Clinical study of PEID in the treatment of LDH based on the position relationship between nucleus pulposus of lumbar disc herniation and compressed nerve root.

Objective: This study addresses the suboptimal outcomes occasionally observed following posterior interlaminar endoscopic lumbar discectomy (PEID). By refining the surgical targeting technique based on the anatomical relationship between herniated nucleus pulposus and the compressed nerve root, this study proposes and evaluates an optimized localization protocol. We compare postoperative recovery outcomes between this optimized method and the conventional PEID approach to support improved clinical implementation.

Methods: In this randomized controlled trial, 199 patients undergoing elective single-level PEID (L4/5 or L5/S1) at our institution from January 2023 to January 2024 were enrolled. Patients were randomly assigned to either an experimental group, in which preoperative planning was guided by imaging-based classification of the nucleus pulposus-nerve root relationship, or a control group, in which conventional positioning was used without this classification reference. The final analysis included 104 patients in the experimental group and 95 in the control group. Clinical outcomes included the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) for both low back and leg pain, assessed preoperatively, at 3 days postoperatively, and at 1, 3, 6, and 12 months postoperatively. Surgical efficacy was further evaluated using the modified MacNab criteria at final follow-up. Radiographic parameters were assessed to compare spinal stability between groups. Subgroup analysis by disc level and herniation classification was also conducted.

Results: Baseline characteristics were comparable between groups, including sex distribution (62 males and 42 females in the experimental group; 50 males and 45 females in the control group) and age (46.49 ± 13.72 vs. 45.89 ± 13.54 years, respectively). No significant differences were observed in baseline clinical or radiologic parameters (P > 0.05). The experimental group exhibited shorter operative times and fewer localization attempts at both L4/5 and L5/S1 levels (P < 0.05). No significant differences were found in pre- and postoperative intervertebral space height indices between groups (P > 0.05). Clinical outcome highlights include: (1) Postoperative VAS scores at day 1 were significantly lower in the experimental group across both disc levels (P < 0.05);(2) Both groups showed significant improvements in VAS and ODI scores postoperatively (P < 0.05), with the experimental group reporting superior VAS scores on day 3 (P < 0.05);(3) At 3 months, the ODI scores for the shoulder and axillary types of L4/5 herniation were significantly better in the experimental group (P < 0.05), though differences diminished at later timepoints (P > 0.05);(4) MacNab criteria showed a significantly higher rate of excellent/good outcomes in the experimental group at final follow-up (P < 0.05);(5) At L5/S1, the ODI scores for all herniation types were lower in the experimental group at 3 months (P < 0.05), but no significant difference in final MacNab scores was observed (P > 0.05).

Conclusion: (1) Preoperative classification and planning based on the anatomical relationship between the nucleus pulposus and nerve root at L4/5 and L5/S1 reduces radiation exposure and surgical trauma.(2) The optimized positioning strategy improves surgical efficiency, clinical efficacy, and patient safety in PEID procedures at these segments.