Risk factors for subsequent vertebral fracture after acute osteoporotic vertebral fractures.

PURPOSE To investigate the incidence and characteristics of subsequent vertebral fracture after osteoporotic vertebral fractures (OVFs) and identify risk factors for subsequent vertebral fractures. METHODS This post-hoc analysis from a prospective randomized multicenter trial included 225 patients with a 48-week follow-up period. Differences between the subsequent and non-subsequent fracture groups were analyzed. RESULTS Of the 225 patients, 15 (6.7%) had a subsequent fracture during the 48-week follow-up. The annual incidence of subsequent vertebral fracture after fresh OVFs in women aged 65-85 years was 68.8 per 1000 person-years. Most patients (73.3%) experienced subsequent vertebral fractures within 6 months. At 48 weeks, European Quality of Life-5 Dimensions, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire pain-related disorder, walking ability, social life function, and lumbar function scores were significantly lower, while the visual analog scale (VAS) for low back pain was higher in patients with subsequent fracture. Cox proportional hazards analysis showed that a VAS score ≥ 70 at 0 weeks was an independent predictor of subsequent vertebral fracture. After adjustment for history of previous fracture, there was a ~ 67% reduction in the risk of subsequent vertebral fracture at the rigid-brace treatment. CONCLUSION Women with a fresh OVF were at higher risk for subsequent vertebral fracture within the next year. Severe low back pain and use of soft braces were associated with higher risk of subsequent vertebral fractures. Therefore, when treating patients after OVFs with these risk factors, more attention may be needed for the occurrence of subsequent vertebral fractures. LEVEL OF EVIDENCE III.