Sagittal Alignment and Segmental Mobility After Cervical Intradural Extramedullary Tumor Surgery: A Comparative Analysis of Unilateral Hemilaminectomy and Laminotomy with Laminoplasty

Abstract

Objectives: In this retrospective comparative cohort study, we aimed to compare surgical efficiency, radiographic facet integrity, and postoperative alignment and mobility between unilateral hemilaminectomy (UL) and laminotomy with laminoplasty (LP) for cervical intradural extramedullary (IDEM) tumors. Methods: Thirty-eight patients (UL: 20; LP: 18) were retrospectively reviewed. Operative variables, tumor characteristics, extent of resection, radiographic facet joint violation (graded 1-4), and sagittal alignment parameters, including global and segmental range of motion (ROM), were evaluated at 1 year postoperatively. Propensity score matching was additionally performed to minimize potential baseline imbalance between groups. Results: The UL group had significantly shorter operative time (178.05 +/- 61.89 vs. 276.06 +/- 121.76 min, p = 0.003) and lower intraoperative blood loss (p < 0.001) than the LP group. Radiographic facet joint violation (Grade >= 2) occurred more frequently in the UL group (25.0% vs. 0%, p = 0.048) but was not associated with postoperative sagittal alignment changes or radiographic instability. Global cervical alignment remained in both groups, but the LP group showed a significantly greater reduction in segmental ROM at 1 year (-6.42 +/- 8.29 degrees vs. 0.06 +/- 7.72 degrees, p = 0.017). These findings were consistent in the propensity score-matched cohort. Conclusions: UL provides favorable operative efficiency and better preservation of segmental cervical mobility than LP, while maintaining comparable clinical and radiographic outcomes. Although radiographic facet joint violation was more frequent in the UL group, postoperative spinal stability was not compromised in this cohort. UL may serve as a safe and motion-preserving alternative in selected patients with cervical IDEM tumors.