Dynamic Interspinous Process Distance and Adjacent Vertebral Fracture After Balloon Kyphoplasty: Preliminary Evidence...

Area of Science:

• Spine surgery
• Osteoporosis management
• Radiographic analysis

Background:

• Adjacent vertebral fractures (AVFs) are a common complication following balloon kyphoplasty (BKP).
• While factors like bone density are known risks, dynamic posterior instability evaluated by interspinous process distance (ISPD) changes remains understudied.
• Investigating novel predictors for AVF is crucial for improving patient outcomes after BKP.

Purpose of the Study:

• To determine if dynamic changes in interspinous process distance (ΔISPD) between standing and supine positions can predict AVFs after BKP for thoracolumbar osteoporotic vertebral fractures (OVFs).
• To test the hypothesis that greater ΔISPD reflects posterior instability and is associated with an increased risk of AVF.

Main Methods:

• Retrospective analysis of 36 patients undergoing BKP for thoracolumbar OVFs.
• Measurement of ISPD in standing and supine lateral radiographs, with ΔISPD normalized to vertebral body height.
• Statistical analysis including Mann-Whitney U test, Fisher's exact test, and Receiver Operating Characteristic (ROC) curve analysis to assess predictive performance.

Main Results:

• AVFs occurred in 33% of patients.
• Normalized ΔISPD was significantly associated with AVF occurrence (p < 0.05).
• ROC analysis indicated moderate predictive performance for normalized ΔISPD with AUC values around 0.75.

Conclusions:

• Dynamic ISPD changes are significantly associated with AVF development post-BKP.
• Normalized ΔISPD is a reproducible radiographic marker potentially useful for identifying high-risk patients.
• Further multicenter validation is needed to confirm ΔISPD's role in preoperative risk stratification for AVF.