Alendronate-associated femoral insufficiency fractures and femoral stress reactions.

PURPOSE To report characteristics and outcomes of 8 patients who underwent intramedullary nailing for alendronate-associated femoral insufficiency fractures. METHODS Records of 7 women and one man aged 54 to 91 (mean, 72) years who underwent intramedullary nailing for spontaneous or low-energy, alendronateassociated femoral insufficiency fractures were retrospectively reviewed. Contralateral femurs were assessed for stress reactions. RESULTS All patients had at least 4 (range, 4-10) years of alendronate use. Five patients had experienced prodromal pain lasting one day to 5 months. Five patients had received concurrent glucocorticoid therapy. At the 6-month follow-up, 6 patients had bony union, one had hypertrophic non-union and underwent dynamisation and nail exchange and eventually achieved union at month 16, and one had fixation loss and underwent nail exchange and bone grafting and eventually achieved union at month 9. In 3 patients, the contralateral femurs were painful, and cortical stress reactions were noted. They underwent prophylactic intramedullary nailing. Radiographs showed no evidence of new stress reactions or fractures. CONCLUSION Contralateral involvement in patients with alendronate-associated femoral insufficiency fractures is not uncommon. Early prophylactic intramedullary nailing may provide effective pain relief and prevent progression to a fracture.