Nonoperative versus Prophylactic Treatment of Bisphosphonate-associated Femoral Stress Fractures

Several studies have identified a specific fracture in the proximal diaphysis of the femur in patients treated with bisphosphonates. The fractures typically are sustained after a low-energy mechanism with the presence of an existing characteristic stress fracture. However, it is unclear whether these patients are best treated nonoperatively or operatively. What is the likelihood of nonoperatively treated bisphosphonate-associated femoral stress fractures progressing to completion and during what time period? If prophylactic fixation is performed, do patients have a shorter hospital length-of-stay compared with patients having surgical fixation after fracture completion? We retrospectively searched for patients older than 50 years receiving bisphosphonate therapy, with either incomplete, nondisplaced stress fractures or completed, displaced fractures in the proximal diaphysis of the femur between July 2002 and April 2009. After applying exclusion criteria, we identified 34 patients with a total of 40 bisphosphonate-associated fractures. The average duration of bisphosphonate use was 77 months. Twenty-eight of 40 (70%) fractures were completed, displaced fractures. Six of the 12 nondisplaced stress fractures initially were treated nonoperatively. The remaining six stress fractures were treated with prophylactic cephalomedullary nail fixation. The minimum followup was 12 months (mean, 36.5 months; range, 12-72 months). Five of the six stress fractures treated nonoperatively progressed to fracture completion and displacement at an average of 10 months (range, 3-18 months). The average hospital stay was 3.7 days for patients treated prophylactically and 6.0 days for patients treated after fracture completion. Our data suggest nonoperative treatment of bisphosphonate-related femoral stress fractures is not a reliable way to treat these fractures as the majority progress to fracture completion. Prophylactic fixation of femoral stress fractures also reduces total hospital admission time. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.