A Lesson from the Failure of Intramedullary Fixation of Atypical Subtrochanteric Fractures

Surgical fixation of subtrochanteric fractures remains technically challenging, even to experienced fracture surgeons. These fractures are often treated with intramedullary devices; fixed-angle plating is an alternative. Recently, there have been an increasing number of reports about bisphosphonate-related atypical femoral fractures occurring at the subtrochanteric or proximal diaphyseal region1-4. These fractures are characterized by cortical beaking, thickening of the femoral cortex prior to fractures, and transverse or short oblique orientation in people who have been on long-term bisphosphonate therapy2,3,5,6. As with the vast majority of trauma-related subtrochanteric fractures, these bisphosphonate-related fractures are usually stabilized with cephalomedullary devices. Surgeons often do not pay adequate attention to the length of the intramedullary nail, which in effect is the working length of the fixation. Short nails are sometimes used for ease of insertion and their availability in most operating rooms. Spanning the distal femoral region with a longer nail is erroneously viewed as unnecessary. In fact, the less biomechanically sound fixation achieved by a short nail will predispose to the occurrence of delayed union, nonunion, and implant breakage. We report two cases of atypical subtrochanteric fractures in patients who had been on long-term bisphosphonate therapy; treatment with short cephalomedullary nails failed in both. We also discuss the underlying failure mechanism. Both patients were informed that data concerning their cases would be submitted for publication, and they provided consent. Case 1. An eighty-two-year-old woman who had taken alendronate for osteoporosis for six years was admitted to the hospital after a …