Laminectomy and fusion better maintains horizontal gaze than laminoplasty in cervical spondylotic myelopathy

Background: Laminectomy and fusion (LF) and laminoplasty (LP) are common treatments for cervical spondylotic myelopathy and myeloradiculopathy. While both procedures show similar clinical improvement, LF requires bony fusion while LP offers motion preservation. Cervical sagittal alignment and horizontal gaze maintenance are key outcome measures, but their comparative effects between LF and LP remain unclear. This study evaluated postoperative horizontal gaze and cervical sagittal alignment in patients undergoing either procedure.

Methods: In this retrospective cohort study at 2 academic centers, patients underwent either LF or LP. Pre/postoperative cervical sagittal alignment parameters were collected, including C2-7 lordosis, C2-7 SVA, Occiput-C2 angle, and T1-slope. The McGregor slope measured horizontal gaze, with 8° flexion to 13° extension as normal range. Primary outcome was horizontal gaze maintenance at minimum 1-year follow-up. Secondary outcomes included changes in cervical spine alignment parameters.

Results: Sixty-four patients (30 LF, 34 LP) completed minimum 1-year follow-up. Pre/postoperative sagittal alignment measures showed no significant differences between groups. Within cohorts, LP increased C2-7 sagittal vertical axis (29.1-37.6 mm, p=.04) while LF decreased C2-7 lordosis (11.5°-5.00°, p=.04). Postoperatively, LF showed significantly more optimally aligned patients (90.0%) versus LP (57.8%) (p<.01). Multivariate analysis indicated LP predicted postoperative horizontal gaze malalignment (OR 13.90 [2.10-286.62], p=.022).

Conclusions: While both procedures yielded comparable cervical sagittal alignment outcomes, LF demonstrated superior maintenance of horizontal gaze. These findings suggest that laminectomy and fusion may preserve horizontal gaze better than laminoplasty.Level of Evidence: III.