ray beam produced by an X-ray tube. With the low-energy beam, attenuation by bone is greater than attenuation by soft tissue. With the high-energy beam, attenuation by bone and soft tissues are similar. The dual X-ray beams are passed through the body regions being scanned (usually posterioanteriorly), and the differential attenuation by bone and soft tissue is analyzed to produce BMD estimates. In addition, a high-quality image is produced to enable the operator of the DXA system to verify that the appropriate body region was scanned. It is important to realize that DXA is 2-dimensional (which is sometimes cited as a weakness of DXA), and the units of BMD are grams of mineral per centimeter squared (g/cm²).

Continue to: When assessing bone status...

 

When assessing bone status for the purpose of determining if a patient is normal, osteopenic, or osteoporotic, the skeletal sites (called regions of interest [ROI]) typically scanned are the proximal femur, lumbar spine, and radius. The BMD of the patient is then compared to a manufacturer-provided normative database of young adults (the logic being that the BMD in the young adult normative population represents maximal peak bone mass). Total body BMD and body composition can also be quantified (grams of lean and fat mass), and custom scans can be designed for other skeletal sites. Specifically, a patient’s BMD is compared to a database of sex- and age-adjusted normal values, and the deviation from normal is expressed as a T-score (the number of standard deviations the patient's BMD is above or below the average BMD of the young adult reference population) and Z-scores (the number of standard deviations a patient's BMD is above or below the average BMD of a sex- and age-matched reference population).³ The International Society for Clinical Densitometry (ISCD) has developed and published well-accepted guidelines used to assist in acquiring high-quality DXA scans and for the diagnosis of osteoporosis using BMD. The accuracy and, especially, the precision of DXA scans can be remarkable when they are performed by trained technologists, and thus, serial scans can be performed to monitor BMD and body composition changes with aging or in response to treatment.

Because of the nature of the scan mechanics and speed, the effective radiation dose with DXA is very low, expressed in microSieverts.^4,5 Generally, the radiation exposure from a series of the lumbar spine, proximal femur, and distal radius is about the same as daily background radiation. Even total body scans present very low exposure due to the scan speed at which any 1 body part is exposed for only a fraction of a second.

BENEFITS OF USING DXA FOR THE ORTHEOPEDIST

At the time of this writing in 2018, the presumption could be made that most physicians in the specialties of internal medicine, rheumatology, endocrinology, radiology, and orthopedics were familiar with the capabilities of DXA to assess BMD for the purpose of diagnosing osteoporosis. However, DXA is likely underused for other purposes, as orthopedists may be unaware of the full capabilities of DXA. Printouts after a scan contain more information than simply BMD, and there are more features and applications of DXA that can potentially be useful to orthopedists.

BONE SIZE

Data from a DXA scan are expressed not only as g/cm² (BMD) but also as total grams in the ROI (known as bone mineral content, abbreviated as BMC), and cm² (area of the ROI). These data may appear on a separate page, being considered ancillary results. The latter 2 variables are rarely included on a report sent to a referring physician; therefore, awareness of their value is probably limited. However, there are instances where such information could be valuable when interpreting results, especially bone size.^6,7 For example, on occasion, patients present with osteopenic lumbar vertebrate but larger than normal vertebral size (area). Many studies have shown that bone size is directly related to bone strength and thus fracture risk.^8,9 Although an understudied phenomenon, large vertebral body size could be protective, counteracting a lower than optimal BMD. Further, because the area of the ROI is measured, it is possible to calculate the bone width (or measure directly with a ruler tool in the software if available) for the area measured. This is especially feasible for tubular bones such as the midshaft of the radius, or more specifically, the classic DXA ROI being the area approximately one third the length of the radius from the distal end, the radius 33% region (actually based on ulna length). Consequently, it is possible to use the width of the radius 33% ROI in addition to BMD and T-score when assessing fracture risk.

CASE STUDY

A 60-year-old man had a DXA series of the lumbar spine, proximal femur, and whole body. His total body T-score was 0.6 (normal), and his total proximal femur T-score was −0.8 (normal), but his lumbar spine vertebrae 2 to 4 T-score was −1.9. As the patient was osteopenic based on the lumbar spine T-score, some physicians may have initiated antiresorptive therapy, especially if other risk factors for fracture were present. Further examination of the ancillary results of the DXA scan revealed that the vertebral body height T-score was a remarkable 1.11 and 1.53 after adjustment for stature (automatic software calculation). These results suggested that the patient had vertebral bodies of above average size, which theoretically would be protective against fracture even though the BMD T-score was below normal. For this patient, this finding mitigated immediate concern about the lumbar spine T-score of −1.9. Although vertebral body size is not typically used in assessing fracture risk, it is useful information that could be factored into the decision to start treatment or watch for further change with aging.

Continue to: Case Series: Distal Radius Fractures...

 

CASE SERIES: DISTAL RADIUS FRACTURES

Table 1 summarizes the data comparing radius 33% ROI T-scores and ROI width in patients who fractured the contralateral radius and normal nonfractured controls.¹⁰  

Table 1. Comparison of Radius Width at the 33% Region of Interest (ROI) and Bone Mineral Density T-Scores in Premenopausal Women With and Without Fractures

	33% ROI T-score	Width of ROI, cm
White women with distal radius fractures
Premenopausal (<49 years), n = 36	-0.2 + 0.9	1.22 + 0.11a
Controls matched for race, age, BMIb
Premenopausal (<49 years), n = 65	-0.1 + 0.8	1.45 + 0.25

For premenopausal women with distal radius fractures, the width of the radius at the radius 33% ROI was significantly smaller than that in controls. However, there was no difference in T-scores between premenopausal women with distal radius fractures and controls. Thus, bone width more accurately identified women with fractures than T-scores based on BMD, and the orthopedist could use bone size in addition to BMD to predict fracture risk in a patient.

PREPARATION FOR SURGERY

For some procedures, there is potential benefit of assessing bone status prior to surgery. That is, determination of low BMD could potentially influence the type of hardware or fixation techniques used in surgery. Various studies have shown that poor bone quality and low BMD can impair purchase with various types of fixation.^11-13 Low preoperative BMD has been shown to be related to high implant migration.¹⁴ Knowledge of BMD could influence the choice of screw type used or the type of implant metal (titanium vs cobalt chrome). Another example is predicting the risk of spine curvature progression in adolescent idiopathic scoliosis.^15-17 It has been reported that low BMD is a risk factor for progression.¹⁵ Knowledge of BMD could potentially help with patient management strategies. For example, a patient with low BMD and vitamin D deficiency could be treated (vitamin D supplementation) prior to planning surgery in an effort to improve the low BMD.

PERIOPROSTHETIC BMD

It is possible to monitor changes in BMD around implants using the periprosthetic software application (this usually needs to be purchased separately from standard software that is installed with a system set-up). Dramatic loss of bone due to stress shielding after total hip arthroplasty (THA) can be a risk factor for implant migration or potentially outright failure of fixation or breakthrough. If bone loss occurs and is observed in the early stages, then antiresorptive treatment can be initiated to limit further loss.^18,19 (Figure 1) shows the image from a periprosthetic scan. 

Standard Gruen zones are the default ROIs.²⁰ It is well established that BMD loss differs from zone to zone, with the greatest loss in zone 7 after THA.

Continue to: A 60-year-old, 215-lb man...

 

CASE REPORT

A 60-year-old, 215-lb man had a total hip replacement using a newly introduced cemented collared cobalt-chromium alloy femoral stem. A baseline periprosthetic DXA scan was performed 6 weeks postoperatively. Compared to baseline, the change in BMD in the Gruen zone 5 was −8.2%, +6.5%, +4.9%, and +9.46% at 3, 6, 12, and 24 months, respectively. In contrast, dramatic BMD loss was seen in Gruen zone 7 (calcar region): −33.2%, −40.8%, −37.1%, and −34.1% at 3, 6, 12, and 24 months, respectively. Similar findings in other patients led to discontinuation of use of this stem in favor of a collarless stem in which less BMD loss was seen in Gruen zone 7. Although additional technologist training is required and scans may not be reimbursable, for research purposes or for evaluating new component prototypes, the periprosthetic DXA scan capability can be useful.

Various other custom scans can be used to detect and quantify vertebral fractures (vertebral fracture assessment application), monitor healing of fractures by scanning through radiolucent cast materials, or for research purposes to assess BMD at unusual locations.^21-23 Other new innovations, such as the ability to perform full-length scans of the femoral shaft and to quantify focal thickening of the lateral cortex to identify beaking, an abnormality associated with atypical femur fracture after long-term bisphosphonate use, continue to expand the utility of DXA. Using standard software, cadaver bones can be scanned prior to biomechanical testing for a variety of purposes, such as ensuring proper matching specimens in test groups. It has been reported that the common practice of using contralateral bone specimens can lead to bias, as the BMD can be significantly different in right and left bones from the same individual.^9,24

TOTAL BODY BMD AND BODY COMPOSITION SCANS

Perhaps the least understood capability of DXA from our experience working with orthopedists is the ability to perform total body scans and to obtain not only total body and regional BMD but also body composition data, namely grams of lean and fat mass.²⁵ Soft tissue (no bone pixels) is partitioned into fat and lean body mass by a calibration procedure (lean mass = total soft tissue –fat mass). DXA has become the standard for body composition assessment given the ease of data acquisition (a total body scan takes only a few minutes), accuracy, and precision of measurements. Compared with other methods (eg, skinfold thickness, bioelectrical impedance, and underwater weighing), it is the only method that gives regional values for fat mass, lean mass, and BMC (this allows the ability to compare left vs right sides).^25-27 The ability to perform regional measurements cannot be overstated, as stable body weight belies potential changes with age and disease that relate to redistribution of fat and lean mass. It is not possible to identify, let alone track, such changes by measuring gross body weight on a scale or with BMI calculations. However, redistribution of fat and lean mass can be monitored in great detail using DXA. Figures 2 and 3 show the typical output from a DXA total body/body composition scan.

 

Total body scans with body composition analyses have many applications. For example, monitoring growth and development or treatment in patients with congenital deformity, metabolic bone disease, osteoporosis, and frailty; patients undergoing rehabilitation; and patients having surgery that could affect the use of a contralateral limb with potential hypertrophy or atrophy. Accurate assessment of percent body fat and fat distribution may help surgeons to improve risk stratification and surgical outcome.^28-30 Fracture risk has been associated with muscle area.²⁸ Simple measurements of quadriceps size underestimates atrophy, and total body composition can quantitate lean mass.³⁰

In sports medicine, body composition assessments could be useful to monitor postoperative recovery and effectiveness of rehabilitation protocols after injury, effectiveness of conditioning and training programs, developmental changes due to sports participation, and for obtaining baseline assessment at the time of preseason physicals.^27,31-34 In athletes, baseline status and morphological adaptations to training have traditionally been measured by anthropometry (eg, skinfold thickness, BMI, limb circumference, etc.), but DXA total body scanning allows for much more detailed assessments with the possibility of subregional quantitation. There is evidence for sports-specific body composition profiles and characteristic adaptations.^27,31-34 Using DXA, adaptive changes as a result of training as well as changes and recovery after surgery or injury can be monitored. For example, quadriceps atrophy usually occurs to some extent after ACL repair, and bone mineral loss and muscle atrophy occur after a limb has been immobilized with a cast. DXA body composition assessment could be used to monitor leg lean mass after surgery for comparison with presurgery values or those of the contralateral noninjured side, or to track recovery of bone mineral and muscle after a cast is removed. Some technical sports, such as tennis and baseball pitching, are known to result in limb asymmetry; DXA body composition could be used to monitor development of right-left arm asymmetry in tennis players or baseball pitchers, and then measures could be taken to balance the asymmetry. Wrestlers and elite dancers are expected to maintain strict weight requirements, but diets are often poor, and as such, DXA body composition could be used to track the effects of dieting and training by comparing serial measurements to baseline to ensure that weight changes include preservation or gain of muscle mass.³¹

Continue to: For older patients...

 

For older patients being followed after orthopedic care, there is a growing concern about age-related loss of muscle mass, or sarcopenia, which can lead to functional impairment (eg, balance, gait, etc.), and physical disability leading to falling and increased risk of fracture.^35-40 Even obese patients can be sarcopenic (a concept known as sarcopenic obesity), and their large body mass can mask the relative deficiency of lean mass.⁴⁰ DXA total body scans can be used to monitor patients at risk for sarcopenia.

Finally, DXA total body composition scans are underused in the pediatric population. Given the low radiation burden, DXA can be used safely in children of all ages. In addition to the same uses as in adults for presurgical assessment, monitoring bone and soft-tissue changes after treatment and rehabilitation, scans can be used to monitor growth and development.⁴¹

CASE STUDY: MONITORING DEVELOPMENT AND TREATMENT

A 12-year-old boy with polyostotic fibrous dysplasia (McCune Albright Syndrome) was started on treatment with cyclic pamidronate to mitigate bone pain and reduce fracture risk. Use of DXA was planned to provide evidence of treatment efficacy by documenting increasing BMD. However, the severe skeletal deformity prevented standard site-specific DXA scans, and consequently, total body scans were effectively used to acquire the BMD data needed to monitor treatment (Figure 4).

CASE STUDY: AGE-RELATED SARCOPENIA

Figure 5 shows images of a 64-year-old woman who was followed after a distal radius fracture. A total body scan and body composition assessment was performed in 2002. At follow-up in 2004, total body weight seemed stable with only a seemingly benign 5.1-lb loss of weight, and the patient’s overall physical appearance was unchanged (Table 2). 

Table 2. Age-Related Changes Potentially Leading to Sarcopenia

	Baseline, 2002	Follow-up, 2004	Change, %
Body weight, kg	57.9 (127.6 lb)	55.6 (122.5 lb)	4
BMI	20.6	19.8
Total body fat, g	13,619	13,390	−1.7
Total body percent fat	23.5	24.1
Total body lean, g	42,038	39,949	−5.0

Dual-energy X-ray absorptiometry scans were performed using a GE Lunar Prodigy system.

However, body composition assessment revealed a disproportionate loss of lean mass, with a resultant total percent body fat increase. This imbalance between the change in fat and lean mass could lead to clinical sarcopenia unless appropriate dietary and exercise measures are taken. Such subtle developing imbalances in body composition could only be quantitated using DXA total body scans.

Continue to: It is not uncommon...

 

CASE STUDY: WEIGHT CHANGE IN A RECREATIONAL ATHLETE

It is not uncommon to encounter patients who have substantial weight changes as a result of lifestyle changes, such as dieting. It is also possible that body weight remains stable, but variable changes occur in the amount and distribution of fat and lean mass. Combining exercise with dieting is more likely to be associated with preservation or gain of lean mass. Such a case is presented. After a knee injury, a club tennis player reported gaining 30 lb in the subsequent 12 months. She enrolled in a DXA study, and serial body composition assessments were performed as she started a diet program and exercised on a treadmill and stationary bike. Table 3 shows body composition changes from baseline. 

Table 3. Body Composition Changes After Dieting and Exercise

			Total Body
	Weight, lb	Body Mass Index	Bone Mineral Density, g/cm2	Fat, g	Lean, g
Baseline	160	27.5	1.245	29,023	39,610
12-month follow-up	148	25.4	1.230	22,581	41,979

Dual-energy X-ray absorptiometry scans were performed using a GE Lunar Prodigy system.

Although gross weight using a scale clearly showed progress in losing weight, it did not provide information about redistribution of fat and lean mass. The DXA body composition assessment showed that at follow up, there was a 22% decrease in total grams of fat and a 6% increase in lean mass (changes were uniform over different body regions). Her BMI still categorized her as being overweight; however, her body composition changes demonstrated that diet and exercise were producing positive results.

CONCLUSION

There are many ways in which DXA technology could provide orthopedists with valuable baseline and postoperative and post-treatment information about their patients. This technology could be used more effectively by orthopedists in both general clinical practice and research.

ABSTRACT

Dual-energy X-ray absorptiometry (DXA) is a well-established technology with an important and well-known role in measuring bone mineral density (BMD) for the purpose of determining fracture risk, diagnosing osteoporosis, and monitoring treatment efficacy. However, aside from the assessment of bone status, DXA is likely underutilized in the field of orthopedics, and most orthopedists may not be aware of the full capabilities of DXA, particularly with regard to total body scans and body composition assessment. For example, DXA would be a valuable tool for monitoring body composition after surgery where compensatory changes in the affected limb may lead to right-left asymmetry (eg, tracking lean mass change after knee surgery), rehabilitation regimens for athletes, congenital and metabolic disorders that affect the musculoskeletal system, or monitoring sarcopenia and frailty in the elderly. Furthermore, preoperative and postoperative regional scans can track BMD changes during healing or alert surgeons to impending problems such as loss of periprosthetic bone, which could lead to implant failure. This article discusses the capabilities of DXA and how this technology could be better used to the advantage of the attending orthopedist.

Dual-energy X-ray absorptiometry, abbreviated as “DXA,” (although usually abbreviated in older literature as “DEXA”) was first introduced in 1987 (Hologic QDR-1000 system, Hologic, Inc) and immediately made all previous forms of radiation-based bone mineral density (BMD) measurement systems obsolete.¹ Since then, there have been many generations of the technology, with the main US manufacturers in 2017 being Hologic, Inc. and GE Lunar. There are 2 forms of DXA, peripheral systems (which usually measure BMD only in the radius, finger bones, or calcaneus) and central systems (which measure the radius, proximal femur [“hip”], lumbar spine, total body, and custom sites). The general principle of how DXA works is based on the differential attenuation of photons by bone, fat, and lean mass.² The DXA technique uses a low- and high-energy X-ray beam produced by an X-ray tube. With the low-energy beam, attenuation by bone is greater than attenuation by soft tissue. With the high-energy beam, attenuation by bone and soft tissues are similar. The dual X-ray beams are passed through the body regions being scanned (usually posterioanteriorly), and the differential attenuation by bone and soft tissue is analyzed to produce BMD estimates. In addition, a high-quality image is produced to enable the operator of the DXA system to verify that the appropriate body region was scanned. It is important to realize that DXA is 2-dimensional (which is sometimes cited as a weakness of DXA), and the units of BMD are grams of mineral per centimeter squared (g/cm²).

Continue to: When assessing bone status...

 

When assessing bone status for the purpose of determining if a patient is normal, osteopenic, or osteoporotic, the skeletal sites (called regions of interest [ROI]) typically scanned are the proximal femur, lumbar spine, and radius. The BMD of the patient is then compared to a manufacturer-provided normative database of young adults (the logic being that the BMD in the young adult normative population represents maximal peak bone mass). Total body BMD and body composition can also be quantified (grams of lean and fat mass), and custom scans can be designed for other skeletal sites. Specifically, a patient’s BMD is compared to a database of sex- and age-adjusted normal values, and the deviation from normal is expressed as a T-score (the number of standard deviations the patient's BMD is above or below the average BMD of the young adult reference population) and Z-scores (the number of standard deviations a patient's BMD is above or below the average BMD of a sex- and age-matched reference population).³ The International Society for Clinical Densitometry (ISCD) has developed and published well-accepted guidelines used to assist in acquiring high-quality DXA scans and for the diagnosis of osteoporosis using BMD. The accuracy and, especially, the precision of DXA scans can be remarkable when they are performed by trained technologists, and thus, serial scans can be performed to monitor BMD and body composition changes with aging or in response to treatment.

Because of the nature of the scan mechanics and speed, the effective radiation dose with DXA is very low, expressed in microSieverts.^4,5 Generally, the radiation exposure from a series of the lumbar spine, proximal femur, and distal radius is about the same as daily background radiation. Even total body scans present very low exposure due to the scan speed at which any 1 body part is exposed for only a fraction of a second.

BENEFITS OF USING DXA FOR THE ORTHEOPEDIST

At the time of this writing in 2018, the presumption could be made that most physicians in the specialties of internal medicine, rheumatology, endocrinology, radiology, and orthopedics were familiar with the capabilities of DXA to assess BMD for the purpose of diagnosing osteoporosis. However, DXA is likely underused for other purposes, as orthopedists may be unaware of the full capabilities of DXA. Printouts after a scan contain more information than simply BMD, and there are more features and applications of DXA that can potentially be useful to orthopedists.

BONE SIZE

Data from a DXA scan are expressed not only as g/cm² (BMD) but also as total grams in the ROI (known as bone mineral content, abbreviated as BMC), and cm² (area of the ROI). These data may appear on a separate page, being considered ancillary results. The latter 2 variables are rarely included on a report sent to a referring physician; therefore, awareness of their value is probably limited. However, there are instances where such information could be valuable when interpreting results, especially bone size.^6,7 For example, on occasion, patients present with osteopenic lumbar vertebrate but larger than normal vertebral size (area). Many studies have shown that bone size is directly related to bone strength and thus fracture risk.^8,9 Although an understudied phenomenon, large vertebral body size could be protective, counteracting a lower than optimal BMD. Further, because the area of the ROI is measured, it is possible to calculate the bone width (or measure directly with a ruler tool in the software if available) for the area measured. This is especially feasible for tubular bones such as the midshaft of the radius, or more specifically, the classic DXA ROI being the area approximately one third the length of the radius from the distal end, the radius 33% region (actually based on ulna length). Consequently, it is possible to use the width of the radius 33% ROI in addition to BMD and T-score when assessing fracture risk.

CASE STUDY

A 60-year-old man had a DXA series of the lumbar spine, proximal femur, and whole body. His total body T-score was 0.6 (normal), and his total proximal femur T-score was −0.8 (normal), but his lumbar spine vertebrae 2 to 4 T-score was −1.9. As the patient was osteopenic based on the lumbar spine T-score, some physicians may have initiated antiresorptive therapy, especially if other risk factors for fracture were present. Further examination of the ancillary results of the DXA scan revealed that the vertebral body height T-score was a remarkable 1.11 and 1.53 after adjustment for stature (automatic software calculation). These results suggested that the patient had vertebral bodies of above average size, which theoretically would be protective against fracture even though the BMD T-score was below normal. For this patient, this finding mitigated immediate concern about the lumbar spine T-score of −1.9. Although vertebral body size is not typically used in assessing fracture risk, it is useful information that could be factored into the decision to start treatment or watch for further change with aging.

Continue to: Case Series: Distal Radius Fractures...

 

CASE SERIES: DISTAL RADIUS FRACTURES

Table 1 summarizes the data comparing radius 33% ROI T-scores and ROI width in patients who fractured the contralateral radius and normal nonfractured controls.¹⁰  

Table 1. Comparison of Radius Width at the 33% Region of Interest (ROI) and Bone Mineral Density T-Scores in Premenopausal Women With and Without Fractures

	33% ROI T-score	Width of ROI, cm
White women with distal radius fractures
Premenopausal (<49 years), n = 36	-0.2 + 0.9	1.22 + 0.11a
Controls matched for race, age, BMIb
Premenopausal (<49 years), n = 65	-0.1 + 0.8	1.45 + 0.25

For premenopausal women with distal radius fractures, the width of the radius at the radius 33% ROI was significantly smaller than that in controls. However, there was no difference in T-scores between premenopausal women with distal radius fractures and controls. Thus, bone width more accurately identified women with fractures than T-scores based on BMD, and the orthopedist could use bone size in addition to BMD to predict fracture risk in a patient.

PREPARATION FOR SURGERY

For some procedures, there is potential benefit of assessing bone status prior to surgery. That is, determination of low BMD could potentially influence the type of hardware or fixation techniques used in surgery. Various studies have shown that poor bone quality and low BMD can impair purchase with various types of fixation.^11-13 Low preoperative BMD has been shown to be related to high implant migration.¹⁴ Knowledge of BMD could influence the choice of screw type used or the type of implant metal (titanium vs cobalt chrome). Another example is predicting the risk of spine curvature progression in adolescent idiopathic scoliosis.^15-17 It has been reported that low BMD is a risk factor for progression.¹⁵ Knowledge of BMD could potentially help with patient management strategies. For example, a patient with low BMD and vitamin D deficiency could be treated (vitamin D supplementation) prior to planning surgery in an effort to improve the low BMD.

PERIOPROSTHETIC BMD

It is possible to monitor changes in BMD around implants using the periprosthetic software application (this usually needs to be purchased separately from standard software that is installed with a system set-up). Dramatic loss of bone due to stress shielding after total hip arthroplasty (THA) can be a risk factor for implant migration or potentially outright failure of fixation or breakthrough. If bone loss occurs and is observed in the early stages, then antiresorptive treatment can be initiated to limit further loss.^18,19 (Figure 1) shows the image from a periprosthetic scan. 

Standard Gruen zones are the default ROIs.²⁰ It is well established that BMD loss differs from zone to zone, with the greatest loss in zone 7 after THA.

Continue to: A 60-year-old, 215-lb man...

 

CASE REPORT

A 60-year-old, 215-lb man had a total hip replacement using a newly introduced cemented collared cobalt-chromium alloy femoral stem. A baseline periprosthetic DXA scan was performed 6 weeks postoperatively. Compared to baseline, the change in BMD in the Gruen zone 5 was −8.2%, +6.5%, +4.9%, and +9.46% at 3, 6, 12, and 24 months, respectively. In contrast, dramatic BMD loss was seen in Gruen zone 7 (calcar region): −33.2%, −40.8%, −37.1%, and −34.1% at 3, 6, 12, and 24 months, respectively. Similar findings in other patients led to discontinuation of use of this stem in favor of a collarless stem in which less BMD loss was seen in Gruen zone 7. Although additional technologist training is required and scans may not be reimbursable, for research purposes or for evaluating new component prototypes, the periprosthetic DXA scan capability can be useful.

Various other custom scans can be used to detect and quantify vertebral fractures (vertebral fracture assessment application), monitor healing of fractures by scanning through radiolucent cast materials, or for research purposes to assess BMD at unusual locations.^21-23 Other new innovations, such as the ability to perform full-length scans of the femoral shaft and to quantify focal thickening of the lateral cortex to identify beaking, an abnormality associated with atypical femur fracture after long-term bisphosphonate use, continue to expand the utility of DXA. Using standard software, cadaver bones can be scanned prior to biomechanical testing for a variety of purposes, such as ensuring proper matching specimens in test groups. It has been reported that the common practice of using contralateral bone specimens can lead to bias, as the BMD can be significantly different in right and left bones from the same individual.^9,24

TOTAL BODY BMD AND BODY COMPOSITION SCANS

Perhaps the least understood capability of DXA from our experience working with orthopedists is the ability to perform total body scans and to obtain not only total body and regional BMD but also body composition data, namely grams of lean and fat mass.²⁵ Soft tissue (no bone pixels) is partitioned into fat and lean body mass by a calibration procedure (lean mass = total soft tissue –fat mass). DXA has become the standard for body composition assessment given the ease of data acquisition (a total body scan takes only a few minutes), accuracy, and precision of measurements. Compared with other methods (eg, skinfold thickness, bioelectrical impedance, and underwater weighing), it is the only method that gives regional values for fat mass, lean mass, and BMC (this allows the ability to compare left vs right sides).^25-27 The ability to perform regional measurements cannot be overstated, as stable body weight belies potential changes with age and disease that relate to redistribution of fat and lean mass. It is not possible to identify, let alone track, such changes by measuring gross body weight on a scale or with BMI calculations. However, redistribution of fat and lean mass can be monitored in great detail using DXA. Figures 2 and 3 show the typical output from a DXA total body/body composition scan.

 

Total body scans with body composition analyses have many applications. For example, monitoring growth and development or treatment in patients with congenital deformity, metabolic bone disease, osteoporosis, and frailty; patients undergoing rehabilitation; and patients having surgery that could affect the use of a contralateral limb with potential hypertrophy or atrophy. Accurate assessment of percent body fat and fat distribution may help surgeons to improve risk stratification and surgical outcome.^28-30 Fracture risk has been associated with muscle area.²⁸ Simple measurements of quadriceps size underestimates atrophy, and total body composition can quantitate lean mass.³⁰

In sports medicine, body composition assessments could be useful to monitor postoperative recovery and effectiveness of rehabilitation protocols after injury, effectiveness of conditioning and training programs, developmental changes due to sports participation, and for obtaining baseline assessment at the time of preseason physicals.^27,31-34 In athletes, baseline status and morphological adaptations to training have traditionally been measured by anthropometry (eg, skinfold thickness, BMI, limb circumference, etc.), but DXA total body scanning allows for much more detailed assessments with the possibility of subregional quantitation. There is evidence for sports-specific body composition profiles and characteristic adaptations.^27,31-34 Using DXA, adaptive changes as a result of training as well as changes and recovery after surgery or injury can be monitored. For example, quadriceps atrophy usually occurs to some extent after ACL repair, and bone mineral loss and muscle atrophy occur after a limb has been immobilized with a cast. DXA body composition assessment could be used to monitor leg lean mass after surgery for comparison with presurgery values or those of the contralateral noninjured side, or to track recovery of bone mineral and muscle after a cast is removed. Some technical sports, such as tennis and baseball pitching, are known to result in limb asymmetry; DXA body composition could be used to monitor development of right-left arm asymmetry in tennis players or baseball pitchers, and then measures could be taken to balance the asymmetry. Wrestlers and elite dancers are expected to maintain strict weight requirements, but diets are often poor, and as such, DXA body composition could be used to track the effects of dieting and training by comparing serial measurements to baseline to ensure that weight changes include preservation or gain of muscle mass.³¹

Continue to: For older patients...

 

For older patients being followed after orthopedic care, there is a growing concern about age-related loss of muscle mass, or sarcopenia, which can lead to functional impairment (eg, balance, gait, etc.), and physical disability leading to falling and increased risk of fracture.^35-40 Even obese patients can be sarcopenic (a concept known as sarcopenic obesity), and their large body mass can mask the relative deficiency of lean mass.⁴⁰ DXA total body scans can be used to monitor patients at risk for sarcopenia.

Finally, DXA total body composition scans are underused in the pediatric population. Given the low radiation burden, DXA can be used safely in children of all ages. In addition to the same uses as in adults for presurgical assessment, monitoring bone and soft-tissue changes after treatment and rehabilitation, scans can be used to monitor growth and development.⁴¹

CASE STUDY: MONITORING DEVELOPMENT AND TREATMENT

A 12-year-old boy with polyostotic fibrous dysplasia (McCune Albright Syndrome) was started on treatment with cyclic pamidronate to mitigate bone pain and reduce fracture risk. Use of DXA was planned to provide evidence of treatment efficacy by documenting increasing BMD. However, the severe skeletal deformity prevented standard site-specific DXA scans, and consequently, total body scans were effectively used to acquire the BMD data needed to monitor treatment (Figure 4).

CASE STUDY: AGE-RELATED SARCOPENIA

Figure 5 shows images of a 64-year-old woman who was followed after a distal radius fracture. A total body scan and body composition assessment was performed in 2002. At follow-up in 2004, total body weight seemed stable with only a seemingly benign 5.1-lb loss of weight, and the patient’s overall physical appearance was unchanged (Table 2). 

Table 2. Age-Related Changes Potentially Leading to Sarcopenia

	Baseline, 2002	Follow-up, 2004	Change, %
Body weight, kg	57.9 (127.6 lb)	55.6 (122.5 lb)	4
BMI	20.6	19.8
Total body fat, g	13,619	13,390	−1.7
Total body percent fat	23.5	24.1
Total body lean, g	42,038	39,949	−5.0

Dual-energy X-ray absorptiometry scans were performed using a GE Lunar Prodigy system.

However, body composition assessment revealed a disproportionate loss of lean mass, with a resultant total percent body fat increase. This imbalance between the change in fat and lean mass could lead to clinical sarcopenia unless appropriate dietary and exercise measures are taken. Such subtle developing imbalances in body composition could only be quantitated using DXA total body scans.

Continue to: It is not uncommon...

 

CASE STUDY: WEIGHT CHANGE IN A RECREATIONAL ATHLETE

It is not uncommon to encounter patients who have substantial weight changes as a result of lifestyle changes, such as dieting. It is also possible that body weight remains stable, but variable changes occur in the amount and distribution of fat and lean mass. Combining exercise with dieting is more likely to be associated with preservation or gain of lean mass. Such a case is presented. After a knee injury, a club tennis player reported gaining 30 lb in the subsequent 12 months. She enrolled in a DXA study, and serial body composition assessments were performed as she started a diet program and exercised on a treadmill and stationary bike. Table 3 shows body composition changes from baseline. 

Table 3. Body Composition Changes After Dieting and Exercise

			Total Body
	Weight, lb	Body Mass Index	Bone Mineral Density, g/cm2	Fat, g	Lean, g
Baseline	160	27.5	1.245	29,023	39,610
12-month follow-up	148	25.4	1.230	22,581	41,979

Dual-energy X-ray absorptiometry scans were performed using a GE Lunar Prodigy system.

Although gross weight using a scale clearly showed progress in losing weight, it did not provide information about redistribution of fat and lean mass. The DXA body composition assessment showed that at follow up, there was a 22% decrease in total grams of fat and a 6% increase in lean mass (changes were uniform over different body regions). Her BMI still categorized her as being overweight; however, her body composition changes demonstrated that diet and exercise were producing positive results.

CONCLUSION

There are many ways in which DXA technology could provide orthopedists with valuable baseline and postoperative and post-treatment information about their patients. This technology could be used more effectively by orthopedists in both general clinical practice and research.

Case

An 84-year-old man, who was a resident at a local nursing home, presented for evaluation after the nursing staff noticed an increasingly swollen mass on the patient’s left groin. The patient’s medical history was significant for bilateral aortofemoral graft surgery, dementia, hypertension, and severe peripheral artery disease (PAD). He was not on any anticoagulation or antiplatelet agents. Due to the patient’s dementia, he was unable to provide a history regarding the onset of the swelling or any other signs or symptoms.

On examination, the patient did not appear in distress. His son, who was the patient’s durable power of attorney, was likewise unable to provide a clear timeframe regarding onset of the mass. The patient had no recent history of trauma and had not undergone any recent medical procedures. Vital signs at presentation were: blood pressure, 110/70 mm Hg; heart rate, 84 beats/min; respiratory rate, 13 breaths/min; and temperature, 98.6°F. Oxygen saturation was 94% on room air.

Clinical examination revealed a pulsatile, purple left groin mass and bruit. The mass was located around the left inguinal ligament and extended down the proximal, inner thigh (Figure 1). There was no drainage or lesions from the mass. Inspection of the patient’s hip demonstrated decreased adduction, limited by the mass; otherwise, there was normal range of motion. The dorsalis pedis and posterior tibial pulses were equal and intact, and the rest of the physical examination was unremarkable.

The patient tolerated the examination without focal signs of discomfort. A Doppler ultrasound revealed findings consistent with a common femoral pseudoaneurysm (PSA) (Figure 2). For better visualization and extension, a computed tomography angiogram (CTA) was obtained, which demonstrated a PSA measuring 11.7 x 10.7 x 7.3 cm; there was no active extravasation (Figure 3).

The patient was started on intravenous normal saline while vascular surgery services was consulted for management and repair. After a discussion with the son regarding the patient’s wishes, surgical intervention was refused and the patient was conservatively managed and transitioned to hospice care.

Discussion

A true aneurysm differs from a PSA in that true aneurysms involve all three layers of the vessel wall. A PSA consists partly of the vessel wall and partly of encapsulating fibrous tissue or surrounding tissue.

Etiology

Femoral artery PSAs can be iatrogenic, for example, develop following cardiac catheterization or at the anastomotic site of previous surgery.¹ The incidence of diagnostic postcatheterization PSA ranges from 0.05% to 2%, whereas interventional postcatheterization PSA ranges from 2% to 6%.²

With the increasing number of peripheral coronary diagnostics and interventions, emergency physicians should include PSA in the differential diagnosis of patients with a recent or remote history of catheterization or bypass grafts. Less commonly, femoral PSAs are caused by non-surgical trauma or infection (ie, mycotic PSA). Patient risk factors for development of PSA include obesity, hypertension, PAD, and anticoagulation.³ Patients with femoral artery PSAs may present with a painful or painless pulsatile mass. Mass effect of the PSA can compress nearby neurovascular structures, leading to femoral neuropathies or limb edema secondary to venous obstruction.⁴ Complications of embolization or thrombosis can cause limb ischemia, neuropathy, and claudication, while rupture may present with a rapidly expanding groin hematoma. Additionally, sizeable PSAs can cause overlying skin necrosis.⁵

Imaging Studies

Diagnosis of a PSA can be made through Doppler ultrasound, which is the preferred imaging modality due to its accuracy, noninvasive nature, and low cost. Doppler ultrasound has been found to have a sensitivity of 94% and specificity of 97% in detecting PSAs. Additional imaging with CTA can provide further definition of vasculopathy.⁶ Treatment should be considered for patients with a symptomatic femoral PSA, a PSA measuring more than 3 cm, or patients who are on anticoagulation therapy. Studies have shown that observation-only and follow-up may be appropriate for patients with a PSA measuring less than 3 cm. A study by Toursarkissian et al⁷ found that the majority of PSAs smaller than 3 cm spontaneously resolved in a mean of 23 days without limb-threatening complications.

Treatment

Traditionally, open surgical repair techniques were the only treatment option for PSAs. However, in the early 1990s, the advent of new techniques such as stenting, coil insertion, ultrasound-guided compression, and ultrasound-guided thrombin injection, have developed as alternatives to open surgical repair; there has been variable success to these minimally invasive approaches.^5,8

 

Ultrasound-Guided Compression. A conservative approach to treating PSAs, ultrasound-guided compression requires sustained compression by a skilled physician. This technique is associated with significant discomfort to the patient.⁵ Ultrasound-Guided Thrombin Injection. This technique is the treatment of choice for postcatheterization PSA. However, this intervention is contraindicated in patients who have concerning features such as an infected PSA, rapid expansion, skin necrosis, or signs of limb ischemia. Additionally, ultrasound-guided thrombin injection is not appropriate for use in patients with a PSA occurring at anastomosis of a synthetic graft and native artery.⁵

Conclusion

Based on our patient’s clinical presentation and history of aortofemoral bypass surgery, we suspected a femoral PSA. While the PSA noted in our patient was sizeable, imaging studies and clinical examination showed no sign of limb ischemia or rupture.

Femoral PSAs are usually iatrogenic in nature, typically developing shortly after catheterization or a previous bypass surgery. The most serious complication of a PSA is rupture, but a thorough examination of the distal extremity is warranted to assess for limb ischemia as well. Ultrasound imaging is considered the modality of choice based on its high sensitivity and sensitivity for detecting PSAs.

Small PSAs (<3 cm) can be managed medically, but larger PSAs (>3 cm) require treatment. Newer techniques, including stenting, coil insertion, ultrasound-guided compression, and ultrasound-guided thrombin injection are alternatives to open surgical repair of larger, uncomplicated PSAs. However, urgent open surgical repair is the only option when there is evidence of a ruptured PSA, ischemia, or skin necrosis.

Case

An 84-year-old man, who was a resident at a local nursing home, presented for evaluation after the nursing staff noticed an increasingly swollen mass on the patient’s left groin. The patient’s medical history was significant for bilateral aortofemoral graft surgery, dementia, hypertension, and severe peripheral artery disease (PAD). He was not on any anticoagulation or antiplatelet agents. Due to the patient’s dementia, he was unable to provide a history regarding the onset of the swelling or any other signs or symptoms.

On examination, the patient did not appear in distress. His son, who was the patient’s durable power of attorney, was likewise unable to provide a clear timeframe regarding onset of the mass. The patient had no recent history of trauma and had not undergone any recent medical procedures. Vital signs at presentation were: blood pressure, 110/70 mm Hg; heart rate, 84 beats/min; respiratory rate, 13 breaths/min; and temperature, 98.6°F. Oxygen saturation was 94% on room air.

Clinical examination revealed a pulsatile, purple left groin mass and bruit. The mass was located around the left inguinal ligament and extended down the proximal, inner thigh (Figure 1). There was no drainage or lesions from the mass. Inspection of the patient’s hip demonstrated decreased adduction, limited by the mass; otherwise, there was normal range of motion. The dorsalis pedis and posterior tibial pulses were equal and intact, and the rest of the physical examination was unremarkable.

The patient tolerated the examination without focal signs of discomfort. A Doppler ultrasound revealed findings consistent with a common femoral pseudoaneurysm (PSA) (Figure 2). For better visualization and extension, a computed tomography angiogram (CTA) was obtained, which demonstrated a PSA measuring 11.7 x 10.7 x 7.3 cm; there was no active extravasation (Figure 3).

The patient was started on intravenous normal saline while vascular surgery services was consulted for management and repair. After a discussion with the son regarding the patient’s wishes, surgical intervention was refused and the patient was conservatively managed and transitioned to hospice care.

Discussion

A true aneurysm differs from a PSA in that true aneurysms involve all three layers of the vessel wall. A PSA consists partly of the vessel wall and partly of encapsulating fibrous tissue or surrounding tissue.

Etiology

Femoral artery PSAs can be iatrogenic, for example, develop following cardiac catheterization or at the anastomotic site of previous surgery.¹ The incidence of diagnostic postcatheterization PSA ranges from 0.05% to 2%, whereas interventional postcatheterization PSA ranges from 2% to 6%.²

With the increasing number of peripheral coronary diagnostics and interventions, emergency physicians should include PSA in the differential diagnosis of patients with a recent or remote history of catheterization or bypass grafts. Less commonly, femoral PSAs are caused by non-surgical trauma or infection (ie, mycotic PSA). Patient risk factors for development of PSA include obesity, hypertension, PAD, and anticoagulation.³ Patients with femoral artery PSAs may present with a painful or painless pulsatile mass. Mass effect of the PSA can compress nearby neurovascular structures, leading to femoral neuropathies or limb edema secondary to venous obstruction.⁴ Complications of embolization or thrombosis can cause limb ischemia, neuropathy, and claudication, while rupture may present with a rapidly expanding groin hematoma. Additionally, sizeable PSAs can cause overlying skin necrosis.⁵

Imaging Studies

Diagnosis of a PSA can be made through Doppler ultrasound, which is the preferred imaging modality due to its accuracy, noninvasive nature, and low cost. Doppler ultrasound has been found to have a sensitivity of 94% and specificity of 97% in detecting PSAs. Additional imaging with CTA can provide further definition of vasculopathy.⁶ Treatment should be considered for patients with a symptomatic femoral PSA, a PSA measuring more than 3 cm, or patients who are on anticoagulation therapy. Studies have shown that observation-only and follow-up may be appropriate for patients with a PSA measuring less than 3 cm. A study by Toursarkissian et al⁷ found that the majority of PSAs smaller than 3 cm spontaneously resolved in a mean of 23 days without limb-threatening complications.

Treatment

Traditionally, open surgical repair techniques were the only treatment option for PSAs. However, in the early 1990s, the advent of new techniques such as stenting, coil insertion, ultrasound-guided compression, and ultrasound-guided thrombin injection, have developed as alternatives to open surgical repair; there has been variable success to these minimally invasive approaches.^5,8

 

Ultrasound-Guided Compression. A conservative approach to treating PSAs, ultrasound-guided compression requires sustained compression by a skilled physician. This technique is associated with significant discomfort to the patient.⁵ Ultrasound-Guided Thrombin Injection. This technique is the treatment of choice for postcatheterization PSA. However, this intervention is contraindicated in patients who have concerning features such as an infected PSA, rapid expansion, skin necrosis, or signs of limb ischemia. Additionally, ultrasound-guided thrombin injection is not appropriate for use in patients with a PSA occurring at anastomosis of a synthetic graft and native artery.⁵

Conclusion

Based on our patient’s clinical presentation and history of aortofemoral bypass surgery, we suspected a femoral PSA. While the PSA noted in our patient was sizeable, imaging studies and clinical examination showed no sign of limb ischemia or rupture.

Femoral PSAs are usually iatrogenic in nature, typically developing shortly after catheterization or a previous bypass surgery. The most serious complication of a PSA is rupture, but a thorough examination of the distal extremity is warranted to assess for limb ischemia as well. Ultrasound imaging is considered the modality of choice based on its high sensitivity and sensitivity for detecting PSAs.

Small PSAs (<3 cm) can be managed medically, but larger PSAs (>3 cm) require treatment. Newer techniques, including stenting, coil insertion, ultrasound-guided compression, and ultrasound-guided thrombin injection are alternatives to open surgical repair of larger, uncomplicated PSAs. However, urgent open surgical repair is the only option when there is evidence of a ruptured PSA, ischemia, or skin necrosis.

Case

An 84-year-old man, who was a resident at a local nursing home, presented for evaluation after the nursing staff noticed an increasingly swollen mass on the patient’s left groin. The patient’s medical history was significant for bilateral aortofemoral graft surgery, dementia, hypertension, and severe peripheral artery disease (PAD). He was not on any anticoagulation or antiplatelet agents. Due to the patient’s dementia, he was unable to provide a history regarding the onset of the swelling or any other signs or symptoms.

On examination, the patient did not appear in distress. His son, who was the patient’s durable power of attorney, was likewise unable to provide a clear timeframe regarding onset of the mass. The patient had no recent history of trauma and had not undergone any recent medical procedures. Vital signs at presentation were: blood pressure, 110/70 mm Hg; heart rate, 84 beats/min; respiratory rate, 13 breaths/min; and temperature, 98.6°F. Oxygen saturation was 94% on room air.

Clinical examination revealed a pulsatile, purple left groin mass and bruit. The mass was located around the left inguinal ligament and extended down the proximal, inner thigh (Figure 1). There was no drainage or lesions from the mass. Inspection of the patient’s hip demonstrated decreased adduction, limited by the mass; otherwise, there was normal range of motion. The dorsalis pedis and posterior tibial pulses were equal and intact, and the rest of the physical examination was unremarkable.

The patient tolerated the examination without focal signs of discomfort. A Doppler ultrasound revealed findings consistent with a common femoral pseudoaneurysm (PSA) (Figure 2). For better visualization and extension, a computed tomography angiogram (CTA) was obtained, which demonstrated a PSA measuring 11.7 x 10.7 x 7.3 cm; there was no active extravasation (Figure 3).

The patient was started on intravenous normal saline while vascular surgery services was consulted for management and repair. After a discussion with the son regarding the patient’s wishes, surgical intervention was refused and the patient was conservatively managed and transitioned to hospice care.

Discussion

A true aneurysm differs from a PSA in that true aneurysms involve all three layers of the vessel wall. A PSA consists partly of the vessel wall and partly of encapsulating fibrous tissue or surrounding tissue.

Etiology

Femoral artery PSAs can be iatrogenic, for example, develop following cardiac catheterization or at the anastomotic site of previous surgery.¹ The incidence of diagnostic postcatheterization PSA ranges from 0.05% to 2%, whereas interventional postcatheterization PSA ranges from 2% to 6%.²

With the increasing number of peripheral coronary diagnostics and interventions, emergency physicians should include PSA in the differential diagnosis of patients with a recent or remote history of catheterization or bypass grafts. Less commonly, femoral PSAs are caused by non-surgical trauma or infection (ie, mycotic PSA). Patient risk factors for development of PSA include obesity, hypertension, PAD, and anticoagulation.³ Patients with femoral artery PSAs may present with a painful or painless pulsatile mass. Mass effect of the PSA can compress nearby neurovascular structures, leading to femoral neuropathies or limb edema secondary to venous obstruction.⁴ Complications of embolization or thrombosis can cause limb ischemia, neuropathy, and claudication, while rupture may present with a rapidly expanding groin hematoma. Additionally, sizeable PSAs can cause overlying skin necrosis.⁵

Imaging Studies

Diagnosis of a PSA can be made through Doppler ultrasound, which is the preferred imaging modality due to its accuracy, noninvasive nature, and low cost. Doppler ultrasound has been found to have a sensitivity of 94% and specificity of 97% in detecting PSAs. Additional imaging with CTA can provide further definition of vasculopathy.⁶ Treatment should be considered for patients with a symptomatic femoral PSA, a PSA measuring more than 3 cm, or patients who are on anticoagulation therapy. Studies have shown that observation-only and follow-up may be appropriate for patients with a PSA measuring less than 3 cm. A study by Toursarkissian et al⁷ found that the majority of PSAs smaller than 3 cm spontaneously resolved in a mean of 23 days without limb-threatening complications.

Treatment

Traditionally, open surgical repair techniques were the only treatment option for PSAs. However, in the early 1990s, the advent of new techniques such as stenting, coil insertion, ultrasound-guided compression, and ultrasound-guided thrombin injection, have developed as alternatives to open surgical repair; there has been variable success to these minimally invasive approaches.^5,8

 

Ultrasound-Guided Compression. A conservative approach to treating PSAs, ultrasound-guided compression requires sustained compression by a skilled physician. This technique is associated with significant discomfort to the patient.⁵ Ultrasound-Guided Thrombin Injection. This technique is the treatment of choice for postcatheterization PSA. However, this intervention is contraindicated in patients who have concerning features such as an infected PSA, rapid expansion, skin necrosis, or signs of limb ischemia. Additionally, ultrasound-guided thrombin injection is not appropriate for use in patients with a PSA occurring at anastomosis of a synthetic graft and native artery.⁵

Conclusion

Based on our patient’s clinical presentation and history of aortofemoral bypass surgery, we suspected a femoral PSA. While the PSA noted in our patient was sizeable, imaging studies and clinical examination showed no sign of limb ischemia or rupture.

Femoral PSAs are usually iatrogenic in nature, typically developing shortly after catheterization or a previous bypass surgery. The most serious complication of a PSA is rupture, but a thorough examination of the distal extremity is warranted to assess for limb ischemia as well. Ultrasound imaging is considered the modality of choice based on its high sensitivity and sensitivity for detecting PSAs.

Small PSAs (<3 cm) can be managed medically, but larger PSAs (>3 cm) require treatment. Newer techniques, including stenting, coil insertion, ultrasound-guided compression, and ultrasound-guided thrombin injection are alternatives to open surgical repair of larger, uncomplicated PSAs. However, urgent open surgical repair is the only option when there is evidence of a ruptured PSA, ischemia, or skin necrosis.

Facial paralysis is a common medical complaint—one that has fascinated ancient and contemporary physicians alike.¹ An idiopathic facial nerve paresis involving the lower motor neuron was described in 1821 by Sir Charles Bell. This entity became known as a Bell’s palsy, the hallmark of which was weakness or complete paralysis of the muscles of one side of the face, with no sparing of the muscles of the forehead. However, not all facial paralysis is due to Bell’s palsy.

We present a case of a patient with a Bell’s palsy mimic to facilitate and guide the differential diagnosis and distinguish conditions from the classical presentation that Bell first described to the more concerning symptoms that may not be immediately obvious. Our case further underscores the importance of performing a thorough assessment to determine the presence of other neurological findings.

Case

A 61-year-old woman presented to the ED for evaluation of right facial droop and sensation of “room spinning.” The patient stated both symptoms began approximately 36 hours prior to presentation, upon awakening. She further noted that the right side of her face felt “funny” and numb.

The patient denied any headache, neck or chest pain, extremity numbness, or weakness, but stated that she felt like she was going to fall toward her right side whenever she attempted to walk. The patient’s medical history was significant for hypertension, for which she was taking losartan. Her surgical history was notable for a left oophorectomy secondary to an ovarian cyst. Regarding the social history, the patient admitted to smoking 90 packs of cigarettes per year, but denied alcohol or illicit drug use.

Upon arrival at the ED, the patient’s vital signs were: blood pressure, 164/86 mm Hg: pulse, 89 beats/min; respiratory rate, 18 breaths/min; and temperature, 98.6°F. Oxygen saturation was 98% on room air.

Physical examination revealed the patient had a right facial droop consistent with right facial palsy. She was unable to wrinkle her right forehead or fully close her right eye. There were no field cuts on confrontation. The patient’s speech was noticeable for a mild dysarthria. The motor examination revealed mild weakness of the left upper extremity and impaired right facial sensation. There were no rashes noted on the face, head, or ears. The patient had slightly impaired hearing in the right ear, which was new in onset. The remainder of the physical examination was unremarkable.

Although the patient exhibited the classic signs of Bell’s palsy, including complete paralysis of the muscles of one side of the face, inability to wrinkle the muscle of the right forehead, and inability to fully close the right eye, she also had concerning symptoms of vertigo, dysarthria, and contralateral upper extremity weakness.

A computed tomography (CT) scan of the head was ordered, which revealed a large mass lesion centered in the right petrous apex, with an associated large component extending medially into the right cerebellopontine angle (CPA) that caused a mass effect on the adjacent brainstem (Figures 1a and 1b).

Upon these findings, the patient was transferred to another facility for neurosurgical evaluation. Magnetic resonance imaging (MRI) studies performed at the receiving hospital demonstrated a large expansile heterogeneous mass lesion centered in the right petrous apex with an associated large, probable hemorrhagic soft-tissue component extending medially into the right CPA, causing a mass effect on the adjacent brainstem and mild obstructive hydrocephalus (Figures 2a and 2b).

The patient was given dexamethasone 10 mg intravenously and taken to the operating room for a right suboccipital craniotomy with subtotal tumor removal. Intraoperative high-voltage stimulation of the fifth to eighth cranial nerves showed no response, indicating significant impairment.

While there were no intraoperative complications, the patient had significant postoperative dysphagia and resultant aspiration. A tracheostomy and percutaneous endoscopic gastrostomy tube were subsequently placed. Results of a biopsy taken during surgery identified an atypical meningioma. The patient remained in the hospital for 4 weeks, after which she was discharged to a long-term care (LTC) and rehabilitation facility.

A repeat CT scan taken 2 months after surgery demonstrated absence of the previously identified large mass (Figure 1b). Three months after discharge from the LTC-rehabilitation facility, MRI of the brain showed continued interval improvement of the previously noted mass centered in the right petrous apex (Figures 3a and 3b).

 

Discussion

Accounts of facial paralysis and facial nerve disorders have been noted throughout history and include accounts of the condition by Hippocrates.¹ Bell’s palsy was named after surgeon Sir Charles Bell, who described a peripheral-nerve paralysis of the facial nerve in 1821. Bell’s work helped to elucidate the anatomy and functional role of the facial nerve.^1,2

Signs and Symptoms

The classic presentation of Bell’s palsy is weakness or complete paralysis of the muscles of one side of the face, with no sparing of the muscles of the forehead. The eyelid on the affected side generally does not close, which can result in ocular irritation due to ineffective lubrication.

A scoring system has been developed by House and Brackmann which grades the degree impairment based on such characteristics as facial muscle function and eye closure.^3,4 Approximately 96% of patients with a Bell’s palsy will improve to a House-Brackmann score of 2 or better within 1 year from diagnosis,⁵ and 85% of patients with Bell’s palsy will show at least some improvement within 3 weeks of onset (Table).² Although the classic description of Bell’s palsy notes the condition as idiopathic, there is an increasing body of evidence in the literature showing a link to herpes simplex virus 1.^5-7

Ramsey-Hunt Syndrome

The relationship between Bell’s palsy and Ramsey-Hunt syndrome is complex and controversial. Ramsey-Hunt syndrome is a constellation of possible complications from varicella-virus infection. Symptoms of Ramsey-Hunt syndrome include facial paralysis, tinnitus, hearing loss, vertigo, hyperacusis (increased sensitivity to certain frequencies and volume ranges of sound), and decreased ocular tearing.⁸ Due to the nature of symptoms associated with Ramsey-Hunt syndrome, it is apparent that the condition involves more than the seventh cranial nerve. In fact, studies have shown that Ramsey-Hunt syndrome can affect the fifth, sixth, eighth, and ninth cranial nerves.⁸

Ramsey-Hunt syndrome, which can present in the absence of cutaneous rash (referred to as zoster sine herpete), is estimated to occur in 8% to 20% of unilateral facial nerve palsies in adult patients.^8,9 Regardless of the etiology of Bell’s palsy, a review of the literature makes it clear that facial nerve paralysis is not synonymous with Bell’s palsy.¹⁰ In one example, Yetter et al¹⁰ describe the case of a patient who, though initially diagnosed with Bell’s palsy, ultimately was found to have a facial palsy due to a parotid gland malignancy.

Likewise, Stomeo¹¹ describes a case of a patient with facial paralysis and profound ipsilateral hearing loss who ultimately was found to have a mucoepithelial carcinoma of the parotid gland. In their report, the authors note that approximately 80% of facial nerve paralysis is due to Bell’s palsy, while 5% is due to malignancy.

In another report, Clemis¹² describes a case in which a patient who initially was diagnosed with Bell’s palsy eventually was found to have an adenoid cystic carcinoma of the parotid. Thus, the authors appropriately emphasize in their report that “all that palsies is not Bell’s.”

Differential Diagnosis

Historical factors, including timing and duration of symptom onset, help to distinguish a Bell’s palsy from other disorders that can mimic this condition. In their study, Brach VanSwewaringen¹³ highlight the fact that “not all facial paralysis is Bell’s palsy.” In their review, the authors describe clues to help distinguish conditions that mimic Bell’s palsy. For example, maximal weakness from Bell’s Palsy typically occurs within 3 to 7 days from symptom onset, and that a more gradual onset of symptoms, with slow or negligible improvement over 6 to 12 months, is more indicative of a space-occupying lesion than Bell’s palsy.¹³It is, however, important to note that although the patient in our case had a central lesion, she experienced an acute onset of symptoms.

The presence of additional symptoms may also suggest an alternative diagnosis. Brach and VanSwearingen¹³ further noted that symptoms associated with the eighth nerve, such as vertigo, tinnitus, and hearing loss may be found in patients with a CPA tumor. In patients with larger tumors, ninth and 10th nerve symptoms, including the impaired hearing noted in our patient, may be present. Some patients with ninth and 10th nerve symptoms may perceive a sense of facial numbness, but actual sensory changes in the facial nerve distribution are unlikely in Bell’s palsy. Gustatory changes, however, are consistent with Bell’s palsy.

Ear pain is consistent with Bell’s palsy and is a signal to be vigilant for the possible emergence of an ear rash, which would suggest the diagnosis of herpes zoster oticus along the trajectory of Ramsey-Hunt syndrome. Facial pain in the area of the facial nerve is inconsistent with Bell’s palsy, while hyperacusis is consistent with Bell’s palsy. Hearing loss is an eighth nerve symptom that is inconsistent with Bell’s palsy.

Similarly, there are physical examination findings that can help distinguish a true Bell’s palsy from a mimic. Changes in tear production are consistent with Bell’s palsy, but imbalance and disequilibrium are not.¹⁴

As previously noted, the patient in this case had difficulty walking and felt as if she was falling toward her right side.

One way to organize the causes of facial paralysis has been proposed by Adour et al.¹⁵ In this system, etiologies are listed as either acute paralysis or chronic, progressive paralysis. Acute paralysis (ie, the sudden onset of symptoms with maximal severity within 2 weeks), of which Bell’s palsy is the most common, can be seen in cases of polyneuritis.

A new case of Bell’s palsy has been estimated to occur in the United States every 10 minutes.⁸ Guillain-Barré syndrome and Lyme disease are also in this category, as is Ramsey-Hunt syndrome. Patients with Lyme disease may have a history of a tick bite or rash.¹⁴

Trauma can also cause acute facial nerve paralysis (eg, blunt trauma-associated facial fracture, penetrating trauma, birth trauma). Unilateral central facial weakness can have a neurological cause, such as a lesion to the contralateral cortex, subcortical white matter, or internal capsule.^2,15 Otitis media can sometimes cause facial paralysis.¹⁶ A cholesteatoma can cause acute facial paralysis.² Malignancies cause 5% of all cases of facial paralysis. Primary parotid tumors of various types are in this category. Metastatic disease from breast, lung, skin, colon, and kidney may cause facial paralysis. As our case illustrates, CPA tumors can cause facial paralysis.¹⁵ It is important to also note that a patient can have both a Bell’s palsy and a concurrent disease. There are a number of case reports in the literature that describe acute onset of facial paralysis as a presenting symptom of malignancy.¹⁷ In addition, there are cases wherein a neurological finding on imaging, such as an acoustic neuroma, was presumed to be the cause of facial paralysis, yet the patient’s symptoms resolved in a manner consistent with Bell’s palsy.¹⁸

For example, Lagman et al¹⁹ described a patient in which a CPA lipoma was presumed to be the cause of the facial paralysis, but the eventual outcome showed the lipoma to have been an incidentaloma.

Conclusion

This case demonstrates a presenting symptom of facial palsy and the presence of a CPA tumor. The presence of vertigo along with other historical and physical examination findings inconsistent with Bell’s palsy prompted the CT scan of the head. A review of the literature suggests a number of important findings in patients with facial palsy to assist the clinician in distinguishing true Bell’s palsy from other diseases that can mimic this condition. This case serves as a reminder of the need to perform a thorough and diligent workup to determine the presence or absence of other neurologic findings prior to closing on the diagnosis of Bell’s palsy.

Facial paralysis is a common medical complaint—one that has fascinated ancient and contemporary physicians alike.¹ An idiopathic facial nerve paresis involving the lower motor neuron was described in 1821 by Sir Charles Bell. This entity became known as a Bell’s palsy, the hallmark of which was weakness or complete paralysis of the muscles of one side of the face, with no sparing of the muscles of the forehead. However, not all facial paralysis is due to Bell’s palsy.

We present a case of a patient with a Bell’s palsy mimic to facilitate and guide the differential diagnosis and distinguish conditions from the classical presentation that Bell first described to the more concerning symptoms that may not be immediately obvious. Our case further underscores the importance of performing a thorough assessment to determine the presence of other neurological findings.

Case

A 61-year-old woman presented to the ED for evaluation of right facial droop and sensation of “room spinning.” The patient stated both symptoms began approximately 36 hours prior to presentation, upon awakening. She further noted that the right side of her face felt “funny” and numb.

The patient denied any headache, neck or chest pain, extremity numbness, or weakness, but stated that she felt like she was going to fall toward her right side whenever she attempted to walk. The patient’s medical history was significant for hypertension, for which she was taking losartan. Her surgical history was notable for a left oophorectomy secondary to an ovarian cyst. Regarding the social history, the patient admitted to smoking 90 packs of cigarettes per year, but denied alcohol or illicit drug use.

Upon arrival at the ED, the patient’s vital signs were: blood pressure, 164/86 mm Hg: pulse, 89 beats/min; respiratory rate, 18 breaths/min; and temperature, 98.6°F. Oxygen saturation was 98% on room air.

Physical examination revealed the patient had a right facial droop consistent with right facial palsy. She was unable to wrinkle her right forehead or fully close her right eye. There were no field cuts on confrontation. The patient’s speech was noticeable for a mild dysarthria. The motor examination revealed mild weakness of the left upper extremity and impaired right facial sensation. There were no rashes noted on the face, head, or ears. The patient had slightly impaired hearing in the right ear, which was new in onset. The remainder of the physical examination was unremarkable.

Although the patient exhibited the classic signs of Bell’s palsy, including complete paralysis of the muscles of one side of the face, inability to wrinkle the muscle of the right forehead, and inability to fully close the right eye, she also had concerning symptoms of vertigo, dysarthria, and contralateral upper extremity weakness.

A computed tomography (CT) scan of the head was ordered, which revealed a large mass lesion centered in the right petrous apex, with an associated large component extending medially into the right cerebellopontine angle (CPA) that caused a mass effect on the adjacent brainstem (Figures 1a and 1b).

Upon these findings, the patient was transferred to another facility for neurosurgical evaluation. Magnetic resonance imaging (MRI) studies performed at the receiving hospital demonstrated a large expansile heterogeneous mass lesion centered in the right petrous apex with an associated large, probable hemorrhagic soft-tissue component extending medially into the right CPA, causing a mass effect on the adjacent brainstem and mild obstructive hydrocephalus (Figures 2a and 2b).

The patient was given dexamethasone 10 mg intravenously and taken to the operating room for a right suboccipital craniotomy with subtotal tumor removal. Intraoperative high-voltage stimulation of the fifth to eighth cranial nerves showed no response, indicating significant impairment.

While there were no intraoperative complications, the patient had significant postoperative dysphagia and resultant aspiration. A tracheostomy and percutaneous endoscopic gastrostomy tube were subsequently placed. Results of a biopsy taken during surgery identified an atypical meningioma. The patient remained in the hospital for 4 weeks, after which she was discharged to a long-term care (LTC) and rehabilitation facility.

A repeat CT scan taken 2 months after surgery demonstrated absence of the previously identified large mass (Figure 1b). Three months after discharge from the LTC-rehabilitation facility, MRI of the brain showed continued interval improvement of the previously noted mass centered in the right petrous apex (Figures 3a and 3b).

 

Discussion

Accounts of facial paralysis and facial nerve disorders have been noted throughout history and include accounts of the condition by Hippocrates.¹ Bell’s palsy was named after surgeon Sir Charles Bell, who described a peripheral-nerve paralysis of the facial nerve in 1821. Bell’s work helped to elucidate the anatomy and functional role of the facial nerve.^1,2

Signs and Symptoms

The classic presentation of Bell’s palsy is weakness or complete paralysis of the muscles of one side of the face, with no sparing of the muscles of the forehead. The eyelid on the affected side generally does not close, which can result in ocular irritation due to ineffective lubrication.

A scoring system has been developed by House and Brackmann which grades the degree impairment based on such characteristics as facial muscle function and eye closure.^3,4 Approximately 96% of patients with a Bell’s palsy will improve to a House-Brackmann score of 2 or better within 1 year from diagnosis,⁵ and 85% of patients with Bell’s palsy will show at least some improvement within 3 weeks of onset (Table).² Although the classic description of Bell’s palsy notes the condition as idiopathic, there is an increasing body of evidence in the literature showing a link to herpes simplex virus 1.^5-7

Ramsey-Hunt Syndrome

The relationship between Bell’s palsy and Ramsey-Hunt syndrome is complex and controversial. Ramsey-Hunt syndrome is a constellation of possible complications from varicella-virus infection. Symptoms of Ramsey-Hunt syndrome include facial paralysis, tinnitus, hearing loss, vertigo, hyperacusis (increased sensitivity to certain frequencies and volume ranges of sound), and decreased ocular tearing.⁸ Due to the nature of symptoms associated with Ramsey-Hunt syndrome, it is apparent that the condition involves more than the seventh cranial nerve. In fact, studies have shown that Ramsey-Hunt syndrome can affect the fifth, sixth, eighth, and ninth cranial nerves.⁸

Ramsey-Hunt syndrome, which can present in the absence of cutaneous rash (referred to as zoster sine herpete), is estimated to occur in 8% to 20% of unilateral facial nerve palsies in adult patients.^8,9 Regardless of the etiology of Bell’s palsy, a review of the literature makes it clear that facial nerve paralysis is not synonymous with Bell’s palsy.¹⁰ In one example, Yetter et al¹⁰ describe the case of a patient who, though initially diagnosed with Bell’s palsy, ultimately was found to have a facial palsy due to a parotid gland malignancy.

Likewise, Stomeo¹¹ describes a case of a patient with facial paralysis and profound ipsilateral hearing loss who ultimately was found to have a mucoepithelial carcinoma of the parotid gland. In their report, the authors note that approximately 80% of facial nerve paralysis is due to Bell’s palsy, while 5% is due to malignancy.

In another report, Clemis¹² describes a case in which a patient who initially was diagnosed with Bell’s palsy eventually was found to have an adenoid cystic carcinoma of the parotid. Thus, the authors appropriately emphasize in their report that “all that palsies is not Bell’s.”

Differential Diagnosis

Historical factors, including timing and duration of symptom onset, help to distinguish a Bell’s palsy from other disorders that can mimic this condition. In their study, Brach VanSwewaringen¹³ highlight the fact that “not all facial paralysis is Bell’s palsy.” In their review, the authors describe clues to help distinguish conditions that mimic Bell’s palsy. For example, maximal weakness from Bell’s Palsy typically occurs within 3 to 7 days from symptom onset, and that a more gradual onset of symptoms, with slow or negligible improvement over 6 to 12 months, is more indicative of a space-occupying lesion than Bell’s palsy.¹³It is, however, important to note that although the patient in our case had a central lesion, she experienced an acute onset of symptoms.

The presence of additional symptoms may also suggest an alternative diagnosis. Brach and VanSwearingen¹³ further noted that symptoms associated with the eighth nerve, such as vertigo, tinnitus, and hearing loss may be found in patients with a CPA tumor. In patients with larger tumors, ninth and 10th nerve symptoms, including the impaired hearing noted in our patient, may be present. Some patients with ninth and 10th nerve symptoms may perceive a sense of facial numbness, but actual sensory changes in the facial nerve distribution are unlikely in Bell’s palsy. Gustatory changes, however, are consistent with Bell’s palsy.

Ear pain is consistent with Bell’s palsy and is a signal to be vigilant for the possible emergence of an ear rash, which would suggest the diagnosis of herpes zoster oticus along the trajectory of Ramsey-Hunt syndrome. Facial pain in the area of the facial nerve is inconsistent with Bell’s palsy, while hyperacusis is consistent with Bell’s palsy. Hearing loss is an eighth nerve symptom that is inconsistent with Bell’s palsy.

Similarly, there are physical examination findings that can help distinguish a true Bell’s palsy from a mimic. Changes in tear production are consistent with Bell’s palsy, but imbalance and disequilibrium are not.¹⁴

As previously noted, the patient in this case had difficulty walking and felt as if she was falling toward her right side.

One way to organize the causes of facial paralysis has been proposed by Adour et al.¹⁵ In this system, etiologies are listed as either acute paralysis or chronic, progressive paralysis. Acute paralysis (ie, the sudden onset of symptoms with maximal severity within 2 weeks), of which Bell’s palsy is the most common, can be seen in cases of polyneuritis.

A new case of Bell’s palsy has been estimated to occur in the United States every 10 minutes.⁸ Guillain-Barré syndrome and Lyme disease are also in this category, as is Ramsey-Hunt syndrome. Patients with Lyme disease may have a history of a tick bite or rash.¹⁴

Trauma can also cause acute facial nerve paralysis (eg, blunt trauma-associated facial fracture, penetrating trauma, birth trauma). Unilateral central facial weakness can have a neurological cause, such as a lesion to the contralateral cortex, subcortical white matter, or internal capsule.^2,15 Otitis media can sometimes cause facial paralysis.¹⁶ A cholesteatoma can cause acute facial paralysis.² Malignancies cause 5% of all cases of facial paralysis. Primary parotid tumors of various types are in this category. Metastatic disease from breast, lung, skin, colon, and kidney may cause facial paralysis. As our case illustrates, CPA tumors can cause facial paralysis.¹⁵ It is important to also note that a patient can have both a Bell’s palsy and a concurrent disease. There are a number of case reports in the literature that describe acute onset of facial paralysis as a presenting symptom of malignancy.¹⁷ In addition, there are cases wherein a neurological finding on imaging, such as an acoustic neuroma, was presumed to be the cause of facial paralysis, yet the patient’s symptoms resolved in a manner consistent with Bell’s palsy.¹⁸

For example, Lagman et al¹⁹ described a patient in which a CPA lipoma was presumed to be the cause of the facial paralysis, but the eventual outcome showed the lipoma to have been an incidentaloma.

Conclusion

This case demonstrates a presenting symptom of facial palsy and the presence of a CPA tumor. The presence of vertigo along with other historical and physical examination findings inconsistent with Bell’s palsy prompted the CT scan of the head. A review of the literature suggests a number of important findings in patients with facial palsy to assist the clinician in distinguishing true Bell’s palsy from other diseases that can mimic this condition. This case serves as a reminder of the need to perform a thorough and diligent workup to determine the presence or absence of other neurologic findings prior to closing on the diagnosis of Bell’s palsy.

Facial paralysis is a common medical complaint—one that has fascinated ancient and contemporary physicians alike.¹ An idiopathic facial nerve paresis involving the lower motor neuron was described in 1821 by Sir Charles Bell. This entity became known as a Bell’s palsy, the hallmark of which was weakness or complete paralysis of the muscles of one side of the face, with no sparing of the muscles of the forehead. However, not all facial paralysis is due to Bell’s palsy.

We present a case of a patient with a Bell’s palsy mimic to facilitate and guide the differential diagnosis and distinguish conditions from the classical presentation that Bell first described to the more concerning symptoms that may not be immediately obvious. Our case further underscores the importance of performing a thorough assessment to determine the presence of other neurological findings.

Case

A 61-year-old woman presented to the ED for evaluation of right facial droop and sensation of “room spinning.” The patient stated both symptoms began approximately 36 hours prior to presentation, upon awakening. She further noted that the right side of her face felt “funny” and numb.

The patient denied any headache, neck or chest pain, extremity numbness, or weakness, but stated that she felt like she was going to fall toward her right side whenever she attempted to walk. The patient’s medical history was significant for hypertension, for which she was taking losartan. Her surgical history was notable for a left oophorectomy secondary to an ovarian cyst. Regarding the social history, the patient admitted to smoking 90 packs of cigarettes per year, but denied alcohol or illicit drug use.

Upon arrival at the ED, the patient’s vital signs were: blood pressure, 164/86 mm Hg: pulse, 89 beats/min; respiratory rate, 18 breaths/min; and temperature, 98.6°F. Oxygen saturation was 98% on room air.

Physical examination revealed the patient had a right facial droop consistent with right facial palsy. She was unable to wrinkle her right forehead or fully close her right eye. There were no field cuts on confrontation. The patient’s speech was noticeable for a mild dysarthria. The motor examination revealed mild weakness of the left upper extremity and impaired right facial sensation. There were no rashes noted on the face, head, or ears. The patient had slightly impaired hearing in the right ear, which was new in onset. The remainder of the physical examination was unremarkable.

Although the patient exhibited the classic signs of Bell’s palsy, including complete paralysis of the muscles of one side of the face, inability to wrinkle the muscle of the right forehead, and inability to fully close the right eye, she also had concerning symptoms of vertigo, dysarthria, and contralateral upper extremity weakness.

A computed tomography (CT) scan of the head was ordered, which revealed a large mass lesion centered in the right petrous apex, with an associated large component extending medially into the right cerebellopontine angle (CPA) that caused a mass effect on the adjacent brainstem (Figures 1a and 1b).

Upon these findings, the patient was transferred to another facility for neurosurgical evaluation. Magnetic resonance imaging (MRI) studies performed at the receiving hospital demonstrated a large expansile heterogeneous mass lesion centered in the right petrous apex with an associated large, probable hemorrhagic soft-tissue component extending medially into the right CPA, causing a mass effect on the adjacent brainstem and mild obstructive hydrocephalus (Figures 2a and 2b).

The patient was given dexamethasone 10 mg intravenously and taken to the operating room for a right suboccipital craniotomy with subtotal tumor removal. Intraoperative high-voltage stimulation of the fifth to eighth cranial nerves showed no response, indicating significant impairment.

While there were no intraoperative complications, the patient had significant postoperative dysphagia and resultant aspiration. A tracheostomy and percutaneous endoscopic gastrostomy tube were subsequently placed. Results of a biopsy taken during surgery identified an atypical meningioma. The patient remained in the hospital for 4 weeks, after which she was discharged to a long-term care (LTC) and rehabilitation facility.

A repeat CT scan taken 2 months after surgery demonstrated absence of the previously identified large mass (Figure 1b). Three months after discharge from the LTC-rehabilitation facility, MRI of the brain showed continued interval improvement of the previously noted mass centered in the right petrous apex (Figures 3a and 3b).

 

Discussion

Accounts of facial paralysis and facial nerve disorders have been noted throughout history and include accounts of the condition by Hippocrates.¹ Bell’s palsy was named after surgeon Sir Charles Bell, who described a peripheral-nerve paralysis of the facial nerve in 1821. Bell’s work helped to elucidate the anatomy and functional role of the facial nerve.^1,2

Signs and Symptoms

The classic presentation of Bell’s palsy is weakness or complete paralysis of the muscles of one side of the face, with no sparing of the muscles of the forehead. The eyelid on the affected side generally does not close, which can result in ocular irritation due to ineffective lubrication.

A scoring system has been developed by House and Brackmann which grades the degree impairment based on such characteristics as facial muscle function and eye closure.^3,4 Approximately 96% of patients with a Bell’s palsy will improve to a House-Brackmann score of 2 or better within 1 year from diagnosis,⁵ and 85% of patients with Bell’s palsy will show at least some improvement within 3 weeks of onset (Table).² Although the classic description of Bell’s palsy notes the condition as idiopathic, there is an increasing body of evidence in the literature showing a link to herpes simplex virus 1.^5-7

Ramsey-Hunt Syndrome

The relationship between Bell’s palsy and Ramsey-Hunt syndrome is complex and controversial. Ramsey-Hunt syndrome is a constellation of possible complications from varicella-virus infection. Symptoms of Ramsey-Hunt syndrome include facial paralysis, tinnitus, hearing loss, vertigo, hyperacusis (increased sensitivity to certain frequencies and volume ranges of sound), and decreased ocular tearing.⁸ Due to the nature of symptoms associated with Ramsey-Hunt syndrome, it is apparent that the condition involves more than the seventh cranial nerve. In fact, studies have shown that Ramsey-Hunt syndrome can affect the fifth, sixth, eighth, and ninth cranial nerves.⁸

Ramsey-Hunt syndrome, which can present in the absence of cutaneous rash (referred to as zoster sine herpete), is estimated to occur in 8% to 20% of unilateral facial nerve palsies in adult patients.^8,9 Regardless of the etiology of Bell’s palsy, a review of the literature makes it clear that facial nerve paralysis is not synonymous with Bell’s palsy.¹⁰ In one example, Yetter et al¹⁰ describe the case of a patient who, though initially diagnosed with Bell’s palsy, ultimately was found to have a facial palsy due to a parotid gland malignancy.

Likewise, Stomeo¹¹ describes a case of a patient with facial paralysis and profound ipsilateral hearing loss who ultimately was found to have a mucoepithelial carcinoma of the parotid gland. In their report, the authors note that approximately 80% of facial nerve paralysis is due to Bell’s palsy, while 5% is due to malignancy.

In another report, Clemis¹² describes a case in which a patient who initially was diagnosed with Bell’s palsy eventually was found to have an adenoid cystic carcinoma of the parotid. Thus, the authors appropriately emphasize in their report that “all that palsies is not Bell’s.”

Differential Diagnosis

Historical factors, including timing and duration of symptom onset, help to distinguish a Bell’s palsy from other disorders that can mimic this condition. In their study, Brach VanSwewaringen¹³ highlight the fact that “not all facial paralysis is Bell’s palsy.” In their review, the authors describe clues to help distinguish conditions that mimic Bell’s palsy. For example, maximal weakness from Bell’s Palsy typically occurs within 3 to 7 days from symptom onset, and that a more gradual onset of symptoms, with slow or negligible improvement over 6 to 12 months, is more indicative of a space-occupying lesion than Bell’s palsy.¹³It is, however, important to note that although the patient in our case had a central lesion, she experienced an acute onset of symptoms.

The presence of additional symptoms may also suggest an alternative diagnosis. Brach and VanSwearingen¹³ further noted that symptoms associated with the eighth nerve, such as vertigo, tinnitus, and hearing loss may be found in patients with a CPA tumor. In patients with larger tumors, ninth and 10th nerve symptoms, including the impaired hearing noted in our patient, may be present. Some patients with ninth and 10th nerve symptoms may perceive a sense of facial numbness, but actual sensory changes in the facial nerve distribution are unlikely in Bell’s palsy. Gustatory changes, however, are consistent with Bell’s palsy.

Ear pain is consistent with Bell’s palsy and is a signal to be vigilant for the possible emergence of an ear rash, which would suggest the diagnosis of herpes zoster oticus along the trajectory of Ramsey-Hunt syndrome. Facial pain in the area of the facial nerve is inconsistent with Bell’s palsy, while hyperacusis is consistent with Bell’s palsy. Hearing loss is an eighth nerve symptom that is inconsistent with Bell’s palsy.

Similarly, there are physical examination findings that can help distinguish a true Bell’s palsy from a mimic. Changes in tear production are consistent with Bell’s palsy, but imbalance and disequilibrium are not.¹⁴

As previously noted, the patient in this case had difficulty walking and felt as if she was falling toward her right side.

One way to organize the causes of facial paralysis has been proposed by Adour et al.¹⁵ In this system, etiologies are listed as either acute paralysis or chronic, progressive paralysis. Acute paralysis (ie, the sudden onset of symptoms with maximal severity within 2 weeks), of which Bell’s palsy is the most common, can be seen in cases of polyneuritis.

A new case of Bell’s palsy has been estimated to occur in the United States every 10 minutes.⁸ Guillain-Barré syndrome and Lyme disease are also in this category, as is Ramsey-Hunt syndrome. Patients with Lyme disease may have a history of a tick bite or rash.¹⁴

Trauma can also cause acute facial nerve paralysis (eg, blunt trauma-associated facial fracture, penetrating trauma, birth trauma). Unilateral central facial weakness can have a neurological cause, such as a lesion to the contralateral cortex, subcortical white matter, or internal capsule.^2,15 Otitis media can sometimes cause facial paralysis.¹⁶ A cholesteatoma can cause acute facial paralysis.² Malignancies cause 5% of all cases of facial paralysis. Primary parotid tumors of various types are in this category. Metastatic disease from breast, lung, skin, colon, and kidney may cause facial paralysis. As our case illustrates, CPA tumors can cause facial paralysis.¹⁵ It is important to also note that a patient can have both a Bell’s palsy and a concurrent disease. There are a number of case reports in the literature that describe acute onset of facial paralysis as a presenting symptom of malignancy.¹⁷ In addition, there are cases wherein a neurological finding on imaging, such as an acoustic neuroma, was presumed to be the cause of facial paralysis, yet the patient’s symptoms resolved in a manner consistent with Bell’s palsy.¹⁸

For example, Lagman et al¹⁹ described a patient in which a CPA lipoma was presumed to be the cause of the facial paralysis, but the eventual outcome showed the lipoma to have been an incidentaloma.

Conclusion

This case demonstrates a presenting symptom of facial palsy and the presence of a CPA tumor. The presence of vertigo along with other historical and physical examination findings inconsistent with Bell’s palsy prompted the CT scan of the head. A review of the literature suggests a number of important findings in patients with facial palsy to assist the clinician in distinguishing true Bell’s palsy from other diseases that can mimic this condition. This case serves as a reminder of the need to perform a thorough and diligent workup to determine the presence or absence of other neurologic findings prior to closing on the diagnosis of Bell’s palsy.

ABSTRACT

A central distal femoral physeal bone bridge in a boy aged 5 years and 7 months was resected with a fluoroscopically guided core reamer placed through a lateral parapatellar approach. At 3-year follow-up, the boy’s leg-length discrepancy was 3.0 cm (3.9 cm preoperatively), and the physeal bone bridge did not recur. The patient had full function and no pain or other patellofemoral complaints. This technique provided direct access to the physeal bone bridge, and complete resection was performed without injury to the adjacent physeal cartilage in the medial and lateral columns of the distal femur, which is expected to grow normally in the absence of the bridge.

A physeal bone bridge is an osseous connection that forms across a physis. It may cause partial premature physeal arrest. Angular deformity and limb-length discrepancy are the main complications caused by physeal bone bridges.^1-4 The indications for the treatment of physeal bridges are well documented.^1-5 Trauma and infection are common causes of distal femoral physeal bone bridges. Arkader and colleagues⁶ showed that among different types of physeal bridges, the Salter-Harris type is significantly associated with complications, among which growth arrest is the most common and occurs in 27.4% of all patients.

The treatment of distal femoral physeal bone bridges is technically difficult and provides variable results. Poor results are reported in 13% to 40% of patients.^7-10 Procedure failure has been attributed to incomplete resection with the persistent tethering and dislodgement of the graft.¹¹ Methods with improved efficacy for the removal of central physeal bridges will help prevent reformation after treatment. We have used a novel technique that allows the direct resection of a central physeal bone bridge in the distal femur through the use of a fluoroscopically guided core reamer. This technique enables the complete removal of the bone bridge and the direct visual assessment of the remaining physis. The patient’s parents provided written informed consent for print and electronic publication of this case report.

CASE

A 3-year-old boy with a history of hemifacial microsomia presented for the evaluation of genu valgum and leg-length discrepancy. His intermalleolar distance at that time was 8 cm. A standing radiograph of his lower extremities demonstrated changes consistent with physiologic genu valgum. He had no history of knee trauma, infection, or pain.

At the age of 5 years and 7 months, the patient returned for a repeat evaluation and was noted to exhibit the progressive valgus deformity of the right leg and a leg-length discrepancy of 3.9 cm (Figure 1). 

Radiographs also showed the presence of a bone bridge of unknown etiology in the boy’s distal femoral physis. Computed tomography and magnetic resonance imaging (MRI) were used to characterize the size and location of the bone bridge, which was found to involve approximately 30% of the physis (Figures 2A-2C). 

Using the multiplier method described by Paley and colleagues,¹² the patient’s projected leg-length discrepancy, assuming complete growth arrest, was approximately 10.2 cm. The risks and benefits of physeal bone bridge resection, including the high rate of recurrence, were discussed with the patient’s family, who wished to proceed with resection.

 

Continue to: With the patient supine on the operating...

 

OPERATIVE TECHNIQUE

With the patient supine on the operating table and after the administration of general anesthesia, 3-dimensional (3-D) fluoroscopy was used to localize the bone bridge, which confirmed the fluoroscopic location that was previously visualized through preoperative 3-D imaging. The leg was elevated, and a tourniquet was applied and inflated. A lateral parapatellar approach was used to isolate the distal femoral physis anteriorly because the bone bridge was centered just lateral to the central portion of the distal femoral physis. A Kirschner wire was placed in the center of the bridge under anteroposterior and lateral fluoroscopic imaging (Figures 3A-3E). 

A series of core reamers were then introduced, starting at 10 mm diameter and increasing to 18 mm diameter before complete resection was accomplished. Irrigation was used to prevent the thermal necrosis of the physis during reaming, and lateral fluoroscopic imaging was used to prevent injury to the posterior neurovascular structures. Each time a reaming was completed, the physeal bone bed was inspected to confirm complete bone bridge resection (Figure 3C). Once 18 mm of the physis had been removed, direct visual inspection confirmed normal physis was present on all sides of the bone that remained following physeal bar resection (Figures 3D and 4A, 4B). 

The defect was irrigated with normal saline and filled with cranioplast (Figure 3E). Cranioplast (the methyl ester of methacrylic acid that easily polymerizes into polymethyl methacrylate) was chosen because the amount of adipose tissue was insufficient for harvesting for interposition given the patient’s lean body habitus. Moreover, the use of the cranioplast prevented the occurrence of exothermic reactions during curing and provided hemostasis because the cranioplast occupied the entire cavity and was strong enough to provide structural support.¹³ When partially set into a putty-like state to allow molding, the cranioplast was carefully contoured within the femoral trochlea. To protect the resection site from pathologic fracture, the patient was placed in a long-leg cast, and only protected weight-bearing with the use of a walker was allowed for 6 weeks.

OUTCOME

The patient healed uneventfully, and early range-of-motion exercises were started 6 weeks postoperatively. At 6-month follow-up, his leg-length discrepancy was 2.7 cm, and the bone bridge did not recur. At 3-year follow-up, his leg-length discrepancy was 3.0 cm, and the bone bridge did not recur. Over the 3 years postoperatively, the patient exhibited 9.8 cm of growth on his operative side and 9.5 cm on his nonoperative side (Figure 5). 

The patient has returned to full function and has had no pain, patellofemoral complaints, or complications associated with the cranioplast. He currently is being followed for his leg-length discrepancy. A contralateral epiphysiodesis is planned to equalize his leg-length discrepancy.

DISCUSSION

Given the considerable growth potential of the distal femoral physis,^1,14-16 an injury to the distal femoral physis and the formation of a physeal bone bridge can have a profound effect on a young patient in terms of leg-length discrepancy and angular deformity. Fracture from trauma or infection is a common cause of physeal bone bridges.^6,17-19 The etiology of our patient’s distal femoral physeal bone bridge is idiopathic, which is considerably less common than other etiologies, and the incidence of idiopathic physeal bone bridge formation is not well established in the literature. Hresko and Kasser²¹ identified atraumatic physeal bone bridge formations in 7 patients. Among the 13 patients with physeal bone bridges described by Broughton and colleagues,²⁰ the cause of bridge formation is unknown in 1.

Physeal bone bridges that form centrally are particularly challenging because they are difficult to visualize through a peripheral approach. A number of methods for resecting central physeal bone bridges have been described. These methods have varying degrees of success. In 1981, Langenskiöld⁷ first described the creation of a metaphyseal mirror and the use of a dental mirror for visualization. This technique, however, yielded unfavorable results in 16% of patients. Williamson and Staheli⁹ reported poor results in 23% of patients. Loraas and Schmale⁴ described the use of an endoscope, termed an osteoscope, for visualization, citing advantages of superior illumination and potential for image magnification and capture. Marsh and Polzhofer⁸ also showed this technique to have low morbidity but poor results in 13% of patients, whereas Moreta and colleagues¹⁰ reported poor results in 2 out of 5 patients. The rate of poor results of these methods may be related to the technical difficulty of using dental mirrors and arthroscopes and can be improved by highly efficient direct methods with improved visualization, such as the method described in this article.

Continue to: Proper imaging is necessary for...

 

Proper imaging is necessary for the accurate quantification of bone bridges to determine resectability and to identify the best surgical approach to resection. MRI with software for the generation of 3-D physeal maps is a reproducible method with good interobserver reliability.^22,23 Intraoperative computer-assisted imaging also is beneficial for determining the extent and location of the resection to ensure complete bone bridge removal.²⁴

To our knowledge, a direct approach through parapatellar arthrotomy for the resection of a centrally located distal femoral physeal bone bridge has not been previously described. This novel technique provided direct access to the physeal bone bridge and was performed without injuring the adjacent physeal cartilage in the medial and lateral columns of the distal femur, which may grow normally in the absence of the bridge. Instead of using a lateral or medial approach with a metaphyseal window,⁴ we directly approached this central bar through a parapatellar approach and were able to completely resect it under direct visualization. This obviated the need for an arthroscope or dental mirror. To remove the entire physeal bone bridge, we needed to resect completely from the anterior cortex to the posterior cortex. Although this technique potentially increased the risk of iatrogenic fracture, we believed that this risk would not differ greatly from that of disrupting the medial or lateral metaphysis and would be more stable with either axial and torsion load. At 3-year follow-up, the patient exhibited restored normal growth in his operative limb relative to that in his nonoperative limb, had not developed angular deformity, and had maintained his previously developed limb-length discrepancy that could be corrected with the epiphysiodesis of his opposite limb at a later date.

The limitations to this technique include the fact that it may be most effective with small-to moderate-sized central physeal bone bridges, although resection has shown good results with up to 70% physeal involvement.⁸ In this patient, the bone bridge was moderately sized (30% of the physis), centrally located, and clearly visible on fluoroscopy. These characteristics increased the technical safety and ease of the procedure. The resection of large, peripheral bridges may destabilize the distal femur. The destabilization of the distal femur, in turn, can lead to fracture. Patellofemoral mechanics may also be affected during the treatment of distal femoral physeal bone bridges. This patient has not experienced any patellofemoral dysfunction or symptoms. Given the patient’s age and significant amount of remaining growth, he will need close monitoring until he reaches skeletal maturity.

This paper will be judged for the Resident Writer’s Award.

ABSTRACT

A central distal femoral physeal bone bridge in a boy aged 5 years and 7 months was resected with a fluoroscopically guided core reamer placed through a lateral parapatellar approach. At 3-year follow-up, the boy’s leg-length discrepancy was 3.0 cm (3.9 cm preoperatively), and the physeal bone bridge did not recur. The patient had full function and no pain or other patellofemoral complaints. This technique provided direct access to the physeal bone bridge, and complete resection was performed without injury to the adjacent physeal cartilage in the medial and lateral columns of the distal femur, which is expected to grow normally in the absence of the bridge.

A physeal bone bridge is an osseous connection that forms across a physis. It may cause partial premature physeal arrest. Angular deformity and limb-length discrepancy are the main complications caused by physeal bone bridges.^1-4 The indications for the treatment of physeal bridges are well documented.^1-5 Trauma and infection are common causes of distal femoral physeal bone bridges. Arkader and colleagues⁶ showed that among different types of physeal bridges, the Salter-Harris type is significantly associated with complications, among which growth arrest is the most common and occurs in 27.4% of all patients.

The treatment of distal femoral physeal bone bridges is technically difficult and provides variable results. Poor results are reported in 13% to 40% of patients.^7-10 Procedure failure has been attributed to incomplete resection with the persistent tethering and dislodgement of the graft.¹¹ Methods with improved efficacy for the removal of central physeal bridges will help prevent reformation after treatment. We have used a novel technique that allows the direct resection of a central physeal bone bridge in the distal femur through the use of a fluoroscopically guided core reamer. This technique enables the complete removal of the bone bridge and the direct visual assessment of the remaining physis. The patient’s parents provided written informed consent for print and electronic publication of this case report.

CASE

A 3-year-old boy with a history of hemifacial microsomia presented for the evaluation of genu valgum and leg-length discrepancy. His intermalleolar distance at that time was 8 cm. A standing radiograph of his lower extremities demonstrated changes consistent with physiologic genu valgum. He had no history of knee trauma, infection, or pain.

At the age of 5 years and 7 months, the patient returned for a repeat evaluation and was noted to exhibit the progressive valgus deformity of the right leg and a leg-length discrepancy of 3.9 cm (Figure 1). 

Radiographs also showed the presence of a bone bridge of unknown etiology in the boy’s distal femoral physis. Computed tomography and magnetic resonance imaging (MRI) were used to characterize the size and location of the bone bridge, which was found to involve approximately 30% of the physis (Figures 2A-2C). 

Using the multiplier method described by Paley and colleagues,¹² the patient’s projected leg-length discrepancy, assuming complete growth arrest, was approximately 10.2 cm. The risks and benefits of physeal bone bridge resection, including the high rate of recurrence, were discussed with the patient’s family, who wished to proceed with resection.

 

Continue to: With the patient supine on the operating...

 

OPERATIVE TECHNIQUE

With the patient supine on the operating table and after the administration of general anesthesia, 3-dimensional (3-D) fluoroscopy was used to localize the bone bridge, which confirmed the fluoroscopic location that was previously visualized through preoperative 3-D imaging. The leg was elevated, and a tourniquet was applied and inflated. A lateral parapatellar approach was used to isolate the distal femoral physis anteriorly because the bone bridge was centered just lateral to the central portion of the distal femoral physis. A Kirschner wire was placed in the center of the bridge under anteroposterior and lateral fluoroscopic imaging (Figures 3A-3E). 

A series of core reamers were then introduced, starting at 10 mm diameter and increasing to 18 mm diameter before complete resection was accomplished. Irrigation was used to prevent the thermal necrosis of the physis during reaming, and lateral fluoroscopic imaging was used to prevent injury to the posterior neurovascular structures. Each time a reaming was completed, the physeal bone bed was inspected to confirm complete bone bridge resection (Figure 3C). Once 18 mm of the physis had been removed, direct visual inspection confirmed normal physis was present on all sides of the bone that remained following physeal bar resection (Figures 3D and 4A, 4B). 

The defect was irrigated with normal saline and filled with cranioplast (Figure 3E). Cranioplast (the methyl ester of methacrylic acid that easily polymerizes into polymethyl methacrylate) was chosen because the amount of adipose tissue was insufficient for harvesting for interposition given the patient’s lean body habitus. Moreover, the use of the cranioplast prevented the occurrence of exothermic reactions during curing and provided hemostasis because the cranioplast occupied the entire cavity and was strong enough to provide structural support.¹³ When partially set into a putty-like state to allow molding, the cranioplast was carefully contoured within the femoral trochlea. To protect the resection site from pathologic fracture, the patient was placed in a long-leg cast, and only protected weight-bearing with the use of a walker was allowed for 6 weeks.

OUTCOME

The patient healed uneventfully, and early range-of-motion exercises were started 6 weeks postoperatively. At 6-month follow-up, his leg-length discrepancy was 2.7 cm, and the bone bridge did not recur. At 3-year follow-up, his leg-length discrepancy was 3.0 cm, and the bone bridge did not recur. Over the 3 years postoperatively, the patient exhibited 9.8 cm of growth on his operative side and 9.5 cm on his nonoperative side (Figure 5). 

The patient has returned to full function and has had no pain, patellofemoral complaints, or complications associated with the cranioplast. He currently is being followed for his leg-length discrepancy. A contralateral epiphysiodesis is planned to equalize his leg-length discrepancy.

DISCUSSION

Given the considerable growth potential of the distal femoral physis,^1,14-16 an injury to the distal femoral physis and the formation of a physeal bone bridge can have a profound effect on a young patient in terms of leg-length discrepancy and angular deformity. Fracture from trauma or infection is a common cause of physeal bone bridges.^6,17-19 The etiology of our patient’s distal femoral physeal bone bridge is idiopathic, which is considerably less common than other etiologies, and the incidence of idiopathic physeal bone bridge formation is not well established in the literature. Hresko and Kasser²¹ identified atraumatic physeal bone bridge formations in 7 patients. Among the 13 patients with physeal bone bridges described by Broughton and colleagues,²⁰ the cause of bridge formation is unknown in 1.

Physeal bone bridges that form centrally are particularly challenging because they are difficult to visualize through a peripheral approach. A number of methods for resecting central physeal bone bridges have been described. These methods have varying degrees of success. In 1981, Langenskiöld⁷ first described the creation of a metaphyseal mirror and the use of a dental mirror for visualization. This technique, however, yielded unfavorable results in 16% of patients. Williamson and Staheli⁹ reported poor results in 23% of patients. Loraas and Schmale⁴ described the use of an endoscope, termed an osteoscope, for visualization, citing advantages of superior illumination and potential for image magnification and capture. Marsh and Polzhofer⁸ also showed this technique to have low morbidity but poor results in 13% of patients, whereas Moreta and colleagues¹⁰ reported poor results in 2 out of 5 patients. The rate of poor results of these methods may be related to the technical difficulty of using dental mirrors and arthroscopes and can be improved by highly efficient direct methods with improved visualization, such as the method described in this article.

Continue to: Proper imaging is necessary for...

 

Proper imaging is necessary for the accurate quantification of bone bridges to determine resectability and to identify the best surgical approach to resection. MRI with software for the generation of 3-D physeal maps is a reproducible method with good interobserver reliability.^22,23 Intraoperative computer-assisted imaging also is beneficial for determining the extent and location of the resection to ensure complete bone bridge removal.²⁴

To our knowledge, a direct approach through parapatellar arthrotomy for the resection of a centrally located distal femoral physeal bone bridge has not been previously described. This novel technique provided direct access to the physeal bone bridge and was performed without injuring the adjacent physeal cartilage in the medial and lateral columns of the distal femur, which may grow normally in the absence of the bridge. Instead of using a lateral or medial approach with a metaphyseal window,⁴ we directly approached this central bar through a parapatellar approach and were able to completely resect it under direct visualization. This obviated the need for an arthroscope or dental mirror. To remove the entire physeal bone bridge, we needed to resect completely from the anterior cortex to the posterior cortex. Although this technique potentially increased the risk of iatrogenic fracture, we believed that this risk would not differ greatly from that of disrupting the medial or lateral metaphysis and would be more stable with either axial and torsion load. At 3-year follow-up, the patient exhibited restored normal growth in his operative limb relative to that in his nonoperative limb, had not developed angular deformity, and had maintained his previously developed limb-length discrepancy that could be corrected with the epiphysiodesis of his opposite limb at a later date.

The limitations to this technique include the fact that it may be most effective with small-to moderate-sized central physeal bone bridges, although resection has shown good results with up to 70% physeal involvement.⁸ In this patient, the bone bridge was moderately sized (30% of the physis), centrally located, and clearly visible on fluoroscopy. These characteristics increased the technical safety and ease of the procedure. The resection of large, peripheral bridges may destabilize the distal femur. The destabilization of the distal femur, in turn, can lead to fracture. Patellofemoral mechanics may also be affected during the treatment of distal femoral physeal bone bridges. This patient has not experienced any patellofemoral dysfunction or symptoms. Given the patient’s age and significant amount of remaining growth, he will need close monitoring until he reaches skeletal maturity.

This paper will be judged for the Resident Writer’s Award.

ABSTRACT

A central distal femoral physeal bone bridge in a boy aged 5 years and 7 months was resected with a fluoroscopically guided core reamer placed through a lateral parapatellar approach. At 3-year follow-up, the boy’s leg-length discrepancy was 3.0 cm (3.9 cm preoperatively), and the physeal bone bridge did not recur. The patient had full function and no pain or other patellofemoral complaints. This technique provided direct access to the physeal bone bridge, and complete resection was performed without injury to the adjacent physeal cartilage in the medial and lateral columns of the distal femur, which is expected to grow normally in the absence of the bridge.

A physeal bone bridge is an osseous connection that forms across a physis. It may cause partial premature physeal arrest. Angular deformity and limb-length discrepancy are the main complications caused by physeal bone bridges.^1-4 The indications for the treatment of physeal bridges are well documented.^1-5 Trauma and infection are common causes of distal femoral physeal bone bridges. Arkader and colleagues⁶ showed that among different types of physeal bridges, the Salter-Harris type is significantly associated with complications, among which growth arrest is the most common and occurs in 27.4% of all patients.

The treatment of distal femoral physeal bone bridges is technically difficult and provides variable results. Poor results are reported in 13% to 40% of patients.^7-10 Procedure failure has been attributed to incomplete resection with the persistent tethering and dislodgement of the graft.¹¹ Methods with improved efficacy for the removal of central physeal bridges will help prevent reformation after treatment. We have used a novel technique that allows the direct resection of a central physeal bone bridge in the distal femur through the use of a fluoroscopically guided core reamer. This technique enables the complete removal of the bone bridge and the direct visual assessment of the remaining physis. The patient’s parents provided written informed consent for print and electronic publication of this case report.

CASE

A 3-year-old boy with a history of hemifacial microsomia presented for the evaluation of genu valgum and leg-length discrepancy. His intermalleolar distance at that time was 8 cm. A standing radiograph of his lower extremities demonstrated changes consistent with physiologic genu valgum. He had no history of knee trauma, infection, or pain.

At the age of 5 years and 7 months, the patient returned for a repeat evaluation and was noted to exhibit the progressive valgus deformity of the right leg and a leg-length discrepancy of 3.9 cm (Figure 1). 

Radiographs also showed the presence of a bone bridge of unknown etiology in the boy’s distal femoral physis. Computed tomography and magnetic resonance imaging (MRI) were used to characterize the size and location of the bone bridge, which was found to involve approximately 30% of the physis (Figures 2A-2C). 

Using the multiplier method described by Paley and colleagues,¹² the patient’s projected leg-length discrepancy, assuming complete growth arrest, was approximately 10.2 cm. The risks and benefits of physeal bone bridge resection, including the high rate of recurrence, were discussed with the patient’s family, who wished to proceed with resection.

 

Continue to: With the patient supine on the operating...

 

OPERATIVE TECHNIQUE

With the patient supine on the operating table and after the administration of general anesthesia, 3-dimensional (3-D) fluoroscopy was used to localize the bone bridge, which confirmed the fluoroscopic location that was previously visualized through preoperative 3-D imaging. The leg was elevated, and a tourniquet was applied and inflated. A lateral parapatellar approach was used to isolate the distal femoral physis anteriorly because the bone bridge was centered just lateral to the central portion of the distal femoral physis. A Kirschner wire was placed in the center of the bridge under anteroposterior and lateral fluoroscopic imaging (Figures 3A-3E). 

A series of core reamers were then introduced, starting at 10 mm diameter and increasing to 18 mm diameter before complete resection was accomplished. Irrigation was used to prevent the thermal necrosis of the physis during reaming, and lateral fluoroscopic imaging was used to prevent injury to the posterior neurovascular structures. Each time a reaming was completed, the physeal bone bed was inspected to confirm complete bone bridge resection (Figure 3C). Once 18 mm of the physis had been removed, direct visual inspection confirmed normal physis was present on all sides of the bone that remained following physeal bar resection (Figures 3D and 4A, 4B). 

The defect was irrigated with normal saline and filled with cranioplast (Figure 3E). Cranioplast (the methyl ester of methacrylic acid that easily polymerizes into polymethyl methacrylate) was chosen because the amount of adipose tissue was insufficient for harvesting for interposition given the patient’s lean body habitus. Moreover, the use of the cranioplast prevented the occurrence of exothermic reactions during curing and provided hemostasis because the cranioplast occupied the entire cavity and was strong enough to provide structural support.¹³ When partially set into a putty-like state to allow molding, the cranioplast was carefully contoured within the femoral trochlea. To protect the resection site from pathologic fracture, the patient was placed in a long-leg cast, and only protected weight-bearing with the use of a walker was allowed for 6 weeks.

OUTCOME

The patient healed uneventfully, and early range-of-motion exercises were started 6 weeks postoperatively. At 6-month follow-up, his leg-length discrepancy was 2.7 cm, and the bone bridge did not recur. At 3-year follow-up, his leg-length discrepancy was 3.0 cm, and the bone bridge did not recur. Over the 3 years postoperatively, the patient exhibited 9.8 cm of growth on his operative side and 9.5 cm on his nonoperative side (Figure 5). 

The patient has returned to full function and has had no pain, patellofemoral complaints, or complications associated with the cranioplast. He currently is being followed for his leg-length discrepancy. A contralateral epiphysiodesis is planned to equalize his leg-length discrepancy.

DISCUSSION

Given the considerable growth potential of the distal femoral physis,^1,14-16 an injury to the distal femoral physis and the formation of a physeal bone bridge can have a profound effect on a young patient in terms of leg-length discrepancy and angular deformity. Fracture from trauma or infection is a common cause of physeal bone bridges.^6,17-19 The etiology of our patient’s distal femoral physeal bone bridge is idiopathic, which is considerably less common than other etiologies, and the incidence of idiopathic physeal bone bridge formation is not well established in the literature. Hresko and Kasser²¹ identified atraumatic physeal bone bridge formations in 7 patients. Among the 13 patients with physeal bone bridges described by Broughton and colleagues,²⁰ the cause of bridge formation is unknown in 1.

Physeal bone bridges that form centrally are particularly challenging because they are difficult to visualize through a peripheral approach. A number of methods for resecting central physeal bone bridges have been described. These methods have varying degrees of success. In 1981, Langenskiöld⁷ first described the creation of a metaphyseal mirror and the use of a dental mirror for visualization. This technique, however, yielded unfavorable results in 16% of patients. Williamson and Staheli⁹ reported poor results in 23% of patients. Loraas and Schmale⁴ described the use of an endoscope, termed an osteoscope, for visualization, citing advantages of superior illumination and potential for image magnification and capture. Marsh and Polzhofer⁸ also showed this technique to have low morbidity but poor results in 13% of patients, whereas Moreta and colleagues¹⁰ reported poor results in 2 out of 5 patients. The rate of poor results of these methods may be related to the technical difficulty of using dental mirrors and arthroscopes and can be improved by highly efficient direct methods with improved visualization, such as the method described in this article.

Continue to: Proper imaging is necessary for...

 

Proper imaging is necessary for the accurate quantification of bone bridges to determine resectability and to identify the best surgical approach to resection. MRI with software for the generation of 3-D physeal maps is a reproducible method with good interobserver reliability.^22,23 Intraoperative computer-assisted imaging also is beneficial for determining the extent and location of the resection to ensure complete bone bridge removal.²⁴

To our knowledge, a direct approach through parapatellar arthrotomy for the resection of a centrally located distal femoral physeal bone bridge has not been previously described. This novel technique provided direct access to the physeal bone bridge and was performed without injuring the adjacent physeal cartilage in the medial and lateral columns of the distal femur, which may grow normally in the absence of the bridge. Instead of using a lateral or medial approach with a metaphyseal window,⁴ we directly approached this central bar through a parapatellar approach and were able to completely resect it under direct visualization. This obviated the need for an arthroscope or dental mirror. To remove the entire physeal bone bridge, we needed to resect completely from the anterior cortex to the posterior cortex. Although this technique potentially increased the risk of iatrogenic fracture, we believed that this risk would not differ greatly from that of disrupting the medial or lateral metaphysis and would be more stable with either axial and torsion load. At 3-year follow-up, the patient exhibited restored normal growth in his operative limb relative to that in his nonoperative limb, had not developed angular deformity, and had maintained his previously developed limb-length discrepancy that could be corrected with the epiphysiodesis of his opposite limb at a later date.

The limitations to this technique include the fact that it may be most effective with small-to moderate-sized central physeal bone bridges, although resection has shown good results with up to 70% physeal involvement.⁸ In this patient, the bone bridge was moderately sized (30% of the physis), centrally located, and clearly visible on fluoroscopy. These characteristics increased the technical safety and ease of the procedure. The resection of large, peripheral bridges may destabilize the distal femur. The destabilization of the distal femur, in turn, can lead to fracture. Patellofemoral mechanics may also be affected during the treatment of distal femoral physeal bone bridges. This patient has not experienced any patellofemoral dysfunction or symptoms. Given the patient’s age and significant amount of remaining growth, he will need close monitoring until he reaches skeletal maturity.

This paper will be judged for the Resident Writer’s Award.

ABSTRACT

This case report is a rare form of lymphoma recurrence which presented as tarsal tunnel syndrome. The patient had been previously treated for the malignancy and was presumed to be in remission; however, standard radiology imaging protocols failed to include the distal extremities on these scans. The patient presented to the orthopedic clinic with tarsal tunnel symptoms and a mass in the tarsal tunnel. A complete evaluation resulted in a diagnosis of recurrence of the malignancy. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body fluorodeoxyglucose positron emission tomography computed tomography when evaluating for recurrence in patients.

Nasal-type, extranodal natural killer/T-cell lymphoma (ENKTL) is a rare form of non-Hodgkin lymphoma (NHL). Malignancies account for only 10% of NHL in Asian and South American populations. However, in Caucasians, it represents <1% of all cases. In addition, at 3:1 male to female ratio, the disease most commonly affects male patients who are 50 to 59 years old.^1-3 The etiology of this malignancy is strongly related to prior infection with Epstein-Barr virus (EBV) as EBV-encoded early small ribonucleic acid on in situ hybridization of lymphoma cells is positive in 95% of cases.^4-6

Typical sites of involvement include the nasal cavity, nasopharynx, and sinuses, causing patients to present with nasal obstruction, chronic sinusitis, or epistaxis. Additionally, ENKTL can occur primarily in the skin, gastrointestinal tract, spleen, and testis, whereas the bone marrow may be involved in 10% of cases. Although rare, unusual sites, including muscle, adrenals, and ovaries, have been published.^7,8

Staging is best performed using the T-staging system, which accounts for the extent of local tumor involvement. Higher stages, such as T3 /T4, equate to locally advanced disease and imply a worse prognosis.^9,10 Computed tomography (CT) and magnetic resonance imaging (MRI) help define local soft tissues and bony involvement. Furthermore, CT of the chest, abdomen, and pelvis as well as bone marrow biopsy are performed as part of the staging process. Lastly, fluorine-18 fluorodeoxyglucose positron emission tomography CT (18-FDG PET-CT) is often used to detect extranodal spread, define the extent of involvement, differentiate between lymphoma and inflammatory masses, and monitor for recurrence.¹¹

Treatment for local ENKTL involves concurrent chemoradiotherapy followed by 3 cycles of etoposide, ifosfamide, cisplatin, and dexamethasone, which results in a complete response rate of 80%, and is the most favorable when comparing treatment modalities.¹² Unfortunately, recurrence rates reach as high as 50%, whereas the 5-year survival rate is 59%.^13,14 For recurrent or disseminated disease, high-dose chemotherapy and hematopoietic stem cell transplantation remain as alternative treatments for patients who have undergone 2 complete remissions and can be curative in some instances.^13,15

Continue to: In summary, ENKTL is a rare form...

 

In summary, ENKTL is a rare form of NHL which classically presents in the nasal cavity; however, this type of lymphoma may present in a variety of extranodal sites.^7,8 Despite the numerous published reports on ENKTL, no study has reported either primary or recurrent ENKTL in the feet or hands. To our knowledge, this is one of the first published cases of a patient who developed a rare and recurring ENKTL in the foot and ankle. The patient provided written informed consent for print and electronic publication of this case report.

CASE

A 59-year-old Caucasian woman was referred to the orthopedic foot and ankle clinic by her primary care physician for right medial ankle pain, skin ulceration, and numbness over the plantar aspect of her right foot. Upon questioning, the patient noted that the pain and numbness were present for almost 6 months. She denied trauma to the concerned area. Previously, the patient was observed and treated elsewhere for plantar fasciitis and was prescribed a brace before being immobilized in a controlled ankle motion (CAM) boot for 6 weeks. At follow-up with her outside provider, the patient had developed skin breakdown over the medial aspect of the right ankle, and this condition was presumed to be caused by the boot. After local wound care failed to improve her skin ulceration, she returned to her primary care physician, who ordered an MRI of the area and referred her to our specialty clinic.

Upon review, the patient’s past medical history included a diagnosis of nasal-type ENKTL. Her malignancy was treated with chemoradiotherapy 2 years prior to her consultation with the foot and ankle clinic.

The patient was noted by her medical oncologist and interventional radiologist to be in complete stage 4 remission since being treated. She underwent routine MRI and CT scans of the head and neck at 6-month intervals and FDG PET-CT scans at 3-month intervals, as per institutional protocol. The examinations showed no evidence of malignancy or metabolically active disease. The last imaging study occurred 2 months prior to admission to the foot and ankle clinic.

The patient consulted her medical oncologist 1 month prior to presenting to our clinic and was noted to exhibit an “excellent response to chemoradiotherapy” and “continues to remain disease free at 2 years.” She was instructed to continue routine follow-up. However, the office notes mentioned no ankle pain and non-healing wounds.

During physical examination, the patient presented an antalgic gait on the right side. Inspection demonstrated an increased circumference of the right ankle compared with the left, with a soft, palpable mass over the medial aspect of her right ankle. A 3 cm × 2 cm, grade 2 abrasion of the skin was observed over the medial mass just posterior to her medial malleolus. Range of motion was within normal limits. The patient exhibited a palpable posterior tibial artery pulse and full strength upon muscle testing of the lower extremities. She featured a positive Tinel’s sign and discomfort over the mass itself, with the pain radiating down to the plantar aspect of her foot and diffuse numbness over the plantar aspect of the foot.

Continue to: Review of her plain radiographs...

 

Review of her plain radiographs demonstrated no bony abnormalities, fractures, nor visible deformity (Figures 1A, 1B). 

MRI of the foot and ankle was reviewed and demonstrated a large soft-tissue mass over the medial aspect of the ankle extending posteriorly to engulf the medial flexor tendons and medial neurovascular bundle (Figures 2A-2C). 

Interestingly, the radiologist’s report only mentioned a “large region of devitalized tissue underlying the known medial ankle ulcer which extended to the tibiotalar and subtalar joints and bone marrow changes in the talus most compatible with osteomyelitis.” FDG PET-CT images from the patient’s past 2 years were reviewed, and the radiologist was contacted to confirm the negative findings. Unfortunately, FDG PET-CT performs no routine imaging below the elbow or knee when evaluating for this particular malignancy (Figure 3).

At presentation, our differential diagnosis included recurrence of the malignancy, secondary malignancy, infection, and inflammatory disease. After a lengthy discussion with the patient and consultation with our institution’s musculoskeletal oncologist, the decision was made to perform a right-ankle mass biopsy and marginal excision with wound irrigation and débridement and tarsal tunnel release.

The patient was placed in the supine position with standard prepping and draping. The medial eschar was excised in an elliptical fashion, and a curvilinear, longitudinal approach was performed within the compartment to access the mass along the posteromedial aspect of the ankle. Although no evidence of infection was observed, the tissue was thickened with areas of necrosis down to the flexor retinaculum. Once the flexor retinaculum was opened, a fibrous, plaque-like mass was observed, and it was encased with flexor tendons and neurovascular structures of the tarsal tunnel. After mass excision, a complete tarsal tunnel release was performed until the neurovascular bundle was free. Irrigation and débridement of the ulcer were performed along with complicated wound closure, and the patient was placed in a well-padded postoperative splint.

Pathology was finalized as a recurrent, EBV-positive, and nasal-type ENKTL. The patient underwent bone marrow biopsy, which yielded negative results. CT of the chest, abdomen, and pelvis were negative for the disease. FDG PET-CT, which included the extremities, was performed and demonstrated increased uptake in the right ankle, consistent with the malignancy (Figure 4). 

The patient was placed on her second cycle of chemoradiotherapy and again showed complete remission. At over 1-year follow-up, the patient’s wound had completely healed, and FDG PET-CT of the extremity was negative for ENKTL recurrence (Figure 5). 

At present, the patient’s medical oncologists recommend a stem cell transplant as the patient exhibited 2 positive responses to chemoradiotherapy.

DISCUSSION

ENKTL is an uncommon form of lymphoma and is exceedingly rare in Caucasian females.^1-3 Although the patient’s primary occurrence was in the nasal cavity, recurrence in the foot and ankle must still be described.^7,8 To our knowledge, this article is one of the first published cases of a patient who developed a rare-recurrence ENKTL about the foot and ankle. Occurrence in extremities is extremely rare that the staging protocol does not include FDG PET-CT of these areas. The patient’s “negative” scans led many providers to neglect the symptoms in her right ankle until the lesion had ulcerated through the skin. If one would have relied on imaging reports and outside records alone, the diagnosis would have been delayed longer or missed all together. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body FDG PET-CT when evaluating for recurrence in patients.

ABSTRACT

This case report is a rare form of lymphoma recurrence which presented as tarsal tunnel syndrome. The patient had been previously treated for the malignancy and was presumed to be in remission; however, standard radiology imaging protocols failed to include the distal extremities on these scans. The patient presented to the orthopedic clinic with tarsal tunnel symptoms and a mass in the tarsal tunnel. A complete evaluation resulted in a diagnosis of recurrence of the malignancy. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body fluorodeoxyglucose positron emission tomography computed tomography when evaluating for recurrence in patients.

Nasal-type, extranodal natural killer/T-cell lymphoma (ENKTL) is a rare form of non-Hodgkin lymphoma (NHL). Malignancies account for only 10% of NHL in Asian and South American populations. However, in Caucasians, it represents <1% of all cases. In addition, at 3:1 male to female ratio, the disease most commonly affects male patients who are 50 to 59 years old.^1-3 The etiology of this malignancy is strongly related to prior infection with Epstein-Barr virus (EBV) as EBV-encoded early small ribonucleic acid on in situ hybridization of lymphoma cells is positive in 95% of cases.^4-6

Typical sites of involvement include the nasal cavity, nasopharynx, and sinuses, causing patients to present with nasal obstruction, chronic sinusitis, or epistaxis. Additionally, ENKTL can occur primarily in the skin, gastrointestinal tract, spleen, and testis, whereas the bone marrow may be involved in 10% of cases. Although rare, unusual sites, including muscle, adrenals, and ovaries, have been published.^7,8

Staging is best performed using the T-staging system, which accounts for the extent of local tumor involvement. Higher stages, such as T3 /T4, equate to locally advanced disease and imply a worse prognosis.^9,10 Computed tomography (CT) and magnetic resonance imaging (MRI) help define local soft tissues and bony involvement. Furthermore, CT of the chest, abdomen, and pelvis as well as bone marrow biopsy are performed as part of the staging process. Lastly, fluorine-18 fluorodeoxyglucose positron emission tomography CT (18-FDG PET-CT) is often used to detect extranodal spread, define the extent of involvement, differentiate between lymphoma and inflammatory masses, and monitor for recurrence.¹¹

Treatment for local ENKTL involves concurrent chemoradiotherapy followed by 3 cycles of etoposide, ifosfamide, cisplatin, and dexamethasone, which results in a complete response rate of 80%, and is the most favorable when comparing treatment modalities.¹² Unfortunately, recurrence rates reach as high as 50%, whereas the 5-year survival rate is 59%.^13,14 For recurrent or disseminated disease, high-dose chemotherapy and hematopoietic stem cell transplantation remain as alternative treatments for patients who have undergone 2 complete remissions and can be curative in some instances.^13,15

Continue to: In summary, ENKTL is a rare form...

 

In summary, ENKTL is a rare form of NHL which classically presents in the nasal cavity; however, this type of lymphoma may present in a variety of extranodal sites.^7,8 Despite the numerous published reports on ENKTL, no study has reported either primary or recurrent ENKTL in the feet or hands. To our knowledge, this is one of the first published cases of a patient who developed a rare and recurring ENKTL in the foot and ankle. The patient provided written informed consent for print and electronic publication of this case report.

CASE

A 59-year-old Caucasian woman was referred to the orthopedic foot and ankle clinic by her primary care physician for right medial ankle pain, skin ulceration, and numbness over the plantar aspect of her right foot. Upon questioning, the patient noted that the pain and numbness were present for almost 6 months. She denied trauma to the concerned area. Previously, the patient was observed and treated elsewhere for plantar fasciitis and was prescribed a brace before being immobilized in a controlled ankle motion (CAM) boot for 6 weeks. At follow-up with her outside provider, the patient had developed skin breakdown over the medial aspect of the right ankle, and this condition was presumed to be caused by the boot. After local wound care failed to improve her skin ulceration, she returned to her primary care physician, who ordered an MRI of the area and referred her to our specialty clinic.

Upon review, the patient’s past medical history included a diagnosis of nasal-type ENKTL. Her malignancy was treated with chemoradiotherapy 2 years prior to her consultation with the foot and ankle clinic.

The patient was noted by her medical oncologist and interventional radiologist to be in complete stage 4 remission since being treated. She underwent routine MRI and CT scans of the head and neck at 6-month intervals and FDG PET-CT scans at 3-month intervals, as per institutional protocol. The examinations showed no evidence of malignancy or metabolically active disease. The last imaging study occurred 2 months prior to admission to the foot and ankle clinic.

The patient consulted her medical oncologist 1 month prior to presenting to our clinic and was noted to exhibit an “excellent response to chemoradiotherapy” and “continues to remain disease free at 2 years.” She was instructed to continue routine follow-up. However, the office notes mentioned no ankle pain and non-healing wounds.

During physical examination, the patient presented an antalgic gait on the right side. Inspection demonstrated an increased circumference of the right ankle compared with the left, with a soft, palpable mass over the medial aspect of her right ankle. A 3 cm × 2 cm, grade 2 abrasion of the skin was observed over the medial mass just posterior to her medial malleolus. Range of motion was within normal limits. The patient exhibited a palpable posterior tibial artery pulse and full strength upon muscle testing of the lower extremities. She featured a positive Tinel’s sign and discomfort over the mass itself, with the pain radiating down to the plantar aspect of her foot and diffuse numbness over the plantar aspect of the foot.

Continue to: Review of her plain radiographs...

 

Review of her plain radiographs demonstrated no bony abnormalities, fractures, nor visible deformity (Figures 1A, 1B). 

MRI of the foot and ankle was reviewed and demonstrated a large soft-tissue mass over the medial aspect of the ankle extending posteriorly to engulf the medial flexor tendons and medial neurovascular bundle (Figures 2A-2C). 

Interestingly, the radiologist’s report only mentioned a “large region of devitalized tissue underlying the known medial ankle ulcer which extended to the tibiotalar and subtalar joints and bone marrow changes in the talus most compatible with osteomyelitis.” FDG PET-CT images from the patient’s past 2 years were reviewed, and the radiologist was contacted to confirm the negative findings. Unfortunately, FDG PET-CT performs no routine imaging below the elbow or knee when evaluating for this particular malignancy (Figure 3).

At presentation, our differential diagnosis included recurrence of the malignancy, secondary malignancy, infection, and inflammatory disease. After a lengthy discussion with the patient and consultation with our institution’s musculoskeletal oncologist, the decision was made to perform a right-ankle mass biopsy and marginal excision with wound irrigation and débridement and tarsal tunnel release.

The patient was placed in the supine position with standard prepping and draping. The medial eschar was excised in an elliptical fashion, and a curvilinear, longitudinal approach was performed within the compartment to access the mass along the posteromedial aspect of the ankle. Although no evidence of infection was observed, the tissue was thickened with areas of necrosis down to the flexor retinaculum. Once the flexor retinaculum was opened, a fibrous, plaque-like mass was observed, and it was encased with flexor tendons and neurovascular structures of the tarsal tunnel. After mass excision, a complete tarsal tunnel release was performed until the neurovascular bundle was free. Irrigation and débridement of the ulcer were performed along with complicated wound closure, and the patient was placed in a well-padded postoperative splint.

Pathology was finalized as a recurrent, EBV-positive, and nasal-type ENKTL. The patient underwent bone marrow biopsy, which yielded negative results. CT of the chest, abdomen, and pelvis were negative for the disease. FDG PET-CT, which included the extremities, was performed and demonstrated increased uptake in the right ankle, consistent with the malignancy (Figure 4). 

The patient was placed on her second cycle of chemoradiotherapy and again showed complete remission. At over 1-year follow-up, the patient’s wound had completely healed, and FDG PET-CT of the extremity was negative for ENKTL recurrence (Figure 5). 

At present, the patient’s medical oncologists recommend a stem cell transplant as the patient exhibited 2 positive responses to chemoradiotherapy.

DISCUSSION

ENKTL is an uncommon form of lymphoma and is exceedingly rare in Caucasian females.^1-3 Although the patient’s primary occurrence was in the nasal cavity, recurrence in the foot and ankle must still be described.^7,8 To our knowledge, this article is one of the first published cases of a patient who developed a rare-recurrence ENKTL about the foot and ankle. Occurrence in extremities is extremely rare that the staging protocol does not include FDG PET-CT of these areas. The patient’s “negative” scans led many providers to neglect the symptoms in her right ankle until the lesion had ulcerated through the skin. If one would have relied on imaging reports and outside records alone, the diagnosis would have been delayed longer or missed all together. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body FDG PET-CT when evaluating for recurrence in patients.

ABSTRACT

This case report is a rare form of lymphoma recurrence which presented as tarsal tunnel syndrome. The patient had been previously treated for the malignancy and was presumed to be in remission; however, standard radiology imaging protocols failed to include the distal extremities on these scans. The patient presented to the orthopedic clinic with tarsal tunnel symptoms and a mass in the tarsal tunnel. A complete evaluation resulted in a diagnosis of recurrence of the malignancy. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body fluorodeoxyglucose positron emission tomography computed tomography when evaluating for recurrence in patients.

Nasal-type, extranodal natural killer/T-cell lymphoma (ENKTL) is a rare form of non-Hodgkin lymphoma (NHL). Malignancies account for only 10% of NHL in Asian and South American populations. However, in Caucasians, it represents <1% of all cases. In addition, at 3:1 male to female ratio, the disease most commonly affects male patients who are 50 to 59 years old.^1-3 The etiology of this malignancy is strongly related to prior infection with Epstein-Barr virus (EBV) as EBV-encoded early small ribonucleic acid on in situ hybridization of lymphoma cells is positive in 95% of cases.^4-6

Typical sites of involvement include the nasal cavity, nasopharynx, and sinuses, causing patients to present with nasal obstruction, chronic sinusitis, or epistaxis. Additionally, ENKTL can occur primarily in the skin, gastrointestinal tract, spleen, and testis, whereas the bone marrow may be involved in 10% of cases. Although rare, unusual sites, including muscle, adrenals, and ovaries, have been published.^7,8

Staging is best performed using the T-staging system, which accounts for the extent of local tumor involvement. Higher stages, such as T3 /T4, equate to locally advanced disease and imply a worse prognosis.^9,10 Computed tomography (CT) and magnetic resonance imaging (MRI) help define local soft tissues and bony involvement. Furthermore, CT of the chest, abdomen, and pelvis as well as bone marrow biopsy are performed as part of the staging process. Lastly, fluorine-18 fluorodeoxyglucose positron emission tomography CT (18-FDG PET-CT) is often used to detect extranodal spread, define the extent of involvement, differentiate between lymphoma and inflammatory masses, and monitor for recurrence.¹¹

Treatment for local ENKTL involves concurrent chemoradiotherapy followed by 3 cycles of etoposide, ifosfamide, cisplatin, and dexamethasone, which results in a complete response rate of 80%, and is the most favorable when comparing treatment modalities.¹² Unfortunately, recurrence rates reach as high as 50%, whereas the 5-year survival rate is 59%.^13,14 For recurrent or disseminated disease, high-dose chemotherapy and hematopoietic stem cell transplantation remain as alternative treatments for patients who have undergone 2 complete remissions and can be curative in some instances.^13,15

Continue to: In summary, ENKTL is a rare form...

 

In summary, ENKTL is a rare form of NHL which classically presents in the nasal cavity; however, this type of lymphoma may present in a variety of extranodal sites.^7,8 Despite the numerous published reports on ENKTL, no study has reported either primary or recurrent ENKTL in the feet or hands. To our knowledge, this is one of the first published cases of a patient who developed a rare and recurring ENKTL in the foot and ankle. The patient provided written informed consent for print and electronic publication of this case report.

CASE

A 59-year-old Caucasian woman was referred to the orthopedic foot and ankle clinic by her primary care physician for right medial ankle pain, skin ulceration, and numbness over the plantar aspect of her right foot. Upon questioning, the patient noted that the pain and numbness were present for almost 6 months. She denied trauma to the concerned area. Previously, the patient was observed and treated elsewhere for plantar fasciitis and was prescribed a brace before being immobilized in a controlled ankle motion (CAM) boot for 6 weeks. At follow-up with her outside provider, the patient had developed skin breakdown over the medial aspect of the right ankle, and this condition was presumed to be caused by the boot. After local wound care failed to improve her skin ulceration, she returned to her primary care physician, who ordered an MRI of the area and referred her to our specialty clinic.

Upon review, the patient’s past medical history included a diagnosis of nasal-type ENKTL. Her malignancy was treated with chemoradiotherapy 2 years prior to her consultation with the foot and ankle clinic.

The patient was noted by her medical oncologist and interventional radiologist to be in complete stage 4 remission since being treated. She underwent routine MRI and CT scans of the head and neck at 6-month intervals and FDG PET-CT scans at 3-month intervals, as per institutional protocol. The examinations showed no evidence of malignancy or metabolically active disease. The last imaging study occurred 2 months prior to admission to the foot and ankle clinic.

The patient consulted her medical oncologist 1 month prior to presenting to our clinic and was noted to exhibit an “excellent response to chemoradiotherapy” and “continues to remain disease free at 2 years.” She was instructed to continue routine follow-up. However, the office notes mentioned no ankle pain and non-healing wounds.

During physical examination, the patient presented an antalgic gait on the right side. Inspection demonstrated an increased circumference of the right ankle compared with the left, with a soft, palpable mass over the medial aspect of her right ankle. A 3 cm × 2 cm, grade 2 abrasion of the skin was observed over the medial mass just posterior to her medial malleolus. Range of motion was within normal limits. The patient exhibited a palpable posterior tibial artery pulse and full strength upon muscle testing of the lower extremities. She featured a positive Tinel’s sign and discomfort over the mass itself, with the pain radiating down to the plantar aspect of her foot and diffuse numbness over the plantar aspect of the foot.

Continue to: Review of her plain radiographs...

 

Review of her plain radiographs demonstrated no bony abnormalities, fractures, nor visible deformity (Figures 1A, 1B). 

MRI of the foot and ankle was reviewed and demonstrated a large soft-tissue mass over the medial aspect of the ankle extending posteriorly to engulf the medial flexor tendons and medial neurovascular bundle (Figures 2A-2C). 

Interestingly, the radiologist’s report only mentioned a “large region of devitalized tissue underlying the known medial ankle ulcer which extended to the tibiotalar and subtalar joints and bone marrow changes in the talus most compatible with osteomyelitis.” FDG PET-CT images from the patient’s past 2 years were reviewed, and the radiologist was contacted to confirm the negative findings. Unfortunately, FDG PET-CT performs no routine imaging below the elbow or knee when evaluating for this particular malignancy (Figure 3).

At presentation, our differential diagnosis included recurrence of the malignancy, secondary malignancy, infection, and inflammatory disease. After a lengthy discussion with the patient and consultation with our institution’s musculoskeletal oncologist, the decision was made to perform a right-ankle mass biopsy and marginal excision with wound irrigation and débridement and tarsal tunnel release.

The patient was placed in the supine position with standard prepping and draping. The medial eschar was excised in an elliptical fashion, and a curvilinear, longitudinal approach was performed within the compartment to access the mass along the posteromedial aspect of the ankle. Although no evidence of infection was observed, the tissue was thickened with areas of necrosis down to the flexor retinaculum. Once the flexor retinaculum was opened, a fibrous, plaque-like mass was observed, and it was encased with flexor tendons and neurovascular structures of the tarsal tunnel. After mass excision, a complete tarsal tunnel release was performed until the neurovascular bundle was free. Irrigation and débridement of the ulcer were performed along with complicated wound closure, and the patient was placed in a well-padded postoperative splint.

Pathology was finalized as a recurrent, EBV-positive, and nasal-type ENKTL. The patient underwent bone marrow biopsy, which yielded negative results. CT of the chest, abdomen, and pelvis were negative for the disease. FDG PET-CT, which included the extremities, was performed and demonstrated increased uptake in the right ankle, consistent with the malignancy (Figure 4). 

The patient was placed on her second cycle of chemoradiotherapy and again showed complete remission. At over 1-year follow-up, the patient’s wound had completely healed, and FDG PET-CT of the extremity was negative for ENKTL recurrence (Figure 5). 

At present, the patient’s medical oncologists recommend a stem cell transplant as the patient exhibited 2 positive responses to chemoradiotherapy.

DISCUSSION

ENKTL is an uncommon form of lymphoma and is exceedingly rare in Caucasian females.^1-3 Although the patient’s primary occurrence was in the nasal cavity, recurrence in the foot and ankle must still be described.^7,8 To our knowledge, this article is one of the first published cases of a patient who developed a rare-recurrence ENKTL about the foot and ankle. Occurrence in extremities is extremely rare that the staging protocol does not include FDG PET-CT of these areas. The patient’s “negative” scans led many providers to neglect the symptoms in her right ankle until the lesion had ulcerated through the skin. If one would have relied on imaging reports and outside records alone, the diagnosis would have been delayed longer or missed all together. This case illustrates the importance of a thorough medical history and personal review of imaging studies, and how a systematic approach can produce the correct diagnosis for any unknown lesion. Furthermore, this case may prompt oncologists to consider obtaining whole-body FDG PET-CT when evaluating for recurrence in patients.

Acute appendicitis is a common condition emergency physicians (EPs) encounter in the ED, and it is also one of the most common general surgeries.¹Although stump appendicitis is a rare, long-term complication of appendectomy, it should always be included in the differential diagnosis of patients presenting with right-sided abdominal pain and a history of appendectomy. Delays in diagnosing stump appendicitis can lead to perforation, gangrene, and sepsis.²

Case

A 33-year-old previously healthy man, whose medical history was significant for an appendectomy 6 months earlier, presented to the ED with progressive and worsening right lower quadrant abdominal pain that radiated to his right testicle. The patient stated that the pain started 3 days prior while he was lifting a bale of hay. He further noted having a fever of 102^oF, nausea, and vomiting hours prior to his arrival at the ED.

Upon presentation, the patient’s vital signs were: heart rate, 89 beats/min; respiratory rate, 17 breaths/min; blood pressure, 132/84 mm Hg; and temperature, 98.9°F. Oxygen saturation was 98% on room air. Physical examination revealed exquisite tenderness in the right lower quadrant and suprapubic region. The testicular examination and the remainder of the physical examination were normal. Laboratory evaluation included a complete blood count and urinalysis, the results of which were significant for an elevated white blood cell count of 17 x 10⁹/Lmicroscopic hematuria, trace leukocyte esterase, and ketones.

A computed tomography (CT) scan of the abdomen and pelvis with intravenous (IV) and oral contrast demonstrated a phlegmonous process surrounding the surgical site, which was concerning for stump appendicitis. The terminal ilium and colon were noted to be normal (Figures 1 and 2). 

The patient was started on IV fluids and IV antibiotics, and received Zosyn in the ED. Surgical service was consulted, and the patient was admitted to the hospital where he continued nonoperative treatment with IV ciprofloxacin and metronidazole. The patient was discharged home on hospital day 3 without further complication. A repeat CT scan was taken of the abdomen and pelvis 3 weeks after discharge, and demonstrated complete resolution of the inflammatory process at the appendiceal stump with chronic scarring.

Discussion

Approximately 7% of patients who present to the ED with abdominal pain are diagnosed with appendicitis.³ Although appendectomy is one of the most common surgical procedures, stump appendicitis is a rare postsurgical complication, with a reported incidence of 1 in 50,000 cases.^4,5

Stump appendicitis is an acute inflammation of the residual appendicular stump; the incidence of stump perforation is approximately 60% to 70%.^4,6 Thus, stump appendicitis has a high morbidity and complication rate. Unfortunately, though stump appendicitis is a condition in which timely diagnosis and intervention are essential to prevent morbidity, due to its rarity and low occurrence, there is often a delay in diagnosis. It is therefore important that EPs include stump appendicitis in the differential diagnosis of patients presenting with right-sided abdominal pain and a history of appendectomy.

Stump appendicitis was initially described by Rose et al in 1945.² This condition is underreported, and the exact causes are still unclear.Of the reported cases of stump appendicitis, approximately 66% developed following an open surgical appendectomy;⁵ therefore, complicated surgery or difficult dissection of the appendix is considered a risk factor for stump appendicitis. Conversely, adequate visualization of the appendiceal base during appendectomy and a stump measuring less than 3 to 5 mm^1,4 are associated with a lower risk for stump appendicitis.

Stump appendicitis can develop as early as a few days postappendectomy or as late as 50 years postappendectomy. Patients with stump appendicitis present with signs and symptoms similar to that of acute appendicitis.^2,4,7 Diagnosis can be made through ultrasound or CT studies, though CT is the preferred modality due to its higher specificity and ability to exclude other causes of right-sided abdominal pain.⁴

Management

Surgical intervention to remove the appendiceal stump is typically the preferred treatment. However, as with our patient, cases of successful and uncomplicated medical management have been reported.^1,2,4

Conclusion

While stump appendicitis is rare, there has been a rise in the number of reported cases over the past few years due to the increasing use and availability of CT.⁴ The diagnosis of stump appendicitis is time-critical to prevent associated complications of stump perforation, gangrene, and sepsis. It is therefore imperative that EPs consider this condition in the differential diagnosis despite a patient history of appendectomy. Our patient presented with a sudden onset of right lower quadrant abdominal pain radiating to his testicle and microscopic hematuria, and stump appendicitis was not in our initial differential diagnosis.

Acute appendicitis is a common condition emergency physicians (EPs) encounter in the ED, and it is also one of the most common general surgeries.¹Although stump appendicitis is a rare, long-term complication of appendectomy, it should always be included in the differential diagnosis of patients presenting with right-sided abdominal pain and a history of appendectomy. Delays in diagnosing stump appendicitis can lead to perforation, gangrene, and sepsis.²

Case

A 33-year-old previously healthy man, whose medical history was significant for an appendectomy 6 months earlier, presented to the ED with progressive and worsening right lower quadrant abdominal pain that radiated to his right testicle. The patient stated that the pain started 3 days prior while he was lifting a bale of hay. He further noted having a fever of 102^oF, nausea, and vomiting hours prior to his arrival at the ED.

Upon presentation, the patient’s vital signs were: heart rate, 89 beats/min; respiratory rate, 17 breaths/min; blood pressure, 132/84 mm Hg; and temperature, 98.9°F. Oxygen saturation was 98% on room air. Physical examination revealed exquisite tenderness in the right lower quadrant and suprapubic region. The testicular examination and the remainder of the physical examination were normal. Laboratory evaluation included a complete blood count and urinalysis, the results of which were significant for an elevated white blood cell count of 17 x 10⁹/Lmicroscopic hematuria, trace leukocyte esterase, and ketones.

A computed tomography (CT) scan of the abdomen and pelvis with intravenous (IV) and oral contrast demonstrated a phlegmonous process surrounding the surgical site, which was concerning for stump appendicitis. The terminal ilium and colon were noted to be normal (Figures 1 and 2). 

The patient was started on IV fluids and IV antibiotics, and received Zosyn in the ED. Surgical service was consulted, and the patient was admitted to the hospital where he continued nonoperative treatment with IV ciprofloxacin and metronidazole. The patient was discharged home on hospital day 3 without further complication. A repeat CT scan was taken of the abdomen and pelvis 3 weeks after discharge, and demonstrated complete resolution of the inflammatory process at the appendiceal stump with chronic scarring.

Discussion

Approximately 7% of patients who present to the ED with abdominal pain are diagnosed with appendicitis.³ Although appendectomy is one of the most common surgical procedures, stump appendicitis is a rare postsurgical complication, with a reported incidence of 1 in 50,000 cases.^4,5

Stump appendicitis is an acute inflammation of the residual appendicular stump; the incidence of stump perforation is approximately 60% to 70%.^4,6 Thus, stump appendicitis has a high morbidity and complication rate. Unfortunately, though stump appendicitis is a condition in which timely diagnosis and intervention are essential to prevent morbidity, due to its rarity and low occurrence, there is often a delay in diagnosis. It is therefore important that EPs include stump appendicitis in the differential diagnosis of patients presenting with right-sided abdominal pain and a history of appendectomy.

Stump appendicitis was initially described by Rose et al in 1945.² This condition is underreported, and the exact causes are still unclear.Of the reported cases of stump appendicitis, approximately 66% developed following an open surgical appendectomy;⁵ therefore, complicated surgery or difficult dissection of the appendix is considered a risk factor for stump appendicitis. Conversely, adequate visualization of the appendiceal base during appendectomy and a stump measuring less than 3 to 5 mm^1,4 are associated with a lower risk for stump appendicitis.

Stump appendicitis can develop as early as a few days postappendectomy or as late as 50 years postappendectomy. Patients with stump appendicitis present with signs and symptoms similar to that of acute appendicitis.^2,4,7 Diagnosis can be made through ultrasound or CT studies, though CT is the preferred modality due to its higher specificity and ability to exclude other causes of right-sided abdominal pain.⁴

Management

Surgical intervention to remove the appendiceal stump is typically the preferred treatment. However, as with our patient, cases of successful and uncomplicated medical management have been reported.^1,2,4

Conclusion

While stump appendicitis is rare, there has been a rise in the number of reported cases over the past few years due to the increasing use and availability of CT.⁴ The diagnosis of stump appendicitis is time-critical to prevent associated complications of stump perforation, gangrene, and sepsis. It is therefore imperative that EPs consider this condition in the differential diagnosis despite a patient history of appendectomy. Our patient presented with a sudden onset of right lower quadrant abdominal pain radiating to his testicle and microscopic hematuria, and stump appendicitis was not in our initial differential diagnosis.

Acute appendicitis is a common condition emergency physicians (EPs) encounter in the ED, and it is also one of the most common general surgeries.¹Although stump appendicitis is a rare, long-term complication of appendectomy, it should always be included in the differential diagnosis of patients presenting with right-sided abdominal pain and a history of appendectomy. Delays in diagnosing stump appendicitis can lead to perforation, gangrene, and sepsis.²

Case

A 33-year-old previously healthy man, whose medical history was significant for an appendectomy 6 months earlier, presented to the ED with progressive and worsening right lower quadrant abdominal pain that radiated to his right testicle. The patient stated that the pain started 3 days prior while he was lifting a bale of hay. He further noted having a fever of 102^oF, nausea, and vomiting hours prior to his arrival at the ED.

Upon presentation, the patient’s vital signs were: heart rate, 89 beats/min; respiratory rate, 17 breaths/min; blood pressure, 132/84 mm Hg; and temperature, 98.9°F. Oxygen saturation was 98% on room air. Physical examination revealed exquisite tenderness in the right lower quadrant and suprapubic region. The testicular examination and the remainder of the physical examination were normal. Laboratory evaluation included a complete blood count and urinalysis, the results of which were significant for an elevated white blood cell count of 17 x 10⁹/Lmicroscopic hematuria, trace leukocyte esterase, and ketones.

A computed tomography (CT) scan of the abdomen and pelvis with intravenous (IV) and oral contrast demonstrated a phlegmonous process surrounding the surgical site, which was concerning for stump appendicitis. The terminal ilium and colon were noted to be normal (Figures 1 and 2). 

The patient was started on IV fluids and IV antibiotics, and received Zosyn in the ED. Surgical service was consulted, and the patient was admitted to the hospital where he continued nonoperative treatment with IV ciprofloxacin and metronidazole. The patient was discharged home on hospital day 3 without further complication. A repeat CT scan was taken of the abdomen and pelvis 3 weeks after discharge, and demonstrated complete resolution of the inflammatory process at the appendiceal stump with chronic scarring.

Discussion

Approximately 7% of patients who present to the ED with abdominal pain are diagnosed with appendicitis.³ Although appendectomy is one of the most common surgical procedures, stump appendicitis is a rare postsurgical complication, with a reported incidence of 1 in 50,000 cases.^4,5

Stump appendicitis is an acute inflammation of the residual appendicular stump; the incidence of stump perforation is approximately 60% to 70%.^4,6 Thus, stump appendicitis has a high morbidity and complication rate. Unfortunately, though stump appendicitis is a condition in which timely diagnosis and intervention are essential to prevent morbidity, due to its rarity and low occurrence, there is often a delay in diagnosis. It is therefore important that EPs include stump appendicitis in the differential diagnosis of patients presenting with right-sided abdominal pain and a history of appendectomy.

Stump appendicitis was initially described by Rose et al in 1945.² This condition is underreported, and the exact causes are still unclear.Of the reported cases of stump appendicitis, approximately 66% developed following an open surgical appendectomy;⁵ therefore, complicated surgery or difficult dissection of the appendix is considered a risk factor for stump appendicitis. Conversely, adequate visualization of the appendiceal base during appendectomy and a stump measuring less than 3 to 5 mm^1,4 are associated with a lower risk for stump appendicitis.

Stump appendicitis can develop as early as a few days postappendectomy or as late as 50 years postappendectomy. Patients with stump appendicitis present with signs and symptoms similar to that of acute appendicitis.^2,4,7 Diagnosis can be made through ultrasound or CT studies, though CT is the preferred modality due to its higher specificity and ability to exclude other causes of right-sided abdominal pain.⁴

Management

Surgical intervention to remove the appendiceal stump is typically the preferred treatment. However, as with our patient, cases of successful and uncomplicated medical management have been reported.^1,2,4

Conclusion

While stump appendicitis is rare, there has been a rise in the number of reported cases over the past few years due to the increasing use and availability of CT.⁴ The diagnosis of stump appendicitis is time-critical to prevent associated complications of stump perforation, gangrene, and sepsis. It is therefore imperative that EPs consider this condition in the differential diagnosis despite a patient history of appendectomy. Our patient presented with a sudden onset of right lower quadrant abdominal pain radiating to his testicle and microscopic hematuria, and stump appendicitis was not in our initial differential diagnosis.