Journal of Osteoporosis and Physical Activity
Open Access

Abstract

Bilateral Typical Femoral Fractures in a Patient with Metastatic Breast Cancer on Long-Term Bisphosphonate Therapy: A Case Report

Yuko Sakamoto

An atypical femoral fracture may be one of the devastating side effects of bisphosphonate. We present a patient who obliged to multiple surgeries for atypical femoral fracture of the femur after bisphosphonate therapy. A 63-yearold woman had been on anti-estrogen therapy for skeletal metastasis of the breast cancer. She received 90 mg of pamidronate disodium for 2 years and 4 mg of zoledronic acid for 4 years. Four month after she developed spontaneous left thigh pain, she fell from a standing height. X-ray films showed a subtrochanteric fracture of the left femur. The patient underwent surgery with an intramedullary nail, and radiation therapy was delivered to the fracture site because the possibility of a pathological fracture was unable to be excluded. Radiographs showed some evidence of callus formation, but the fracture line persisted. Two years later, the intramedullary nail broke at a screw hole in radiographs. Bipolar hip arthroplasty was performed and bone chips were grafted at the fracture site. Ten weeks after the operation, callus formation was satisfactory and she was able to walk without pain. One year after the first operation on the left femur, she complained of spontaneous pain in the right thigh and radiographs showed a lateral cortical beak sign with no evident fracture line. The patient underwent intramedullary nailing to prevent subsequent fracture. The radiological fracture sign were improved one year after the operation. The prophylactic intramedullary nailing is effective for the patients with lateral cortical thickening and/or a medial spike on X-ray.