Impact of C3 Laminectomy Versus C3 Laminoplasty on Cervical Alignment.

Abstract

Retrospective cohort study. To evaluate how C3 laminectomy affects cervical alignment compared with laminoplasty alone. Cervical laminoplasty is a motion-preserving procedure for decompressing the spinal cord in patients with symptomatic cervical stenosis. Some surgeons perform a laminectomy at C3 rather than a laminoplasty. The study evaluates the radiographic impact of C3 laminectomy versus C3 laminoplasty on postoperative cervical sagittal alignment (CSA) after open-door laminoplasty. We retrospectively reviewed patients at a single institution who underwent C3-C6 laminoplasty (LP) or C4-C6 laminoplasty with C3 laminectomy (LN). Patients were divided into 2 groups based on surgical approach, and cervical alignment was assessed using standard radiographic measures at preoperative, first erect, 6-month, and 1-year follow-up intervals. Unpaired t tests and χ2 tests were used for statistical analysis, with significance set at P≤0.05. A total of 133 patients (46 females) were included: 66% in the LP and 34% in LN. Preoperative alignment parameters (C2-C7 Cobb angle, C2-C3 Cobb angle, C4-C7 Cobb angle, and cSVA) were similar between groups (P>0.05). At 1-year follow-up, the LP group had significant C2-C7 (5.34 degrees, P=0.0002) and C4-C7 (7.13 degees, P<0.0001) lordosis loss, while the LN group showed smaller, nonsignificant changes (C2-C7: 3.08 degrees, P=0.1406; C4-C7: 1.86 degrees, P=0.3405). The cSVA increased significantly in the LP group (-0.64 cm, P=0.0010) but not in the LN group (-0.33 cm, P=0.1690). Loss of lordosis (≥ -10 degrees change) at the C4-C7 level occurred in 38% of LP patients compared with 15% of LN patients. Regarding the cervical sagittal vertical axis (cSVA), a ≥ 4 cm change was observed in 2% of patients in both groups. C3 laminectomy preserves cervical lordosis and sagittal alignment, and is noninferior to laminoplasty alone. Level III.