INTRODUCTION
Osteoporotic vertebral fractures (OVF) may lead to the occurrence of vacuum phenomenon (VP) not only in the affected vertebrae but also in adjacent intervertebral discs. Balloon kyphoplasty (BKP) stabilizes the vertebra and restores vertebral height, leading to the disappearance of disc vacuum phenomenon (DVP) in some cases, though it remains in others. This study aimed to investigate the frequency and progression of DVP before and after BKP, and to identify the predictive factors for persistent DVP following BKP.
METHODS
We included 188 OVF patients who underwent BKP and were evaluated with CT scans before surgery and within 3 months postoperatively, excluding cases with concomitant fusion surgery. We investigated the presence of DVP before and after BKP and analyzed factors influencing DVP changes, including cement injection volume, presence of cement leakage, preoperative MRI Pfirrmann classification, pre- and postoperative Beck index, presence of posterior wall fractures, and their association with DVP progression. Statistical analyses included descriptive statistics, comparison between two groups, and logistic regression. In multivariate logistic regression, factors with a p-value < 0.20 in univariate analysis and potential confounders based on previous studies were included.
RESULTS
The frequency of DVP before surgery was 37% (69 cases), and DVP disappeared postoperatively in 30% (21 cases). Among the 63% (119 cases) without preoperative DVP, 17% (20 cases) developed DVP after surgery. Multivariate analysis identified severe preoperative Pfirrmann classification of the cranial disc and the presence of preoperative caudal disc DVP as significant predictors of residual or new DVP post-BKP.
DISCUSSION
In this study, the frequency of adjacent disc VP in OVF patients was 36.7%. Previous reports indicated a DVP occurrence of 1–21% in healthy individuals and 38–73% in patients with degenerative spinal diseases, suggesting that OVF itself does not significantly increase DVP occurrence. Post-BKP, DVP disappeared in 30% of cases with preoperative DVP, suggesting that BKP may contribute to improved disc stability, in addition to treating vertebral fractures. Predictive factors for persistent DVP post-BKP included severe Pfirrmann classification and preoperative DVP, indicating that pre-existing disc degeneration and disc damage at the time of vertebral fracture may influence DVP persistence.