Application of a multidimensional and process-oriented evaluation system in PELD bridging therapy for lumbar spinal infections: a self-controlled retrospective study of 27 cases.

BACKGROUND: Conventional cure rates are too stringent for percutaneous endoscopic lumbar discectomy (PELD)-based endoscopic debridement and drainage as a minimally invasive bridging procedure for spinal infections; a multidimensional evaluation system is needed. METHODS: This single-center retrospective self-controlled study included 27 patients with modified Pola classification (POLA) type IV lumbar infections who underwent Stage I PELD-based endoscopic debridement and drainage followed by Stage II definitive surgery. The procedure was evaluated as a planned bridging intervention within an integrated treatment pathway rather than as an isolated curative treatment. A multidimensional system assessed biochemical, clinical (pain, appetite, temperature), imaging (magnetic resonance imaging (MRI)-based modified POLA), and anesthesiologist scores. Paired t-tests and Wilcoxon tests were used for within-patient comparisons. RESULTS: Stage I PELD-based endoscopic debridement and drainage was completed in all patients (mean operation time, 82.4 min; mean blood loss, 18.5 mL; culture positivity, 55.6%). At final follow-up, visual analog scale (VAS) back-pain score decreased from 8.15 to 0.67, Oswestry Disability Index (ODI) decreased from 76.15% to 11.78%, and 36-Item Short Form Health Survey (SF-36) increased from 26.26 to 83.74 (all P<0.001). C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) decreased before Stage II surgery, body temperature improved, appetite improved in 63%, and modified POLA grading improved. These findings suggested clinical stabilization during the bridging window, whereas nutritional indicators (albumin, hemoglobin, and body mass index (BMI)) did not significantly change. CONCLUSION: PELD-based endoscopic debridement and drainage appears to be a feasible minimally invasive bridging strategy for modified POLA type IV lumbar infections. The observed improvements should be interpreted as preliminary evidence of clinical stabilization during staged treatment rather than proof of an independent curative effect of PELD. The proposed multidimensional evaluation system provides an exploratory framework for assessing early bridging response and requires further validation in larger controlled cohorts.