The American Journal of Orthopedics

The combination of urban sprawl and a large deer population has caused deer–motor vehicle collisions to become a major concern over the past few decades. According to State Farm Insurance industry data, New York State drivers in 2010-2011 had a 1 in 149.5 likelihood of colliding with a deer over the year, compared with a national average of 1 in 183.4.¹ Reports from the Midwest have highlighted the frequency and severity of this type of accident.^2-4 Frequent performance of orthopedic procedures in this subset of trauma patients prompted a local review to determine the frequency and severity of injuries. This series differs from the Midwest studies in the existence of a universal helmet law for all motorcyclists and passengers in New York State. Other studies looking at this type of accident were performed in states, including Minnesota and Wisconsin, that require helmets only for riders younger than 18 years or persons with an instructional permit.⁵

The Erie County Medical Center (ECMC) is a level I trauma center located in Buffalo, New York, and serves much of western New York, as well as part of northwestern Pennsylvania and, occasionally, southern Ontario, Canada. Because the ECMC receives almost all major trauma cases in the region, we had sufficient records to explore the incidence and the severity of deer–motorcycle accidents in these regions. In addition to adding to the limited data analyzing crash outcomes, we also looked at the numbers and proportions of motorcycle accidents attributable to deer and compared these with results from studies from different geographical regions. Because the number of registered motorcycles in Erie Country is among the highest in New York State, and because of the increased severity of motorcycle–deer collisions relative to other motor vehicle–deer collisions, this issue has both safety and financial considerations.

Materials and Methods

A retrospective review of records from ECMC was performed to capture all records from motorcycle accidents from May 2007 through June 2011. The population was identified to include only motorcycle accidents that were caused by collision with deer.

Injury severity was standardized using the Injury Severity Score (ISS), and the level of consciousness on arrival was standardized using the Glasgow Coma Scale (GCS). Chart abstraction included patient age, identification of the patient as driver or passenger of the motorcycle, use of helmet, time of year, types of injuries, length of hospital stay, and whether the patient lost consciousness. Patient age was also abstracted for the entire initial screen of all motorcycle accidents regardless of mechanism.

Statistical analysis was done using SPSS (IBM SPSS Statistics for Windows, Version 19.0; IBM Corp., Armonk, New York). Continuous data were analyzed using the appropriate descriptive statistics. Comparisons were made using Student t test, and a 0.05 level of significance was accepted.

Results

The initial screening of the trauma database returned 487 patients who had been involved in a motorcycle accident; of these, 39 patients were in an accident that involved a deer. According to one medical record, the spouse of a patient was a passenger who was dead at the scene, although there was no separate medical record for this person; this person was included in our data. Therefore, our total study population numbered 40 patients involved in 36 accidents, with 36 drivers and 4 passengers; 35 were men and 5 were women, with the women accounting for all 4 passengers and 1 driver. The mean (SD) patient age for deer–motorcycle collisions was 48.9 (8.9) years (range, 21-64 years). This was significantly higher than the mean (SD) age for all motorcycle accidents from the ECMC trauma database, which was 41.9 (13.9) years (range, 17-79 years) (P < .002).

The majority of accidents (31; 86%) with deer occurred during the months of May through September, with the most occurring in June (11; 31%). There was only 1 (3%) in October, 3 (8%) in November, and 1 (3%) in January. The number of collisions per year averaged 9.75, with a range of 8 to 12 from 2007-2010. (The year 2011 was omitted because data were collected before the year was complete). The presence or absence of helmet use was recorded in 22 cases. Of these, 21 patients had been wearing a helmet (95%), and only 1 patient was unhelmeted. Among all riders involved in motorcycle accidents from the trauma database, the presence or absence of a helmet was recorded in 271 cases. Of these, 262 (97%) were wearing a helmet. The average length of hospital stay was 6 days, with 6 patients having stays that were 10 days or longer, and the longest stay was 31 days. Thirty-three medical records noted whether the patient described loss of consciousness after the accident; of these, 14 (42%) claimed loss of consciousness and the remaining 19 (58%) denied any loss of consciousness after the accident. The mean (SD) ISS for deer–motorcycle collisions was 17.1 (9.8), and the mean (SD) GCS was 14.3 (2.5).

Chest, orthopedic, and head injuries were the most common injuries seen in deer–motorcycle collisions (Table). Head injuries, including the 1 patient who was confirmed to not have been wearing a helmet, accounted for 15.0% of the total injuries. This patient also had a longer length of stay at 19 days than the average of 6 days. Rib fractures were the most common injury, occurring in 20 (50%) patients. The 1 recorded fatality was the passenger of a patient who was dead at the scene.

Twenty-five (62.5%) patients in this series had injuries that are traditionally treated by orthopedic trauma surgeons, including scapular, clavicle, pelvic, and extremity fractures. Upper and lower extremity injuries occurred 10 (8.3%) and 15 (12.5%) times respectively, with the lower extremity injuries including long bone fractures, foot and ankle fractures, and 1 lower extremity traumatic amputation. Fourteen (35%) patients underwent one or more orthopedic surgical procedures.

Discussion

Although animal–vehicle collisions have been described in the literature, comparatively little data are available for the subset of animal–motorcycle accidents. This is an important gap considering that fatalities in collisions with animals were 6 times more likely to be persons riding motorcycles, although animal collisions are more common with other vehicles.⁶

Smoot and colleagues² also reported that motorcycle collisions with deer tend to result in a higher injury severity than collisions of other vehicles with deer. According to reports for Midwestern regions, motorcycle-versus-deer accidents are a significant problem, causing a large number of serious injuries as well as creating the financial burden of vehicle damage and medical costs.^2,3 However, the overall data are limited, and there is not much detailed information available for western New York.

Because of the large number of motorcyclists in New York State, it is important to consider accident data in this subset of the population. In 2010, 340,260 motorcycles were registered in New York State, with Erie County having the second highest number (21,745) of motorcycles registered.⁷ These numbers increased to 345,820 and 22,183 motorcycles, respectively, in 2011.⁸ In that year, the number of police-reported motorcycle accidents in New York decreased to 4855 from 5047 accidents in 2010, although both numbers are increased from 4647 accidents in 2009.^9-11 Despite the decrease in total police-reported motorcycle accidents from 2010 to 2011, the trend in motorcycle accidents involving an animal’s action has steadily increased from 313 (6.7%) in 2009 to 335 (6.6%) in 2010 to 401 (8.3%) in 2011.^9-11 Although these data from the New York State Department of Motor Vehicles are not further broken down by animal species, it can be reasonably surmised that most of these are caused by deer. This inference is supported by data from Bramati and colleagues⁴ showing that 81% of animal–vehicle collisions involved deer, as well as by the Wildlife-Vehicle Collision Reduction Study that showed deer were involved in 54.4% of animal–vehicle collisions in California and more than 90% of animal–vehicle collisions in Illinois and Minnesota.^4,12 These studies predominantly comprised collisions involving animals capable of causing substantial property damage on impact, such as deer or larger animals. This, along with the evidence of higher ISS seen in motorcyclists in deer-related traffic injuries,² supports the intuitive thought that motorcyclists are at increased risk for injury and fatality relative to other motor vehicles involved in accidents.

Williams and Wells¹³ reviewed 147 fatal wildlife–vehicle fatalities from 9 regions and found that the 2 most common fatalities were the motorcycle driver or passenger after striking an animal or an object. Jones¹⁴ also reported that the most common fatal wildlife–vehicle crashes involved motorcycles, as did fatal-accident reporting system data in the Wildlife-Vehicle Collision Reduction Study, which confirmed that approximately 30% of fatal crashes with animals involved motorcycles.¹²

Interestingly, the age of patients involved in motorcycle–deer collisions tends to be higher than that of patients involved in other motorcycle accidents. The numbers in our study reflect results in other study populations that suggest motorcycle riders who collide with deer are generally older than riders in other accidents who are more likely to be younger.⁴ One explanation is that younger riders may drive faster and more recklessly than older and experienced riders, resulting in an increased number of accidents unrelated to deer. Another consideration places younger drivers less commonly on roads where wildlife crashes more often occur (ie, roads that are rural, 2-lane).

Helmet use, when reported, was very high in our study population, most likely as a result of New York State’s mandatory helmet law for motorcyclists. Our data showed that more than 95% of patients whose charts documented helmet usage were wearing helmets at the time of the collision, compared with a Wisconsin study showing that only 29% of patients were wearing helmets.³ This may explain the proportion of head injuries in our study being 15.0% compared with the 29.5% in the Wisconsin study.³ Although both datasets involved a limited number of patients, the results suggest that mandatory helmet laws are effective in preventing head injuries. Also, the only patient in our study who was confirmed to have not been wearing a helmet had a much longer length of hospital stay than the average patient (19 vs 6 days). William and Wells¹³ found that 65% of motorcyclists killed in collisions with animals were not wearing helmets, and they believed that many of these fatalities could have been prevented with helmet use. Again, these limited data suggest the effectiveness of mandatory helmet use.

Two other factors, season and time of day, are important to consider in motorcycle collisions with deer. According to our data, 86% of these collisions occur in the warmer months, May through September, peaking in June. This is similar to findings from the Wisconsin study showing June and July as the peak months for deer–motorcycle collisions and a study in Minnesota where 61% of these crashes occurred in the summer months.^2,3 These data most likely indicate increased motorcycle traffic in favorable weather conditions. Although time of accident could not be determined through our retrospective review, multiple studies have shown that the majority of collisions with deer tend to be between dusk and dawn. Smoot and colleagues² found that 56% of vehicle collisions with deer occurred between 5 pm and midnight, with 80% between 5 pm and 6 am.² Similarly, Nelson and colleagues³ found that 54.5% of collisions happened in a 4-hour period, from 6 pm to 10 pm. These data indicate that motorcycle operators should be especially vigilant in the morning and evening hours when deer may be more active.

Other than driver awareness and vigilance, prevention efforts can involve wildlife fencing, alert systems, and deer-culling programs. Fences are used extensively, most commonly on larger thoroughfares, and have been shown effective in reducing wildlife vehicle crashes by 80% to 90%.¹² Animal detection systems using sensors to detect large wildlife approaching the roadway can activate warning signs to alert approaching drivers. Such systems have been installed in more than 30 locations in North America and Europe with variable effectiveness.¹² However, there are typically no standards or guidelines for the collection of data about wildlife–vehicle crashes. Data are collected inconsistently and often haphazardly, and methods vary between states and agencies. Some transportation agencies do not collect this type of data at all. Without reliable, consistent data, it is difficult to identify road sections where mitigation methods may be required, to select appropriate mitigation measures, or to evaluate whether that effort is making a difference.

Culling systems for deer populations are frequently discussed, often in suburban as well as rural settings. Recreational hunting ordinances, higher limits on the number of females a hunter can bag, and occasional use of professional shooters can be applicable in less rural areas. Their effectiveness is debatable and tends to be time-limited.

Conclusion

This study highlights the fairly common occurrence and relative severity of deer–motorcycle crashes in an upstate New York setting, approximating published series from the Midwest. Helmet laws may lower rates of head injury in motorcycle–wildlife crashes. Finally, there are no fender benders when the chosen vehicle sports no fenders, so motorcyclists need to be especially vigilant in order to avoid collisions with deer and other wildlife.

The combination of urban sprawl and a large deer population has caused deer–motor vehicle collisions to become a major concern over the past few decades. According to State Farm Insurance industry data, New York State drivers in 2010-2011 had a 1 in 149.5 likelihood of colliding with a deer over the year, compared with a national average of 1 in 183.4.¹ Reports from the Midwest have highlighted the frequency and severity of this type of accident.^2-4 Frequent performance of orthopedic procedures in this subset of trauma patients prompted a local review to determine the frequency and severity of injuries. This series differs from the Midwest studies in the existence of a universal helmet law for all motorcyclists and passengers in New York State. Other studies looking at this type of accident were performed in states, including Minnesota and Wisconsin, that require helmets only for riders younger than 18 years or persons with an instructional permit.⁵

The Erie County Medical Center (ECMC) is a level I trauma center located in Buffalo, New York, and serves much of western New York, as well as part of northwestern Pennsylvania and, occasionally, southern Ontario, Canada. Because the ECMC receives almost all major trauma cases in the region, we had sufficient records to explore the incidence and the severity of deer–motorcycle accidents in these regions. In addition to adding to the limited data analyzing crash outcomes, we also looked at the numbers and proportions of motorcycle accidents attributable to deer and compared these with results from studies from different geographical regions. Because the number of registered motorcycles in Erie Country is among the highest in New York State, and because of the increased severity of motorcycle–deer collisions relative to other motor vehicle–deer collisions, this issue has both safety and financial considerations.

Materials and Methods

A retrospective review of records from ECMC was performed to capture all records from motorcycle accidents from May 2007 through June 2011. The population was identified to include only motorcycle accidents that were caused by collision with deer.

Injury severity was standardized using the Injury Severity Score (ISS), and the level of consciousness on arrival was standardized using the Glasgow Coma Scale (GCS). Chart abstraction included patient age, identification of the patient as driver or passenger of the motorcycle, use of helmet, time of year, types of injuries, length of hospital stay, and whether the patient lost consciousness. Patient age was also abstracted for the entire initial screen of all motorcycle accidents regardless of mechanism.

Statistical analysis was done using SPSS (IBM SPSS Statistics for Windows, Version 19.0; IBM Corp., Armonk, New York). Continuous data were analyzed using the appropriate descriptive statistics. Comparisons were made using Student t test, and a 0.05 level of significance was accepted.

Results

The initial screening of the trauma database returned 487 patients who had been involved in a motorcycle accident; of these, 39 patients were in an accident that involved a deer. According to one medical record, the spouse of a patient was a passenger who was dead at the scene, although there was no separate medical record for this person; this person was included in our data. Therefore, our total study population numbered 40 patients involved in 36 accidents, with 36 drivers and 4 passengers; 35 were men and 5 were women, with the women accounting for all 4 passengers and 1 driver. The mean (SD) patient age for deer–motorcycle collisions was 48.9 (8.9) years (range, 21-64 years). This was significantly higher than the mean (SD) age for all motorcycle accidents from the ECMC trauma database, which was 41.9 (13.9) years (range, 17-79 years) (P < .002).

The majority of accidents (31; 86%) with deer occurred during the months of May through September, with the most occurring in June (11; 31%). There was only 1 (3%) in October, 3 (8%) in November, and 1 (3%) in January. The number of collisions per year averaged 9.75, with a range of 8 to 12 from 2007-2010. (The year 2011 was omitted because data were collected before the year was complete). The presence or absence of helmet use was recorded in 22 cases. Of these, 21 patients had been wearing a helmet (95%), and only 1 patient was unhelmeted. Among all riders involved in motorcycle accidents from the trauma database, the presence or absence of a helmet was recorded in 271 cases. Of these, 262 (97%) were wearing a helmet. The average length of hospital stay was 6 days, with 6 patients having stays that were 10 days or longer, and the longest stay was 31 days. Thirty-three medical records noted whether the patient described loss of consciousness after the accident; of these, 14 (42%) claimed loss of consciousness and the remaining 19 (58%) denied any loss of consciousness after the accident. The mean (SD) ISS for deer–motorcycle collisions was 17.1 (9.8), and the mean (SD) GCS was 14.3 (2.5).

Chest, orthopedic, and head injuries were the most common injuries seen in deer–motorcycle collisions (Table). Head injuries, including the 1 patient who was confirmed to not have been wearing a helmet, accounted for 15.0% of the total injuries. This patient also had a longer length of stay at 19 days than the average of 6 days. Rib fractures were the most common injury, occurring in 20 (50%) patients. The 1 recorded fatality was the passenger of a patient who was dead at the scene.

Twenty-five (62.5%) patients in this series had injuries that are traditionally treated by orthopedic trauma surgeons, including scapular, clavicle, pelvic, and extremity fractures. Upper and lower extremity injuries occurred 10 (8.3%) and 15 (12.5%) times respectively, with the lower extremity injuries including long bone fractures, foot and ankle fractures, and 1 lower extremity traumatic amputation. Fourteen (35%) patients underwent one or more orthopedic surgical procedures.

Discussion

Although animal–vehicle collisions have been described in the literature, comparatively little data are available for the subset of animal–motorcycle accidents. This is an important gap considering that fatalities in collisions with animals were 6 times more likely to be persons riding motorcycles, although animal collisions are more common with other vehicles.⁶

Smoot and colleagues² also reported that motorcycle collisions with deer tend to result in a higher injury severity than collisions of other vehicles with deer. According to reports for Midwestern regions, motorcycle-versus-deer accidents are a significant problem, causing a large number of serious injuries as well as creating the financial burden of vehicle damage and medical costs.^2,3 However, the overall data are limited, and there is not much detailed information available for western New York.

Because of the large number of motorcyclists in New York State, it is important to consider accident data in this subset of the population. In 2010, 340,260 motorcycles were registered in New York State, with Erie County having the second highest number (21,745) of motorcycles registered.⁷ These numbers increased to 345,820 and 22,183 motorcycles, respectively, in 2011.⁸ In that year, the number of police-reported motorcycle accidents in New York decreased to 4855 from 5047 accidents in 2010, although both numbers are increased from 4647 accidents in 2009.^9-11 Despite the decrease in total police-reported motorcycle accidents from 2010 to 2011, the trend in motorcycle accidents involving an animal’s action has steadily increased from 313 (6.7%) in 2009 to 335 (6.6%) in 2010 to 401 (8.3%) in 2011.^9-11 Although these data from the New York State Department of Motor Vehicles are not further broken down by animal species, it can be reasonably surmised that most of these are caused by deer. This inference is supported by data from Bramati and colleagues⁴ showing that 81% of animal–vehicle collisions involved deer, as well as by the Wildlife-Vehicle Collision Reduction Study that showed deer were involved in 54.4% of animal–vehicle collisions in California and more than 90% of animal–vehicle collisions in Illinois and Minnesota.^4,12 These studies predominantly comprised collisions involving animals capable of causing substantial property damage on impact, such as deer or larger animals. This, along with the evidence of higher ISS seen in motorcyclists in deer-related traffic injuries,² supports the intuitive thought that motorcyclists are at increased risk for injury and fatality relative to other motor vehicles involved in accidents.

Williams and Wells¹³ reviewed 147 fatal wildlife–vehicle fatalities from 9 regions and found that the 2 most common fatalities were the motorcycle driver or passenger after striking an animal or an object. Jones¹⁴ also reported that the most common fatal wildlife–vehicle crashes involved motorcycles, as did fatal-accident reporting system data in the Wildlife-Vehicle Collision Reduction Study, which confirmed that approximately 30% of fatal crashes with animals involved motorcycles.¹²

Interestingly, the age of patients involved in motorcycle–deer collisions tends to be higher than that of patients involved in other motorcycle accidents. The numbers in our study reflect results in other study populations that suggest motorcycle riders who collide with deer are generally older than riders in other accidents who are more likely to be younger.⁴ One explanation is that younger riders may drive faster and more recklessly than older and experienced riders, resulting in an increased number of accidents unrelated to deer. Another consideration places younger drivers less commonly on roads where wildlife crashes more often occur (ie, roads that are rural, 2-lane).

Helmet use, when reported, was very high in our study population, most likely as a result of New York State’s mandatory helmet law for motorcyclists. Our data showed that more than 95% of patients whose charts documented helmet usage were wearing helmets at the time of the collision, compared with a Wisconsin study showing that only 29% of patients were wearing helmets.³ This may explain the proportion of head injuries in our study being 15.0% compared with the 29.5% in the Wisconsin study.³ Although both datasets involved a limited number of patients, the results suggest that mandatory helmet laws are effective in preventing head injuries. Also, the only patient in our study who was confirmed to have not been wearing a helmet had a much longer length of hospital stay than the average patient (19 vs 6 days). William and Wells¹³ found that 65% of motorcyclists killed in collisions with animals were not wearing helmets, and they believed that many of these fatalities could have been prevented with helmet use. Again, these limited data suggest the effectiveness of mandatory helmet use.

Two other factors, season and time of day, are important to consider in motorcycle collisions with deer. According to our data, 86% of these collisions occur in the warmer months, May through September, peaking in June. This is similar to findings from the Wisconsin study showing June and July as the peak months for deer–motorcycle collisions and a study in Minnesota where 61% of these crashes occurred in the summer months.^2,3 These data most likely indicate increased motorcycle traffic in favorable weather conditions. Although time of accident could not be determined through our retrospective review, multiple studies have shown that the majority of collisions with deer tend to be between dusk and dawn. Smoot and colleagues² found that 56% of vehicle collisions with deer occurred between 5 pm and midnight, with 80% between 5 pm and 6 am.² Similarly, Nelson and colleagues³ found that 54.5% of collisions happened in a 4-hour period, from 6 pm to 10 pm. These data indicate that motorcycle operators should be especially vigilant in the morning and evening hours when deer may be more active.

Other than driver awareness and vigilance, prevention efforts can involve wildlife fencing, alert systems, and deer-culling programs. Fences are used extensively, most commonly on larger thoroughfares, and have been shown effective in reducing wildlife vehicle crashes by 80% to 90%.¹² Animal detection systems using sensors to detect large wildlife approaching the roadway can activate warning signs to alert approaching drivers. Such systems have been installed in more than 30 locations in North America and Europe with variable effectiveness.¹² However, there are typically no standards or guidelines for the collection of data about wildlife–vehicle crashes. Data are collected inconsistently and often haphazardly, and methods vary between states and agencies. Some transportation agencies do not collect this type of data at all. Without reliable, consistent data, it is difficult to identify road sections where mitigation methods may be required, to select appropriate mitigation measures, or to evaluate whether that effort is making a difference.

Culling systems for deer populations are frequently discussed, often in suburban as well as rural settings. Recreational hunting ordinances, higher limits on the number of females a hunter can bag, and occasional use of professional shooters can be applicable in less rural areas. Their effectiveness is debatable and tends to be time-limited.

Conclusion

This study highlights the fairly common occurrence and relative severity of deer–motorcycle crashes in an upstate New York setting, approximating published series from the Midwest. Helmet laws may lower rates of head injury in motorcycle–wildlife crashes. Finally, there are no fender benders when the chosen vehicle sports no fenders, so motorcyclists need to be especially vigilant in order to avoid collisions with deer and other wildlife.

The combination of urban sprawl and a large deer population has caused deer–motor vehicle collisions to become a major concern over the past few decades. According to State Farm Insurance industry data, New York State drivers in 2010-2011 had a 1 in 149.5 likelihood of colliding with a deer over the year, compared with a national average of 1 in 183.4.¹ Reports from the Midwest have highlighted the frequency and severity of this type of accident.^2-4 Frequent performance of orthopedic procedures in this subset of trauma patients prompted a local review to determine the frequency and severity of injuries. This series differs from the Midwest studies in the existence of a universal helmet law for all motorcyclists and passengers in New York State. Other studies looking at this type of accident were performed in states, including Minnesota and Wisconsin, that require helmets only for riders younger than 18 years or persons with an instructional permit.⁵

The Erie County Medical Center (ECMC) is a level I trauma center located in Buffalo, New York, and serves much of western New York, as well as part of northwestern Pennsylvania and, occasionally, southern Ontario, Canada. Because the ECMC receives almost all major trauma cases in the region, we had sufficient records to explore the incidence and the severity of deer–motorcycle accidents in these regions. In addition to adding to the limited data analyzing crash outcomes, we also looked at the numbers and proportions of motorcycle accidents attributable to deer and compared these with results from studies from different geographical regions. Because the number of registered motorcycles in Erie Country is among the highest in New York State, and because of the increased severity of motorcycle–deer collisions relative to other motor vehicle–deer collisions, this issue has both safety and financial considerations.

Materials and Methods

A retrospective review of records from ECMC was performed to capture all records from motorcycle accidents from May 2007 through June 2011. The population was identified to include only motorcycle accidents that were caused by collision with deer.

Injury severity was standardized using the Injury Severity Score (ISS), and the level of consciousness on arrival was standardized using the Glasgow Coma Scale (GCS). Chart abstraction included patient age, identification of the patient as driver or passenger of the motorcycle, use of helmet, time of year, types of injuries, length of hospital stay, and whether the patient lost consciousness. Patient age was also abstracted for the entire initial screen of all motorcycle accidents regardless of mechanism.

Statistical analysis was done using SPSS (IBM SPSS Statistics for Windows, Version 19.0; IBM Corp., Armonk, New York). Continuous data were analyzed using the appropriate descriptive statistics. Comparisons were made using Student t test, and a 0.05 level of significance was accepted.

Results

The initial screening of the trauma database returned 487 patients who had been involved in a motorcycle accident; of these, 39 patients were in an accident that involved a deer. According to one medical record, the spouse of a patient was a passenger who was dead at the scene, although there was no separate medical record for this person; this person was included in our data. Therefore, our total study population numbered 40 patients involved in 36 accidents, with 36 drivers and 4 passengers; 35 were men and 5 were women, with the women accounting for all 4 passengers and 1 driver. The mean (SD) patient age for deer–motorcycle collisions was 48.9 (8.9) years (range, 21-64 years). This was significantly higher than the mean (SD) age for all motorcycle accidents from the ECMC trauma database, which was 41.9 (13.9) years (range, 17-79 years) (P < .002).

The majority of accidents (31; 86%) with deer occurred during the months of May through September, with the most occurring in June (11; 31%). There was only 1 (3%) in October, 3 (8%) in November, and 1 (3%) in January. The number of collisions per year averaged 9.75, with a range of 8 to 12 from 2007-2010. (The year 2011 was omitted because data were collected before the year was complete). The presence or absence of helmet use was recorded in 22 cases. Of these, 21 patients had been wearing a helmet (95%), and only 1 patient was unhelmeted. Among all riders involved in motorcycle accidents from the trauma database, the presence or absence of a helmet was recorded in 271 cases. Of these, 262 (97%) were wearing a helmet. The average length of hospital stay was 6 days, with 6 patients having stays that were 10 days or longer, and the longest stay was 31 days. Thirty-three medical records noted whether the patient described loss of consciousness after the accident; of these, 14 (42%) claimed loss of consciousness and the remaining 19 (58%) denied any loss of consciousness after the accident. The mean (SD) ISS for deer–motorcycle collisions was 17.1 (9.8), and the mean (SD) GCS was 14.3 (2.5).

Chest, orthopedic, and head injuries were the most common injuries seen in deer–motorcycle collisions (Table). Head injuries, including the 1 patient who was confirmed to not have been wearing a helmet, accounted for 15.0% of the total injuries. This patient also had a longer length of stay at 19 days than the average of 6 days. Rib fractures were the most common injury, occurring in 20 (50%) patients. The 1 recorded fatality was the passenger of a patient who was dead at the scene.

Twenty-five (62.5%) patients in this series had injuries that are traditionally treated by orthopedic trauma surgeons, including scapular, clavicle, pelvic, and extremity fractures. Upper and lower extremity injuries occurred 10 (8.3%) and 15 (12.5%) times respectively, with the lower extremity injuries including long bone fractures, foot and ankle fractures, and 1 lower extremity traumatic amputation. Fourteen (35%) patients underwent one or more orthopedic surgical procedures.

Discussion

Although animal–vehicle collisions have been described in the literature, comparatively little data are available for the subset of animal–motorcycle accidents. This is an important gap considering that fatalities in collisions with animals were 6 times more likely to be persons riding motorcycles, although animal collisions are more common with other vehicles.⁶

Smoot and colleagues² also reported that motorcycle collisions with deer tend to result in a higher injury severity than collisions of other vehicles with deer. According to reports for Midwestern regions, motorcycle-versus-deer accidents are a significant problem, causing a large number of serious injuries as well as creating the financial burden of vehicle damage and medical costs.^2,3 However, the overall data are limited, and there is not much detailed information available for western New York.

Because of the large number of motorcyclists in New York State, it is important to consider accident data in this subset of the population. In 2010, 340,260 motorcycles were registered in New York State, with Erie County having the second highest number (21,745) of motorcycles registered.⁷ These numbers increased to 345,820 and 22,183 motorcycles, respectively, in 2011.⁸ In that year, the number of police-reported motorcycle accidents in New York decreased to 4855 from 5047 accidents in 2010, although both numbers are increased from 4647 accidents in 2009.^9-11 Despite the decrease in total police-reported motorcycle accidents from 2010 to 2011, the trend in motorcycle accidents involving an animal’s action has steadily increased from 313 (6.7%) in 2009 to 335 (6.6%) in 2010 to 401 (8.3%) in 2011.^9-11 Although these data from the New York State Department of Motor Vehicles are not further broken down by animal species, it can be reasonably surmised that most of these are caused by deer. This inference is supported by data from Bramati and colleagues⁴ showing that 81% of animal–vehicle collisions involved deer, as well as by the Wildlife-Vehicle Collision Reduction Study that showed deer were involved in 54.4% of animal–vehicle collisions in California and more than 90% of animal–vehicle collisions in Illinois and Minnesota.^4,12 These studies predominantly comprised collisions involving animals capable of causing substantial property damage on impact, such as deer or larger animals. This, along with the evidence of higher ISS seen in motorcyclists in deer-related traffic injuries,² supports the intuitive thought that motorcyclists are at increased risk for injury and fatality relative to other motor vehicles involved in accidents.

Williams and Wells¹³ reviewed 147 fatal wildlife–vehicle fatalities from 9 regions and found that the 2 most common fatalities were the motorcycle driver or passenger after striking an animal or an object. Jones¹⁴ also reported that the most common fatal wildlife–vehicle crashes involved motorcycles, as did fatal-accident reporting system data in the Wildlife-Vehicle Collision Reduction Study, which confirmed that approximately 30% of fatal crashes with animals involved motorcycles.¹²

Interestingly, the age of patients involved in motorcycle–deer collisions tends to be higher than that of patients involved in other motorcycle accidents. The numbers in our study reflect results in other study populations that suggest motorcycle riders who collide with deer are generally older than riders in other accidents who are more likely to be younger.⁴ One explanation is that younger riders may drive faster and more recklessly than older and experienced riders, resulting in an increased number of accidents unrelated to deer. Another consideration places younger drivers less commonly on roads where wildlife crashes more often occur (ie, roads that are rural, 2-lane).

Helmet use, when reported, was very high in our study population, most likely as a result of New York State’s mandatory helmet law for motorcyclists. Our data showed that more than 95% of patients whose charts documented helmet usage were wearing helmets at the time of the collision, compared with a Wisconsin study showing that only 29% of patients were wearing helmets.³ This may explain the proportion of head injuries in our study being 15.0% compared with the 29.5% in the Wisconsin study.³ Although both datasets involved a limited number of patients, the results suggest that mandatory helmet laws are effective in preventing head injuries. Also, the only patient in our study who was confirmed to have not been wearing a helmet had a much longer length of hospital stay than the average patient (19 vs 6 days). William and Wells¹³ found that 65% of motorcyclists killed in collisions with animals were not wearing helmets, and they believed that many of these fatalities could have been prevented with helmet use. Again, these limited data suggest the effectiveness of mandatory helmet use.

Two other factors, season and time of day, are important to consider in motorcycle collisions with deer. According to our data, 86% of these collisions occur in the warmer months, May through September, peaking in June. This is similar to findings from the Wisconsin study showing June and July as the peak months for deer–motorcycle collisions and a study in Minnesota where 61% of these crashes occurred in the summer months.^2,3 These data most likely indicate increased motorcycle traffic in favorable weather conditions. Although time of accident could not be determined through our retrospective review, multiple studies have shown that the majority of collisions with deer tend to be between dusk and dawn. Smoot and colleagues² found that 56% of vehicle collisions with deer occurred between 5 pm and midnight, with 80% between 5 pm and 6 am.² Similarly, Nelson and colleagues³ found that 54.5% of collisions happened in a 4-hour period, from 6 pm to 10 pm. These data indicate that motorcycle operators should be especially vigilant in the morning and evening hours when deer may be more active.

Other than driver awareness and vigilance, prevention efforts can involve wildlife fencing, alert systems, and deer-culling programs. Fences are used extensively, most commonly on larger thoroughfares, and have been shown effective in reducing wildlife vehicle crashes by 80% to 90%.¹² Animal detection systems using sensors to detect large wildlife approaching the roadway can activate warning signs to alert approaching drivers. Such systems have been installed in more than 30 locations in North America and Europe with variable effectiveness.¹² However, there are typically no standards or guidelines for the collection of data about wildlife–vehicle crashes. Data are collected inconsistently and often haphazardly, and methods vary between states and agencies. Some transportation agencies do not collect this type of data at all. Without reliable, consistent data, it is difficult to identify road sections where mitigation methods may be required, to select appropriate mitigation measures, or to evaluate whether that effort is making a difference.

Culling systems for deer populations are frequently discussed, often in suburban as well as rural settings. Recreational hunting ordinances, higher limits on the number of females a hunter can bag, and occasional use of professional shooters can be applicable in less rural areas. Their effectiveness is debatable and tends to be time-limited.

Conclusion

This study highlights the fairly common occurrence and relative severity of deer–motorcycle crashes in an upstate New York setting, approximating published series from the Midwest. Helmet laws may lower rates of head injury in motorcycle–wildlife crashes. Finally, there are no fender benders when the chosen vehicle sports no fenders, so motorcyclists need to be especially vigilant in order to avoid collisions with deer and other wildlife.

A new trial has found that life expectancy of newly diagnosed and treated osteoporosis patients is in excess of 15 years in women younger than 75, and in men younger than 60, according to a study published online ahead of print May 21 in Journal of Bone and Mineral Research.

“How best to treat patients with osteoporosis is a really simple issue when it comes to beginning treatment, but deciding how long to treat for is really very challenging,” said lead author Bo Abrahamsen, MD, PhD, Professor and Consultant Endocrinologist at Glostrup Hospital in Copenhagen.

Researchers conducted an observational study in Danish national registries tracking prescriptions for osteoporosis drugs, comorbid conditions, and deaths. Investigators included 58,637 patients and 225,084 age- and gender-matched control subjects. Information on deaths until the end of 2013 was retrieved, providing a follow-up period of 10 to 17 years.

In men younger than 80 and women younger than 60, the relative risk of dying declined from being strongly increased in the first year to a stable but elevated level in subsequent years. In women older than 65 through 70, there was only a small elevation in risk in the first year of treatment followed by lower than background mortality.

The residual life expectancy of a 50-year-old man beginning osteoporosis treatment was estimated to be 18.2 years; for a 75-year-old man it was 7.5 years. Estimates in women were 26.4 years and 13.5 years for the same age groups, respectively.

According to the researchers, their findings show an excess mortality in men and in women below age 70 who are treated for osteoporosis, compared with the background population. This excess risk, they said, is more pronounced in the first few years on treatment. The average life expectancy of osteoporosis patients is in excess of 15 years in women below the age of 75 and in men below the age of 60, highlighting the importance of developing tools for long-term management.

“The present study shows that most of the patients we treat have a long life expectancy. Therefore it is absolutely vital that we are not complacent but develop evidence-based strategies for the long-term management of osteoporosis,” stated Dr. Abrahamsen.

A new trial has found that life expectancy of newly diagnosed and treated osteoporosis patients is in excess of 15 years in women younger than 75, and in men younger than 60, according to a study published online ahead of print May 21 in Journal of Bone and Mineral Research.

“How best to treat patients with osteoporosis is a really simple issue when it comes to beginning treatment, but deciding how long to treat for is really very challenging,” said lead author Bo Abrahamsen, MD, PhD, Professor and Consultant Endocrinologist at Glostrup Hospital in Copenhagen.

Researchers conducted an observational study in Danish national registries tracking prescriptions for osteoporosis drugs, comorbid conditions, and deaths. Investigators included 58,637 patients and 225,084 age- and gender-matched control subjects. Information on deaths until the end of 2013 was retrieved, providing a follow-up period of 10 to 17 years.

In men younger than 80 and women younger than 60, the relative risk of dying declined from being strongly increased in the first year to a stable but elevated level in subsequent years. In women older than 65 through 70, there was only a small elevation in risk in the first year of treatment followed by lower than background mortality.

The residual life expectancy of a 50-year-old man beginning osteoporosis treatment was estimated to be 18.2 years; for a 75-year-old man it was 7.5 years. Estimates in women were 26.4 years and 13.5 years for the same age groups, respectively.

According to the researchers, their findings show an excess mortality in men and in women below age 70 who are treated for osteoporosis, compared with the background population. This excess risk, they said, is more pronounced in the first few years on treatment. The average life expectancy of osteoporosis patients is in excess of 15 years in women below the age of 75 and in men below the age of 60, highlighting the importance of developing tools for long-term management.

“The present study shows that most of the patients we treat have a long life expectancy. Therefore it is absolutely vital that we are not complacent but develop evidence-based strategies for the long-term management of osteoporosis,” stated Dr. Abrahamsen.

A new trial has found that life expectancy of newly diagnosed and treated osteoporosis patients is in excess of 15 years in women younger than 75, and in men younger than 60, according to a study published online ahead of print May 21 in Journal of Bone and Mineral Research.

“How best to treat patients with osteoporosis is a really simple issue when it comes to beginning treatment, but deciding how long to treat for is really very challenging,” said lead author Bo Abrahamsen, MD, PhD, Professor and Consultant Endocrinologist at Glostrup Hospital in Copenhagen.

Researchers conducted an observational study in Danish national registries tracking prescriptions for osteoporosis drugs, comorbid conditions, and deaths. Investigators included 58,637 patients and 225,084 age- and gender-matched control subjects. Information on deaths until the end of 2013 was retrieved, providing a follow-up period of 10 to 17 years.

In men younger than 80 and women younger than 60, the relative risk of dying declined from being strongly increased in the first year to a stable but elevated level in subsequent years. In women older than 65 through 70, there was only a small elevation in risk in the first year of treatment followed by lower than background mortality.

The residual life expectancy of a 50-year-old man beginning osteoporosis treatment was estimated to be 18.2 years; for a 75-year-old man it was 7.5 years. Estimates in women were 26.4 years and 13.5 years for the same age groups, respectively.

According to the researchers, their findings show an excess mortality in men and in women below age 70 who are treated for osteoporosis, compared with the background population. This excess risk, they said, is more pronounced in the first few years on treatment. The average life expectancy of osteoporosis patients is in excess of 15 years in women below the age of 75 and in men below the age of 60, highlighting the importance of developing tools for long-term management.

“The present study shows that most of the patients we treat have a long life expectancy. Therefore it is absolutely vital that we are not complacent but develop evidence-based strategies for the long-term management of osteoporosis,” stated Dr. Abrahamsen.

In the post–Affordable Care Act landscape of American health care, an explosion of alternative payment methods and other creative initiatives has occurred as patients, providers, and payers all seek higher-quality care at lower costs.¹ These factors impact every level of the health care system, from large academic medical institutions in major cities to small single hospitals in rural community settings.² Co-management arrangements are among the many innovative organizational structures that have arisen with the goals of efficiency and quality. For many reasons, a co-management arrangement has specific applicability and appeal in orthopedic surgery, and the popularity of this form of physician–hospital alignment is growing.³

Definition

In health care, and particularly even within orthopedic surgery, the term co-management can have multiple definitions. It can refer to shared responsibility for patient care across service lines—such as the “co-management” by both hospitalists and orthopedic surgeons of elderly patients with multiple chronic medical comorbidities as well as an acute hip fracture or a total knee replacement.^4-7 In academic settings, it may refer to the delegation of duties from attending professors to residents in co-managing patients.

In the realm of health care business and finance, however, the term co-management arrangement (CMA) refers to the shared responsibility for a hospital service line by the hospital administration and the physicians involved in that service line. While the basic concept is not necessarily a new one, it is growing in popularity and expanding in scope, creative application, and effectiveness within the current post-reform environment.⁸ This model of clinical and financial integration has been implemented in multiple different medical subspecialties, from cardiology and oncology to gastroenterology and vision care.^9,10 As applied to orthopedic surgery, CMAs create a situation in which orthopedic surgeons participate intimately in the management of the entire musculoskeletal service line, including inpatient and outpatient services. Orthopedics was identified as 1 of the top 3 specialties for clinical CMAs (after cardiology and imaging) in a recent survey of more than 258 hospital executives.¹¹ Because orthopedic surgery represents an extremely profitable service line for most hospitals, it becomes an ideal target for optimization under a CMA because even relatively small percentage increases in efficiency or profitability can pay relatively large dividends for the hospital.¹²

Under a CMA, the physicians are compensated for their time and efforts, and they provide services across clinical and nonclinical areas. Because orthopedic surgeons are most familiar with the details of their specialty and the unique needs of their patients, they are the best suited to make decisions, both clinical and nonclinical, that impact the provision of that care. The details of individual CMAs will vary based on specific situational factors, but the common goal of improved patient care and greater economic efficiency drive the underlying theme of shared responsibility and physician–hospital alignment.¹³

A CMA is different from some other recent innovative forms of organizational or financial structure. A CMA is not the same as direct employment^14,15 or “pay-for-performance,”¹⁶ because both of these methods of physician–hospital alignment lack the incentivized structure of a CMA. While a CMA is similar to a “gainsharing” arrangement because both hospitals and physicians benefit, it has a very different legal structure.¹⁷ A CMA also resembles a joint venture, but it differs in its goal of a focus on management roles.¹⁸ Bundled-pricing arrangements tend to focus on the end-price of an “episode of care” rather than the system that provides it.¹⁹ While CMAs may be more involved than many other forms of organizational structure, a CMA does not have the level of complexity and interaction required for a formal accountable care organization (ACO).²⁰

Principles of Co-Management Arrangements

Because countless variances exist across the country within local and regional orthopedic markets, no single prescription for success exists to guide co-management arrangements for every potential situation.^21,22 Several basic principles, however, should characterize any attempted CMA. Without a foundation in these principles, the CMA may risk suboptimal performance or overt failure.

Focus on the Patient

The most basic shared concern of the 2 parties of a CMA (surgeons and hospitals) is the patient. While each side may have different strengths and varying methods of reaching clinical and financial goals, they should be able to agree on the fundamental idea of patient-centered care. Indeed, the patient experience has become a popular buzzword in many areas of medicine,²³ and it particularly applies as a foundational principle of CMAs. A focus on the patient does not directly guarantee success, because there are numerous other details and features of a productive CMA. Failure to focus on the patient, however, will lead to problems.

Evidence-Based Decision-Making

As the information age progresses, clinical, operational, and financial decisions are all best made based on data. Over the last 10 years, evidence-based medicine (EBM) has become the norm in orthopedic surgery for the evaluation of techniques, implants, medications, and other treatment options.²⁴ This data-based clinical concept parallels the development of its cousin on the administrative side, evidence-based management.25 Both forms of “EBM” focus on using a synthesis of the best available data to inform decision-making to maximize outcomes. In a CMA, evidence-based decision-making should pervade all aspects of the endeavor.

Physician Leadership

Co-management arrangements cannot succeed with involvement and input exclusively from hospital officials. Physicians must not only participate in these arrangements, but they must take the key leadership roles.²⁶ Physicians can learn relevant skills in business administration much quicker and easier than administrators can gain clinical skill and experience. Therefore, effective CMAs should have appropriately qualified physicians in essential leadership positions whenever possible.^27,28

Appropriate Physician Compensation

While physicians may benefit from CMAs in many intangible economic ways, such as increased volume or increased time efficiency, the process of creating and operating a CMA does not inherently generate any revenue for the physicians involved. Indeed, the primary raw materials that an orthopedic surgeon possesses are time and expertise. Investment of an orthopedist’s time and expertise represents utilization of a considerably valuable resource that demands commensurate compensation.²⁹ Hospitals can save exponentially more money through a robust CMA than they might spend for the surgeon’s time and efforts to create it,²³ and they should expect returns commensurate with the amount invested.³⁰ Stated simply, the CMA will not work unless physicians are compensated to make it work.

While appropriate compensation for time and effort may seem an obvious and basic element of success for any endeavor, the determination of such compensation for a CMA is fraught with difficulty and danger.³ The primary concern is the calculation of “fair market value” or “commercial reasonableness” of the management services provided by the orthopedic surgeon to the hospital.^23,31-33 Any amount perceived as too low may discourage surgeon participation. On the other hand, amounts that exceed fair market value may constitute remuneration that can result in severe federal legal penalties. Any compensation agreement must comply with provisions of the Stark laws and the federal Anti-Kickback Statute, as well as the Civil Monetary Penalties Statute, the more recent Sunshine Act, and other laws.^34-37

Consequently, creation of a well-designed compensation plan is thus one of the most critical principles of a CMA.³⁸ Physician compensation for participation in a CMA should focus on 2 major areas—a base payment for time spent in design and management of the arrangement, and a bonus payment for reaching certain predefined quality and efficiency goals through the arrangement.^{3,22,27,32,34,39} As mentioned above, physicians must, at a minimum, receive fair compensation for their time and efforts. In addition, creation of incentives through a clearly defined, performance-based reward structure can further drive surgeons’ motivation for dedicated effort and creativity.⁹ It is critical to note that a CMA differs from a gainsharing arrangement because physicians usually do not share a percentage of actual hospital savings under a CMA.³¹ A gainsharing arrangement, however, usually involves physicians receiving a defined percentage of any real dollar savings created for the hospital through the relationship.¹⁷

Transparency

Transparency is a common feature of any business relationship in which 2 distinct entities must work together to achieve a mutual goal. Co-management arrangements are no exception to this rule; multiple experts have identified transparency and trust as foundational elements for success.^30,40 To ensure transparency without compromising patient confidentiality, trade secrets, or other valuable restricted information from unnecessary or potentially dangerous exposure, participants in the CMA should develop a transparency plan in the early stages of the relationship. This plan should expressly state exactly what information is to be shared, when, with whom, and in what manner. By balancing information sharing with information security, CMA participants can more comfortably communicate and develop trust. 

Reasonable and Modifiable Goals

While the overarching raison d’être of a CMA is to increase efficiency and improve quality, these worthy purposes must be broken down into specific, measurable goals that are unique to each arrangement. These goals should be aggressive enough to make an impact, but they should also be reasonably achievable within a designated period. In many cases, these goals will reflect or follow the regulatory stipulations of various governing bodies, such as the Centers for Medicare and Medicaid Services (CMS) or The Joint Commission.³¹ Because these entities may frequently change or update their rules (and even their own institutional names!), the CMA must also have a structure that can rapidly respond to alterations in the regulatory landscape.³¹ The goals should be modifiable and amendable on an as-needed basis with an appropriate vote of the CMA stakeholders, rather than renewable only when the arrangement’s term ends. Without such situational responsiveness, the rapidly undulating world of health care may render the CMA’s goals either laughably low or impossibly high.

Accountability

A CMA must incorporate the concept of accountability throughout its organizational structure. Although this principle will take many different forms and have different applications, it is critical to the effectiveness of a CMA. Traditional hospital management often focuses on financial goals rather than patient-care goals, and physicians must be able to hold management accountable when these goals conflict. A CMA’s legal structure must have elements of accountability and methods of resolving conflict, such as provisions for arbitration or mediation by a designated third party. When goals are not met or if they are exceeded, there must be ways of both disciplining and rewarding those responsible. Ultimately, accountability must be woven into the culture created under the CMA, and this process flows through every element of the agreement, from its contractual legal and leadership structure to its operational and financial logistics.

General Operational Elements of Co-Management Arrangements

While CMAs must be governed by basic principles, they must also involve several general operational elements. The specifics of these elements will vary by situation, but surgeons must consider each in the creation and operation of a CMA.

Legal Structure

Most CMAs involve the creation of a separate legal structural entity that will assume responsibility for management of the hospital’s service line.^37,39 This entity often takes the form of a limited liability company (LLC).³³ Its members may be all physicians, or it may be jointly owned by the hospital and the physicians.³⁹ The legal structure of the company will depend on state laws and local precedent, and a lawyer with extensive experience in health care law should create it and its governing documents.³⁷ Alternatively, some hospitals may consider directly employing physicians to co-manage a service line, but this simpler model may prove less effective than a true CMA because of the lack of independence for the physicians involved.^30,36 Indeed, the maintenance of physician independence is one of the strongest features of a CMA, and it should be carefully protected in the entity’s legal structure.

Like any relationship, a CMA may end, and its creators need to “begin with the end in mind” when creating its formative documents. Physicians should engage expert legal assistance in the structuring of the parts of the contract that govern the unwinding of the agreement. If the CMA performs poorly, or if the hospital becomes insolvent in spite of the CMA, the involved physicians may face liability charges or other legal entanglements. Because the escape clause of the CMA contract may be the doctors’ only shield in such situations, this part of the agreement should be meticulously reviewed by the physicians and by knowledgeable legal counsel.

Legal Compliance

Ultimately, the CMA may implicate federal Stark laws, anti-kickback laws, antitrust laws, Civil Monetary Penalties Statute, the False Claims Act, 501(c)(3) tax exemption rules, and provider-based status rules. These may have severe penalties, including imprisonment, if violated.^32,34,36,37 As such, the participants in any arrangement must make certain that the CMA complies with all applicable regulations in both its composition and function.^38,41 Participants in CMAs should make all efforts to avoid such legal pitfalls through investigation of safe harbor provisions, special exemptions, and other key features of the relevant laws.^37,42 While these regulations will remain in constant flux, governmental regulatory agencies have given guidelines about acceptable structure for CMAs.^43,44

For CMAs, a critical feature is the level of participation of the LLC members in the defined activities of the CMA.⁴² Participation requirements, such as meeting attendance, changes in practice based on defined goals and metrics, and financial contributions, must be included in the operating agreement of the LLC.³³ Compliance of all active members with these clearly defined requirements will both improve operations and morale and also decrease legal risk for both the CMA and its individual members.²⁸ Furthermore, certain conduct that may run afoul of regulations should be very specifically prohibited in the member contracts. Such behavior may include pay-for-referral arrangements rather than pay-for-performance, asymmetric income distribution through the LLC, and other activities that limit patient choice.³⁷ The salary and bonus structure must be very carefully designed and monitored, because they can have significant legal implications if not managed correctly. Independent audits should be part of the compliance plan for any CMA, and many authorities recommend limits on the total compensation to physicians as part of a CMA, as well as time limits on the agreement itself.⁴⁴

Leadership and Reporting Structure

All CMAs should have a medical director who is responsible for the success of the operation. Beneath the medical director, the leadership and reporting structure will vary based on the size of the hospital and the number of surgeons. In some situations, single individuals may assume multiple roles; other situations may dictate the need for many more people. The structure may take the shape of multiple directors and even a committee for the principal areas in a large institution, but only 1 or 2 additional individuals may be required in a small hospital setting. In any case, the leadership and reporting structure should be established as part of the basic formative documents of the CMA, with all duties and responsibilities of each participant clearly defined.

Facilities Management

Management of the physical and operational aspects of the site of service is a core component of any CMA. While the hospital usually owns the facilities, it is the surgeons who must work within them. The specifics of the physical plant can impact issues such as infection rate, inventory availability, maximum volume levels, and patient perception or satisfaction. The manner in which the facilities management conducts operations is also important; large size and nice equipment do not necessarily translate into efficiency or quality. A CMA should, therefore, have a surgeon or committee whose primary role is to oversee the relevant details of the hospital’s physical and operational issues. These details will include topics such as assignment of operative suites, choices of implants, room turnover, supplies, antibiotic availability, and other matters. Because of their experience and knowledge of the operational effects of administrative decisions, orthopedic surgeons are uniquely positioned to maximize the value of existing facilities and to oversee updates or changes as needed.

Personnel Management

Even in disadvantaged or smaller facilities, maximization of human resources can often overcome challenges of inadequate physical plant or tight finances. Alternatively, poor management of staff can thwart the efforts of even the largest and best-endowed hospitals. Because practicing orthopedists are likely to know the talents and skills of key local personnel from having worked alongside them, surgeons are well suited to help direct placement and management of personnel as part of a CMA. Surgeons can effectively identify behaviors that deserve reward and can identify staff members that refuse to be team players or otherwise do not help meet larger goals. Involvement of surgeons in personnel management also helps speed the ability to have near real-time responsiveness to issues that may arise. 

Clinical Data Management

Ultimately, quality metrics become the grading scale for the clinical aspects of the CMA. Selection of appropriate metrics constitutes a foundational element of the overall process and demands meticulous attention to detail.³⁸ Multiple site-specific clinical scoring systems exist in orthopedic surgery, from the International Knee Documentation Committee (IKDC) score for knees to the American Shoulder and Elbow Surgeons (ASES) score for shoulders.^45,46 Additional quality metrics exist for more generalized clinical success measurement, such as the Short Form–36 Health Survey (SF-36) score.⁴⁷ Governmental agencies and other national organizations have also mandated certain clinical metrics through programs such as the Surgical Care Improvement Project (SCIP).⁴⁸ Once the type and manner of desired clinical data are identified, they must be collected, processed, stored, and evaluated. Surgeon participation in and oversight of clinical data management is crucial, because orthopedists will be the best suited to interpret and apply the data and relevant trends and conclusions.

Financial Data Management

Financial concerns constitute perhaps the strongest driving force behind many of the current reform initiatives and alternative payment options in the health care landscape. For a CMA, financial success must be clearly and constantly measured and displayed for the endeavor to be successful. Since both sides have a large potential for financial gain and loss in a CMA, surgeons and hospitals must ensure that the best-qualified and most dedicated individuals oversee financial issues. Although transparency is important in all areas of a CMA, it is imperative and must be a dominating feature of the arrangement’s financial management. Financial goals, furthermore, must be clearly defined and realistic, with continuous reevaluation as the relationship moves forward. As part of the transparency plan, relevant financial data should be shared and discussed at regular intervals.

Quality and Effectiveness Reporting

An ideal co-management agreement not only reaches its goals of improved patient care and increased financial efficiency, but it can document and report achievement of these goals as well. Just as corporations must report their financial effectiveness to their shareholders, CMAs must report their own overall effectiveness to their respective stakeholders. Payers, patients, providers, and participant hospitals all have a stake in proving that the CMA has been successful—and that it will continue to be successful. Effectiveness reporting becomes the most important element of all, because the ultimate purpose is self-preservation of the CMA. Reporting should document successes and failures in all relevant elements of the arrangement, with a focus on clinical and financial data. Reports should employ both internal and external benchmarks as a means of evaluating results. Most CMAs will have a designated officer or committee tasked with the responsibility for measurement and reporting of quality and effectiveness.²⁶ Clinical and financial data are combined into an overall big picture of the achievements of the CMA.

Conclusion

Co-management arrangements represent a popular current option for physicians and surgeons to increase alignment and achieve the mutually beneficial goals of increased quality and efficiency. In orthopedics, CMAs essentially consist of surgeons and hospital administrators working together to manage the musculoskeletal service line at a hospital. While the details of specific arrangements will vary according to individual situations, certain basic principles and important general operational elements characterize most successful CMAs. Since physician ownership of hospitals is now banned under the Affordable Care Act, CMAs can be seen as a physician-managed hospital within a hospital, with many of the benefits that have historically resulted from physician ownership and participation in management.^27,49 As health care reform progresses, CMAs will likely become more widespread, more refined, more effective, and more profitable.

In the post–Affordable Care Act landscape of American health care, an explosion of alternative payment methods and other creative initiatives has occurred as patients, providers, and payers all seek higher-quality care at lower costs.¹ These factors impact every level of the health care system, from large academic medical institutions in major cities to small single hospitals in rural community settings.² Co-management arrangements are among the many innovative organizational structures that have arisen with the goals of efficiency and quality. For many reasons, a co-management arrangement has specific applicability and appeal in orthopedic surgery, and the popularity of this form of physician–hospital alignment is growing.³

Definition

In health care, and particularly even within orthopedic surgery, the term co-management can have multiple definitions. It can refer to shared responsibility for patient care across service lines—such as the “co-management” by both hospitalists and orthopedic surgeons of elderly patients with multiple chronic medical comorbidities as well as an acute hip fracture or a total knee replacement.^4-7 In academic settings, it may refer to the delegation of duties from attending professors to residents in co-managing patients.

In the realm of health care business and finance, however, the term co-management arrangement (CMA) refers to the shared responsibility for a hospital service line by the hospital administration and the physicians involved in that service line. While the basic concept is not necessarily a new one, it is growing in popularity and expanding in scope, creative application, and effectiveness within the current post-reform environment.⁸ This model of clinical and financial integration has been implemented in multiple different medical subspecialties, from cardiology and oncology to gastroenterology and vision care.^9,10 As applied to orthopedic surgery, CMAs create a situation in which orthopedic surgeons participate intimately in the management of the entire musculoskeletal service line, including inpatient and outpatient services. Orthopedics was identified as 1 of the top 3 specialties for clinical CMAs (after cardiology and imaging) in a recent survey of more than 258 hospital executives.¹¹ Because orthopedic surgery represents an extremely profitable service line for most hospitals, it becomes an ideal target for optimization under a CMA because even relatively small percentage increases in efficiency or profitability can pay relatively large dividends for the hospital.¹²

Under a CMA, the physicians are compensated for their time and efforts, and they provide services across clinical and nonclinical areas. Because orthopedic surgeons are most familiar with the details of their specialty and the unique needs of their patients, they are the best suited to make decisions, both clinical and nonclinical, that impact the provision of that care. The details of individual CMAs will vary based on specific situational factors, but the common goal of improved patient care and greater economic efficiency drive the underlying theme of shared responsibility and physician–hospital alignment.¹³

A CMA is different from some other recent innovative forms of organizational or financial structure. A CMA is not the same as direct employment^14,15 or “pay-for-performance,”¹⁶ because both of these methods of physician–hospital alignment lack the incentivized structure of a CMA. While a CMA is similar to a “gainsharing” arrangement because both hospitals and physicians benefit, it has a very different legal structure.¹⁷ A CMA also resembles a joint venture, but it differs in its goal of a focus on management roles.¹⁸ Bundled-pricing arrangements tend to focus on the end-price of an “episode of care” rather than the system that provides it.¹⁹ While CMAs may be more involved than many other forms of organizational structure, a CMA does not have the level of complexity and interaction required for a formal accountable care organization (ACO).²⁰

Principles of Co-Management Arrangements

Because countless variances exist across the country within local and regional orthopedic markets, no single prescription for success exists to guide co-management arrangements for every potential situation.^21,22 Several basic principles, however, should characterize any attempted CMA. Without a foundation in these principles, the CMA may risk suboptimal performance or overt failure.

Focus on the Patient

The most basic shared concern of the 2 parties of a CMA (surgeons and hospitals) is the patient. While each side may have different strengths and varying methods of reaching clinical and financial goals, they should be able to agree on the fundamental idea of patient-centered care. Indeed, the patient experience has become a popular buzzword in many areas of medicine,²³ and it particularly applies as a foundational principle of CMAs. A focus on the patient does not directly guarantee success, because there are numerous other details and features of a productive CMA. Failure to focus on the patient, however, will lead to problems.

Evidence-Based Decision-Making

As the information age progresses, clinical, operational, and financial decisions are all best made based on data. Over the last 10 years, evidence-based medicine (EBM) has become the norm in orthopedic surgery for the evaluation of techniques, implants, medications, and other treatment options.²⁴ This data-based clinical concept parallels the development of its cousin on the administrative side, evidence-based management.25 Both forms of “EBM” focus on using a synthesis of the best available data to inform decision-making to maximize outcomes. In a CMA, evidence-based decision-making should pervade all aspects of the endeavor.

Physician Leadership

Co-management arrangements cannot succeed with involvement and input exclusively from hospital officials. Physicians must not only participate in these arrangements, but they must take the key leadership roles.²⁶ Physicians can learn relevant skills in business administration much quicker and easier than administrators can gain clinical skill and experience. Therefore, effective CMAs should have appropriately qualified physicians in essential leadership positions whenever possible.^27,28

Appropriate Physician Compensation

While physicians may benefit from CMAs in many intangible economic ways, such as increased volume or increased time efficiency, the process of creating and operating a CMA does not inherently generate any revenue for the physicians involved. Indeed, the primary raw materials that an orthopedic surgeon possesses are time and expertise. Investment of an orthopedist’s time and expertise represents utilization of a considerably valuable resource that demands commensurate compensation.²⁹ Hospitals can save exponentially more money through a robust CMA than they might spend for the surgeon’s time and efforts to create it,²³ and they should expect returns commensurate with the amount invested.³⁰ Stated simply, the CMA will not work unless physicians are compensated to make it work.

While appropriate compensation for time and effort may seem an obvious and basic element of success for any endeavor, the determination of such compensation for a CMA is fraught with difficulty and danger.³ The primary concern is the calculation of “fair market value” or “commercial reasonableness” of the management services provided by the orthopedic surgeon to the hospital.^23,31-33 Any amount perceived as too low may discourage surgeon participation. On the other hand, amounts that exceed fair market value may constitute remuneration that can result in severe federal legal penalties. Any compensation agreement must comply with provisions of the Stark laws and the federal Anti-Kickback Statute, as well as the Civil Monetary Penalties Statute, the more recent Sunshine Act, and other laws.^34-37

Consequently, creation of a well-designed compensation plan is thus one of the most critical principles of a CMA.³⁸ Physician compensation for participation in a CMA should focus on 2 major areas—a base payment for time spent in design and management of the arrangement, and a bonus payment for reaching certain predefined quality and efficiency goals through the arrangement.^{3,22,27,32,34,39} As mentioned above, physicians must, at a minimum, receive fair compensation for their time and efforts. In addition, creation of incentives through a clearly defined, performance-based reward structure can further drive surgeons’ motivation for dedicated effort and creativity.⁹ It is critical to note that a CMA differs from a gainsharing arrangement because physicians usually do not share a percentage of actual hospital savings under a CMA.³¹ A gainsharing arrangement, however, usually involves physicians receiving a defined percentage of any real dollar savings created for the hospital through the relationship.¹⁷

Transparency

Transparency is a common feature of any business relationship in which 2 distinct entities must work together to achieve a mutual goal. Co-management arrangements are no exception to this rule; multiple experts have identified transparency and trust as foundational elements for success.^30,40 To ensure transparency without compromising patient confidentiality, trade secrets, or other valuable restricted information from unnecessary or potentially dangerous exposure, participants in the CMA should develop a transparency plan in the early stages of the relationship. This plan should expressly state exactly what information is to be shared, when, with whom, and in what manner. By balancing information sharing with information security, CMA participants can more comfortably communicate and develop trust. 

Reasonable and Modifiable Goals

While the overarching raison d’être of a CMA is to increase efficiency and improve quality, these worthy purposes must be broken down into specific, measurable goals that are unique to each arrangement. These goals should be aggressive enough to make an impact, but they should also be reasonably achievable within a designated period. In many cases, these goals will reflect or follow the regulatory stipulations of various governing bodies, such as the Centers for Medicare and Medicaid Services (CMS) or The Joint Commission.³¹ Because these entities may frequently change or update their rules (and even their own institutional names!), the CMA must also have a structure that can rapidly respond to alterations in the regulatory landscape.³¹ The goals should be modifiable and amendable on an as-needed basis with an appropriate vote of the CMA stakeholders, rather than renewable only when the arrangement’s term ends. Without such situational responsiveness, the rapidly undulating world of health care may render the CMA’s goals either laughably low or impossibly high.

Accountability

A CMA must incorporate the concept of accountability throughout its organizational structure. Although this principle will take many different forms and have different applications, it is critical to the effectiveness of a CMA. Traditional hospital management often focuses on financial goals rather than patient-care goals, and physicians must be able to hold management accountable when these goals conflict. A CMA’s legal structure must have elements of accountability and methods of resolving conflict, such as provisions for arbitration or mediation by a designated third party. When goals are not met or if they are exceeded, there must be ways of both disciplining and rewarding those responsible. Ultimately, accountability must be woven into the culture created under the CMA, and this process flows through every element of the agreement, from its contractual legal and leadership structure to its operational and financial logistics.

General Operational Elements of Co-Management Arrangements

While CMAs must be governed by basic principles, they must also involve several general operational elements. The specifics of these elements will vary by situation, but surgeons must consider each in the creation and operation of a CMA.

Legal Structure

Most CMAs involve the creation of a separate legal structural entity that will assume responsibility for management of the hospital’s service line.^37,39 This entity often takes the form of a limited liability company (LLC).³³ Its members may be all physicians, or it may be jointly owned by the hospital and the physicians.³⁹ The legal structure of the company will depend on state laws and local precedent, and a lawyer with extensive experience in health care law should create it and its governing documents.³⁷ Alternatively, some hospitals may consider directly employing physicians to co-manage a service line, but this simpler model may prove less effective than a true CMA because of the lack of independence for the physicians involved.^30,36 Indeed, the maintenance of physician independence is one of the strongest features of a CMA, and it should be carefully protected in the entity’s legal structure.

Like any relationship, a CMA may end, and its creators need to “begin with the end in mind” when creating its formative documents. Physicians should engage expert legal assistance in the structuring of the parts of the contract that govern the unwinding of the agreement. If the CMA performs poorly, or if the hospital becomes insolvent in spite of the CMA, the involved physicians may face liability charges or other legal entanglements. Because the escape clause of the CMA contract may be the doctors’ only shield in such situations, this part of the agreement should be meticulously reviewed by the physicians and by knowledgeable legal counsel.

Legal Compliance

Ultimately, the CMA may implicate federal Stark laws, anti-kickback laws, antitrust laws, Civil Monetary Penalties Statute, the False Claims Act, 501(c)(3) tax exemption rules, and provider-based status rules. These may have severe penalties, including imprisonment, if violated.^32,34,36,37 As such, the participants in any arrangement must make certain that the CMA complies with all applicable regulations in both its composition and function.^38,41 Participants in CMAs should make all efforts to avoid such legal pitfalls through investigation of safe harbor provisions, special exemptions, and other key features of the relevant laws.^37,42 While these regulations will remain in constant flux, governmental regulatory agencies have given guidelines about acceptable structure for CMAs.^43,44

For CMAs, a critical feature is the level of participation of the LLC members in the defined activities of the CMA.⁴² Participation requirements, such as meeting attendance, changes in practice based on defined goals and metrics, and financial contributions, must be included in the operating agreement of the LLC.³³ Compliance of all active members with these clearly defined requirements will both improve operations and morale and also decrease legal risk for both the CMA and its individual members.²⁸ Furthermore, certain conduct that may run afoul of regulations should be very specifically prohibited in the member contracts. Such behavior may include pay-for-referral arrangements rather than pay-for-performance, asymmetric income distribution through the LLC, and other activities that limit patient choice.³⁷ The salary and bonus structure must be very carefully designed and monitored, because they can have significant legal implications if not managed correctly. Independent audits should be part of the compliance plan for any CMA, and many authorities recommend limits on the total compensation to physicians as part of a CMA, as well as time limits on the agreement itself.⁴⁴

Leadership and Reporting Structure

All CMAs should have a medical director who is responsible for the success of the operation. Beneath the medical director, the leadership and reporting structure will vary based on the size of the hospital and the number of surgeons. In some situations, single individuals may assume multiple roles; other situations may dictate the need for many more people. The structure may take the shape of multiple directors and even a committee for the principal areas in a large institution, but only 1 or 2 additional individuals may be required in a small hospital setting. In any case, the leadership and reporting structure should be established as part of the basic formative documents of the CMA, with all duties and responsibilities of each participant clearly defined.

Facilities Management

Management of the physical and operational aspects of the site of service is a core component of any CMA. While the hospital usually owns the facilities, it is the surgeons who must work within them. The specifics of the physical plant can impact issues such as infection rate, inventory availability, maximum volume levels, and patient perception or satisfaction. The manner in which the facilities management conducts operations is also important; large size and nice equipment do not necessarily translate into efficiency or quality. A CMA should, therefore, have a surgeon or committee whose primary role is to oversee the relevant details of the hospital’s physical and operational issues. These details will include topics such as assignment of operative suites, choices of implants, room turnover, supplies, antibiotic availability, and other matters. Because of their experience and knowledge of the operational effects of administrative decisions, orthopedic surgeons are uniquely positioned to maximize the value of existing facilities and to oversee updates or changes as needed.

Personnel Management

Even in disadvantaged or smaller facilities, maximization of human resources can often overcome challenges of inadequate physical plant or tight finances. Alternatively, poor management of staff can thwart the efforts of even the largest and best-endowed hospitals. Because practicing orthopedists are likely to know the talents and skills of key local personnel from having worked alongside them, surgeons are well suited to help direct placement and management of personnel as part of a CMA. Surgeons can effectively identify behaviors that deserve reward and can identify staff members that refuse to be team players or otherwise do not help meet larger goals. Involvement of surgeons in personnel management also helps speed the ability to have near real-time responsiveness to issues that may arise. 

Clinical Data Management

Ultimately, quality metrics become the grading scale for the clinical aspects of the CMA. Selection of appropriate metrics constitutes a foundational element of the overall process and demands meticulous attention to detail.³⁸ Multiple site-specific clinical scoring systems exist in orthopedic surgery, from the International Knee Documentation Committee (IKDC) score for knees to the American Shoulder and Elbow Surgeons (ASES) score for shoulders.^45,46 Additional quality metrics exist for more generalized clinical success measurement, such as the Short Form–36 Health Survey (SF-36) score.⁴⁷ Governmental agencies and other national organizations have also mandated certain clinical metrics through programs such as the Surgical Care Improvement Project (SCIP).⁴⁸ Once the type and manner of desired clinical data are identified, they must be collected, processed, stored, and evaluated. Surgeon participation in and oversight of clinical data management is crucial, because orthopedists will be the best suited to interpret and apply the data and relevant trends and conclusions.

Financial Data Management

Financial concerns constitute perhaps the strongest driving force behind many of the current reform initiatives and alternative payment options in the health care landscape. For a CMA, financial success must be clearly and constantly measured and displayed for the endeavor to be successful. Since both sides have a large potential for financial gain and loss in a CMA, surgeons and hospitals must ensure that the best-qualified and most dedicated individuals oversee financial issues. Although transparency is important in all areas of a CMA, it is imperative and must be a dominating feature of the arrangement’s financial management. Financial goals, furthermore, must be clearly defined and realistic, with continuous reevaluation as the relationship moves forward. As part of the transparency plan, relevant financial data should be shared and discussed at regular intervals.

Quality and Effectiveness Reporting

An ideal co-management agreement not only reaches its goals of improved patient care and increased financial efficiency, but it can document and report achievement of these goals as well. Just as corporations must report their financial effectiveness to their shareholders, CMAs must report their own overall effectiveness to their respective stakeholders. Payers, patients, providers, and participant hospitals all have a stake in proving that the CMA has been successful—and that it will continue to be successful. Effectiveness reporting becomes the most important element of all, because the ultimate purpose is self-preservation of the CMA. Reporting should document successes and failures in all relevant elements of the arrangement, with a focus on clinical and financial data. Reports should employ both internal and external benchmarks as a means of evaluating results. Most CMAs will have a designated officer or committee tasked with the responsibility for measurement and reporting of quality and effectiveness.²⁶ Clinical and financial data are combined into an overall big picture of the achievements of the CMA.

Conclusion

Co-management arrangements represent a popular current option for physicians and surgeons to increase alignment and achieve the mutually beneficial goals of increased quality and efficiency. In orthopedics, CMAs essentially consist of surgeons and hospital administrators working together to manage the musculoskeletal service line at a hospital. While the details of specific arrangements will vary according to individual situations, certain basic principles and important general operational elements characterize most successful CMAs. Since physician ownership of hospitals is now banned under the Affordable Care Act, CMAs can be seen as a physician-managed hospital within a hospital, with many of the benefits that have historically resulted from physician ownership and participation in management.^27,49 As health care reform progresses, CMAs will likely become more widespread, more refined, more effective, and more profitable.

In the post–Affordable Care Act landscape of American health care, an explosion of alternative payment methods and other creative initiatives has occurred as patients, providers, and payers all seek higher-quality care at lower costs.¹ These factors impact every level of the health care system, from large academic medical institutions in major cities to small single hospitals in rural community settings.² Co-management arrangements are among the many innovative organizational structures that have arisen with the goals of efficiency and quality. For many reasons, a co-management arrangement has specific applicability and appeal in orthopedic surgery, and the popularity of this form of physician–hospital alignment is growing.³

Definition

In health care, and particularly even within orthopedic surgery, the term co-management can have multiple definitions. It can refer to shared responsibility for patient care across service lines—such as the “co-management” by both hospitalists and orthopedic surgeons of elderly patients with multiple chronic medical comorbidities as well as an acute hip fracture or a total knee replacement.^4-7 In academic settings, it may refer to the delegation of duties from attending professors to residents in co-managing patients.

In the realm of health care business and finance, however, the term co-management arrangement (CMA) refers to the shared responsibility for a hospital service line by the hospital administration and the physicians involved in that service line. While the basic concept is not necessarily a new one, it is growing in popularity and expanding in scope, creative application, and effectiveness within the current post-reform environment.⁸ This model of clinical and financial integration has been implemented in multiple different medical subspecialties, from cardiology and oncology to gastroenterology and vision care.^9,10 As applied to orthopedic surgery, CMAs create a situation in which orthopedic surgeons participate intimately in the management of the entire musculoskeletal service line, including inpatient and outpatient services. Orthopedics was identified as 1 of the top 3 specialties for clinical CMAs (after cardiology and imaging) in a recent survey of more than 258 hospital executives.¹¹ Because orthopedic surgery represents an extremely profitable service line for most hospitals, it becomes an ideal target for optimization under a CMA because even relatively small percentage increases in efficiency or profitability can pay relatively large dividends for the hospital.¹²

Under a CMA, the physicians are compensated for their time and efforts, and they provide services across clinical and nonclinical areas. Because orthopedic surgeons are most familiar with the details of their specialty and the unique needs of their patients, they are the best suited to make decisions, both clinical and nonclinical, that impact the provision of that care. The details of individual CMAs will vary based on specific situational factors, but the common goal of improved patient care and greater economic efficiency drive the underlying theme of shared responsibility and physician–hospital alignment.¹³

A CMA is different from some other recent innovative forms of organizational or financial structure. A CMA is not the same as direct employment^14,15 or “pay-for-performance,”¹⁶ because both of these methods of physician–hospital alignment lack the incentivized structure of a CMA. While a CMA is similar to a “gainsharing” arrangement because both hospitals and physicians benefit, it has a very different legal structure.¹⁷ A CMA also resembles a joint venture, but it differs in its goal of a focus on management roles.¹⁸ Bundled-pricing arrangements tend to focus on the end-price of an “episode of care” rather than the system that provides it.¹⁹ While CMAs may be more involved than many other forms of organizational structure, a CMA does not have the level of complexity and interaction required for a formal accountable care organization (ACO).²⁰

Principles of Co-Management Arrangements

Because countless variances exist across the country within local and regional orthopedic markets, no single prescription for success exists to guide co-management arrangements for every potential situation.^21,22 Several basic principles, however, should characterize any attempted CMA. Without a foundation in these principles, the CMA may risk suboptimal performance or overt failure.

Focus on the Patient

The most basic shared concern of the 2 parties of a CMA (surgeons and hospitals) is the patient. While each side may have different strengths and varying methods of reaching clinical and financial goals, they should be able to agree on the fundamental idea of patient-centered care. Indeed, the patient experience has become a popular buzzword in many areas of medicine,²³ and it particularly applies as a foundational principle of CMAs. A focus on the patient does not directly guarantee success, because there are numerous other details and features of a productive CMA. Failure to focus on the patient, however, will lead to problems.

Evidence-Based Decision-Making

As the information age progresses, clinical, operational, and financial decisions are all best made based on data. Over the last 10 years, evidence-based medicine (EBM) has become the norm in orthopedic surgery for the evaluation of techniques, implants, medications, and other treatment options.²⁴ This data-based clinical concept parallels the development of its cousin on the administrative side, evidence-based management.25 Both forms of “EBM” focus on using a synthesis of the best available data to inform decision-making to maximize outcomes. In a CMA, evidence-based decision-making should pervade all aspects of the endeavor.

Physician Leadership

Co-management arrangements cannot succeed with involvement and input exclusively from hospital officials. Physicians must not only participate in these arrangements, but they must take the key leadership roles.²⁶ Physicians can learn relevant skills in business administration much quicker and easier than administrators can gain clinical skill and experience. Therefore, effective CMAs should have appropriately qualified physicians in essential leadership positions whenever possible.^27,28

Appropriate Physician Compensation

While physicians may benefit from CMAs in many intangible economic ways, such as increased volume or increased time efficiency, the process of creating and operating a CMA does not inherently generate any revenue for the physicians involved. Indeed, the primary raw materials that an orthopedic surgeon possesses are time and expertise. Investment of an orthopedist’s time and expertise represents utilization of a considerably valuable resource that demands commensurate compensation.²⁹ Hospitals can save exponentially more money through a robust CMA than they might spend for the surgeon’s time and efforts to create it,²³ and they should expect returns commensurate with the amount invested.³⁰ Stated simply, the CMA will not work unless physicians are compensated to make it work.

While appropriate compensation for time and effort may seem an obvious and basic element of success for any endeavor, the determination of such compensation for a CMA is fraught with difficulty and danger.³ The primary concern is the calculation of “fair market value” or “commercial reasonableness” of the management services provided by the orthopedic surgeon to the hospital.^23,31-33 Any amount perceived as too low may discourage surgeon participation. On the other hand, amounts that exceed fair market value may constitute remuneration that can result in severe federal legal penalties. Any compensation agreement must comply with provisions of the Stark laws and the federal Anti-Kickback Statute, as well as the Civil Monetary Penalties Statute, the more recent Sunshine Act, and other laws.^34-37

Consequently, creation of a well-designed compensation plan is thus one of the most critical principles of a CMA.³⁸ Physician compensation for participation in a CMA should focus on 2 major areas—a base payment for time spent in design and management of the arrangement, and a bonus payment for reaching certain predefined quality and efficiency goals through the arrangement.^{3,22,27,32,34,39} As mentioned above, physicians must, at a minimum, receive fair compensation for their time and efforts. In addition, creation of incentives through a clearly defined, performance-based reward structure can further drive surgeons’ motivation for dedicated effort and creativity.⁹ It is critical to note that a CMA differs from a gainsharing arrangement because physicians usually do not share a percentage of actual hospital savings under a CMA.³¹ A gainsharing arrangement, however, usually involves physicians receiving a defined percentage of any real dollar savings created for the hospital through the relationship.¹⁷

Transparency

Transparency is a common feature of any business relationship in which 2 distinct entities must work together to achieve a mutual goal. Co-management arrangements are no exception to this rule; multiple experts have identified transparency and trust as foundational elements for success.^30,40 To ensure transparency without compromising patient confidentiality, trade secrets, or other valuable restricted information from unnecessary or potentially dangerous exposure, participants in the CMA should develop a transparency plan in the early stages of the relationship. This plan should expressly state exactly what information is to be shared, when, with whom, and in what manner. By balancing information sharing with information security, CMA participants can more comfortably communicate and develop trust. 

Reasonable and Modifiable Goals

While the overarching raison d’être of a CMA is to increase efficiency and improve quality, these worthy purposes must be broken down into specific, measurable goals that are unique to each arrangement. These goals should be aggressive enough to make an impact, but they should also be reasonably achievable within a designated period. In many cases, these goals will reflect or follow the regulatory stipulations of various governing bodies, such as the Centers for Medicare and Medicaid Services (CMS) or The Joint Commission.³¹ Because these entities may frequently change or update their rules (and even their own institutional names!), the CMA must also have a structure that can rapidly respond to alterations in the regulatory landscape.³¹ The goals should be modifiable and amendable on an as-needed basis with an appropriate vote of the CMA stakeholders, rather than renewable only when the arrangement’s term ends. Without such situational responsiveness, the rapidly undulating world of health care may render the CMA’s goals either laughably low or impossibly high.

Accountability

A CMA must incorporate the concept of accountability throughout its organizational structure. Although this principle will take many different forms and have different applications, it is critical to the effectiveness of a CMA. Traditional hospital management often focuses on financial goals rather than patient-care goals, and physicians must be able to hold management accountable when these goals conflict. A CMA’s legal structure must have elements of accountability and methods of resolving conflict, such as provisions for arbitration or mediation by a designated third party. When goals are not met or if they are exceeded, there must be ways of both disciplining and rewarding those responsible. Ultimately, accountability must be woven into the culture created under the CMA, and this process flows through every element of the agreement, from its contractual legal and leadership structure to its operational and financial logistics.

General Operational Elements of Co-Management Arrangements

While CMAs must be governed by basic principles, they must also involve several general operational elements. The specifics of these elements will vary by situation, but surgeons must consider each in the creation and operation of a CMA.

Legal Structure

Most CMAs involve the creation of a separate legal structural entity that will assume responsibility for management of the hospital’s service line.^37,39 This entity often takes the form of a limited liability company (LLC).³³ Its members may be all physicians, or it may be jointly owned by the hospital and the physicians.³⁹ The legal structure of the company will depend on state laws and local precedent, and a lawyer with extensive experience in health care law should create it and its governing documents.³⁷ Alternatively, some hospitals may consider directly employing physicians to co-manage a service line, but this simpler model may prove less effective than a true CMA because of the lack of independence for the physicians involved.^30,36 Indeed, the maintenance of physician independence is one of the strongest features of a CMA, and it should be carefully protected in the entity’s legal structure.

Like any relationship, a CMA may end, and its creators need to “begin with the end in mind” when creating its formative documents. Physicians should engage expert legal assistance in the structuring of the parts of the contract that govern the unwinding of the agreement. If the CMA performs poorly, or if the hospital becomes insolvent in spite of the CMA, the involved physicians may face liability charges or other legal entanglements. Because the escape clause of the CMA contract may be the doctors’ only shield in such situations, this part of the agreement should be meticulously reviewed by the physicians and by knowledgeable legal counsel.

Legal Compliance

Ultimately, the CMA may implicate federal Stark laws, anti-kickback laws, antitrust laws, Civil Monetary Penalties Statute, the False Claims Act, 501(c)(3) tax exemption rules, and provider-based status rules. These may have severe penalties, including imprisonment, if violated.^32,34,36,37 As such, the participants in any arrangement must make certain that the CMA complies with all applicable regulations in both its composition and function.^38,41 Participants in CMAs should make all efforts to avoid such legal pitfalls through investigation of safe harbor provisions, special exemptions, and other key features of the relevant laws.^37,42 While these regulations will remain in constant flux, governmental regulatory agencies have given guidelines about acceptable structure for CMAs.^43,44

For CMAs, a critical feature is the level of participation of the LLC members in the defined activities of the CMA.⁴² Participation requirements, such as meeting attendance, changes in practice based on defined goals and metrics, and financial contributions, must be included in the operating agreement of the LLC.³³ Compliance of all active members with these clearly defined requirements will both improve operations and morale and also decrease legal risk for both the CMA and its individual members.²⁸ Furthermore, certain conduct that may run afoul of regulations should be very specifically prohibited in the member contracts. Such behavior may include pay-for-referral arrangements rather than pay-for-performance, asymmetric income distribution through the LLC, and other activities that limit patient choice.³⁷ The salary and bonus structure must be very carefully designed and monitored, because they can have significant legal implications if not managed correctly. Independent audits should be part of the compliance plan for any CMA, and many authorities recommend limits on the total compensation to physicians as part of a CMA, as well as time limits on the agreement itself.⁴⁴

Leadership and Reporting Structure

All CMAs should have a medical director who is responsible for the success of the operation. Beneath the medical director, the leadership and reporting structure will vary based on the size of the hospital and the number of surgeons. In some situations, single individuals may assume multiple roles; other situations may dictate the need for many more people. The structure may take the shape of multiple directors and even a committee for the principal areas in a large institution, but only 1 or 2 additional individuals may be required in a small hospital setting. In any case, the leadership and reporting structure should be established as part of the basic formative documents of the CMA, with all duties and responsibilities of each participant clearly defined.

Facilities Management

Management of the physical and operational aspects of the site of service is a core component of any CMA. While the hospital usually owns the facilities, it is the surgeons who must work within them. The specifics of the physical plant can impact issues such as infection rate, inventory availability, maximum volume levels, and patient perception or satisfaction. The manner in which the facilities management conducts operations is also important; large size and nice equipment do not necessarily translate into efficiency or quality. A CMA should, therefore, have a surgeon or committee whose primary role is to oversee the relevant details of the hospital’s physical and operational issues. These details will include topics such as assignment of operative suites, choices of implants, room turnover, supplies, antibiotic availability, and other matters. Because of their experience and knowledge of the operational effects of administrative decisions, orthopedic surgeons are uniquely positioned to maximize the value of existing facilities and to oversee updates or changes as needed.

Personnel Management

Even in disadvantaged or smaller facilities, maximization of human resources can often overcome challenges of inadequate physical plant or tight finances. Alternatively, poor management of staff can thwart the efforts of even the largest and best-endowed hospitals. Because practicing orthopedists are likely to know the talents and skills of key local personnel from having worked alongside them, surgeons are well suited to help direct placement and management of personnel as part of a CMA. Surgeons can effectively identify behaviors that deserve reward and can identify staff members that refuse to be team players or otherwise do not help meet larger goals. Involvement of surgeons in personnel management also helps speed the ability to have near real-time responsiveness to issues that may arise. 

Clinical Data Management

Ultimately, quality metrics become the grading scale for the clinical aspects of the CMA. Selection of appropriate metrics constitutes a foundational element of the overall process and demands meticulous attention to detail.³⁸ Multiple site-specific clinical scoring systems exist in orthopedic surgery, from the International Knee Documentation Committee (IKDC) score for knees to the American Shoulder and Elbow Surgeons (ASES) score for shoulders.^45,46 Additional quality metrics exist for more generalized clinical success measurement, such as the Short Form–36 Health Survey (SF-36) score.⁴⁷ Governmental agencies and other national organizations have also mandated certain clinical metrics through programs such as the Surgical Care Improvement Project (SCIP).⁴⁸ Once the type and manner of desired clinical data are identified, they must be collected, processed, stored, and evaluated. Surgeon participation in and oversight of clinical data management is crucial, because orthopedists will be the best suited to interpret and apply the data and relevant trends and conclusions.

Financial Data Management

Financial concerns constitute perhaps the strongest driving force behind many of the current reform initiatives and alternative payment options in the health care landscape. For a CMA, financial success must be clearly and constantly measured and displayed for the endeavor to be successful. Since both sides have a large potential for financial gain and loss in a CMA, surgeons and hospitals must ensure that the best-qualified and most dedicated individuals oversee financial issues. Although transparency is important in all areas of a CMA, it is imperative and must be a dominating feature of the arrangement’s financial management. Financial goals, furthermore, must be clearly defined and realistic, with continuous reevaluation as the relationship moves forward. As part of the transparency plan, relevant financial data should be shared and discussed at regular intervals.

Quality and Effectiveness Reporting

An ideal co-management agreement not only reaches its goals of improved patient care and increased financial efficiency, but it can document and report achievement of these goals as well. Just as corporations must report their financial effectiveness to their shareholders, CMAs must report their own overall effectiveness to their respective stakeholders. Payers, patients, providers, and participant hospitals all have a stake in proving that the CMA has been successful—and that it will continue to be successful. Effectiveness reporting becomes the most important element of all, because the ultimate purpose is self-preservation of the CMA. Reporting should document successes and failures in all relevant elements of the arrangement, with a focus on clinical and financial data. Reports should employ both internal and external benchmarks as a means of evaluating results. Most CMAs will have a designated officer or committee tasked with the responsibility for measurement and reporting of quality and effectiveness.²⁶ Clinical and financial data are combined into an overall big picture of the achievements of the CMA.

Conclusion

Co-management arrangements represent a popular current option for physicians and surgeons to increase alignment and achieve the mutually beneficial goals of increased quality and efficiency. In orthopedics, CMAs essentially consist of surgeons and hospital administrators working together to manage the musculoskeletal service line at a hospital. While the details of specific arrangements will vary according to individual situations, certain basic principles and important general operational elements characterize most successful CMAs. Since physician ownership of hospitals is now banned under the Affordable Care Act, CMAs can be seen as a physician-managed hospital within a hospital, with many of the benefits that have historically resulted from physician ownership and participation in management.^27,49 As health care reform progresses, CMAs will likely become more widespread, more refined, more effective, and more profitable.

Abaloparatide-SC, an injectable drug being studied for the treatment of postmenopausal osteoporosis, reduces the rate of new spinal fractures by 86%, as well as provide statistically significant reductions in the fracture rate at other parts of the body, according to data from the phase 3 ACTIVE fracture prevention trial (ACTIVE trial). Results from the ACTIVE trial were reported at the Endocrine Society’s 97th Annual Meeting in San Diego.

“The investigational drug abaloparatide-SC, if approved, may offer patients the potential to reduce their risk of fracture and increase bone density at all sites, even the most difficult to treat, such as the hip and wrist,” said lead investigator Paul Miller, MD, Medical Director of the Colorado Center for Bone Research in Lakewood.

Abaloparatide-SC is a new manmade form of human parathyroid hormone-related protein that is manufactured by Radius Health (Waltham, Massachusetts). The drugmaker is studying the medication in various forms, including a transdermal patch, in addition to the subcutaneous injection studied in the ACTIVE trial.

During the ACTIVE trial, researchers studied whether abaloparatide-SC can reduce fractures in postmenopausal women with severe osteoporosis who have a high fracture risk. The investigators compared rates of new fractures in 690 women who received a daily injection of abaloparatide-SC (80 mcg) and 711 women who received inactive placebo shots. Neither group of women knew which treatment they received. A third group of 717 women received a daily injection of teriparatide (20 mcg) in an unblinded fashion. All patients also received calcium and vitamin D supplements.

Over 18 months of treatment, the abaloparatide-SC-treated group had the greatest reduction in the rate of new vertebral fractures shown on x-ray, Dr. Miller reported. Compared with the placebo group’s new vertebral fracture rate of 4.2%, women who were treated with abaloparatide-SC had a new vertebral fracture rate of about 0.58%, representing an 86% reduction in the rate of broken bones at the spine, according to Dr. Miller.

“We believe this reduction seen in the abaloparatide-SC-treated group could be the largest reduction ever demonstrated in the vertebral fracture rate for any potential therapeutic drug being researched for the treatment of postmenopausal osteoporosis,” Dr. Miller said.

For nonvertebral fractures, Dr. Miller said abaloparatide-SC treatment had a 43% fracture-rate reduction compared to that of placebo. The rate of vertebral and nonvertebral fractures combined decreased by 45% in the abaloparatide-SC-treated group versus the placebo group. Additionally, the time to the first nonvertebral fracture was significantly delayed for women receiving abaloparatide-SC than for those who received a placebo, he said.

Results of patients’ bone mineral density tests also were compared between the two drug treatment groups. “Abaloparatide-SC resulted in more bone growth, at a faster rate, at more skeletal sites, and in more patients than teriparatide,” stated Dr. Miller.

Abaloparatide-SC, an injectable drug being studied for the treatment of postmenopausal osteoporosis, reduces the rate of new spinal fractures by 86%, as well as provide statistically significant reductions in the fracture rate at other parts of the body, according to data from the phase 3 ACTIVE fracture prevention trial (ACTIVE trial). Results from the ACTIVE trial were reported at the Endocrine Society’s 97th Annual Meeting in San Diego.

“The investigational drug abaloparatide-SC, if approved, may offer patients the potential to reduce their risk of fracture and increase bone density at all sites, even the most difficult to treat, such as the hip and wrist,” said lead investigator Paul Miller, MD, Medical Director of the Colorado Center for Bone Research in Lakewood.

Abaloparatide-SC is a new manmade form of human parathyroid hormone-related protein that is manufactured by Radius Health (Waltham, Massachusetts). The drugmaker is studying the medication in various forms, including a transdermal patch, in addition to the subcutaneous injection studied in the ACTIVE trial.

During the ACTIVE trial, researchers studied whether abaloparatide-SC can reduce fractures in postmenopausal women with severe osteoporosis who have a high fracture risk. The investigators compared rates of new fractures in 690 women who received a daily injection of abaloparatide-SC (80 mcg) and 711 women who received inactive placebo shots. Neither group of women knew which treatment they received. A third group of 717 women received a daily injection of teriparatide (20 mcg) in an unblinded fashion. All patients also received calcium and vitamin D supplements.

Over 18 months of treatment, the abaloparatide-SC-treated group had the greatest reduction in the rate of new vertebral fractures shown on x-ray, Dr. Miller reported. Compared with the placebo group’s new vertebral fracture rate of 4.2%, women who were treated with abaloparatide-SC had a new vertebral fracture rate of about 0.58%, representing an 86% reduction in the rate of broken bones at the spine, according to Dr. Miller.

“We believe this reduction seen in the abaloparatide-SC-treated group could be the largest reduction ever demonstrated in the vertebral fracture rate for any potential therapeutic drug being researched for the treatment of postmenopausal osteoporosis,” Dr. Miller said.

For nonvertebral fractures, Dr. Miller said abaloparatide-SC treatment had a 43% fracture-rate reduction compared to that of placebo. The rate of vertebral and nonvertebral fractures combined decreased by 45% in the abaloparatide-SC-treated group versus the placebo group. Additionally, the time to the first nonvertebral fracture was significantly delayed for women receiving abaloparatide-SC than for those who received a placebo, he said.

Results of patients’ bone mineral density tests also were compared between the two drug treatment groups. “Abaloparatide-SC resulted in more bone growth, at a faster rate, at more skeletal sites, and in more patients than teriparatide,” stated Dr. Miller.

Abaloparatide-SC, an injectable drug being studied for the treatment of postmenopausal osteoporosis, reduces the rate of new spinal fractures by 86%, as well as provide statistically significant reductions in the fracture rate at other parts of the body, according to data from the phase 3 ACTIVE fracture prevention trial (ACTIVE trial). Results from the ACTIVE trial were reported at the Endocrine Society’s 97th Annual Meeting in San Diego.

“The investigational drug abaloparatide-SC, if approved, may offer patients the potential to reduce their risk of fracture and increase bone density at all sites, even the most difficult to treat, such as the hip and wrist,” said lead investigator Paul Miller, MD, Medical Director of the Colorado Center for Bone Research in Lakewood.

Abaloparatide-SC is a new manmade form of human parathyroid hormone-related protein that is manufactured by Radius Health (Waltham, Massachusetts). The drugmaker is studying the medication in various forms, including a transdermal patch, in addition to the subcutaneous injection studied in the ACTIVE trial.

During the ACTIVE trial, researchers studied whether abaloparatide-SC can reduce fractures in postmenopausal women with severe osteoporosis who have a high fracture risk. The investigators compared rates of new fractures in 690 women who received a daily injection of abaloparatide-SC (80 mcg) and 711 women who received inactive placebo shots. Neither group of women knew which treatment they received. A third group of 717 women received a daily injection of teriparatide (20 mcg) in an unblinded fashion. All patients also received calcium and vitamin D supplements.

Over 18 months of treatment, the abaloparatide-SC-treated group had the greatest reduction in the rate of new vertebral fractures shown on x-ray, Dr. Miller reported. Compared with the placebo group’s new vertebral fracture rate of 4.2%, women who were treated with abaloparatide-SC had a new vertebral fracture rate of about 0.58%, representing an 86% reduction in the rate of broken bones at the spine, according to Dr. Miller.

“We believe this reduction seen in the abaloparatide-SC-treated group could be the largest reduction ever demonstrated in the vertebral fracture rate for any potential therapeutic drug being researched for the treatment of postmenopausal osteoporosis,” Dr. Miller said.

For nonvertebral fractures, Dr. Miller said abaloparatide-SC treatment had a 43% fracture-rate reduction compared to that of placebo. The rate of vertebral and nonvertebral fractures combined decreased by 45% in the abaloparatide-SC-treated group versus the placebo group. Additionally, the time to the first nonvertebral fracture was significantly delayed for women receiving abaloparatide-SC than for those who received a placebo, he said.

Results of patients’ bone mineral density tests also were compared between the two drug treatment groups. “Abaloparatide-SC resulted in more bone growth, at a faster rate, at more skeletal sites, and in more patients than teriparatide,” stated Dr. Miller.

Patients who have osteoporosis face a 1.76-fold higher risk of developing sudden sensorineural hearing loss (SSHL) than those who do not have the bone disease, according to a study published online ahead of print April 16 in the Journal of Clinical Endocrinology & Metabolism.

“A growing body of evidence indicates that osteoporosis affects not only bone health, but the cardiovascular and cerebrovascular systems,” said study author Kai-Jen Tien, MD, from the Chi Mei Medical Center in Taiwan.

SSHL, also called sudden deafness, is an unexplained, rapid loss of hearing that typically happens in one ear, according to the National Institute on Deafness and Other Communication Disorders. It can happen at once or over the course of several days. Although about half of the people who develop SSHL will spontaneously regain their hearing, immediate treatment is recommended. About 85% of those who are treated for the condition recover some hearing.

This retrospective cohort study examined medical records for 10,660 Taiwan residents who were diagnosed with osteoporosis between 1999 and 2008, and compared them to 31,980 controls who did not have the condition. Using national insurance records, the researchers analyzed how many participants were diagnosed with sudden deafness by the end of 2011.

The participants who were diagnosed with osteoporosis had a much higher risk of developing SSHL than the control group. Among the participants who had osteoporosis, 91 were diagnosed with SSHL during the follow-up period. In comparison, the control group, which was triple the size, included 155 people who were diagnosed with SSHL.

Dr. Tien and colleagues theorized that cardiovascular risk factors, bone demineralization, inflammation, and endothelial dysfunction may contribute to the association between osteoporosis and SSHL.

“More people worldwide are suffering from osteoporosis, and our work shows they are at risk of sensorineural hearing loss, as well as bone fracture and other problems,” Dr. Tien said. “Patients who have osteoporosis should be aware they need to seek medical help immediately if they experience hearing loss.”

Dr. Tien stated, “Our findings suggest sudden sensorineural hearing loss can be another broader health problem connected to osteoporosis.”

Patients who have osteoporosis face a 1.76-fold higher risk of developing sudden sensorineural hearing loss (SSHL) than those who do not have the bone disease, according to a study published online ahead of print April 16 in the Journal of Clinical Endocrinology & Metabolism.

“A growing body of evidence indicates that osteoporosis affects not only bone health, but the cardiovascular and cerebrovascular systems,” said study author Kai-Jen Tien, MD, from the Chi Mei Medical Center in Taiwan.

SSHL, also called sudden deafness, is an unexplained, rapid loss of hearing that typically happens in one ear, according to the National Institute on Deafness and Other Communication Disorders. It can happen at once or over the course of several days. Although about half of the people who develop SSHL will spontaneously regain their hearing, immediate treatment is recommended. About 85% of those who are treated for the condition recover some hearing.

This retrospective cohort study examined medical records for 10,660 Taiwan residents who were diagnosed with osteoporosis between 1999 and 2008, and compared them to 31,980 controls who did not have the condition. Using national insurance records, the researchers analyzed how many participants were diagnosed with sudden deafness by the end of 2011.

The participants who were diagnosed with osteoporosis had a much higher risk of developing SSHL than the control group. Among the participants who had osteoporosis, 91 were diagnosed with SSHL during the follow-up period. In comparison, the control group, which was triple the size, included 155 people who were diagnosed with SSHL.

Dr. Tien and colleagues theorized that cardiovascular risk factors, bone demineralization, inflammation, and endothelial dysfunction may contribute to the association between osteoporosis and SSHL.

“More people worldwide are suffering from osteoporosis, and our work shows they are at risk of sensorineural hearing loss, as well as bone fracture and other problems,” Dr. Tien said. “Patients who have osteoporosis should be aware they need to seek medical help immediately if they experience hearing loss.”

Dr. Tien stated, “Our findings suggest sudden sensorineural hearing loss can be another broader health problem connected to osteoporosis.”

Patients who have osteoporosis face a 1.76-fold higher risk of developing sudden sensorineural hearing loss (SSHL) than those who do not have the bone disease, according to a study published online ahead of print April 16 in the Journal of Clinical Endocrinology & Metabolism.

“A growing body of evidence indicates that osteoporosis affects not only bone health, but the cardiovascular and cerebrovascular systems,” said study author Kai-Jen Tien, MD, from the Chi Mei Medical Center in Taiwan.

SSHL, also called sudden deafness, is an unexplained, rapid loss of hearing that typically happens in one ear, according to the National Institute on Deafness and Other Communication Disorders. It can happen at once or over the course of several days. Although about half of the people who develop SSHL will spontaneously regain their hearing, immediate treatment is recommended. About 85% of those who are treated for the condition recover some hearing.

This retrospective cohort study examined medical records for 10,660 Taiwan residents who were diagnosed with osteoporosis between 1999 and 2008, and compared them to 31,980 controls who did not have the condition. Using national insurance records, the researchers analyzed how many participants were diagnosed with sudden deafness by the end of 2011.

The participants who were diagnosed with osteoporosis had a much higher risk of developing SSHL than the control group. Among the participants who had osteoporosis, 91 were diagnosed with SSHL during the follow-up period. In comparison, the control group, which was triple the size, included 155 people who were diagnosed with SSHL.

Dr. Tien and colleagues theorized that cardiovascular risk factors, bone demineralization, inflammation, and endothelial dysfunction may contribute to the association between osteoporosis and SSHL.

“More people worldwide are suffering from osteoporosis, and our work shows they are at risk of sensorineural hearing loss, as well as bone fracture and other problems,” Dr. Tien said. “Patients who have osteoporosis should be aware they need to seek medical help immediately if they experience hearing loss.”

Dr. Tien stated, “Our findings suggest sudden sensorineural hearing loss can be another broader health problem connected to osteoporosis.”

Most patients who underwent surgery to repair and rebuild an anterior cruciate ligament (ACL) tear showed significant improvement in physical function at 2 years, which continued for at least 6 years following surgery, according to a study published April 1 in the Journal of Bone & Joint Surgery. Younger patient age, lower body mass index, and having the remnants of the torn ACL completely excised during surgery were among the strongest predictors of positive, long-term outcome.

In this study, researchers reviewed and evaluated the outcomes of 1,411 patients (44% female; average patient age at enrollment, 23) who underwent ACL surgery between 2002 and 2004 at four major medical centers. Each patient completed questionnaires that assessed health, well-being, and function prior to surgery, and again at 2 and 6 years after surgery.

“We found that health-related quality of life was significantly improved following ACL reconstruction, and this improvement was still present 6 years following surgery,” said lead study author Warren R. Dunn, MD, MPH, an orthopedic surgeon at the University of Wisconsin in Madison.

At baseline, the average physical health score was 41.9 and the mean mental health score was 51.7. At 2 years after surgery, the physical and mental health scores were stable at 53.6 and 52 points, respectively, and 54 and 52.4 points at year 6.

Among the study’s findings:

• ACL reconstruction resulted in large improvements in the physical function scores, with a mean improvement of 12 points (out of 100) at 2 years and 6 years following surgery.

• At 6 years following ACL surgery, patients gained a mean 5.3 quality-adjusted life years.

• Baseline activity level was a significant predictor of mental health scores, but not physical function scores.

• Predictors of worse postoperative outcomes were a shorter follow-up time post-surgery, revision ACL reconstruction, smoking at baseline, fewer years of education, and damage to the cartilage under the chondromalacia patella.

• Physical function continued to improve over the long term following reconstruction. Patients requiring a revision reconstruction did not fare as well as patients undergoing a single reconstruction.

• Mental health scores over the 6-year period did not significantly change, but scores consistently remained above the population norm of 50 points.

“The predictors for good and poorer outcomes may be helpful when counseling patients who are considering ACL surgery,” stated Dr. Dunn.

Most patients who underwent surgery to repair and rebuild an anterior cruciate ligament (ACL) tear showed significant improvement in physical function at 2 years, which continued for at least 6 years following surgery, according to a study published April 1 in the Journal of Bone & Joint Surgery. Younger patient age, lower body mass index, and having the remnants of the torn ACL completely excised during surgery were among the strongest predictors of positive, long-term outcome.

In this study, researchers reviewed and evaluated the outcomes of 1,411 patients (44% female; average patient age at enrollment, 23) who underwent ACL surgery between 2002 and 2004 at four major medical centers. Each patient completed questionnaires that assessed health, well-being, and function prior to surgery, and again at 2 and 6 years after surgery.

“We found that health-related quality of life was significantly improved following ACL reconstruction, and this improvement was still present 6 years following surgery,” said lead study author Warren R. Dunn, MD, MPH, an orthopedic surgeon at the University of Wisconsin in Madison.

At baseline, the average physical health score was 41.9 and the mean mental health score was 51.7. At 2 years after surgery, the physical and mental health scores were stable at 53.6 and 52 points, respectively, and 54 and 52.4 points at year 6.

Among the study’s findings:

• ACL reconstruction resulted in large improvements in the physical function scores, with a mean improvement of 12 points (out of 100) at 2 years and 6 years following surgery.

• At 6 years following ACL surgery, patients gained a mean 5.3 quality-adjusted life years.

• Baseline activity level was a significant predictor of mental health scores, but not physical function scores.

• Predictors of worse postoperative outcomes were a shorter follow-up time post-surgery, revision ACL reconstruction, smoking at baseline, fewer years of education, and damage to the cartilage under the chondromalacia patella.

• Physical function continued to improve over the long term following reconstruction. Patients requiring a revision reconstruction did not fare as well as patients undergoing a single reconstruction.

• Mental health scores over the 6-year period did not significantly change, but scores consistently remained above the population norm of 50 points.

“The predictors for good and poorer outcomes may be helpful when counseling patients who are considering ACL surgery,” stated Dr. Dunn.

Most patients who underwent surgery to repair and rebuild an anterior cruciate ligament (ACL) tear showed significant improvement in physical function at 2 years, which continued for at least 6 years following surgery, according to a study published April 1 in the Journal of Bone & Joint Surgery. Younger patient age, lower body mass index, and having the remnants of the torn ACL completely excised during surgery were among the strongest predictors of positive, long-term outcome.

In this study, researchers reviewed and evaluated the outcomes of 1,411 patients (44% female; average patient age at enrollment, 23) who underwent ACL surgery between 2002 and 2004 at four major medical centers. Each patient completed questionnaires that assessed health, well-being, and function prior to surgery, and again at 2 and 6 years after surgery.

“We found that health-related quality of life was significantly improved following ACL reconstruction, and this improvement was still present 6 years following surgery,” said lead study author Warren R. Dunn, MD, MPH, an orthopedic surgeon at the University of Wisconsin in Madison.

At baseline, the average physical health score was 41.9 and the mean mental health score was 51.7. At 2 years after surgery, the physical and mental health scores were stable at 53.6 and 52 points, respectively, and 54 and 52.4 points at year 6.

Among the study’s findings:

• ACL reconstruction resulted in large improvements in the physical function scores, with a mean improvement of 12 points (out of 100) at 2 years and 6 years following surgery.

• At 6 years following ACL surgery, patients gained a mean 5.3 quality-adjusted life years.

• Baseline activity level was a significant predictor of mental health scores, but not physical function scores.

• Predictors of worse postoperative outcomes were a shorter follow-up time post-surgery, revision ACL reconstruction, smoking at baseline, fewer years of education, and damage to the cartilage under the chondromalacia patella.

• Physical function continued to improve over the long term following reconstruction. Patients requiring a revision reconstruction did not fare as well as patients undergoing a single reconstruction.

• Mental health scores over the 6-year period did not significantly change, but scores consistently remained above the population norm of 50 points.

“The predictors for good and poorer outcomes may be helpful when counseling patients who are considering ACL surgery,” stated Dr. Dunn.

Hibernomas are rare benign soft-tissue tumors originally described as pseudolipomas by Merkel¹ in 1906. Gery coined the term hibernoma in 1914, after noting the multivacuolated cytoplasm of the tumor cells and its resemblance to normal brown fat found in hibernating animals.²

Hibernomas represent 2% of all benign fat-containing tumors and are composed of brown adipocytes, which are histologically different from the white fat of lipomas. Hibernomas usually develop between ages 20 and 40 years, and their incidence is slightly higher in males.

Diffusely present in human newborns, brown fat usually regresses by 8 weeks of age.³ Residual brown fat deposits may remain in the neck, axilla, shoulder, thorax, thigh, retroperitoneum, and periscapular/interscapular regions.⁴ All these vestigial areas are therefore common locations of hibernomas, with the thigh accounting for up to 30% of cases.⁵ These tumors are seldom identified in the abdomen, popliteal fossa, or even intracranially. Injury to brown fat cells in these locations, either by infection, inflammation, or trauma, is considered a predisposing risk factor for development of hibernomas.⁶

Clinical Presentation

Clinically, hibernomas present as slow-growing, painless soft-tissue masses. Physical examination usually reveals a palpable, solitary, soft, and rubbery mass within the subcutaneous fat, which is freely mobile and not attached to deep layers. These tumors may rarely produce steroid hormones and result in a paraneoplastic syndrome. Even though these tumors are usually large at presentation, compression of adjacent structures seldom occurs.

Histology and Differential Diagnosis

The characteristic hibernoma cell is a multivacuolated adipocyte with centrally located nucleus, indistinct nucleolus, and coarsely granular eosinophilic (or pale) cytoplasm (Figure 1). Cytoplasmic vacuoles are uniform, round, regular, and small and stain for neutral fat. Nuclei are usually small with no or rare atypia. These multivacuolated brown fat–like tumor cells usually stain positive for S100 and CD31, usually stain negative for CD34 and p53, and can show 11q13-21 rearrangements, also seen in lipomas and liposarcomas. Hibernomas have 4 histologic variants: typical (classic), myxoid, lipoma-like, and spindle-cell.⁵ The typical hibernoma, the most common, contains a varying mixture of brown and white fat cells. The myxoid type, second most common, is composed of hibernoma cells floating in a loose acellular myxoid stroma. The lipoma-like variant consists of a few scattered hibernoma cells in a predominance of white fat cells. The spindle-cell variant, the rarest, has features of typical hibernoma and spindle-cell lipoma.⁷

Grossly, hibernomas are well encapsulated, soft, and lobular with prominent feeding vessels.⁸ They typically are tan or brown because of their hypervascularity and abundant mitochondria. Tumor size ranges from 1 to 24 cm (mean, 9.4 cm).⁹ These tumors are well-defined intermuscular/intramuscular, subcutaneous, or retroperitoneal lesions that tend to grow along fascial planes and displace surrounding structures rather than invade them. Delicate branching capillaries are usually seen within the tumor.

Although rare, hibernoma should be included in the differential diagnosis of lipomatous soft-tissue tumors.¹⁰ Imaging findings of hibernoma are not specific; other differential diagnostic considerations for a mass with a signal similar to that of fat or containing large intratumoral vessels include angiolipoma, intramuscular hemangioma with fat, spindle-cell lipoma, pleomorphic lipoma, lipoblastoma, hemangiopericytoma, and hemangioblastoma,^11-15 as well as malignant processes, including lipoma-like well-differentiated liposarcoma and myxoid liposarcoma.¹⁶ Other entities that should be considered include residual brown fat and rhabdomyoma.

Hibernomas are histologically distinguished from well-differentiated liposarcomas by location (liposarcomas tend to be deep), atypia, presence of a prominent “plexiform” capillary pattern, and specific molecular translocations, including t (12;16). Lipomas have lipocytes that are not multivacuolated, and residual brown fat does not present as a distinct mass. Rhabdomyomas are distinguished by an absence of cytoplasmic lipid vacuoles.

Imaging

Conventional radiography may show a radiolucent mass without internal mineralization or associated osseous abnormalities⁴ (Figure 2). Calcifications are notably absent.¹⁷ Sonographically, hibernomas are well-circumscribed, solid, hyperechoic masses with increased internal vascular flow on both grayscale and color Doppler sampling; however their appearance is not pathognomonic (Figure 3). Angiography reveals a hypervascular tumor that may have internal arteriovenous shunting.¹⁸ Hibernomas have a heterogeneous appearance on computed tomography (CT) and magnetic resonance imaging (MRI) because of the variable distribution of brown fat cells, white fat cells, myxoid material, and spindle cells within the individual tumor subtypes.⁵ CT of these tumors shows internal septations and low attenuation values, between those of fat and muscle¹⁹ (Figure 4). Intravenous contrast enhances internal septa, but enhancement varies from none to intense, and from generalized to focal, depending on internal tumor composition.^3,17,20-22

Hibernomas are usually hyperintense to skeletal muscle on T1-weighted MRI but slightly hypointense to subcutaneous fat because of the different gyromagnetic ratios and precessional frequencies of protons in white fat versus those in brown fat¹⁷ (Figure 5). Rarely, lesions are isointense to skeletal muscle on T1-weighted images.²³ On T2-weighted images, high signal intensity similar to that of subcutaneous fat is typical.²⁴ Flow voids can be readily identified.²⁵ Short tau inversion recovery (STIR) MRI shows some areas with signal intensity higher than that of subcutaneous fat, and other areas of fat suppression.⁹ Ritchie and colleagues²¹ reported that hibernomas histologically composed of more than 70% multivacuolated adipocytes tended to have MRI signal characteristics different from those of subcutaneous fat, and those with less than 70% multivacuolated adipocytes tended to have signal characteristics paralleling those of subcutaneous fat. Myxoid hibernomas have higher signal intensity on T2-weighted and STIR MRI because of high water content.^17,21,26,27

Hibernomas demonstrate moderate uptake on bone scintigraphy blood pool images and mild uptake on delayed images.⁴ Positron emission tomography (PET) is useful in differentiating hibernomas from other fat-containing lesions.⁹ Hibernomas demonstrate intense fluorine-18 fluorodeoxyglucose uptake because, unlike other adipogenic tumors, hibernomas contain abundant mitochondria and are highly metabolically active.²⁸

Treatment and Prognosis

Complete surgical excision is the treatment of choice; given the behavior of the benign tumor, marginal complete excision is considered curative.⁵ Intralesional excision may be the only option for large tumors that are near nerves or vessels. However, intralesional excision may result in continued growth and local recurrence.

At surgery, these tumors usually are encapsulated and/or adherent to skeletal muscle or bone, without invasion, and easily separated from surrounding soft tissues.²⁹ No specific surgical considerations are required beyond standard oncological principles, including careful dissection of adjacent nerves and vessels, and hemostasis. Hibernomas have the potential for significant bleeding during surgical excision. In this setting, embolization becomes a consideration, given the identification of large intratumoral vessels and the benign course of these lesions.

Hibernomas are rare benign soft-tissue tumors originally described as pseudolipomas by Merkel¹ in 1906. Gery coined the term hibernoma in 1914, after noting the multivacuolated cytoplasm of the tumor cells and its resemblance to normal brown fat found in hibernating animals.²

Hibernomas represent 2% of all benign fat-containing tumors and are composed of brown adipocytes, which are histologically different from the white fat of lipomas. Hibernomas usually develop between ages 20 and 40 years, and their incidence is slightly higher in males.

Diffusely present in human newborns, brown fat usually regresses by 8 weeks of age.³ Residual brown fat deposits may remain in the neck, axilla, shoulder, thorax, thigh, retroperitoneum, and periscapular/interscapular regions.⁴ All these vestigial areas are therefore common locations of hibernomas, with the thigh accounting for up to 30% of cases.⁵ These tumors are seldom identified in the abdomen, popliteal fossa, or even intracranially. Injury to brown fat cells in these locations, either by infection, inflammation, or trauma, is considered a predisposing risk factor for development of hibernomas.⁶

Clinical Presentation

Clinically, hibernomas present as slow-growing, painless soft-tissue masses. Physical examination usually reveals a palpable, solitary, soft, and rubbery mass within the subcutaneous fat, which is freely mobile and not attached to deep layers. These tumors may rarely produce steroid hormones and result in a paraneoplastic syndrome. Even though these tumors are usually large at presentation, compression of adjacent structures seldom occurs.

Histology and Differential Diagnosis

The characteristic hibernoma cell is a multivacuolated adipocyte with centrally located nucleus, indistinct nucleolus, and coarsely granular eosinophilic (or pale) cytoplasm (Figure 1). Cytoplasmic vacuoles are uniform, round, regular, and small and stain for neutral fat. Nuclei are usually small with no or rare atypia. These multivacuolated brown fat–like tumor cells usually stain positive for S100 and CD31, usually stain negative for CD34 and p53, and can show 11q13-21 rearrangements, also seen in lipomas and liposarcomas. Hibernomas have 4 histologic variants: typical (classic), myxoid, lipoma-like, and spindle-cell.⁵ The typical hibernoma, the most common, contains a varying mixture of brown and white fat cells. The myxoid type, second most common, is composed of hibernoma cells floating in a loose acellular myxoid stroma. The lipoma-like variant consists of a few scattered hibernoma cells in a predominance of white fat cells. The spindle-cell variant, the rarest, has features of typical hibernoma and spindle-cell lipoma.⁷

Grossly, hibernomas are well encapsulated, soft, and lobular with prominent feeding vessels.⁸ They typically are tan or brown because of their hypervascularity and abundant mitochondria. Tumor size ranges from 1 to 24 cm (mean, 9.4 cm).⁹ These tumors are well-defined intermuscular/intramuscular, subcutaneous, or retroperitoneal lesions that tend to grow along fascial planes and displace surrounding structures rather than invade them. Delicate branching capillaries are usually seen within the tumor.

Although rare, hibernoma should be included in the differential diagnosis of lipomatous soft-tissue tumors.¹⁰ Imaging findings of hibernoma are not specific; other differential diagnostic considerations for a mass with a signal similar to that of fat or containing large intratumoral vessels include angiolipoma, intramuscular hemangioma with fat, spindle-cell lipoma, pleomorphic lipoma, lipoblastoma, hemangiopericytoma, and hemangioblastoma,^11-15 as well as malignant processes, including lipoma-like well-differentiated liposarcoma and myxoid liposarcoma.¹⁶ Other entities that should be considered include residual brown fat and rhabdomyoma.

Hibernomas are histologically distinguished from well-differentiated liposarcomas by location (liposarcomas tend to be deep), atypia, presence of a prominent “plexiform” capillary pattern, and specific molecular translocations, including t (12;16). Lipomas have lipocytes that are not multivacuolated, and residual brown fat does not present as a distinct mass. Rhabdomyomas are distinguished by an absence of cytoplasmic lipid vacuoles.

Imaging

Conventional radiography may show a radiolucent mass without internal mineralization or associated osseous abnormalities⁴ (Figure 2). Calcifications are notably absent.¹⁷ Sonographically, hibernomas are well-circumscribed, solid, hyperechoic masses with increased internal vascular flow on both grayscale and color Doppler sampling; however their appearance is not pathognomonic (Figure 3). Angiography reveals a hypervascular tumor that may have internal arteriovenous shunting.¹⁸ Hibernomas have a heterogeneous appearance on computed tomography (CT) and magnetic resonance imaging (MRI) because of the variable distribution of brown fat cells, white fat cells, myxoid material, and spindle cells within the individual tumor subtypes.⁵ CT of these tumors shows internal septations and low attenuation values, between those of fat and muscle¹⁹ (Figure 4). Intravenous contrast enhances internal septa, but enhancement varies from none to intense, and from generalized to focal, depending on internal tumor composition.^3,17,20-22

Hibernomas are usually hyperintense to skeletal muscle on T1-weighted MRI but slightly hypointense to subcutaneous fat because of the different gyromagnetic ratios and precessional frequencies of protons in white fat versus those in brown fat¹⁷ (Figure 5). Rarely, lesions are isointense to skeletal muscle on T1-weighted images.²³ On T2-weighted images, high signal intensity similar to that of subcutaneous fat is typical.²⁴ Flow voids can be readily identified.²⁵ Short tau inversion recovery (STIR) MRI shows some areas with signal intensity higher than that of subcutaneous fat, and other areas of fat suppression.⁹ Ritchie and colleagues²¹ reported that hibernomas histologically composed of more than 70% multivacuolated adipocytes tended to have MRI signal characteristics different from those of subcutaneous fat, and those with less than 70% multivacuolated adipocytes tended to have signal characteristics paralleling those of subcutaneous fat. Myxoid hibernomas have higher signal intensity on T2-weighted and STIR MRI because of high water content.^17,21,26,27

Hibernomas demonstrate moderate uptake on bone scintigraphy blood pool images and mild uptake on delayed images.⁴ Positron emission tomography (PET) is useful in differentiating hibernomas from other fat-containing lesions.⁹ Hibernomas demonstrate intense fluorine-18 fluorodeoxyglucose uptake because, unlike other adipogenic tumors, hibernomas contain abundant mitochondria and are highly metabolically active.²⁸

Treatment and Prognosis

Complete surgical excision is the treatment of choice; given the behavior of the benign tumor, marginal complete excision is considered curative.⁵ Intralesional excision may be the only option for large tumors that are near nerves or vessels. However, intralesional excision may result in continued growth and local recurrence.

At surgery, these tumors usually are encapsulated and/or adherent to skeletal muscle or bone, without invasion, and easily separated from surrounding soft tissues.²⁹ No specific surgical considerations are required beyond standard oncological principles, including careful dissection of adjacent nerves and vessels, and hemostasis. Hibernomas have the potential for significant bleeding during surgical excision. In this setting, embolization becomes a consideration, given the identification of large intratumoral vessels and the benign course of these lesions.

Hibernomas are rare benign soft-tissue tumors originally described as pseudolipomas by Merkel¹ in 1906. Gery coined the term hibernoma in 1914, after noting the multivacuolated cytoplasm of the tumor cells and its resemblance to normal brown fat found in hibernating animals.²

Hibernomas represent 2% of all benign fat-containing tumors and are composed of brown adipocytes, which are histologically different from the white fat of lipomas. Hibernomas usually develop between ages 20 and 40 years, and their incidence is slightly higher in males.

Diffusely present in human newborns, brown fat usually regresses by 8 weeks of age.³ Residual brown fat deposits may remain in the neck, axilla, shoulder, thorax, thigh, retroperitoneum, and periscapular/interscapular regions.⁴ All these vestigial areas are therefore common locations of hibernomas, with the thigh accounting for up to 30% of cases.⁵ These tumors are seldom identified in the abdomen, popliteal fossa, or even intracranially. Injury to brown fat cells in these locations, either by infection, inflammation, or trauma, is considered a predisposing risk factor for development of hibernomas.⁶

Clinical Presentation

Clinically, hibernomas present as slow-growing, painless soft-tissue masses. Physical examination usually reveals a palpable, solitary, soft, and rubbery mass within the subcutaneous fat, which is freely mobile and not attached to deep layers. These tumors may rarely produce steroid hormones and result in a paraneoplastic syndrome. Even though these tumors are usually large at presentation, compression of adjacent structures seldom occurs.

Histology and Differential Diagnosis

The characteristic hibernoma cell is a multivacuolated adipocyte with centrally located nucleus, indistinct nucleolus, and coarsely granular eosinophilic (or pale) cytoplasm (Figure 1). Cytoplasmic vacuoles are uniform, round, regular, and small and stain for neutral fat. Nuclei are usually small with no or rare atypia. These multivacuolated brown fat–like tumor cells usually stain positive for S100 and CD31, usually stain negative for CD34 and p53, and can show 11q13-21 rearrangements, also seen in lipomas and liposarcomas. Hibernomas have 4 histologic variants: typical (classic), myxoid, lipoma-like, and spindle-cell.⁵ The typical hibernoma, the most common, contains a varying mixture of brown and white fat cells. The myxoid type, second most common, is composed of hibernoma cells floating in a loose acellular myxoid stroma. The lipoma-like variant consists of a few scattered hibernoma cells in a predominance of white fat cells. The spindle-cell variant, the rarest, has features of typical hibernoma and spindle-cell lipoma.⁷

Grossly, hibernomas are well encapsulated, soft, and lobular with prominent feeding vessels.⁸ They typically are tan or brown because of their hypervascularity and abundant mitochondria. Tumor size ranges from 1 to 24 cm (mean, 9.4 cm).⁹ These tumors are well-defined intermuscular/intramuscular, subcutaneous, or retroperitoneal lesions that tend to grow along fascial planes and displace surrounding structures rather than invade them. Delicate branching capillaries are usually seen within the tumor.

Although rare, hibernoma should be included in the differential diagnosis of lipomatous soft-tissue tumors.¹⁰ Imaging findings of hibernoma are not specific; other differential diagnostic considerations for a mass with a signal similar to that of fat or containing large intratumoral vessels include angiolipoma, intramuscular hemangioma with fat, spindle-cell lipoma, pleomorphic lipoma, lipoblastoma, hemangiopericytoma, and hemangioblastoma,^11-15 as well as malignant processes, including lipoma-like well-differentiated liposarcoma and myxoid liposarcoma.¹⁶ Other entities that should be considered include residual brown fat and rhabdomyoma.

Hibernomas are histologically distinguished from well-differentiated liposarcomas by location (liposarcomas tend to be deep), atypia, presence of a prominent “plexiform” capillary pattern, and specific molecular translocations, including t (12;16). Lipomas have lipocytes that are not multivacuolated, and residual brown fat does not present as a distinct mass. Rhabdomyomas are distinguished by an absence of cytoplasmic lipid vacuoles.

Imaging

Conventional radiography may show a radiolucent mass without internal mineralization or associated osseous abnormalities⁴ (Figure 2). Calcifications are notably absent.¹⁷ Sonographically, hibernomas are well-circumscribed, solid, hyperechoic masses with increased internal vascular flow on both grayscale and color Doppler sampling; however their appearance is not pathognomonic (Figure 3). Angiography reveals a hypervascular tumor that may have internal arteriovenous shunting.¹⁸ Hibernomas have a heterogeneous appearance on computed tomography (CT) and magnetic resonance imaging (MRI) because of the variable distribution of brown fat cells, white fat cells, myxoid material, and spindle cells within the individual tumor subtypes.⁵ CT of these tumors shows internal septations and low attenuation values, between those of fat and muscle¹⁹ (Figure 4). Intravenous contrast enhances internal septa, but enhancement varies from none to intense, and from generalized to focal, depending on internal tumor composition.^3,17,20-22

Hibernomas are usually hyperintense to skeletal muscle on T1-weighted MRI but slightly hypointense to subcutaneous fat because of the different gyromagnetic ratios and precessional frequencies of protons in white fat versus those in brown fat¹⁷ (Figure 5). Rarely, lesions are isointense to skeletal muscle on T1-weighted images.²³ On T2-weighted images, high signal intensity similar to that of subcutaneous fat is typical.²⁴ Flow voids can be readily identified.²⁵ Short tau inversion recovery (STIR) MRI shows some areas with signal intensity higher than that of subcutaneous fat, and other areas of fat suppression.⁹ Ritchie and colleagues²¹ reported that hibernomas histologically composed of more than 70% multivacuolated adipocytes tended to have MRI signal characteristics different from those of subcutaneous fat, and those with less than 70% multivacuolated adipocytes tended to have signal characteristics paralleling those of subcutaneous fat. Myxoid hibernomas have higher signal intensity on T2-weighted and STIR MRI because of high water content.^17,21,26,27

Hibernomas demonstrate moderate uptake on bone scintigraphy blood pool images and mild uptake on delayed images.⁴ Positron emission tomography (PET) is useful in differentiating hibernomas from other fat-containing lesions.⁹ Hibernomas demonstrate intense fluorine-18 fluorodeoxyglucose uptake because, unlike other adipogenic tumors, hibernomas contain abundant mitochondria and are highly metabolically active.²⁸

Treatment and Prognosis

Complete surgical excision is the treatment of choice; given the behavior of the benign tumor, marginal complete excision is considered curative.⁵ Intralesional excision may be the only option for large tumors that are near nerves or vessels. However, intralesional excision may result in continued growth and local recurrence.

At surgery, these tumors usually are encapsulated and/or adherent to skeletal muscle or bone, without invasion, and easily separated from surrounding soft tissues.²⁹ No specific surgical considerations are required beyond standard oncological principles, including careful dissection of adjacent nerves and vessels, and hemostasis. Hibernomas have the potential for significant bleeding during surgical excision. In this setting, embolization becomes a consideration, given the identification of large intratumoral vessels and the benign course of these lesions.