Effect of anterior cervical discectomy and fusion versus laminoplasty on spinocranial angle in patients with multilevel cervical spondylotic myelopathy: A retrospective cohort study

This study compared anterior and posterior surgeries regarding sagittal spinocranial angle (SCA) and other sagittal balance metrics, analyzed correlations between radiographic changes and clinical outcomes, and identified the superior surgical strategy for multilevel cervical spondylotic myelopathy (MCSM). This retrospective cohort enrolled 51 patients receiving anterior cervical discectomy and fusion (ACDF) and 69 undergoing posterior laminoplasty (LP) between 2014 and 2021, with a minimum 24-month follow-up. Serial radiography, CT, and MRI measured SCA, surrogate C7 slope (for unavailable T1 slope), C2-C7 Cobb angle (CA), cSVA, and T1sCA at preoperation, early postoperation (5-7 days), and final follow-up. Clinical endpoints included JOA score, neurological recovery rate (RR), NDI, and SF-36. Multivariate regression and linear mixed-effects models adjusted for age, gender, BMI, baseline scores, and operative segments to clarify the independent impacts of surgery and sagittal parameter shifts on clinical results. Both procedures significantly improved all quality-of-life metrics (P < .05). ACDF yielded superior final RR (50.50 ± 24.71% vs 44.98 ± 17.77%, P = .026) and lower NDI (12.90 ± 4.15 vs 14.97 ± 3.52, P = .009). At final follow-up, ACDF presented larger C7 slope and CA (all P ≤ .047), alongside reduced SCA, T1sCA and cSVA (all P < .001). Multivariate analyses confirmed ACDF independently predicted lower follow-up NDI (β = -2.31, P = .009), while elevated ΔSCA independently aggravated NDI (β = 0.38, P = .002); neither ACDF nor ΔSCA independently correlated with JOA RR (all P > .05). ACDF independently drove postoperative SCA reduction (β = -11.52, P < .001). Relative to LP, ACDF reduces postoperative SCA and improves NDI and neurological recovery. Constrained by its retrospective nonrandomized design, these findings await prospective randomized verification; surgical selection should be individualized per patient pathology and sagittal balance.