Role of Thoracolumbar Fascia Injury Classification in Predicting Percutaneous Vertebroplasty Outcomes for Osteoporotic Vertebral Compression Fractures

Objective: Thoracolumbar fascia injury is one of the important causes of suboptimal early analgesic outcomes following percutaneous vertebroplasty (PVP). Previous studies have predominantly treated thoracolumbar fascia injury as a binary variable, overlooking the heterogeneity in the extent of injury. This study aimed to establish an MRI-based classification system for thoracolumbar fascia injury and to evaluate the impact of different classification types on early postoperative pain relief and time to ambulation after PVP. Methods: A retrospective analysis was conducted on the medical records of patients with osteoporotic vertebral compression fractures (OVCFs) who underwent PVP at our institution between January 2023 and January 2025. A total of 56 patients with concomitant thoracolumbar fascia injury were enrolled. Based on the longitudinal extent of fascial edema on preoperative MRI T2-weighted short tau inversion recovery (T2-STIR) sequences, patients were classified into the localized type (n=11), segmental continuous type (n=21), and extensive multisegmental type (n=24). The reproducibility of the classification was evaluated using interobserver and intraobserver reliability analyses based on Cohen’s kappa coefficients. The primary patient-reported outcome measures (PROMs) were the visual analogue scale (VAS) scores during turning over and standing. The Oswestry Disability Index (ODI) served as the secondary PROM. Additionally, the achievement rates of the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) for VAS and ODI at the final follow-up were evaluated across groups. Results: No statistically significant differences in baseline PROMs were observed among the three groups ( P > 0.05). The interobserver and intraobserver reliability for the classification were substantial to almost perfect, with Cohen’s kappa coefficients of 0.85 (95% CI, 0.74– 0.96) and 0.88 (95% CI, 0.78– 0.98), respectively. Within the first postoperative month, the standing VAS scores and ODI in the extensive multisegmental type group were significantly higher than those in the segmental continuous type and localized type groups ( P < 0.05), and the segmental continuous type group was also significantly higher than the localized type group ( P < 0.05). At 3 months postoperatively and at the final follow-up, no statistically significant differences were observed among the three groups ( P > 0.05). At the final follow-up, the achievement rates of MCID and PASS did not differ significantly among the three groups ( P > 0.05). On postoperative days 1 and 3, the proportion of patients meeting ambulation criteria in the localized type group was significantly higher than that in the segmental continuous type and extensive multisegmental type groups ( P < 0.05). Following comprehensive treatment, all patients met the ambulation criteria within 7 days postoperatively. Conclusion: The findings of this preliminary study suggest that the classification of thoracolumbar fascia injury is closely associated with the degree of early postoperative pain relief and time to ambulation after PVP. The more extensive the injury, the more severe the early residual pain and the more delayed the ambulation. Preoperative MRI-based classification of thoracolumbar fascia injury should be emphasized to more accurately predict postoperative outcomes following PVP, formulate individualized perioperative management plans, such as proactive multimodal analgesia and appropriately delayed mobilization for patients with extensive multisegmental injury, and provide patients with more targeted prognostic counseling. Keywords: osteoporotic vertebral compression fracture, percutaneous vertebroplasty, thoracolumbar fascia injury, patient-reported outcome measures