Atypical Femoral Fractures in a Patient with Continuous Decreasing BMD after Only 1.5 Years of Bisphosphonate Treatment

Abstract

Objective: Bisphosphonates were accepted first line treatment for osteoporosis. Long-term bisphosphonate treatment has been reported to be complicated with osteonecrosis of jaw (ONJ) and atypical fracture of femur. It is proposed to be the result of impaired remodeling of minor injury of bone. An atypical fracture occurs on a patient received only 1.5 years of bisphosphonate treatment with continuous decreasing bone mineral density. Case Presentation: This is a 53-year-old female Taiwanese. She has rheumatoid arthritis and has received long-term glucocorticoid treatment. Continuous decrease of bone mineral density in the serial BMD examination after alendronate treatment can be found. Thigh pain occurs after only 1.5 years of bisphosphonate treatment and it progresses to atypical fracture. Conclusions: Atypical fracture can occur in patients receive only shortterm bisphosphonate treatment even BMD is still decreased after bisphosphonate treatment. Autoimmune disease, glucocorticoid treatment, Asian and female may be the possible risk factors.

Osteonecrosis of the Jaw and Bilateral Atypical Femoral Fracture Both Occurring During Treatment for Osteoporosis: A Case Report

“… 5 Additional risk factors recognized but not consistent in studies were prior low-energy fracture, glucocorticoid therapy for more than six months, active rheumatoid arthritis, serum 25-hydroxyvitamin D (25-OHD) concentration below 16 ng/mL, female gender, younger age, diabetes and use of proton-pump inhibitor. 5 , 6 The pathogenesis of AFF is also still not fully understood but is also thought to be related to altered bone remodeling by antiresorptive agents which is supposed to repair microcracks formed by mechanical stresses. Long-term decrease in bone turnover also leads to deterioration of mechanical properties of bone tissue.…”

“…7 Treatment recommendation by ASBMR for AFF includes discontinuation of bisphosphonates, adequate calcium and vitamin D supplementation, limitation of weight-bearing through the use of crutches or a walker for patients with minimal pain, prophylactic nail fixation and therapy with teriparatide. 6 …”

“…7 Treatment recommendation by ASBMR for AFF includes discontinuation of bisphosphonates, adequate calcium and vitamin D supplementation, limitation of weight-bearing through the use of crutches or a walker for patients with minimal pain, prophylactic nail fixation and therapy with teriparatide. 6 ONJ is characterized by an exposed necrotic bone in the maxillofacial region persisting for at least eight weeks despite appropriate therapy in a patient with exposure to potent antiresorptive or anti-angiogenic agents with no history of radiation therapy to craniofacial region. 4 Although the pathogenesis of ONJ is still unclear, it is thought that the antiresorptive agents by altering bone remodeling as well as by their antiangiogenic property, in combination with trauma such as a tooth extraction or inflammation/infection from periodontal or periapical disease can lead to bone necrosis.…”