Multiple ipsilateral femoral stress fractures in a patient taking denosumab for osteoporosis-a case report

Abstract

This is the first report describing three ipsilateral femoral stress fractures in a patient taking denosumab.

Introduction: Multiple reports of atypical femur fractures (AFF) in patients receiving denosumab have emerged recently. Denosumab is an anti-resorptive agent approved for treatment of osteoporosis. It is a human monoclonal antibody which blocks osteoclast activation, maturation, and function.

Methods: This is a case report of a 74-year-old female patient who sustained three stress fractures of her left femur.

Results: The patient healed her fractures after intramedullary nailing of the femur and was able to return to her activities.

Conclusions: High index of suspicion is needed in any patient with osteoporosis on denosumab complaining of thigh or groin pain. Careful examination and radiographic studies of both femurs are warranted if AFF is discovered.

Keywords: Atypical femur fractures; Bisphosphonates; Denosumab; Osteoporosis; Prolia; Stress fractures.