Successful teriparatide treatment of atypical fracture after long-term use of alendronate without surgical procedure in a postmenopausal woman

Abstract

Bisphosphonates are used as first-line therapy for postmenopausal osteoporosis owing to their potent inhibition of bone resorption. Long-term use of bisphosphonates may lead to low-energy femoral subtrochanteric or shaft fractures in a very few patients. The aim of this study was to describe the clinical course of a patient treated with alendronate for 3 years who developed an atypical femoral fracture and to hypothesize the beneficial effects of teriparatide on the healing of the patient's atypical femoral fracture. A 63-year-old Asian woman had a lumbar osteoporotic fracture and received 70 mg of alendronate for 3 years. Pain and soreness in the thigh presented initially and exacerbated thereafter. X-ray revealed a right femoral diaphysis stress fracture. She then received teriparatide for the treatment of osteoporosis and the femoral atypical fracture. Pain and tenderness improved remarkably after teriparatide treatment for 1 month, and these symptoms disappeared after teriparatide treatment for 9 months. The patient also received raloxifen as further therapy, and the fracture line had completely disappeared by 15 months after treatment. Even though a previous study has reported that teriparatide healed stress fractures in a rat model and even with the time course of fracture healing in our patient, we are still not certain that teriparatide played a primary role in the positive response to therapy. Vitamin D therapy, calcium, and alendronate discontinuation may have played secondary roles. This case report may serve to introduce a direction for future research into the pharmacological treatment of atypical femoral fractures. Surgical treatment of incomplete atypical femoral fractures may be a safer method.