Retrospective Analysis of Imaging Influencing Factors and Early Stability of Cage Subsidence After Percutaneous Endoscopic Lumbar Interbody Fusion.

OBJECTIVE: To identify imaging predictors of cage subsidence following percutaneous endoscopic lumbar interbody fusion (PELIF) and assess their association with early postoperative clinical outcomes, and to conduct the analysis through a retrospective design. METHODS: A retrospective analysis was conducted on 189 patients who underwent PELIF between January 2022 and June 2024. Patients were classified into subsidence (48 cases) and non-subsidence (141 cases) groups based on radiographic criteria. After screening the differential indicators through single-factor analysis, a multivariate logistic regression was used to identify independent imaging risk factors. Clinical outcomes, including lumbar range of motion (ROM), Visual Analog Scale (VAS), and Oswestry Disability Index (ODI), were compared between groups at baseline, 6 months, and final follow-up. RESULTS: Compared with the non-subsidence group, the endplate bone quality (EBQ) score and vertebral bone quality (VBQ) score of the subsidence group patients were both increased, while the average CT value of the vertebral body, the average CT value of the upper and lower vertebral bodies of the responsible segment, and the area of the multifidus muscle were significantly decreased (P < 0.05). Multivariate logistic regression analysis showed that EBQ score (OR=2.061, 95% CI: 1.458~2.915) and VBQ score (OR=1.854, 95% CI: 1.362~2.527) were independent risk factors for device subsidence, while average CT values of vertebral bodies (OR=0.240, 95% CI: 0.132~0.437), average CT values of upper and lower vertebral bodies of the responsible segment (OR=0.347, 95% CI: 0.228~0.528), and multifidus muscle area (OR=0.453, 95% CI: 0.291~0.705) were protective factors (P<0.05). Compared with the non-subsidence group, the ROM of the patients in the subsidence group was significantly lower at 6 months after surgery and at the last follow-up (P < 0.05), and the VAS score and ODI score were also significantly higher (P < 0.05). CONCLUSION: Imaging parameters, including vertebral CT values, EBQ/VBQ scores, and multifidus muscle area, are significant predictors of cage subsidence after PELIF. Subsidence is associated with poorer early postoperative outcomes. Based on the results of the above retrospective analysis, comprehensive preoperative imaging assessment is essential for risk stratification and optimizing surgical strategies.