Clinical Outcomes of Balloon Kyphoplasty for Osteoporotic Vertebral Fractures With Posterior Element Injury: A Retrospective Study.

Introduction Balloon kyphoplasty (BKP) has been shown to be effective in treating osteoporotic vertebral fractures (OVFs); however, its applicability in cases with posterior element injury remains unclear. Posterior element injuries may reflect underlying spinal instability, which could affect clinical outcomes. This study aimed to evaluate the efficacy of BKP in OVFs complicated by posterior element injury. Materials and methods We retrospectively analyzed 18 of 189 patients who underwent BKP between 2012 and 2023, in whom posterior element injury was confirmed by magnetic resonance imaging (MRI). Pain improvement at three months postoperatively was assessed using the numerical rating scale (NRS), and the presence of adjacent vertebral fractures (AVFs) was recorded. Patients with both NRS < 4 and no AVFs were classified as having a favorable outcome. Clinical and radiographic factors, including age, sex, fracture location, bone mineral density, fracture history, kyphotic angle, and vertebral instability, were compared between favorable and unfavorable outcome groups. Results The mean age of the 18 patients was 82 ± 6 years; there were six males and 12 females. At three months after BKP, eight patients (44%) had NRS ≥ 4, and seven patients (39%) developed AVFs. Vertebral instability ≥10° was significantly more common in the unfavorable outcome group than in the favorable outcome group (10/11 (91%) vs. 2/7 (29%), p = 0.006). Conclusions BKP can still be effective for OVFs with posterior element injury; however, its efficacy appears limited in cases with significant vertebral instability. Alternative stabilization strategies may be considered in such cases.