Disturbance of osteonal bone remodeling and high tensile stresses on the lateral cortex in atypical femoral fracture after long-term treatment with Risedronate and Alfacalcidol for osteoporosis

Atypical femur fracture associated with common anti-osteoporosis drugs in FDA adverse event reporting system

Atypical femur fracture (AFF) is a rare but catastrophic adverse event first reported in the long-term use of alendronate, one of the most commonly used drugs for osteoporosis currently. However, further evidence is needed to learn more regarding other common anti-osteoporosis drugs and the risk for AFF. In this study, reports of AFF were identified from Food and Drug Administration Adverse Event Reporting System database. Disproportionality analyses were performed to examine the reporting odds ratio (ROR), information component (IC) and adjusted ROR (adj. ROR) signals for AFF for common anti-osteoporosis drugs. A total of 1692 unique AFF reports were identified. The disproportionality signals (the lower bound of 95% confidence interval > 1 for ROR and adjusted ROR, and > 0 for IC) were detected for alendronate, denosumab, pamidronate, risedronate, zoledronate, ibandronate, and teriparatide while no signal was detected for raloxifene, abaloparatide, and romosozumab. When restricted in patients with osteoporosis, the disproportionality signals were still detected for alendronate, pamidronate, risedronate, denosumab, and ibandronate. Our results suggest that alendronate has the largest risk signal, while the risks varied among different bisphosphonates. In addition, denosumab was found statistically associated with AFF in both the entire database and patients with osteoporosis.

Advancement in the Treatment of Osteoporosis and the Effects on Bone Healing

Osteoporosis (OP) is a major global health concern, with aging being one of the most important risk factors. Osteoarthritis (OA) is also an age-related disorder. Patients with OP and/or OA may be treated surgically for fractures or when their quality of life is impaired. Poor bone quality due to OP can seriously complicate the stability of a bone fixation construct and/or surgical fracture treatment. This review summarizes the current knowledge on the pathophysiology of normal and osteoporotic bone healing, the effect of a bone fracture on bone turnover markers, the diagnosis of a low bone mineral density (BMD) before surgical intervention, and the effect of available anti-osteoporosis treatment. Interventions that improve bone health may enhance the probability of favorable surgical outcomes. Fracture healing and the treatment of atypical femoral fractures are also discussed.

Generalized Uncoupled Bone Remodeling Associated With Delayed Healing of Fatigue Fractures

Fatigue fractures in bones are common injuries with load‐bearing activities, during which the remodeling aimed at removing microdamage has been suggested to play a role in increasing related fracture risk. Much attention has been given to the uncoupling between osteoclastic bone resorption and osteoblastic osteogenesis in fatigue fracture cases; however, the underlying pathophysiologic mechanisms of impaired fracture healing are yet unknown. Here we report multiple fatigue fractures in a physically active woman receiving contraceptive pills for years. Her fracture healing was remarkably slow, although she has been otherwise healthy. The patient underwent bone biopsy of the iliac crest that showed remarkable peritrabecular fibrosis with increased osteoclastic bone resorption combined with relatively low bone formation. Analysis of bone biochemical composition revealed a more complex picture: First, notable declines in bone mineral content–based parameters indicating abnormal mineralization were evident in both cancellous and cortical bone. Second, there was elevation in mineral crystal size, perfection, and collagen maturity in her bone tissues from different anatomical sites. To our knowledge, this is the first report showing generalized uncoupling in bone remodeling, increased peritrabecular fibrosis, and bone compositional changes associated with delayed healing of fatigue fractures. These results may explain delayed healing of fatigue and stress fractures. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Breast Cancer with Bone Metastasis: Molecular Insights and Clinical Management

Despite the remarkable advances in the diagnosis and treatment of breast cancer patients, the presence or development of metastasis remains an incurable condition. Bone is one of the most frequent sites of distant dissemination and negatively impacts on patient's survival and overall frailty. The interplay between tumor cells and the bone microenvironment induces bone destruction and tumor progression. To date, the clinical management of bone metastatic breast cancer encompasses anti-tumor systemic therapies along with bone-targeting agents, aimed at slowing bone resorption to reduce the risk of skeletal-related events. However, their effect on patients' survival remains controversial. Unraveling the biology that governs the interplay between breast neoplastic cells and bone tissue would provide means for the development of new therapeutic agents. This article outlines the state-of-the art in the characterization and targeting the bone metastasis in breast cancer, focusing on the major clinical and translational studies on this clinically relevant topic.