Risk Factors for Residual Back Pain After Balloon Kyphoplasty for Osteoporotic Vertebral Fracture

Balloon kyphoplasty (BKP) is a method for the management of osteoporotic vertebral body fracture (OVF). However, improvement in back pain (BP) is poor in some patients, also previous reports have not elucidated the exact incidence and risk factors for residual BP after BKP. We clarified the characteristics of residual BP after BKP in patients with OVF. In this study, we hypothesize that some risk factors may exist for residual BP 2 years after the treatment of OVF with BKP. A multicenter cohort study was performed where patients who received BKP within 2 months of OVF injury were followed-up for 2 years. BP at 6 months after surgery and final observation was evaluated by Visual Analog Scale (VAS) score. Patients with a score of 40 mm or more were allocated to the residual BP group, and comparisons between the residual back pain group and the improved group were made for bone density, kyphosis, mobility of the fractured vertebral body, total spinal column alignment, and fracture type (fracture of the posterior element, pedicle fracture, presence or absence of posterior wall damage, etc.). Also, Short Form 36 (SF-36) for physical component summary (PCS) and mental component summary (MCS) at the final follow-up was evaluated in each radiological finding. Of 116 cases, 79 (68