Endoscopic posterior cervical canal decompression versus laminoplasty for two-level cervical spondylotic myelopathy: clinical outcomes and finite element analysis

To comprehensively evaluate the clinical efficacy, surgical invasiveness, learning curve, and biomechanical characteristics between endoscopic posterior cervical canal decompression (Endo-PCCD) and laminoplasty (LP) in patients with two-level cervical spondylotic myelopathy (CSM). This study uniquely integrates clinical outcomes, cumulative sum (CUSUM) learning curve analysis, and finite element modeling to provide a multidimensional comparison between the two procedures.

This retrospective study included 95 patients with CSM, of whom 45 underwent Endo-PCCD and 50 underwent LP. Baseline characteristics, perioperative parameters, and clinical outcomes (VAS, JOA, and NDI) were compared. DSA improvement rates were measured at C3-C5, C4-C6, and C5-C7 levels. Learning curves were assessed based on cumulative sum (CUSUM) analysis. Cervical finite element models were developed to evaluate the segmental range of motion (ROM) of Endo-PCCD and LP under identical loading conditions.

Baseline characteristics were comparable between groups. The Endo-PCCD group showed significantly shorter operative time, lower drainage volume, and higher postoperative hemoglobin (Hb) levels (all P < 0.05). Clinical outcomes were similar at all follow-up time points. DSA improvement was significantly greater in the LP group at C5-C7 (P < 0.001), with no differences at other levels. Proficiency thresholds were 25 cases for Endo-PCCD and 19 cases for LP. Finite element analysis indicated that the LP model exhibited increased segmental ROM under flexion and extension, whereas the Endo-PCCD model maintained motion patterns closer to the intact spine.

Endo-PCCD achieves clinical outcomes comparable to LP while offering a potential trend toward reduced surgical invasiveness and may better preserve physiological cervical biomechanics, although LP may provide greater decompression at certain levels.

Clinical trial number Not applicable.