Risk factors for subsequent vertebral fractures following a previous hip fracture

Introduction The purpose of our study was to evaluate the incidence and to identify risk factors of subsequent vertebral fractures after hip fractures, and to determine whether the subsequent vertebral fracture increases the mortality rate of elderly hip fracture patients. Materials and methods From January 2009 to July 2016, 1,554 patients were diagnosed as having a hip fracture and were treated surgically at our institution. Among them, 1121 patients age > 50 years at the time of injury and were followed up for 1 year or longer after the hip fracture surgery. In these patients, radiographs of the hip and spine were taken at each follow-up. We reviewed medical records and radiographs of these patients. Among the 1121 patients, 107 patients (9.5%) had subsequent vertebral fractures after the hip fracture during entire follow-up periods. Results In multivariable analysis, previous history of vertebral fracture [odds ratio (OR), 2.62;p < 0.001], medication possession rate (MPR) of osteoporosis treatment < 80% (OR, 1.92;p = 0.014), and a lower lumbar bone mineral density (BMD) (OR, 2.58;p = 0.001) appeared as risk factors for subsequent vertebral fractures. Conclusion However, the subsequent vertebral fractures did not affect the mortality after the hip fractures. Age >= 70 years [hazard ration (HR) 2.70;p = .039], body mass index < 18.5 kg/m(2)(HR, 2.57;p =0 .048), and Charlson comorbidity index >= 2 (HR, 2.04;p =0.036) were risk factors of the death. Timely management is warranted to prevent subsequent vertebral fractures in hip fracture patients with risk factors.