Subtrochanteric insufficiency fractures associated with bisphosphonate use: 2 case reports and review.

Insufficiency fractures are beginning to emerge in case reports of patients on long-term bisphosphonate therapy. The side effects associated with the long-term use of bisphosphonates were once thought to only involve renal and gastrointestinal (GI) toxicity and osteonecrosis of the jaw, but it is becoming clear that the very condition bisphosphonates were meant to treat could be causing another, trading insufficiency fractures for another type of insufficiency fracture. We review the literature concerning this surprising trend in addition to providing 2 case reports and conclude that these fractures do occur, that they can heal uneventfully, and that further research is needed to determine optimum treatment algorithms concerning duration of treatment and to weigh the potential benefits and morbidity of bisphosphonate treatment.