The American Journal of Orthopedics

Several surgical options are available for treatment of supracondylar and intercondylar distal femur fractures, AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association) type 33. Preserving the osseous blood supply via indirect reduction techniques has been shown to increase union rates without the need for bone grafting.^1,2 The Less-Invasive Stabilization System (LISS) made by Synthes (Paoli, Pennsylvania) melds minimally invasive internal fixation with multiple fixed-angle distal screws. It allows for submuscular placement, percutaneous unicortical screws in the diaphysis, and preservation of the metaphyseal fracture soft-tissue envelope.³

Proper lateral placement of the plate on the femur proximally can be difficult. Kregor and colleagues³ noted that 6% of cases did not have ideal placement on the lateral shaft of the femur when the 13-hole LISS plate was used. They advocated making a small incision at the proximal end of the LISS plate to aid in proper lateral placement. Kolb and colleagues⁴ noted that 2 of 31 patients had a “cutting out” of the proximal screws on LISS plates with anterior placement on the femur that eventually required repeat surgery in order to heal. This malpositioned plate was present at the end of the operation. These authors also recommended a proximal incision to avoid the issue. Schütz and colleagues⁵ noted that there were 4 cases of implant loosening among 107 distal femur fractures treated with LISS plating and that the unicortical screws in the diaphysis had loosened. They suggested anterior placement of the plate as a possible reason for fixation failure.

Although several studies have noted proximal screw pull-out, and proximal anterior malposition in the sagittal plane of the LISS plate has been suggested as a possible cause, we found no studies comparing incorrect proximal positioning on the femoral shaft with correct lateral placement of the LISS plate. Therefore, we used a previously established biomechanical model to compare LISS plates proximally placed either too anterior or too posterior to the direct lateral position on the femoral shaft. The constructs were tested in axial, torsional, and cyclical axial modes to assess plastic and total deformation, stiffness, and fixation failure.

Materials and Methods

Using fourth-generation femoral synthetic composite bones (Sawbones; Pacific Research Laboratories, Vashon, Washington) and a 13-hole Synthes femoral LISS plate, we made 3 groups of 9 specimens each, for a total of 27 femurs. The number of specimens was based on a power assessment in a study by Khalafi and colleagues.⁸ Several studies have validated use of Sawbones instead of cadavers in biomechanical testing to prevent variability.^6-9 Proximal fixation was achieved with 5 unicortical screws (26 mm long) at screw holes 13, 11, 9, 7, and 4. All distal screw holes were filled for distal fixation with 75-mm-long screws to achieve bicortical fixation.

After application of the LISS plate, an AO/OTA 33-A3 fracture model was created in each specimen. A 1-cm gap was made 6 cm proximal to the intercondylar notch to create an unstable distal femur fracture pattern. In the method described by Zlowodzki and colleagues,¹⁰ an additional 3-cm cut was made diagonally in the medial cortex to prevent contact of the bone during mechanical testing.

Three different plate positions were used. The correct group was placed directly laterally proximally (Figure 1A). One incorrect group was plated with the proximal aspect of the plate 1 cm anterior (anterior group) (Figure 1B), and another incorrect group was plated with the proximal aspect of the plate 1 cm posterior (posterior group) (Figure 1C). Anterior or posterior plate placement resulted in some of the proximal screws having a more tangential placement, with fewer screws engaged compared with the properly placed plate.

The distal and proximal ends of each specimen were held to simulate the mechanical axis of the femur. This design was based on a model by Cordey and colleagues.¹¹ A materials testing system (MTS, Minneapolis, Minnesota) was used for mechanical testing of the model.

Based on the protocol of Khalafi and colleagues,⁸ the models were tested in axial, torsional, and cyclical axial modes (Figures 2, 3). Axial loading consisted of a preload of 100 N followed by a compressive loading rate of 100 mm per minute in a displacement control mode. Testing was considered completed when 1 of 3 events occurred: 500 N was reached, the medial fracture gap closed, or fixation was lost. Torsional loading involved a preload of 5 Nm and subsequent torqueing at 20° per minute up to 20 Nm or loss of fixation or screw pull-out.⁸ Cyclical axial loading was based on protocols described by Marti and colleagues² and Zlowodzki and colleagues.¹⁰ The initial load was 10 cycles of 300 N. Each subsequent load increment was increased by 100 N up to 1000 N, providing 10-second rest increments. This loading was conducted in a displacement control mode at 0.75 mm per second. Testing was aborted on fixation loss or complete closure of the medial fracture gap.

After testing was completed, statistically significant between-groups differences in plastic deformation and axial and torsional stiffness were determined by performing a Tukey-Kramer honestly significant difference test. Significance was set at P ≤ .05.

Results

During axial loading, there was no visual loss of fixation or change in displacement of the fracture gap for any group, and there was no screw cut-out or pull-out from the cortex during testing. In 1 plate in the posterior group, the most proximal screw made only loose contact with the cortex at only the distal portion of the screw. There was no significant difference (P = .9762) in stiffness in axial loading between the anterior group and the correct group. There was a significant (P = .0261) 16.4% increase in stiffness in the posterior group compared with the correct group (Table).

There was no screw cut-out, fixation failure, or change in displacement of the fracture gap for any group during torsional loading. There was a statistically significant (P = .0062) 12% increase in mean torsional stiffness in the anterior group compared with the correct group. There was no statistically significant difference (P = .1623) between the posterior group and the correct group (Table).

For cyclical axial testing, total deformation and plastic deformation were obtained by determining displacement under the initial 100 N load in the static/resting state. That number was then subtracted from maximum displacement, the peak value on the time-versus-displacement graph, to obtain the value for total deformation. Plastic deformation was calculated by subtracting initial displacement from final displacement in the static/resting state. The static/resting state is represented by the dips in displacement after each cycle on the time-versus-displacement graph (Figure 4).

There was a statistically significant (P = .0207) 14% increase in total deformation of the anteriorly positioned plate compared with the correctly positioned plate. There was no statistically significant difference in total deformation between the posteriorly placed plates and the correctly placed plates (Table).

There was no significant difference in plastic deformation between any of the groups in this study. There was no screw cut-out or fixation loss in any group to suggest a clinically relevant difference based on proximal placement of the LISS plate.

Discussion

In evaluating the stability of various constructs for fixation of distal femur fractures, the literature is consistent in reporting stiffness as the key factor. Stiffness is determined most often in terms of motion at the fracture site, as measured by displacement under axial and torsional loads.^2,8,10,13 The LISS plate, which acts essentially as an “internal fixator” with proximal unicortical fixed-angle locking screws, has been shown to be comparable to other established methods of fixation.^10,12 Zlowodzki and colleagues¹⁰ reported that the LISS plate had a higher load to failure when compared with angled blade plating and intramedullary nailing. Their study used fresh-frozen cadaver specimens from patients 70 years old or older. They concluded that, for distal femur fractures in osteoporotic bone, the LISS plate provided improved distal fixation.

In the present study, the posteriorly placed LISS plate outperformed the correctly placed plate in axial stiffness by 16.4%. However, there was no statistically significant difference in torsional stiffness and cyclical axial loading. This result is difficult to explain given that there was no screw cut-out or fixation loss for any of the constructs. Theoretically, with less proximal screw purchase in the posteriorly placed plate, the overall construct should be more susceptible to screw cut-out and fixation loss resulting in less axial stiffness overall.

Khalafi and colleagues⁸ created a distal femur fracture model using Sawbones with a 1-cm fracture gap. Using the 9-hole LISS plate for fixation, they tested this construct under axial, torsional, and cyclical axial loads. They tested 2 groups of 9 femurs. For group 1, the LISS plate was placed in the correct position on the distal femur, with the proximal end in the correct position on the femoral shaft. In group 2, the LISS plate was rotated 1 cm anteriorly. They found that axial stiffness (N/mm) was 21.5% greater in the correctly positioned plate. The anteriorly positioned group demonstrated 55% more irreversible or plastic deformation. The authors concluded that correct positioning of the femoral LISS plate provided improved mechanical stability.

Overall, our study results did not agree with those of Khalafi and colleagues⁸ in terms of the mechanical stability of a malpositioned LISS plate. Our construct showed a significant increase in torsional stiffness in the anteriorly placed plate. However, our construct also showed a significant increase in total deformation in cyclical axial loading in the anteriorly placed plate. There was no increased plastic deformation in either of the incorrectly placed groups in our study. The difference in results between studies can best be explained by the difference in plate lengths. We used a 13-hole plate, and Khalafi and colleagues⁸ used a 9-hole plate. Our theory is that the longer plate provided more resistance to relatively minor variations in plate position at the proximal end and thus resulted in less change in stiffness and stability around the fracture site.

Our model differed from that used in other biomechanical studies using Sawbones to simulate distal femur fractures in that it used the entire femur, including the proximal portion.^8,13 This setup theoretically resulted in a more anatomical weight distribution compared with other models, in which the proximal portion of the femur was potted in polymethylmethacrylate. This difference in weight distribution could explain the variation in our results compared with other biomechanical studies. In addition, with use of different boundary conditions, the distal femur had unconstrained distal motion similar to the native environment of the femur.

This study had several limitations. First is its relatively low power (9 femurs per group). Although groups of 9 specimens in 2 groups were used in the study by Khalafi and colleagues⁸, testing a larger number of femurs could potentially identify more subtle differences between the 3 groups in our study. Second, given that femoral LISS plates come in different lengths, this study could be expanded to include the other plate sizes, as plate length could potentially play a role in stability at the fracture site. Third, though this Sawbones model has consistently reproduced the stability characteristics of human bone without variation between specimens, an osteoporotic model could be explored, as the femoral LISS plate is often used in osteoporotic fractures.^7,14

Conclusion

Overall, our study results showed that 1-cm variations, anterior or posterior, had little effect on axial or torsional stiffness or plastic deformation under cyclical axial loading. Although these data can be promising for clinical application, the anterior placement of the LISS plate noted in failed fixation in other studies necessitates cautious interpretation of this study. Our use of a 13-hole (longer) plate, versus the 9-hole plate used in other studies, could explain the lack of variation between the 2 groups as well as the stability and tolerance of inappropriate placement. An osteoporotic model could help clinicians further discern the importance of accurate proximal placement of the femoral LISS plate.

Several surgical options are available for treatment of supracondylar and intercondylar distal femur fractures, AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association) type 33. Preserving the osseous blood supply via indirect reduction techniques has been shown to increase union rates without the need for bone grafting.^1,2 The Less-Invasive Stabilization System (LISS) made by Synthes (Paoli, Pennsylvania) melds minimally invasive internal fixation with multiple fixed-angle distal screws. It allows for submuscular placement, percutaneous unicortical screws in the diaphysis, and preservation of the metaphyseal fracture soft-tissue envelope.³

Proper lateral placement of the plate on the femur proximally can be difficult. Kregor and colleagues³ noted that 6% of cases did not have ideal placement on the lateral shaft of the femur when the 13-hole LISS plate was used. They advocated making a small incision at the proximal end of the LISS plate to aid in proper lateral placement. Kolb and colleagues⁴ noted that 2 of 31 patients had a “cutting out” of the proximal screws on LISS plates with anterior placement on the femur that eventually required repeat surgery in order to heal. This malpositioned plate was present at the end of the operation. These authors also recommended a proximal incision to avoid the issue. Schütz and colleagues⁵ noted that there were 4 cases of implant loosening among 107 distal femur fractures treated with LISS plating and that the unicortical screws in the diaphysis had loosened. They suggested anterior placement of the plate as a possible reason for fixation failure.

Although several studies have noted proximal screw pull-out, and proximal anterior malposition in the sagittal plane of the LISS plate has been suggested as a possible cause, we found no studies comparing incorrect proximal positioning on the femoral shaft with correct lateral placement of the LISS plate. Therefore, we used a previously established biomechanical model to compare LISS plates proximally placed either too anterior or too posterior to the direct lateral position on the femoral shaft. The constructs were tested in axial, torsional, and cyclical axial modes to assess plastic and total deformation, stiffness, and fixation failure.

Materials and Methods

Using fourth-generation femoral synthetic composite bones (Sawbones; Pacific Research Laboratories, Vashon, Washington) and a 13-hole Synthes femoral LISS plate, we made 3 groups of 9 specimens each, for a total of 27 femurs. The number of specimens was based on a power assessment in a study by Khalafi and colleagues.⁸ Several studies have validated use of Sawbones instead of cadavers in biomechanical testing to prevent variability.^6-9 Proximal fixation was achieved with 5 unicortical screws (26 mm long) at screw holes 13, 11, 9, 7, and 4. All distal screw holes were filled for distal fixation with 75-mm-long screws to achieve bicortical fixation.

After application of the LISS plate, an AO/OTA 33-A3 fracture model was created in each specimen. A 1-cm gap was made 6 cm proximal to the intercondylar notch to create an unstable distal femur fracture pattern. In the method described by Zlowodzki and colleagues,¹⁰ an additional 3-cm cut was made diagonally in the medial cortex to prevent contact of the bone during mechanical testing.

Three different plate positions were used. The correct group was placed directly laterally proximally (Figure 1A). One incorrect group was plated with the proximal aspect of the plate 1 cm anterior (anterior group) (Figure 1B), and another incorrect group was plated with the proximal aspect of the plate 1 cm posterior (posterior group) (Figure 1C). Anterior or posterior plate placement resulted in some of the proximal screws having a more tangential placement, with fewer screws engaged compared with the properly placed plate.

The distal and proximal ends of each specimen were held to simulate the mechanical axis of the femur. This design was based on a model by Cordey and colleagues.¹¹ A materials testing system (MTS, Minneapolis, Minnesota) was used for mechanical testing of the model.

Based on the protocol of Khalafi and colleagues,⁸ the models were tested in axial, torsional, and cyclical axial modes (Figures 2, 3). Axial loading consisted of a preload of 100 N followed by a compressive loading rate of 100 mm per minute in a displacement control mode. Testing was considered completed when 1 of 3 events occurred: 500 N was reached, the medial fracture gap closed, or fixation was lost. Torsional loading involved a preload of 5 Nm and subsequent torqueing at 20° per minute up to 20 Nm or loss of fixation or screw pull-out.⁸ Cyclical axial loading was based on protocols described by Marti and colleagues² and Zlowodzki and colleagues.¹⁰ The initial load was 10 cycles of 300 N. Each subsequent load increment was increased by 100 N up to 1000 N, providing 10-second rest increments. This loading was conducted in a displacement control mode at 0.75 mm per second. Testing was aborted on fixation loss or complete closure of the medial fracture gap.

After testing was completed, statistically significant between-groups differences in plastic deformation and axial and torsional stiffness were determined by performing a Tukey-Kramer honestly significant difference test. Significance was set at P ≤ .05.

Results

During axial loading, there was no visual loss of fixation or change in displacement of the fracture gap for any group, and there was no screw cut-out or pull-out from the cortex during testing. In 1 plate in the posterior group, the most proximal screw made only loose contact with the cortex at only the distal portion of the screw. There was no significant difference (P = .9762) in stiffness in axial loading between the anterior group and the correct group. There was a significant (P = .0261) 16.4% increase in stiffness in the posterior group compared with the correct group (Table).

There was no screw cut-out, fixation failure, or change in displacement of the fracture gap for any group during torsional loading. There was a statistically significant (P = .0062) 12% increase in mean torsional stiffness in the anterior group compared with the correct group. There was no statistically significant difference (P = .1623) between the posterior group and the correct group (Table).

For cyclical axial testing, total deformation and plastic deformation were obtained by determining displacement under the initial 100 N load in the static/resting state. That number was then subtracted from maximum displacement, the peak value on the time-versus-displacement graph, to obtain the value for total deformation. Plastic deformation was calculated by subtracting initial displacement from final displacement in the static/resting state. The static/resting state is represented by the dips in displacement after each cycle on the time-versus-displacement graph (Figure 4).

There was a statistically significant (P = .0207) 14% increase in total deformation of the anteriorly positioned plate compared with the correctly positioned plate. There was no statistically significant difference in total deformation between the posteriorly placed plates and the correctly placed plates (Table).

There was no significant difference in plastic deformation between any of the groups in this study. There was no screw cut-out or fixation loss in any group to suggest a clinically relevant difference based on proximal placement of the LISS plate.

Discussion

In evaluating the stability of various constructs for fixation of distal femur fractures, the literature is consistent in reporting stiffness as the key factor. Stiffness is determined most often in terms of motion at the fracture site, as measured by displacement under axial and torsional loads.^2,8,10,13 The LISS plate, which acts essentially as an “internal fixator” with proximal unicortical fixed-angle locking screws, has been shown to be comparable to other established methods of fixation.^10,12 Zlowodzki and colleagues¹⁰ reported that the LISS plate had a higher load to failure when compared with angled blade plating and intramedullary nailing. Their study used fresh-frozen cadaver specimens from patients 70 years old or older. They concluded that, for distal femur fractures in osteoporotic bone, the LISS plate provided improved distal fixation.

In the present study, the posteriorly placed LISS plate outperformed the correctly placed plate in axial stiffness by 16.4%. However, there was no statistically significant difference in torsional stiffness and cyclical axial loading. This result is difficult to explain given that there was no screw cut-out or fixation loss for any of the constructs. Theoretically, with less proximal screw purchase in the posteriorly placed plate, the overall construct should be more susceptible to screw cut-out and fixation loss resulting in less axial stiffness overall.

Khalafi and colleagues⁸ created a distal femur fracture model using Sawbones with a 1-cm fracture gap. Using the 9-hole LISS plate for fixation, they tested this construct under axial, torsional, and cyclical axial loads. They tested 2 groups of 9 femurs. For group 1, the LISS plate was placed in the correct position on the distal femur, with the proximal end in the correct position on the femoral shaft. In group 2, the LISS plate was rotated 1 cm anteriorly. They found that axial stiffness (N/mm) was 21.5% greater in the correctly positioned plate. The anteriorly positioned group demonstrated 55% more irreversible or plastic deformation. The authors concluded that correct positioning of the femoral LISS plate provided improved mechanical stability.

Overall, our study results did not agree with those of Khalafi and colleagues⁸ in terms of the mechanical stability of a malpositioned LISS plate. Our construct showed a significant increase in torsional stiffness in the anteriorly placed plate. However, our construct also showed a significant increase in total deformation in cyclical axial loading in the anteriorly placed plate. There was no increased plastic deformation in either of the incorrectly placed groups in our study. The difference in results between studies can best be explained by the difference in plate lengths. We used a 13-hole plate, and Khalafi and colleagues⁸ used a 9-hole plate. Our theory is that the longer plate provided more resistance to relatively minor variations in plate position at the proximal end and thus resulted in less change in stiffness and stability around the fracture site.

Our model differed from that used in other biomechanical studies using Sawbones to simulate distal femur fractures in that it used the entire femur, including the proximal portion.^8,13 This setup theoretically resulted in a more anatomical weight distribution compared with other models, in which the proximal portion of the femur was potted in polymethylmethacrylate. This difference in weight distribution could explain the variation in our results compared with other biomechanical studies. In addition, with use of different boundary conditions, the distal femur had unconstrained distal motion similar to the native environment of the femur.

This study had several limitations. First is its relatively low power (9 femurs per group). Although groups of 9 specimens in 2 groups were used in the study by Khalafi and colleagues⁸, testing a larger number of femurs could potentially identify more subtle differences between the 3 groups in our study. Second, given that femoral LISS plates come in different lengths, this study could be expanded to include the other plate sizes, as plate length could potentially play a role in stability at the fracture site. Third, though this Sawbones model has consistently reproduced the stability characteristics of human bone without variation between specimens, an osteoporotic model could be explored, as the femoral LISS plate is often used in osteoporotic fractures.^7,14

Conclusion

Overall, our study results showed that 1-cm variations, anterior or posterior, had little effect on axial or torsional stiffness or plastic deformation under cyclical axial loading. Although these data can be promising for clinical application, the anterior placement of the LISS plate noted in failed fixation in other studies necessitates cautious interpretation of this study. Our use of a 13-hole (longer) plate, versus the 9-hole plate used in other studies, could explain the lack of variation between the 2 groups as well as the stability and tolerance of inappropriate placement. An osteoporotic model could help clinicians further discern the importance of accurate proximal placement of the femoral LISS plate.

Several surgical options are available for treatment of supracondylar and intercondylar distal femur fractures, AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association) type 33. Preserving the osseous blood supply via indirect reduction techniques has been shown to increase union rates without the need for bone grafting.^1,2 The Less-Invasive Stabilization System (LISS) made by Synthes (Paoli, Pennsylvania) melds minimally invasive internal fixation with multiple fixed-angle distal screws. It allows for submuscular placement, percutaneous unicortical screws in the diaphysis, and preservation of the metaphyseal fracture soft-tissue envelope.³

Proper lateral placement of the plate on the femur proximally can be difficult. Kregor and colleagues³ noted that 6% of cases did not have ideal placement on the lateral shaft of the femur when the 13-hole LISS plate was used. They advocated making a small incision at the proximal end of the LISS plate to aid in proper lateral placement. Kolb and colleagues⁴ noted that 2 of 31 patients had a “cutting out” of the proximal screws on LISS plates with anterior placement on the femur that eventually required repeat surgery in order to heal. This malpositioned plate was present at the end of the operation. These authors also recommended a proximal incision to avoid the issue. Schütz and colleagues⁵ noted that there were 4 cases of implant loosening among 107 distal femur fractures treated with LISS plating and that the unicortical screws in the diaphysis had loosened. They suggested anterior placement of the plate as a possible reason for fixation failure.

Although several studies have noted proximal screw pull-out, and proximal anterior malposition in the sagittal plane of the LISS plate has been suggested as a possible cause, we found no studies comparing incorrect proximal positioning on the femoral shaft with correct lateral placement of the LISS plate. Therefore, we used a previously established biomechanical model to compare LISS plates proximally placed either too anterior or too posterior to the direct lateral position on the femoral shaft. The constructs were tested in axial, torsional, and cyclical axial modes to assess plastic and total deformation, stiffness, and fixation failure.

Materials and Methods

Using fourth-generation femoral synthetic composite bones (Sawbones; Pacific Research Laboratories, Vashon, Washington) and a 13-hole Synthes femoral LISS plate, we made 3 groups of 9 specimens each, for a total of 27 femurs. The number of specimens was based on a power assessment in a study by Khalafi and colleagues.⁸ Several studies have validated use of Sawbones instead of cadavers in biomechanical testing to prevent variability.^6-9 Proximal fixation was achieved with 5 unicortical screws (26 mm long) at screw holes 13, 11, 9, 7, and 4. All distal screw holes were filled for distal fixation with 75-mm-long screws to achieve bicortical fixation.

After application of the LISS plate, an AO/OTA 33-A3 fracture model was created in each specimen. A 1-cm gap was made 6 cm proximal to the intercondylar notch to create an unstable distal femur fracture pattern. In the method described by Zlowodzki and colleagues,¹⁰ an additional 3-cm cut was made diagonally in the medial cortex to prevent contact of the bone during mechanical testing.

Three different plate positions were used. The correct group was placed directly laterally proximally (Figure 1A). One incorrect group was plated with the proximal aspect of the plate 1 cm anterior (anterior group) (Figure 1B), and another incorrect group was plated with the proximal aspect of the plate 1 cm posterior (posterior group) (Figure 1C). Anterior or posterior plate placement resulted in some of the proximal screws having a more tangential placement, with fewer screws engaged compared with the properly placed plate.

The distal and proximal ends of each specimen were held to simulate the mechanical axis of the femur. This design was based on a model by Cordey and colleagues.¹¹ A materials testing system (MTS, Minneapolis, Minnesota) was used for mechanical testing of the model.

Based on the protocol of Khalafi and colleagues,⁸ the models were tested in axial, torsional, and cyclical axial modes (Figures 2, 3). Axial loading consisted of a preload of 100 N followed by a compressive loading rate of 100 mm per minute in a displacement control mode. Testing was considered completed when 1 of 3 events occurred: 500 N was reached, the medial fracture gap closed, or fixation was lost. Torsional loading involved a preload of 5 Nm and subsequent torqueing at 20° per minute up to 20 Nm or loss of fixation or screw pull-out.⁸ Cyclical axial loading was based on protocols described by Marti and colleagues² and Zlowodzki and colleagues.¹⁰ The initial load was 10 cycles of 300 N. Each subsequent load increment was increased by 100 N up to 1000 N, providing 10-second rest increments. This loading was conducted in a displacement control mode at 0.75 mm per second. Testing was aborted on fixation loss or complete closure of the medial fracture gap.

After testing was completed, statistically significant between-groups differences in plastic deformation and axial and torsional stiffness were determined by performing a Tukey-Kramer honestly significant difference test. Significance was set at P ≤ .05.

Results

During axial loading, there was no visual loss of fixation or change in displacement of the fracture gap for any group, and there was no screw cut-out or pull-out from the cortex during testing. In 1 plate in the posterior group, the most proximal screw made only loose contact with the cortex at only the distal portion of the screw. There was no significant difference (P = .9762) in stiffness in axial loading between the anterior group and the correct group. There was a significant (P = .0261) 16.4% increase in stiffness in the posterior group compared with the correct group (Table).

There was no screw cut-out, fixation failure, or change in displacement of the fracture gap for any group during torsional loading. There was a statistically significant (P = .0062) 12% increase in mean torsional stiffness in the anterior group compared with the correct group. There was no statistically significant difference (P = .1623) between the posterior group and the correct group (Table).

For cyclical axial testing, total deformation and plastic deformation were obtained by determining displacement under the initial 100 N load in the static/resting state. That number was then subtracted from maximum displacement, the peak value on the time-versus-displacement graph, to obtain the value for total deformation. Plastic deformation was calculated by subtracting initial displacement from final displacement in the static/resting state. The static/resting state is represented by the dips in displacement after each cycle on the time-versus-displacement graph (Figure 4).

There was a statistically significant (P = .0207) 14% increase in total deformation of the anteriorly positioned plate compared with the correctly positioned plate. There was no statistically significant difference in total deformation between the posteriorly placed plates and the correctly placed plates (Table).

There was no significant difference in plastic deformation between any of the groups in this study. There was no screw cut-out or fixation loss in any group to suggest a clinically relevant difference based on proximal placement of the LISS plate.

Discussion

In evaluating the stability of various constructs for fixation of distal femur fractures, the literature is consistent in reporting stiffness as the key factor. Stiffness is determined most often in terms of motion at the fracture site, as measured by displacement under axial and torsional loads.^2,8,10,13 The LISS plate, which acts essentially as an “internal fixator” with proximal unicortical fixed-angle locking screws, has been shown to be comparable to other established methods of fixation.^10,12 Zlowodzki and colleagues¹⁰ reported that the LISS plate had a higher load to failure when compared with angled blade plating and intramedullary nailing. Their study used fresh-frozen cadaver specimens from patients 70 years old or older. They concluded that, for distal femur fractures in osteoporotic bone, the LISS plate provided improved distal fixation.

In the present study, the posteriorly placed LISS plate outperformed the correctly placed plate in axial stiffness by 16.4%. However, there was no statistically significant difference in torsional stiffness and cyclical axial loading. This result is difficult to explain given that there was no screw cut-out or fixation loss for any of the constructs. Theoretically, with less proximal screw purchase in the posteriorly placed plate, the overall construct should be more susceptible to screw cut-out and fixation loss resulting in less axial stiffness overall.

Khalafi and colleagues⁸ created a distal femur fracture model using Sawbones with a 1-cm fracture gap. Using the 9-hole LISS plate for fixation, they tested this construct under axial, torsional, and cyclical axial loads. They tested 2 groups of 9 femurs. For group 1, the LISS plate was placed in the correct position on the distal femur, with the proximal end in the correct position on the femoral shaft. In group 2, the LISS plate was rotated 1 cm anteriorly. They found that axial stiffness (N/mm) was 21.5% greater in the correctly positioned plate. The anteriorly positioned group demonstrated 55% more irreversible or plastic deformation. The authors concluded that correct positioning of the femoral LISS plate provided improved mechanical stability.

Overall, our study results did not agree with those of Khalafi and colleagues⁸ in terms of the mechanical stability of a malpositioned LISS plate. Our construct showed a significant increase in torsional stiffness in the anteriorly placed plate. However, our construct also showed a significant increase in total deformation in cyclical axial loading in the anteriorly placed plate. There was no increased plastic deformation in either of the incorrectly placed groups in our study. The difference in results between studies can best be explained by the difference in plate lengths. We used a 13-hole plate, and Khalafi and colleagues⁸ used a 9-hole plate. Our theory is that the longer plate provided more resistance to relatively minor variations in plate position at the proximal end and thus resulted in less change in stiffness and stability around the fracture site.

Our model differed from that used in other biomechanical studies using Sawbones to simulate distal femur fractures in that it used the entire femur, including the proximal portion.^8,13 This setup theoretically resulted in a more anatomical weight distribution compared with other models, in which the proximal portion of the femur was potted in polymethylmethacrylate. This difference in weight distribution could explain the variation in our results compared with other biomechanical studies. In addition, with use of different boundary conditions, the distal femur had unconstrained distal motion similar to the native environment of the femur.

This study had several limitations. First is its relatively low power (9 femurs per group). Although groups of 9 specimens in 2 groups were used in the study by Khalafi and colleagues⁸, testing a larger number of femurs could potentially identify more subtle differences between the 3 groups in our study. Second, given that femoral LISS plates come in different lengths, this study could be expanded to include the other plate sizes, as plate length could potentially play a role in stability at the fracture site. Third, though this Sawbones model has consistently reproduced the stability characteristics of human bone without variation between specimens, an osteoporotic model could be explored, as the femoral LISS plate is often used in osteoporotic fractures.^7,14

Conclusion

Overall, our study results showed that 1-cm variations, anterior or posterior, had little effect on axial or torsional stiffness or plastic deformation under cyclical axial loading. Although these data can be promising for clinical application, the anterior placement of the LISS plate noted in failed fixation in other studies necessitates cautious interpretation of this study. Our use of a 13-hole (longer) plate, versus the 9-hole plate used in other studies, could explain the lack of variation between the 2 groups as well as the stability and tolerance of inappropriate placement. An osteoporotic model could help clinicians further discern the importance of accurate proximal placement of the femoral LISS plate.

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts or animal products. Infection of total knee or hip arthroplasty by Brucella species is a rare complication with only 18 cases reported in the English literature.^1-12 We describe a case of an infected total hip replacement, its treatment, and 2-year follow-up and review the available literature. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 67-year-old Spanish-speaking woman, a native of Mexico, presented with a painful right total hip arthroplasty (THA) 2 years after implantation in Chihuahua, Mexico. The patient reported 1 year of increasing thigh pain with recent onset of start-up pain, and also mild groin pain. The patient reported an uneventful postoperative course without wound drainage and denied any history of fevers, chills, or night sweats after the procedure. Preoperative notes and radiographs were unavailable for review. Radiographic evaluation showed a hybrid construct with a well-fixed–appearing, uncemented acetabular component but a failed cemented femoral stem (Figures 1A, 1B). Although we discussed revision surgery, the patient elected not to proceed with surgery or to undergo evaluation to rule out infection. Nine months later, she returned with worsening pain and requested revision surgery; radiographs showed progressive bone loss around the cement mantle (Figures 2A, 2B).

Hematologic evaluation showed an erythrocyte sedimentation rate (ESR) of 54 mm/h (normal, 0-27 mm/h) and C-reactive protein (CRP) level of 0.24 mg/L (normal, <0.8). An aspiration of the hip with fluoroscopic guidance produced a small sample (0.2 mL) of yellow synovial fluid. There was not enough fluid for cell count, but fluid culture was negative.

The patient was taken to the operating room for revision THA. Because of concern about progressive bone loss and elevated infectious indices, the administration of antibiotics was delayed until we obtained sufficient deep-tissue specimens. Before opening the capsule, we introduced a syringe into the joint and aspirated 10 mL of cloudy yellow synovial fluid that was sent for cell count. Additional findings at surgery included a grossly loose stem with a fragmented cement mantle surrounded by poor bone stock with anterior cortical bone loss and a loose acetabular component with pockets of cavitary bone loss. Frozen section showed up to 5 nucleated cells per high power field, and the cell count showed 1480 nucleated cells/µL (50% polymorphonuclear cells). The equivocal intraoperative findings (cell count and frozen section) and the loose femoral and acetabular components with significant bone loss were sufficiently concerning that we removed the components and placed a cement spacer rather than proceed with revision arthroplasty (Figures 3A, 3B). The surgeon, first assistant, and scrub technician wore body exhaust suits. We performed irrigation of the wound bed with pulse lavage.

Intraoperative cultures (synovial fluid, joint capsule synovium, and femur pseudocapsule) were positive after 8 days and growing B abortus. Infectious disease consultants prescribed rifampin 300 mg twice daily and doxycycline 100 mg twice daily for 5 months. Follow-up ESR and CRP returned to normal range. A preoperative aspiration of the hip was negative as well. The patient returned to the operating room at 6 months for re-implantation using uncemented components; synovial fluid and tissue cultures taken at this time were negative. Two years after re-implantation, the patient is doing well without evidence of infection (Figures 4A, 4B). Additional follow-up will be required to monitor for infection and implant survival. Additional history taken from the patient after the culture results revealed that her development of hip pain was preceded by a febrile illness consistent with brucellosis. 

Because of the nature of the procedure (irrigation and débridement using pulse lavage), we were concerned about aerosolization of Brucella bacteria and possible transmission to all staff present during the procedure. After consulting with the New Mexico Department of Health (NMDOH) and the Centers for Disease Control and Prevention (CDC), all surgical, anesthesia, and support personnel present in the operative suite  and staff who cleaned the room after the procedure were treated prophylactically (rifampin 600 mg daily, doxycycline 100 mg twice daily for 3 weeks) to prevent development of brucellosis.¹³ All 15 operating room personnel who were exposed elected to proceed with antibiotic prophylaxis. In addition to prophylactic antibiotics, serial serologic testing for anti-Brucella antibodies was conducted at baseline and 2, 4, 6, and 24 weeks postexposure to monitor for the development of Brucella infection. There were no conversions to positive antibody status. No personnel complained of symptoms that would indicate development of brucellosis. At the recommendation of NMDOH and CDC, all staff in the operating room during and immediately after the re-implantation procedure wore properly fitting N-95 disposable respiratory masks (3M, St. Paul, Minnesota) to guard against the potential risk of further exposure.

Discussion

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts. Transmission can occur via breaks in the skin in direct contact, through the ingestion of unpasteurized dairy products or raw meat, or through ingestion of aerosolized bacteria. Transmission via aerosolization has been described during medical procedures.

Brucella is endemic in India, Middle Eastern and Mediterranean countries, Central Asia, and South America. Brucella species are gram-negative coccobacilli that are capable of surviving within phagocytic cells, making antibiotic treatment difficult. Brucellosis is a febrile illness that occurs after a 1- to 3-week incubation period and is often accompanied by headache, arthralgias, and hepatosplenomegaly. Osteoarticular infection is the most common complication, occurring in 10% to 85% of cases and usually involves the sacroiliac joint and the large joints of the lower extremity. Spondylitis, bursitis, tenosynovitis, endocarditis, colitis, meningitis, and osteomyelitis have also been described.^7,14-17

As mentioned previously, 18 cases of infected THAs and total knee arthroplasties (TKAs) in 16 patients were identified in the English literature: 9 THAs and 9 TKAs.^1-12 With the exception of 1 case reported in Texas, all others were from the Middle East or the Mediterranean region. In these patients, symptom onset occurred from 2 months to 14 years from the time of the index surgery, and symptom duration ranged from 1 month to 2 years prior to presentation. The exposure was not reported in 2 cases, but the remaining patients either ingested unpasteurized dairy products or worked closely with livestock. Laboratory evaluation revealed elevated ESR or CRP in 8 cases. In 7 cases, no laboratory results were reported, although 1 had a draining sinus. In 1 case, the ESR was normal, but a bone scan was positive. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (one aspirate yielded Acinetobacter baumanii). Only 3 cases reported a time-to-culture positivity (1 “prolonged” and 2 took 7 days).

Eight cases presented with loose components, while 1 case was not reported, and the remaining were presumed to be well-fixed. In cases that were identified as loose, 5 underwent a 2-stage revision and 2 underwent a 1-stage revision (in one of the 1-stage revisions, the infection was identified only after the revision from intra-operative cultures). Of those with well-fixed components, 7 patients with 9 infected joints (including the case where no preoperative description of the components was reported) were treated with oral antibiotics only (range, 6 weeks to 26 months) and 1 with irrigation and débridement and oral antibiotics. Among those treated only with antibiotics, there were 2 failures (2 joints) leading to revision surgery. The other 5 cases were reportedly doing well between 8 months and 5 years after treatment. There were no reports of transmission to hospital or laboratory personnel in any of these cases nor were there reports of precautions to limit exposure for operating room staff or hospital personnel. 

Failure of TKA or THA secondary to periprosthetic infection by Brucella species is rare, and this represents only the second reported case in the United States.⁴ This case highlights several important principles. Maintaining a high level of suspicion for infection in cases of failed joint arthroplasty is important. In addition, as more international travel occurs and patients are seen from areas where Brucella is endemic, the possibility of this infectious etiology should be considered. Based on reported cases, patients will usually have elevated ESR or CRP; all (except 2 cases in which no exposure was reported) had known exposure to unpasteurized dairy products or livestock. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (1 aspirate yielded Acinetobacter baumanii). In this case, ESR and CRP were elevated, and infection was suspected but joint aspiration was negative. The initial aspiration was cultured for 5 days and previous data, as well as that presented here, suggest that prolonged culture may provide diagnostic value.¹⁸ The patient had resided in an endemic area and had exposure to unpasteurized dairy products, but Brucella infection was not considered and, therefore, no precautions were taken.

Of the reported cases, only 1 met major criteria for periprosthetic joint infection (draining sinus) while 10 of the remaining 15 cases were positive for minor criteria of periprosthetic joint infection (elevated ESR or CRP, or positive culture from joint aspiration).¹⁹ Unfortunately, the available case reports did not detail the extent to which preoperative periprosthetic joint infection could be established based on minor criteria for periprosthetic joint infection (elevated joint synovial white blood cell count or neutrophil percentage, intra-articular purulence, or elevated neutrophil count on periprosthetic tissue histologic analysis).¹⁹

Periprosthetic joint infection by Brucella species is so rare that specific recommendations for this infectious etiology based on 18 reported cases would be overreaching. However, Brucella should be considered when evaluating a potentially infected joint replacement where the possibility of exposure exists (eg, travel to or previous residence in endemic areas, close contact with livestock, or ingestion of unpasteurized dairy products in endemic regions), with the potential for transmission to operating room and hospital personnel also considered. If there is concern about Brucella involvement, tissue and fluid specimens should be labeled so that laboratory personnel can take appropriate precautions. Brucella can be cultured using routine techniques on standard, nonselective media, but the culture time-to-growth may be prolonged. Culture plates should be held for 14 days before reporting no growth of Brucella if it is suspected; the New Mexico Department of Health Microbiology Laboratory holds routine cultures for 1 week after a report of no growth. Thus, a suspicion of Brucella should be communicated in order for culture time to be adjusted if the holding of culture plates after an initial report of no growth is not standard practice. If operative intervention is planned and brucellosis is known, personnel should be notified of the possibility of exposure and appropriate measures taken (ie, wearing N-95 respiratory masks during the procedure and considering other methods of irrigation less likely to aerosolize particulates). It is not known if preoperative antibiotic therapy can sufficiently lower the bacterial load to make aerosolization less likely. If brucellosis is suspected but not identified preoperatively, wearing N-95 respiratory masks should be considered during any open procedures. 

Conclusion

In cases of Brucella infection and loose components, 1- or 2-stage revision with appropriate antibiotic therapy is indicated. (There is not enough data to recommend either 1- or 2-stage revision.) Several reports comment on the ability to treat periprosthetic joint infection in the setting of well-fixed components with antibiotic therapy alone. While this appears to have been successful in 7 of 9 infected joints reported in the literature, length of follow-up ranged from 8 months to 5 years, with no report of length of follow-up in some cases. Antibiotic therapy duration ranged from 6 weeks to 26 months, and the antibiotic treatment involved combination therapy with multiple agents reported but, most commonly, doxycycline, rifampin, and streptomycin. With 2 of 9 (22%) joints failing antibiotic therapy alone and those reported to be successful having relatively short-term follow-up, this treatment strategy should be approached with caution.

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts or animal products. Infection of total knee or hip arthroplasty by Brucella species is a rare complication with only 18 cases reported in the English literature.^1-12 We describe a case of an infected total hip replacement, its treatment, and 2-year follow-up and review the available literature. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 67-year-old Spanish-speaking woman, a native of Mexico, presented with a painful right total hip arthroplasty (THA) 2 years after implantation in Chihuahua, Mexico. The patient reported 1 year of increasing thigh pain with recent onset of start-up pain, and also mild groin pain. The patient reported an uneventful postoperative course without wound drainage and denied any history of fevers, chills, or night sweats after the procedure. Preoperative notes and radiographs were unavailable for review. Radiographic evaluation showed a hybrid construct with a well-fixed–appearing, uncemented acetabular component but a failed cemented femoral stem (Figures 1A, 1B). Although we discussed revision surgery, the patient elected not to proceed with surgery or to undergo evaluation to rule out infection. Nine months later, she returned with worsening pain and requested revision surgery; radiographs showed progressive bone loss around the cement mantle (Figures 2A, 2B).

Hematologic evaluation showed an erythrocyte sedimentation rate (ESR) of 54 mm/h (normal, 0-27 mm/h) and C-reactive protein (CRP) level of 0.24 mg/L (normal, <0.8). An aspiration of the hip with fluoroscopic guidance produced a small sample (0.2 mL) of yellow synovial fluid. There was not enough fluid for cell count, but fluid culture was negative.

The patient was taken to the operating room for revision THA. Because of concern about progressive bone loss and elevated infectious indices, the administration of antibiotics was delayed until we obtained sufficient deep-tissue specimens. Before opening the capsule, we introduced a syringe into the joint and aspirated 10 mL of cloudy yellow synovial fluid that was sent for cell count. Additional findings at surgery included a grossly loose stem with a fragmented cement mantle surrounded by poor bone stock with anterior cortical bone loss and a loose acetabular component with pockets of cavitary bone loss. Frozen section showed up to 5 nucleated cells per high power field, and the cell count showed 1480 nucleated cells/µL (50% polymorphonuclear cells). The equivocal intraoperative findings (cell count and frozen section) and the loose femoral and acetabular components with significant bone loss were sufficiently concerning that we removed the components and placed a cement spacer rather than proceed with revision arthroplasty (Figures 3A, 3B). The surgeon, first assistant, and scrub technician wore body exhaust suits. We performed irrigation of the wound bed with pulse lavage.

Intraoperative cultures (synovial fluid, joint capsule synovium, and femur pseudocapsule) were positive after 8 days and growing B abortus. Infectious disease consultants prescribed rifampin 300 mg twice daily and doxycycline 100 mg twice daily for 5 months. Follow-up ESR and CRP returned to normal range. A preoperative aspiration of the hip was negative as well. The patient returned to the operating room at 6 months for re-implantation using uncemented components; synovial fluid and tissue cultures taken at this time were negative. Two years after re-implantation, the patient is doing well without evidence of infection (Figures 4A, 4B). Additional follow-up will be required to monitor for infection and implant survival. Additional history taken from the patient after the culture results revealed that her development of hip pain was preceded by a febrile illness consistent with brucellosis. 

Because of the nature of the procedure (irrigation and débridement using pulse lavage), we were concerned about aerosolization of Brucella bacteria and possible transmission to all staff present during the procedure. After consulting with the New Mexico Department of Health (NMDOH) and the Centers for Disease Control and Prevention (CDC), all surgical, anesthesia, and support personnel present in the operative suite  and staff who cleaned the room after the procedure were treated prophylactically (rifampin 600 mg daily, doxycycline 100 mg twice daily for 3 weeks) to prevent development of brucellosis.¹³ All 15 operating room personnel who were exposed elected to proceed with antibiotic prophylaxis. In addition to prophylactic antibiotics, serial serologic testing for anti-Brucella antibodies was conducted at baseline and 2, 4, 6, and 24 weeks postexposure to monitor for the development of Brucella infection. There were no conversions to positive antibody status. No personnel complained of symptoms that would indicate development of brucellosis. At the recommendation of NMDOH and CDC, all staff in the operating room during and immediately after the re-implantation procedure wore properly fitting N-95 disposable respiratory masks (3M, St. Paul, Minnesota) to guard against the potential risk of further exposure.

Discussion

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts. Transmission can occur via breaks in the skin in direct contact, through the ingestion of unpasteurized dairy products or raw meat, or through ingestion of aerosolized bacteria. Transmission via aerosolization has been described during medical procedures.

Brucella is endemic in India, Middle Eastern and Mediterranean countries, Central Asia, and South America. Brucella species are gram-negative coccobacilli that are capable of surviving within phagocytic cells, making antibiotic treatment difficult. Brucellosis is a febrile illness that occurs after a 1- to 3-week incubation period and is often accompanied by headache, arthralgias, and hepatosplenomegaly. Osteoarticular infection is the most common complication, occurring in 10% to 85% of cases and usually involves the sacroiliac joint and the large joints of the lower extremity. Spondylitis, bursitis, tenosynovitis, endocarditis, colitis, meningitis, and osteomyelitis have also been described.^7,14-17

As mentioned previously, 18 cases of infected THAs and total knee arthroplasties (TKAs) in 16 patients were identified in the English literature: 9 THAs and 9 TKAs.^1-12 With the exception of 1 case reported in Texas, all others were from the Middle East or the Mediterranean region. In these patients, symptom onset occurred from 2 months to 14 years from the time of the index surgery, and symptom duration ranged from 1 month to 2 years prior to presentation. The exposure was not reported in 2 cases, but the remaining patients either ingested unpasteurized dairy products or worked closely with livestock. Laboratory evaluation revealed elevated ESR or CRP in 8 cases. In 7 cases, no laboratory results were reported, although 1 had a draining sinus. In 1 case, the ESR was normal, but a bone scan was positive. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (one aspirate yielded Acinetobacter baumanii). Only 3 cases reported a time-to-culture positivity (1 “prolonged” and 2 took 7 days).

Eight cases presented with loose components, while 1 case was not reported, and the remaining were presumed to be well-fixed. In cases that were identified as loose, 5 underwent a 2-stage revision and 2 underwent a 1-stage revision (in one of the 1-stage revisions, the infection was identified only after the revision from intra-operative cultures). Of those with well-fixed components, 7 patients with 9 infected joints (including the case where no preoperative description of the components was reported) were treated with oral antibiotics only (range, 6 weeks to 26 months) and 1 with irrigation and débridement and oral antibiotics. Among those treated only with antibiotics, there were 2 failures (2 joints) leading to revision surgery. The other 5 cases were reportedly doing well between 8 months and 5 years after treatment. There were no reports of transmission to hospital or laboratory personnel in any of these cases nor were there reports of precautions to limit exposure for operating room staff or hospital personnel. 

Failure of TKA or THA secondary to periprosthetic infection by Brucella species is rare, and this represents only the second reported case in the United States.⁴ This case highlights several important principles. Maintaining a high level of suspicion for infection in cases of failed joint arthroplasty is important. In addition, as more international travel occurs and patients are seen from areas where Brucella is endemic, the possibility of this infectious etiology should be considered. Based on reported cases, patients will usually have elevated ESR or CRP; all (except 2 cases in which no exposure was reported) had known exposure to unpasteurized dairy products or livestock. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (1 aspirate yielded Acinetobacter baumanii). In this case, ESR and CRP were elevated, and infection was suspected but joint aspiration was negative. The initial aspiration was cultured for 5 days and previous data, as well as that presented here, suggest that prolonged culture may provide diagnostic value.¹⁸ The patient had resided in an endemic area and had exposure to unpasteurized dairy products, but Brucella infection was not considered and, therefore, no precautions were taken.

Of the reported cases, only 1 met major criteria for periprosthetic joint infection (draining sinus) while 10 of the remaining 15 cases were positive for minor criteria of periprosthetic joint infection (elevated ESR or CRP, or positive culture from joint aspiration).¹⁹ Unfortunately, the available case reports did not detail the extent to which preoperative periprosthetic joint infection could be established based on minor criteria for periprosthetic joint infection (elevated joint synovial white blood cell count or neutrophil percentage, intra-articular purulence, or elevated neutrophil count on periprosthetic tissue histologic analysis).¹⁹

Periprosthetic joint infection by Brucella species is so rare that specific recommendations for this infectious etiology based on 18 reported cases would be overreaching. However, Brucella should be considered when evaluating a potentially infected joint replacement where the possibility of exposure exists (eg, travel to or previous residence in endemic areas, close contact with livestock, or ingestion of unpasteurized dairy products in endemic regions), with the potential for transmission to operating room and hospital personnel also considered. If there is concern about Brucella involvement, tissue and fluid specimens should be labeled so that laboratory personnel can take appropriate precautions. Brucella can be cultured using routine techniques on standard, nonselective media, but the culture time-to-growth may be prolonged. Culture plates should be held for 14 days before reporting no growth of Brucella if it is suspected; the New Mexico Department of Health Microbiology Laboratory holds routine cultures for 1 week after a report of no growth. Thus, a suspicion of Brucella should be communicated in order for culture time to be adjusted if the holding of culture plates after an initial report of no growth is not standard practice. If operative intervention is planned and brucellosis is known, personnel should be notified of the possibility of exposure and appropriate measures taken (ie, wearing N-95 respiratory masks during the procedure and considering other methods of irrigation less likely to aerosolize particulates). It is not known if preoperative antibiotic therapy can sufficiently lower the bacterial load to make aerosolization less likely. If brucellosis is suspected but not identified preoperatively, wearing N-95 respiratory masks should be considered during any open procedures. 

Conclusion

In cases of Brucella infection and loose components, 1- or 2-stage revision with appropriate antibiotic therapy is indicated. (There is not enough data to recommend either 1- or 2-stage revision.) Several reports comment on the ability to treat periprosthetic joint infection in the setting of well-fixed components with antibiotic therapy alone. While this appears to have been successful in 7 of 9 infected joints reported in the literature, length of follow-up ranged from 8 months to 5 years, with no report of length of follow-up in some cases. Antibiotic therapy duration ranged from 6 weeks to 26 months, and the antibiotic treatment involved combination therapy with multiple agents reported but, most commonly, doxycycline, rifampin, and streptomycin. With 2 of 9 (22%) joints failing antibiotic therapy alone and those reported to be successful having relatively short-term follow-up, this treatment strategy should be approached with caution.

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts or animal products. Infection of total knee or hip arthroplasty by Brucella species is a rare complication with only 18 cases reported in the English literature.^1-12 We describe a case of an infected total hip replacement, its treatment, and 2-year follow-up and review the available literature. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 67-year-old Spanish-speaking woman, a native of Mexico, presented with a painful right total hip arthroplasty (THA) 2 years after implantation in Chihuahua, Mexico. The patient reported 1 year of increasing thigh pain with recent onset of start-up pain, and also mild groin pain. The patient reported an uneventful postoperative course without wound drainage and denied any history of fevers, chills, or night sweats after the procedure. Preoperative notes and radiographs were unavailable for review. Radiographic evaluation showed a hybrid construct with a well-fixed–appearing, uncemented acetabular component but a failed cemented femoral stem (Figures 1A, 1B). Although we discussed revision surgery, the patient elected not to proceed with surgery or to undergo evaluation to rule out infection. Nine months later, she returned with worsening pain and requested revision surgery; radiographs showed progressive bone loss around the cement mantle (Figures 2A, 2B).

Hematologic evaluation showed an erythrocyte sedimentation rate (ESR) of 54 mm/h (normal, 0-27 mm/h) and C-reactive protein (CRP) level of 0.24 mg/L (normal, <0.8). An aspiration of the hip with fluoroscopic guidance produced a small sample (0.2 mL) of yellow synovial fluid. There was not enough fluid for cell count, but fluid culture was negative.

The patient was taken to the operating room for revision THA. Because of concern about progressive bone loss and elevated infectious indices, the administration of antibiotics was delayed until we obtained sufficient deep-tissue specimens. Before opening the capsule, we introduced a syringe into the joint and aspirated 10 mL of cloudy yellow synovial fluid that was sent for cell count. Additional findings at surgery included a grossly loose stem with a fragmented cement mantle surrounded by poor bone stock with anterior cortical bone loss and a loose acetabular component with pockets of cavitary bone loss. Frozen section showed up to 5 nucleated cells per high power field, and the cell count showed 1480 nucleated cells/µL (50% polymorphonuclear cells). The equivocal intraoperative findings (cell count and frozen section) and the loose femoral and acetabular components with significant bone loss were sufficiently concerning that we removed the components and placed a cement spacer rather than proceed with revision arthroplasty (Figures 3A, 3B). The surgeon, first assistant, and scrub technician wore body exhaust suits. We performed irrigation of the wound bed with pulse lavage.

Intraoperative cultures (synovial fluid, joint capsule synovium, and femur pseudocapsule) were positive after 8 days and growing B abortus. Infectious disease consultants prescribed rifampin 300 mg twice daily and doxycycline 100 mg twice daily for 5 months. Follow-up ESR and CRP returned to normal range. A preoperative aspiration of the hip was negative as well. The patient returned to the operating room at 6 months for re-implantation using uncemented components; synovial fluid and tissue cultures taken at this time were negative. Two years after re-implantation, the patient is doing well without evidence of infection (Figures 4A, 4B). Additional follow-up will be required to monitor for infection and implant survival. Additional history taken from the patient after the culture results revealed that her development of hip pain was preceded by a febrile illness consistent with brucellosis. 

Because of the nature of the procedure (irrigation and débridement using pulse lavage), we were concerned about aerosolization of Brucella bacteria and possible transmission to all staff present during the procedure. After consulting with the New Mexico Department of Health (NMDOH) and the Centers for Disease Control and Prevention (CDC), all surgical, anesthesia, and support personnel present in the operative suite  and staff who cleaned the room after the procedure were treated prophylactically (rifampin 600 mg daily, doxycycline 100 mg twice daily for 3 weeks) to prevent development of brucellosis.¹³ All 15 operating room personnel who were exposed elected to proceed with antibiotic prophylaxis. In addition to prophylactic antibiotics, serial serologic testing for anti-Brucella antibodies was conducted at baseline and 2, 4, 6, and 24 weeks postexposure to monitor for the development of Brucella infection. There were no conversions to positive antibody status. No personnel complained of symptoms that would indicate development of brucellosis. At the recommendation of NMDOH and CDC, all staff in the operating room during and immediately after the re-implantation procedure wore properly fitting N-95 disposable respiratory masks (3M, St. Paul, Minnesota) to guard against the potential risk of further exposure.

Discussion

Brucellosis is a zoonotic disease transmitted to humans through contact with animal hosts. Transmission can occur via breaks in the skin in direct contact, through the ingestion of unpasteurized dairy products or raw meat, or through ingestion of aerosolized bacteria. Transmission via aerosolization has been described during medical procedures.

Brucella is endemic in India, Middle Eastern and Mediterranean countries, Central Asia, and South America. Brucella species are gram-negative coccobacilli that are capable of surviving within phagocytic cells, making antibiotic treatment difficult. Brucellosis is a febrile illness that occurs after a 1- to 3-week incubation period and is often accompanied by headache, arthralgias, and hepatosplenomegaly. Osteoarticular infection is the most common complication, occurring in 10% to 85% of cases and usually involves the sacroiliac joint and the large joints of the lower extremity. Spondylitis, bursitis, tenosynovitis, endocarditis, colitis, meningitis, and osteomyelitis have also been described.^7,14-17

As mentioned previously, 18 cases of infected THAs and total knee arthroplasties (TKAs) in 16 patients were identified in the English literature: 9 THAs and 9 TKAs.^1-12 With the exception of 1 case reported in Texas, all others were from the Middle East or the Mediterranean region. In these patients, symptom onset occurred from 2 months to 14 years from the time of the index surgery, and symptom duration ranged from 1 month to 2 years prior to presentation. The exposure was not reported in 2 cases, but the remaining patients either ingested unpasteurized dairy products or worked closely with livestock. Laboratory evaluation revealed elevated ESR or CRP in 8 cases. In 7 cases, no laboratory results were reported, although 1 had a draining sinus. In 1 case, the ESR was normal, but a bone scan was positive. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (one aspirate yielded Acinetobacter baumanii). Only 3 cases reported a time-to-culture positivity (1 “prolonged” and 2 took 7 days).

Eight cases presented with loose components, while 1 case was not reported, and the remaining were presumed to be well-fixed. In cases that were identified as loose, 5 underwent a 2-stage revision and 2 underwent a 1-stage revision (in one of the 1-stage revisions, the infection was identified only after the revision from intra-operative cultures). Of those with well-fixed components, 7 patients with 9 infected joints (including the case where no preoperative description of the components was reported) were treated with oral antibiotics only (range, 6 weeks to 26 months) and 1 with irrigation and débridement and oral antibiotics. Among those treated only with antibiotics, there were 2 failures (2 joints) leading to revision surgery. The other 5 cases were reportedly doing well between 8 months and 5 years after treatment. There were no reports of transmission to hospital or laboratory personnel in any of these cases nor were there reports of precautions to limit exposure for operating room staff or hospital personnel. 

Failure of TKA or THA secondary to periprosthetic infection by Brucella species is rare, and this represents only the second reported case in the United States.⁴ This case highlights several important principles. Maintaining a high level of suspicion for infection in cases of failed joint arthroplasty is important. In addition, as more international travel occurs and patients are seen from areas where Brucella is endemic, the possibility of this infectious etiology should be considered. Based on reported cases, patients will usually have elevated ESR or CRP; all (except 2 cases in which no exposure was reported) had known exposure to unpasteurized dairy products or livestock. Joint aspiration yielded Brucella species in 8 cases, was negative in 3, and not reported in 5 cases (1 aspirate yielded Acinetobacter baumanii). In this case, ESR and CRP were elevated, and infection was suspected but joint aspiration was negative. The initial aspiration was cultured for 5 days and previous data, as well as that presented here, suggest that prolonged culture may provide diagnostic value.¹⁸ The patient had resided in an endemic area and had exposure to unpasteurized dairy products, but Brucella infection was not considered and, therefore, no precautions were taken.

Of the reported cases, only 1 met major criteria for periprosthetic joint infection (draining sinus) while 10 of the remaining 15 cases were positive for minor criteria of periprosthetic joint infection (elevated ESR or CRP, or positive culture from joint aspiration).¹⁹ Unfortunately, the available case reports did not detail the extent to which preoperative periprosthetic joint infection could be established based on minor criteria for periprosthetic joint infection (elevated joint synovial white blood cell count or neutrophil percentage, intra-articular purulence, or elevated neutrophil count on periprosthetic tissue histologic analysis).¹⁹

Periprosthetic joint infection by Brucella species is so rare that specific recommendations for this infectious etiology based on 18 reported cases would be overreaching. However, Brucella should be considered when evaluating a potentially infected joint replacement where the possibility of exposure exists (eg, travel to or previous residence in endemic areas, close contact with livestock, or ingestion of unpasteurized dairy products in endemic regions), with the potential for transmission to operating room and hospital personnel also considered. If there is concern about Brucella involvement, tissue and fluid specimens should be labeled so that laboratory personnel can take appropriate precautions. Brucella can be cultured using routine techniques on standard, nonselective media, but the culture time-to-growth may be prolonged. Culture plates should be held for 14 days before reporting no growth of Brucella if it is suspected; the New Mexico Department of Health Microbiology Laboratory holds routine cultures for 1 week after a report of no growth. Thus, a suspicion of Brucella should be communicated in order for culture time to be adjusted if the holding of culture plates after an initial report of no growth is not standard practice. If operative intervention is planned and brucellosis is known, personnel should be notified of the possibility of exposure and appropriate measures taken (ie, wearing N-95 respiratory masks during the procedure and considering other methods of irrigation less likely to aerosolize particulates). It is not known if preoperative antibiotic therapy can sufficiently lower the bacterial load to make aerosolization less likely. If brucellosis is suspected but not identified preoperatively, wearing N-95 respiratory masks should be considered during any open procedures. 

Conclusion

In cases of Brucella infection and loose components, 1- or 2-stage revision with appropriate antibiotic therapy is indicated. (There is not enough data to recommend either 1- or 2-stage revision.) Several reports comment on the ability to treat periprosthetic joint infection in the setting of well-fixed components with antibiotic therapy alone. While this appears to have been successful in 7 of 9 infected joints reported in the literature, length of follow-up ranged from 8 months to 5 years, with no report of length of follow-up in some cases. Antibiotic therapy duration ranged from 6 weeks to 26 months, and the antibiotic treatment involved combination therapy with multiple agents reported but, most commonly, doxycycline, rifampin, and streptomycin. With 2 of 9 (22%) joints failing antibiotic therapy alone and those reported to be successful having relatively short-term follow-up, this treatment strategy should be approached with caution.

Researchers have honed in on a way to replace the meniscus, using a personalized 3D-printed implant in sheep, according to a study published online December 10, 2014, in Science Translational Medicine. The therapy, successfully tested in sheep, could provide the first effective and long-lasting repair of damaged menisci.

“At present, there’s little that orthopedists can do to regenerate a torn knee meniscus,” said lead study author Jeremy Mao, DDS, PhD, the Edwin S. Robinson Professor of Dentistry in Orthopedic Surgery at Columbia University Medical Center in New York. “In contrast, we’re jumpstarting the process within the body, using factors that promote endogenous stem cells for tissue regeneration.”

This process was tested on 11 sheep. Knees of sheep were chosen because of their close resemblance to the human knee. In this study, the sheep were randomized to have part of their knee meniscus replaced with a protein-infused 3D scaffold or a 3D scaffold without protein.

Dr. Mao’s approach starts with MRI scans of the intact meniscus in the undamaged knee, which is then converted into a 3D image. Data from the image are then used to drive a 3D printer, which produces a scaffold in the exact shape of the meniscus, down to a resolution of 10 microns. The scaffold is infused with connective growth factor (CTGF) and transforming growth factor β3 (TGFβ3). Dr. Mao’s team found that sequential delivery of these two proteins attracts existing stem cells from the body and induces them to form meniscal tissue.

After three months, treated animals were walking normally. In a postmortem analysis, the researchers found that the regenerated meniscus in the treatment group had structural and mechanical properties very similar to those of natural meniscus. In sheep, the meniscus regenerates at a rate of about 4 to 6 weeks. Eventually, the scaffold dissolves and is eliminated by the body.

Researchers have honed in on a way to replace the meniscus, using a personalized 3D-printed implant in sheep, according to a study published online December 10, 2014, in Science Translational Medicine. The therapy, successfully tested in sheep, could provide the first effective and long-lasting repair of damaged menisci.

“At present, there’s little that orthopedists can do to regenerate a torn knee meniscus,” said lead study author Jeremy Mao, DDS, PhD, the Edwin S. Robinson Professor of Dentistry in Orthopedic Surgery at Columbia University Medical Center in New York. “In contrast, we’re jumpstarting the process within the body, using factors that promote endogenous stem cells for tissue regeneration.”

This process was tested on 11 sheep. Knees of sheep were chosen because of their close resemblance to the human knee. In this study, the sheep were randomized to have part of their knee meniscus replaced with a protein-infused 3D scaffold or a 3D scaffold without protein.

Dr. Mao’s approach starts with MRI scans of the intact meniscus in the undamaged knee, which is then converted into a 3D image. Data from the image are then used to drive a 3D printer, which produces a scaffold in the exact shape of the meniscus, down to a resolution of 10 microns. The scaffold is infused with connective growth factor (CTGF) and transforming growth factor β3 (TGFβ3). Dr. Mao’s team found that sequential delivery of these two proteins attracts existing stem cells from the body and induces them to form meniscal tissue.

After three months, treated animals were walking normally. In a postmortem analysis, the researchers found that the regenerated meniscus in the treatment group had structural and mechanical properties very similar to those of natural meniscus. In sheep, the meniscus regenerates at a rate of about 4 to 6 weeks. Eventually, the scaffold dissolves and is eliminated by the body.

Researchers have honed in on a way to replace the meniscus, using a personalized 3D-printed implant in sheep, according to a study published online December 10, 2014, in Science Translational Medicine. The therapy, successfully tested in sheep, could provide the first effective and long-lasting repair of damaged menisci.

“At present, there’s little that orthopedists can do to regenerate a torn knee meniscus,” said lead study author Jeremy Mao, DDS, PhD, the Edwin S. Robinson Professor of Dentistry in Orthopedic Surgery at Columbia University Medical Center in New York. “In contrast, we’re jumpstarting the process within the body, using factors that promote endogenous stem cells for tissue regeneration.”

This process was tested on 11 sheep. Knees of sheep were chosen because of their close resemblance to the human knee. In this study, the sheep were randomized to have part of their knee meniscus replaced with a protein-infused 3D scaffold or a 3D scaffold without protein.

Dr. Mao’s approach starts with MRI scans of the intact meniscus in the undamaged knee, which is then converted into a 3D image. Data from the image are then used to drive a 3D printer, which produces a scaffold in the exact shape of the meniscus, down to a resolution of 10 microns. The scaffold is infused with connective growth factor (CTGF) and transforming growth factor β3 (TGFβ3). Dr. Mao’s team found that sequential delivery of these two proteins attracts existing stem cells from the body and induces them to form meniscal tissue.

After three months, treated animals were walking normally. In a postmortem analysis, the researchers found that the regenerated meniscus in the treatment group had structural and mechanical properties very similar to those of natural meniscus. In sheep, the meniscus regenerates at a rate of about 4 to 6 weeks. Eventually, the scaffold dissolves and is eliminated by the body.

DALLAS—Injecting long-acting liposomal bupivacaine into the tissue surrounding the knee during knee replacement surgery may provide a faster receovery and higher patient satisfaction, according to a report presented at the recent American Association for Hip and Knee Surgeons meeting.

“The pain scores for this injection technique averaged about 3/10, which is similar to the pain scores seen with our traditional method,” said Jason Davis, MD, a Henry Ford West Bloomfield Hospital joint replacement surgeon and senior study author. “Patients had pain relief for up to 2 days after surgery and better knee function compared with the traditional method.”

In the study, 216 patients were evaluated for pain control the first 2 days after surgery from October 2012 to September 2013. Half of the patients received the traditional pain control method with continuous femoral nerve blockade, in which common numbing medicine is injected into the groin area, blunting the main nerve down the front of the knee—a method that calls for a pain pump to extend pain control for two days but causes some leg weakness.

“Pain control came at the price of weakness and made patients somewhat tentative when walking during their hospital stay,” stated Dr. Davis.

The other half of patients received the liposomal bupivacaine injection at the site of the surgery. With this method, Dr. Davis says many patients were able to walk comfortably within hours after surgery.

Dr. Davis said that the injection around the knee itself “optimizes pain control early on” without the side effects of the traditional technique. “Function-wise, it was a lot easier for patients to move around more confidently,” Dr. Davis stated.

“In the past decade, we’ve made major advancements in pain control for knee replacement surgery. This option is a promising, viable one for our patients,” Dr. Davis said.

DALLAS—Injecting long-acting liposomal bupivacaine into the tissue surrounding the knee during knee replacement surgery may provide a faster receovery and higher patient satisfaction, according to a report presented at the recent American Association for Hip and Knee Surgeons meeting.

“The pain scores for this injection technique averaged about 3/10, which is similar to the pain scores seen with our traditional method,” said Jason Davis, MD, a Henry Ford West Bloomfield Hospital joint replacement surgeon and senior study author. “Patients had pain relief for up to 2 days after surgery and better knee function compared with the traditional method.”

In the study, 216 patients were evaluated for pain control the first 2 days after surgery from October 2012 to September 2013. Half of the patients received the traditional pain control method with continuous femoral nerve blockade, in which common numbing medicine is injected into the groin area, blunting the main nerve down the front of the knee—a method that calls for a pain pump to extend pain control for two days but causes some leg weakness.

“Pain control came at the price of weakness and made patients somewhat tentative when walking during their hospital stay,” stated Dr. Davis.

The other half of patients received the liposomal bupivacaine injection at the site of the surgery. With this method, Dr. Davis says many patients were able to walk comfortably within hours after surgery.

Dr. Davis said that the injection around the knee itself “optimizes pain control early on” without the side effects of the traditional technique. “Function-wise, it was a lot easier for patients to move around more confidently,” Dr. Davis stated.

“In the past decade, we’ve made major advancements in pain control for knee replacement surgery. This option is a promising, viable one for our patients,” Dr. Davis said.

DALLAS—Injecting long-acting liposomal bupivacaine into the tissue surrounding the knee during knee replacement surgery may provide a faster receovery and higher patient satisfaction, according to a report presented at the recent American Association for Hip and Knee Surgeons meeting.

“The pain scores for this injection technique averaged about 3/10, which is similar to the pain scores seen with our traditional method,” said Jason Davis, MD, a Henry Ford West Bloomfield Hospital joint replacement surgeon and senior study author. “Patients had pain relief for up to 2 days after surgery and better knee function compared with the traditional method.”

In the study, 216 patients were evaluated for pain control the first 2 days after surgery from October 2012 to September 2013. Half of the patients received the traditional pain control method with continuous femoral nerve blockade, in which common numbing medicine is injected into the groin area, blunting the main nerve down the front of the knee—a method that calls for a pain pump to extend pain control for two days but causes some leg weakness.

“Pain control came at the price of weakness and made patients somewhat tentative when walking during their hospital stay,” stated Dr. Davis.

The other half of patients received the liposomal bupivacaine injection at the site of the surgery. With this method, Dr. Davis says many patients were able to walk comfortably within hours after surgery.

Dr. Davis said that the injection around the knee itself “optimizes pain control early on” without the side effects of the traditional technique. “Function-wise, it was a lot easier for patients to move around more confidently,” Dr. Davis stated.

“In the past decade, we’ve made major advancements in pain control for knee replacement surgery. This option is a promising, viable one for our patients,” Dr. Davis said.

Women with moderate to severe vasomotor symptoms (VMS) have lower bone mineral density and increased hip fracture rates, according to a study published online ahead of print December 18, 2014, in Journal of Clinical Endocrinology & Metabolism.

“This is the first large cohort study to examine the relationship between menopausal symptoms and bone health in menopausal women,” said lead author, Carolyn J. Crandall, MD, MS, of the David Geffen School of Medicine at the University of California, Los Angeles.

Data were examined from 23,573 participants in the Women’s Health Initiative (WHI) Clinical Trial. The participants were women between the ages of 50 and 79. This study, which was conducted at 40 clinical centers across the country, tracked women’s annual visits for 8 years on average.

Participants were asked about their menopausal symptoms, including hot flashes and night sweats, during their initial visit. WHI participants were monitored for fractures during the follow-up period. Among the study participants, 4,867 had their bone mineral density measured as part of a sub-study.

The analysis found that women who reported having moderate to severe hot flashes when they entered the study were more likely to fracture a hip during the follow-up period than were women who showed no menopausal symptoms. In addition, after researchers adjusted for age, body mass index, and demographic factors, they found that women who had moderate to severe menopausal symptoms had lower bone mass density at the neck and spine during the follow-up period than women with no symptoms.

“Our findings suggest that women who exhibit moderate or severe menopausal symptoms are more likely to have issues with bone health than their peers,” said Dr. Crandall. “Improved understanding would help clinicians advise women on how to better prevent osteoporosis and other bone conditions. Women who have hot flashes and want to protect their bones may benefit from healthy lifestyle habits such as avoiding smoking and excessive alcohol consumption, exercising, and getting sufficient calcium and vitamin D,” said Dr. Crandall.

Women with moderate to severe vasomotor symptoms (VMS) have lower bone mineral density and increased hip fracture rates, according to a study published online ahead of print December 18, 2014, in Journal of Clinical Endocrinology & Metabolism.

“This is the first large cohort study to examine the relationship between menopausal symptoms and bone health in menopausal women,” said lead author, Carolyn J. Crandall, MD, MS, of the David Geffen School of Medicine at the University of California, Los Angeles.

Data were examined from 23,573 participants in the Women’s Health Initiative (WHI) Clinical Trial. The participants were women between the ages of 50 and 79. This study, which was conducted at 40 clinical centers across the country, tracked women’s annual visits for 8 years on average.

Participants were asked about their menopausal symptoms, including hot flashes and night sweats, during their initial visit. WHI participants were monitored for fractures during the follow-up period. Among the study participants, 4,867 had their bone mineral density measured as part of a sub-study.

The analysis found that women who reported having moderate to severe hot flashes when they entered the study were more likely to fracture a hip during the follow-up period than were women who showed no menopausal symptoms. In addition, after researchers adjusted for age, body mass index, and demographic factors, they found that women who had moderate to severe menopausal symptoms had lower bone mass density at the neck and spine during the follow-up period than women with no symptoms.

“Our findings suggest that women who exhibit moderate or severe menopausal symptoms are more likely to have issues with bone health than their peers,” said Dr. Crandall. “Improved understanding would help clinicians advise women on how to better prevent osteoporosis and other bone conditions. Women who have hot flashes and want to protect their bones may benefit from healthy lifestyle habits such as avoiding smoking and excessive alcohol consumption, exercising, and getting sufficient calcium and vitamin D,” said Dr. Crandall.

Women with moderate to severe vasomotor symptoms (VMS) have lower bone mineral density and increased hip fracture rates, according to a study published online ahead of print December 18, 2014, in Journal of Clinical Endocrinology & Metabolism.

“This is the first large cohort study to examine the relationship between menopausal symptoms and bone health in menopausal women,” said lead author, Carolyn J. Crandall, MD, MS, of the David Geffen School of Medicine at the University of California, Los Angeles.

Data were examined from 23,573 participants in the Women’s Health Initiative (WHI) Clinical Trial. The participants were women between the ages of 50 and 79. This study, which was conducted at 40 clinical centers across the country, tracked women’s annual visits for 8 years on average.

Participants were asked about their menopausal symptoms, including hot flashes and night sweats, during their initial visit. WHI participants were monitored for fractures during the follow-up period. Among the study participants, 4,867 had their bone mineral density measured as part of a sub-study.

The analysis found that women who reported having moderate to severe hot flashes when they entered the study were more likely to fracture a hip during the follow-up period than were women who showed no menopausal symptoms. In addition, after researchers adjusted for age, body mass index, and demographic factors, they found that women who had moderate to severe menopausal symptoms had lower bone mass density at the neck and spine during the follow-up period than women with no symptoms.

“Our findings suggest that women who exhibit moderate or severe menopausal symptoms are more likely to have issues with bone health than their peers,” said Dr. Crandall. “Improved understanding would help clinicians advise women on how to better prevent osteoporosis and other bone conditions. Women who have hot flashes and want to protect their bones may benefit from healthy lifestyle habits such as avoiding smoking and excessive alcohol consumption, exercising, and getting sufficient calcium and vitamin D,” said Dr. Crandall.

Although some guidelines recommend use of bisphosphonates for men on androgen deprivation therapy (ADT), a study published in the December 3, 2014, JAMA reports that prescriptions for these drugs remain low, even for those men at high risk of subsequent fractures.

“Although the optimal rate of bisphosphonate use in men on ADT is unknown, it is reasonable that most men with prior osteoporosis or fracture should be taking a bisphosphonate or other effective bone medication,” stated Husayn Gulamhusein, BHSc, of the University Health Network in Toronto, and his research colleagues.

Using administrative databases at the Institute for Clinical Evaluative Sciences and the Ontario Cancer Registry, Mr. Gulamhusein and his team examined rates of bisphosphonate prescriptions in men initiating ADT in Ontario between 1995 and 2012. The study group included men ages 66 or older who were starting ADT for prostate cancer, who had undergone surgical removal of one or both testicles, or who received at least 6 months of continuous medical ADT and survived at least one year after ADT initiation.

Bisphosphonate claims within 12 months of ADT initiation were captured through drug database claims. Bisphosphonate prescription was examined for three groups: all nonusers of bisphosphonates, those with prior osteoporosis, and those with prior fragility fracture.

A total of 35,487 men with prostate cancer who began ADT during the study period were identified. Bisphosphonate claims among all nonusers increased from 0.35 per 100 persons in 1995 to 1997 to 3.40 per 100 persons in 2010 to 2012. Rates remained low, even among those with prior osteoporosis or fragility fracture. Among all three groups, peak bisphosphonate claims occurred between 2007 to 2009, with a high of 11.89 per 100 persons in those with prior osteoporosis.

Mr. Gulamhusein and his research team speculate that the decrease in bisphosphonate prescriptions after 2009 may be partly due to recent negative media attention regarding the association of bisphosphonates with rare osteonecrosis of the jaw and atypical femoral fractures. “This is appropriate for groups at low risk for fractures, but the decrease in use for high-risk patients is troubling,” the study authors wrote.

Although some guidelines recommend use of bisphosphonates for men on androgen deprivation therapy (ADT), a study published in the December 3, 2014, JAMA reports that prescriptions for these drugs remain low, even for those men at high risk of subsequent fractures.

“Although the optimal rate of bisphosphonate use in men on ADT is unknown, it is reasonable that most men with prior osteoporosis or fracture should be taking a bisphosphonate or other effective bone medication,” stated Husayn Gulamhusein, BHSc, of the University Health Network in Toronto, and his research colleagues.

Using administrative databases at the Institute for Clinical Evaluative Sciences and the Ontario Cancer Registry, Mr. Gulamhusein and his team examined rates of bisphosphonate prescriptions in men initiating ADT in Ontario between 1995 and 2012. The study group included men ages 66 or older who were starting ADT for prostate cancer, who had undergone surgical removal of one or both testicles, or who received at least 6 months of continuous medical ADT and survived at least one year after ADT initiation.

Bisphosphonate claims within 12 months of ADT initiation were captured through drug database claims. Bisphosphonate prescription was examined for three groups: all nonusers of bisphosphonates, those with prior osteoporosis, and those with prior fragility fracture.

A total of 35,487 men with prostate cancer who began ADT during the study period were identified. Bisphosphonate claims among all nonusers increased from 0.35 per 100 persons in 1995 to 1997 to 3.40 per 100 persons in 2010 to 2012. Rates remained low, even among those with prior osteoporosis or fragility fracture. Among all three groups, peak bisphosphonate claims occurred between 2007 to 2009, with a high of 11.89 per 100 persons in those with prior osteoporosis.

Mr. Gulamhusein and his research team speculate that the decrease in bisphosphonate prescriptions after 2009 may be partly due to recent negative media attention regarding the association of bisphosphonates with rare osteonecrosis of the jaw and atypical femoral fractures. “This is appropriate for groups at low risk for fractures, but the decrease in use for high-risk patients is troubling,” the study authors wrote.

Although some guidelines recommend use of bisphosphonates for men on androgen deprivation therapy (ADT), a study published in the December 3, 2014, JAMA reports that prescriptions for these drugs remain low, even for those men at high risk of subsequent fractures.

“Although the optimal rate of bisphosphonate use in men on ADT is unknown, it is reasonable that most men with prior osteoporosis or fracture should be taking a bisphosphonate or other effective bone medication,” stated Husayn Gulamhusein, BHSc, of the University Health Network in Toronto, and his research colleagues.

Using administrative databases at the Institute for Clinical Evaluative Sciences and the Ontario Cancer Registry, Mr. Gulamhusein and his team examined rates of bisphosphonate prescriptions in men initiating ADT in Ontario between 1995 and 2012. The study group included men ages 66 or older who were starting ADT for prostate cancer, who had undergone surgical removal of one or both testicles, or who received at least 6 months of continuous medical ADT and survived at least one year after ADT initiation.

Bisphosphonate claims within 12 months of ADT initiation were captured through drug database claims. Bisphosphonate prescription was examined for three groups: all nonusers of bisphosphonates, those with prior osteoporosis, and those with prior fragility fracture.

A total of 35,487 men with prostate cancer who began ADT during the study period were identified. Bisphosphonate claims among all nonusers increased from 0.35 per 100 persons in 1995 to 1997 to 3.40 per 100 persons in 2010 to 2012. Rates remained low, even among those with prior osteoporosis or fragility fracture. Among all three groups, peak bisphosphonate claims occurred between 2007 to 2009, with a high of 11.89 per 100 persons in those with prior osteoporosis.

Mr. Gulamhusein and his research team speculate that the decrease in bisphosphonate prescriptions after 2009 may be partly due to recent negative media attention regarding the association of bisphosphonates with rare osteonecrosis of the jaw and atypical femoral fractures. “This is appropriate for groups at low risk for fractures, but the decrease in use for high-risk patients is troubling,” the study authors wrote.

The incidence of periprosthetic supracondylar fractures of the femur after total knee arthroplasty (TKA) ranges from 0.6% to 2.5%.¹ Treatment of periprosthetic fractures is often complicated by advanced patient age and osteoporosis, which frequently accompanies these fractures. Management of a periprosthetic fracture depends on the relation between the fracture site and the prosthesis, displacement of the prosthesis, integrity of the fixation of the prosthesis, extent of the bone loss caused by fracture comminution or preexisting osteolysis, general health of the patient, and surgeon expertise.^2,3 The aim is to achieve fracture union around a stable, well-aligned arthroplasty with preserved or restored bone stock and therefore to return the patient to previous level of function. Although nonoperative treatments have been shown to be successful,^4,5 in the great majority of cases surgical treatment is advised for these fractures.^6-10 In cases in which bone stock is adequate for fixation rather than replacement of the distal femur, 2 modalities are commonly used: retrograde intramedullary nailing and locking plates. Each has its drawbacks and advantages.^11,12

Although external fixation has been used in the treatment of distal femoral fractures,¹³ it is seldom considered in the treatment of periprosthetic fractures. Several authors have described cases that used external fixators, occasionally spanning the knee. The specific types of external fixators discussed in the literature have included ring fixators,^14-17 hybrid fixators,¹⁸ and uniplanar nonspanning fixators^14,19 (Table). Use of a simple anterior spanning external fixator in treating a periprosthetic femoral fracture has received little attention in the literature.

The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 54-year-old woman with previous total hip arthroplasty (THA) and ipsilateral TKA tripped on a carpet and sustained a comminuted fracture of the distal femur just above the TKA prosthesis (Figure 1). She was a Jehovah’s Witness and thus refused all blood products. She had an extensive history of osteoporosis, morbid obesity (5 feet tall, 250 pounds; body mass index, 49), diabetes, and rheumatoid arthritis. Evaluation by the internal medicine service revealed severe coronary artery disease on a stress thallium test and anemia with hematocrit of 24%. Given the patient’s medical comorbidities and religious status, and the location of the comminuted distal femur fracture, several treatment options were considered. First was nonoperative treatment with a cast or cast-brace (hinged cast). Because of her body habitus, however, we thought she would very likely experience skin complications, inadequate immobilization of the bone, and significant discomfort. Ultimately, use of a spanning external fixator was chosen as the safest course, given the significant medical risks accompanying a more extensive surgical reconstruction. With the spanning external fixator, the main risks were the inability to fully control fracture alignment and the potential introduction of infection into the functional THA. We thought that, by limiting the amount of time in the fixator and managing the pin site aggressively, we could minimize the risk for infection in this setting.

The procedure was performed with the patient under general anesthesia. During surgery, a lateral image of the femur was used to identify the distal end of the THA prosthesis. A level was marked 2 to 3 cm distal to the tip of this prosthesis, and another about 1 cm above the fracture (noted to be above the most proximal extent of the knee joint). These planned pin-entry sites were prepared from an anterior approach with incisions (using a No. 11 blade) of about 1 cm each. Blunt dissection was carried down to the femur. Each planned pin site was predrilled with a 3.5-mm drill; then, a 5-mm Shanz pin was placed. This process was repeated immediately distal to the tibial component and at the junction of the mid and distal thirds of the tibia (Figure 2). The preliminary external fixator frame was then applied. Once the reduction was satisfactory in the anteroposterior and lateral planes, the fixator clamps were tightened. A second row of bars was then incorporated.

Six weeks after surgery, radiographs showed early callus formation. Removing the external fixator and examining the knee under anesthesia confirmed there was no significant motion through the fracture site. A cast-brace (fiberglass thigh segment, fiberglass lower leg cast with hinged knee segment) was then applied. We remained concerned about skin complications but were encouraged by the early healing achieved with the fixator. The patient was started on a physical therapy program of gait training with a walker and toe-touch weight-bearing on the injured extremity. She also started a limited lower-extremity strengthening program. Three months after surgery, she was tolerating weight-bearing on the injured extremity with no pain. At 6 months, knee radiographs showed fracture consolidation with active range of motion of 10° to 120° and no pain (Figures 3A, 3B). Distal sensation, motor function, and vascular examination were normal. Two years after surgery, radiographs of the right knee showed minor malalignment in the coronal and sagittal planes (Figures 4A, 4B) and complete consolidation of the fracture.

Discussion

Periprosthetic fractures of the femur after TKA often occur in the setting of osteopenia, and some are associated with concurrent implant loosening. In most cases, these fractures require surgical stabilization. Nevertheless, the goals of treatment are to obtain and maintain anatomical alignment and stability to allow early range of motion. Nonoperative options include skeletal traction, cast, pins and plaster, and cast-brace.^3-5,20 Operative options include intramedullary fixation,^12,21 stabilization with various plates,^21-23 revision knee arthroplasty, and arthrodesis.¹ Treatment selection should be based on patient health, fracture displacement, comminution, osteopenia severity, and status of the prosthetic components.

The present case exemplifies some of the highest degrees of medical and surgical risk factors in people with a periprosthetic femoral fracture after TKA. Patients with rheumatoid arthritis, patients having corticosteroid treatment, patients of advanced age, and female patients are all at higher risk for supracondylar femoral fracture.⁹ Our patient had these risk factors on a background of anemia and extensive coronary artery disease. Given her past medical history and refusal of blood products out of religious belief, we thought she was too high risk for extensive surgical treatment for her fracture. In addition, she was not an ideal candidate for nonoperative treatment, as a periprosthetic fracture typically is treated with surgical revision or open reduction and internal fixation. Therefore, we selected an unconventional treatment modality, typically used as a temporizing measure in severe fractures around the knee—a spanning external fixator worn for 6 weeks and a cast-brace for an additional 6 weeks. This led to successful clinical and radiographic outcomes. We consider spanning external fixation a viable option for periprosthetic fractures after TKA in morbidly obese patients with relatively well-aligned fractures and extremely high risk for medical complications associated with traditional open surgery.

The incidence of periprosthetic supracondylar fractures of the femur after total knee arthroplasty (TKA) ranges from 0.6% to 2.5%.¹ Treatment of periprosthetic fractures is often complicated by advanced patient age and osteoporosis, which frequently accompanies these fractures. Management of a periprosthetic fracture depends on the relation between the fracture site and the prosthesis, displacement of the prosthesis, integrity of the fixation of the prosthesis, extent of the bone loss caused by fracture comminution or preexisting osteolysis, general health of the patient, and surgeon expertise.^2,3 The aim is to achieve fracture union around a stable, well-aligned arthroplasty with preserved or restored bone stock and therefore to return the patient to previous level of function. Although nonoperative treatments have been shown to be successful,^4,5 in the great majority of cases surgical treatment is advised for these fractures.^6-10 In cases in which bone stock is adequate for fixation rather than replacement of the distal femur, 2 modalities are commonly used: retrograde intramedullary nailing and locking plates. Each has its drawbacks and advantages.^11,12

Although external fixation has been used in the treatment of distal femoral fractures,¹³ it is seldom considered in the treatment of periprosthetic fractures. Several authors have described cases that used external fixators, occasionally spanning the knee. The specific types of external fixators discussed in the literature have included ring fixators,^14-17 hybrid fixators,¹⁸ and uniplanar nonspanning fixators^14,19 (Table). Use of a simple anterior spanning external fixator in treating a periprosthetic femoral fracture has received little attention in the literature.

The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 54-year-old woman with previous total hip arthroplasty (THA) and ipsilateral TKA tripped on a carpet and sustained a comminuted fracture of the distal femur just above the TKA prosthesis (Figure 1). She was a Jehovah’s Witness and thus refused all blood products. She had an extensive history of osteoporosis, morbid obesity (5 feet tall, 250 pounds; body mass index, 49), diabetes, and rheumatoid arthritis. Evaluation by the internal medicine service revealed severe coronary artery disease on a stress thallium test and anemia with hematocrit of 24%. Given the patient’s medical comorbidities and religious status, and the location of the comminuted distal femur fracture, several treatment options were considered. First was nonoperative treatment with a cast or cast-brace (hinged cast). Because of her body habitus, however, we thought she would very likely experience skin complications, inadequate immobilization of the bone, and significant discomfort. Ultimately, use of a spanning external fixator was chosen as the safest course, given the significant medical risks accompanying a more extensive surgical reconstruction. With the spanning external fixator, the main risks were the inability to fully control fracture alignment and the potential introduction of infection into the functional THA. We thought that, by limiting the amount of time in the fixator and managing the pin site aggressively, we could minimize the risk for infection in this setting.

The procedure was performed with the patient under general anesthesia. During surgery, a lateral image of the femur was used to identify the distal end of the THA prosthesis. A level was marked 2 to 3 cm distal to the tip of this prosthesis, and another about 1 cm above the fracture (noted to be above the most proximal extent of the knee joint). These planned pin-entry sites were prepared from an anterior approach with incisions (using a No. 11 blade) of about 1 cm each. Blunt dissection was carried down to the femur. Each planned pin site was predrilled with a 3.5-mm drill; then, a 5-mm Shanz pin was placed. This process was repeated immediately distal to the tibial component and at the junction of the mid and distal thirds of the tibia (Figure 2). The preliminary external fixator frame was then applied. Once the reduction was satisfactory in the anteroposterior and lateral planes, the fixator clamps were tightened. A second row of bars was then incorporated.

Six weeks after surgery, radiographs showed early callus formation. Removing the external fixator and examining the knee under anesthesia confirmed there was no significant motion through the fracture site. A cast-brace (fiberglass thigh segment, fiberglass lower leg cast with hinged knee segment) was then applied. We remained concerned about skin complications but were encouraged by the early healing achieved with the fixator. The patient was started on a physical therapy program of gait training with a walker and toe-touch weight-bearing on the injured extremity. She also started a limited lower-extremity strengthening program. Three months after surgery, she was tolerating weight-bearing on the injured extremity with no pain. At 6 months, knee radiographs showed fracture consolidation with active range of motion of 10° to 120° and no pain (Figures 3A, 3B). Distal sensation, motor function, and vascular examination were normal. Two years after surgery, radiographs of the right knee showed minor malalignment in the coronal and sagittal planes (Figures 4A, 4B) and complete consolidation of the fracture.

Discussion

Periprosthetic fractures of the femur after TKA often occur in the setting of osteopenia, and some are associated with concurrent implant loosening. In most cases, these fractures require surgical stabilization. Nevertheless, the goals of treatment are to obtain and maintain anatomical alignment and stability to allow early range of motion. Nonoperative options include skeletal traction, cast, pins and plaster, and cast-brace.^3-5,20 Operative options include intramedullary fixation,^12,21 stabilization with various plates,^21-23 revision knee arthroplasty, and arthrodesis.¹ Treatment selection should be based on patient health, fracture displacement, comminution, osteopenia severity, and status of the prosthetic components.

The present case exemplifies some of the highest degrees of medical and surgical risk factors in people with a periprosthetic femoral fracture after TKA. Patients with rheumatoid arthritis, patients having corticosteroid treatment, patients of advanced age, and female patients are all at higher risk for supracondylar femoral fracture.⁹ Our patient had these risk factors on a background of anemia and extensive coronary artery disease. Given her past medical history and refusal of blood products out of religious belief, we thought she was too high risk for extensive surgical treatment for her fracture. In addition, she was not an ideal candidate for nonoperative treatment, as a periprosthetic fracture typically is treated with surgical revision or open reduction and internal fixation. Therefore, we selected an unconventional treatment modality, typically used as a temporizing measure in severe fractures around the knee—a spanning external fixator worn for 6 weeks and a cast-brace for an additional 6 weeks. This led to successful clinical and radiographic outcomes. We consider spanning external fixation a viable option for periprosthetic fractures after TKA in morbidly obese patients with relatively well-aligned fractures and extremely high risk for medical complications associated with traditional open surgery.

The incidence of periprosthetic supracondylar fractures of the femur after total knee arthroplasty (TKA) ranges from 0.6% to 2.5%.¹ Treatment of periprosthetic fractures is often complicated by advanced patient age and osteoporosis, which frequently accompanies these fractures. Management of a periprosthetic fracture depends on the relation between the fracture site and the prosthesis, displacement of the prosthesis, integrity of the fixation of the prosthesis, extent of the bone loss caused by fracture comminution or preexisting osteolysis, general health of the patient, and surgeon expertise.^2,3 The aim is to achieve fracture union around a stable, well-aligned arthroplasty with preserved or restored bone stock and therefore to return the patient to previous level of function. Although nonoperative treatments have been shown to be successful,^4,5 in the great majority of cases surgical treatment is advised for these fractures.^6-10 In cases in which bone stock is adequate for fixation rather than replacement of the distal femur, 2 modalities are commonly used: retrograde intramedullary nailing and locking plates. Each has its drawbacks and advantages.^11,12

Although external fixation has been used in the treatment of distal femoral fractures,¹³ it is seldom considered in the treatment of periprosthetic fractures. Several authors have described cases that used external fixators, occasionally spanning the knee. The specific types of external fixators discussed in the literature have included ring fixators,^14-17 hybrid fixators,¹⁸ and uniplanar nonspanning fixators^14,19 (Table). Use of a simple anterior spanning external fixator in treating a periprosthetic femoral fracture has received little attention in the literature.

The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 54-year-old woman with previous total hip arthroplasty (THA) and ipsilateral TKA tripped on a carpet and sustained a comminuted fracture of the distal femur just above the TKA prosthesis (Figure 1). She was a Jehovah’s Witness and thus refused all blood products. She had an extensive history of osteoporosis, morbid obesity (5 feet tall, 250 pounds; body mass index, 49), diabetes, and rheumatoid arthritis. Evaluation by the internal medicine service revealed severe coronary artery disease on a stress thallium test and anemia with hematocrit of 24%. Given the patient’s medical comorbidities and religious status, and the location of the comminuted distal femur fracture, several treatment options were considered. First was nonoperative treatment with a cast or cast-brace (hinged cast). Because of her body habitus, however, we thought she would very likely experience skin complications, inadequate immobilization of the bone, and significant discomfort. Ultimately, use of a spanning external fixator was chosen as the safest course, given the significant medical risks accompanying a more extensive surgical reconstruction. With the spanning external fixator, the main risks were the inability to fully control fracture alignment and the potential introduction of infection into the functional THA. We thought that, by limiting the amount of time in the fixator and managing the pin site aggressively, we could minimize the risk for infection in this setting.

The procedure was performed with the patient under general anesthesia. During surgery, a lateral image of the femur was used to identify the distal end of the THA prosthesis. A level was marked 2 to 3 cm distal to the tip of this prosthesis, and another about 1 cm above the fracture (noted to be above the most proximal extent of the knee joint). These planned pin-entry sites were prepared from an anterior approach with incisions (using a No. 11 blade) of about 1 cm each. Blunt dissection was carried down to the femur. Each planned pin site was predrilled with a 3.5-mm drill; then, a 5-mm Shanz pin was placed. This process was repeated immediately distal to the tibial component and at the junction of the mid and distal thirds of the tibia (Figure 2). The preliminary external fixator frame was then applied. Once the reduction was satisfactory in the anteroposterior and lateral planes, the fixator clamps were tightened. A second row of bars was then incorporated.

Six weeks after surgery, radiographs showed early callus formation. Removing the external fixator and examining the knee under anesthesia confirmed there was no significant motion through the fracture site. A cast-brace (fiberglass thigh segment, fiberglass lower leg cast with hinged knee segment) was then applied. We remained concerned about skin complications but were encouraged by the early healing achieved with the fixator. The patient was started on a physical therapy program of gait training with a walker and toe-touch weight-bearing on the injured extremity. She also started a limited lower-extremity strengthening program. Three months after surgery, she was tolerating weight-bearing on the injured extremity with no pain. At 6 months, knee radiographs showed fracture consolidation with active range of motion of 10° to 120° and no pain (Figures 3A, 3B). Distal sensation, motor function, and vascular examination were normal. Two years after surgery, radiographs of the right knee showed minor malalignment in the coronal and sagittal planes (Figures 4A, 4B) and complete consolidation of the fracture.

Discussion

Periprosthetic fractures of the femur after TKA often occur in the setting of osteopenia, and some are associated with concurrent implant loosening. In most cases, these fractures require surgical stabilization. Nevertheless, the goals of treatment are to obtain and maintain anatomical alignment and stability to allow early range of motion. Nonoperative options include skeletal traction, cast, pins and plaster, and cast-brace.^3-5,20 Operative options include intramedullary fixation,^12,21 stabilization with various plates,^21-23 revision knee arthroplasty, and arthrodesis.¹ Treatment selection should be based on patient health, fracture displacement, comminution, osteopenia severity, and status of the prosthetic components.

The present case exemplifies some of the highest degrees of medical and surgical risk factors in people with a periprosthetic femoral fracture after TKA. Patients with rheumatoid arthritis, patients having corticosteroid treatment, patients of advanced age, and female patients are all at higher risk for supracondylar femoral fracture.⁹ Our patient had these risk factors on a background of anemia and extensive coronary artery disease. Given her past medical history and refusal of blood products out of religious belief, we thought she was too high risk for extensive surgical treatment for her fracture. In addition, she was not an ideal candidate for nonoperative treatment, as a periprosthetic fracture typically is treated with surgical revision or open reduction and internal fixation. Therefore, we selected an unconventional treatment modality, typically used as a temporizing measure in severe fractures around the knee—a spanning external fixator worn for 6 weeks and a cast-brace for an additional 6 weeks. This led to successful clinical and radiographic outcomes. We consider spanning external fixation a viable option for periprosthetic fractures after TKA in morbidly obese patients with relatively well-aligned fractures and extremely high risk for medical complications associated with traditional open surgery.