Managing delayed union of fragility fractures of the pelvis successfully using romosozumab: A case report

Fragility fractures of the pelvis (FFPs) are typically caused by minor trauma or without any trauma in older individuals with osteoporosis. In recent years, FFP incidence has increased considerably owing to the increasing number of individuals in the aging population as well as impaired daily life. Surgeries are the main treatment options for some types of FFPs; however, the potential of the use of romosozumab, an FDA-approved humanized monoclonal antibody that can bind and inhibit sclerostin, is yet to be evaluated. Romosozumab substantially increases bone mineral density (BMD) in the spine and the hip, improves bone strength, and prevents the occurrence of new fractures. Previous studies have demonstrated the efficacy of romosozumab in promoting fracture healing, including the healing of nonunion in some fractures. Herein, we present a case of a 61-year-old woman who had FFP delayed union, after falling 4 months before visiting our hospital. She presented with bilateral buttock and leg pain. Baseline BMD measured using dual-energy X-ray absorptiometry revealed a T-score of -3.8 and -3.2 for the lumbar spine and total hip, respectively. As the patient's BMD indicated a high risk of fractures, romosozumab was administered. Her pain improved 3 months after the medication. Computed tomography taken after 3 months revealed that the fracture had healed, suggesting that romosozumab is an effective medication for treating FFP delayed union and nonunion.