Stand-up test predicts occurrence of non-traumatic vertebral fracture in outpatient women with osteoporosis

Introduction The purpose of this retrospective study was to clarify the incidence of non-traumatic vertebral fracture among outpatient women with osteoporosis and to determine whether the stand-up test predicted the occurrence of non-traumatic vertebral fracture. Materials and methods A total of 242 postmenopausal women over 60 years of age who received outpatient osteoporosis treatment at our hospital between November 2013 and July 2020 were longitudinally evaluated in this study. We obtained medical information and radiographic parameters, including sagittal vertical axis, thoracic kyphosis, pelvic incidence, lumbar lordosis, pelvic tilt, and sacral slope at baseline. Additionally, we measured physical parameters, including height, weight, body mass index, lumbar bone mineral density, visual analog scale score for pain, and the stand-up test. Results Vertebral fractures occurred in 20 of 242 participants (8.3%), and accounted for 48.8% the 41 total fractures in the study group. Among vertebral fractures, eight (40.0%) were traumatic, resulting from falls, and 12 (60.0%) were non-traumatic. Cox multivariate logistic regression analysis adjusted for age, body mass index, lumbar bone mineral density, and the time to non-traumatic vertebral fracture showed that the sagittal vertical axis (HR = 1.013, 95% CI 1.001–1.026), stand-up test score (HR = 3.977, 95% CI 1.156–13.683), and presence of difficulty with standing from a 20-cm-high seat using both legs (HR = 3.329, 95% CI 1.625–6.82) were independent risk factors for the occurrence of non-traumatic vertebral fracture. Conclusion The stand-up test may be useful as a simple screening tool for non-traumatic vertebral fracture in patients with osteoporosis.