Can long-term bisphosphonate use causes low-energy fractures? A case report.

Bisphosphonates are inorganic pyrophosphate analog which accumulate on the bone surface, cause osteoclast apoptosis, and inhibit bone resorption. The nitrogen-containing bisphosphonates continue to be the drug of choice for the treatment of osteoporosis in both men and women. Although histomorphometric studies including bone biopsies have not shown any evidence of microcracks, recent studies have revealed that potent bisphosphonates are responsible for the oversuppression of bone turnover leading to microdamages, reduced bone strength, and increased fracture risk. There are individual cases reporting atypical femoral fractures and severely suppressed bone turnover along with long-term (≥ 5 years) use of biphosphonates. In this study, we report on a 74-year-old woman with a history of continuous alendronate use for nearly 16 years who presented to the emergency department with right proximal humerus and left femur fracture.