Spontaneous non-traumatic stress fractures in bilateral femoral shafts in a patient treated with bisphosphonates

Bisphosphonates are potent inhibitors of bone resorption and widely used to treat osteoporosis. Extensive studies have shown that therapy with bisphosphonates improves bone density and decreases fracture risk. However, concerns have been raised about potential over-suppression of bone turnover during long-term use of bisphosphonates, resulting in increased susceptibility to and delayed healing of non-spinal fractures. We report a patient who sustained non-traumatic stress fractures in bilateral femoral shafts with delayed healing after long-term bisphosphonate therapy. She underwent open reduction and surgical internal fixation. Although bisphosphonates effectively prevent vertebral fractures, and their safety has been tested in randomized trials, we must emphasize the need for awareness of the possibility that long-term suppression of bone turnover with bisphosphonates may eventually lead to an accumulation of fatigue-induced damage and adverse skeletal effects such as delayed fracture healing.