Association Between Adjacent Disc Vacuum Phenomenon and Adjacent Vertebral Fracture After Balloon Kyphoplasty for Osteoporotic Vertebral Fractures: A Retrospective Multicenter Study.

Study DesignRetrospective observational study.ObjectivesTo determine whether the preoperative adjacent disc vacuum phenomenon (ADVP) is associated with an increased risk of adjacent vertebral fracture (AVF) after balloon kyphoplasty (BKP) for osteoporotic vertebral fractures.MethodsThe clinical and radiological data of 124 consecutive patients who underwent BKP at T11-L2 were retrospectively reviewed. ADVP was defined as radiolucent gas within the intervertebral disc space on preoperative computed tomography (CT). Patients were classified as ADVP-positive or ADVP-negative. The incidence of AVF was compared between the groups, and independent risk factors were assessed using multivariate logistic regression. Multiple imputation was performed, and propensity score matching (PSM) was used to adjust for potential confounding factors because bone mineral density data were partially missing.ResultsADVP was identified in 48 patients (38.7%). AVF occurred in 21 patients (16.9%) and was significantly more frequent in the ADVP-positive group than in the ADVP-negative group (31.2% vs 7.9%;