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

Study Design Retrospective observational study. Objectives To 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. Methods The 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. Results ADVP 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%; P < 0.01). Univariate analysis showed that the presence of ADVP and longer symptom duration were significantly associated with AVF. Multivariate logistic regression identified ADVP as an independent risk factor for AVF (odds ratio 4.97; 95% confidence interval 1.71-14.5; P = 0.003). This association remained consistent after multiple imputation and PSM. Conclusions Preoperative ADVP is associated with an increased risk of AVF after BKP. Incorporating the assessment of ADVP into preoperative CT evaluation may help identify patients at a higher risk of AVF.