Three-Level Cervical Disc Arthroplasty Combined With Fusion Versus Three-Level ACDF: A Systematic Review and Meta-Analysis

Study DesignSystematic Review.ObjectivesTo compare clinical, radiological, and complication outcomes between three-level hybrid surgery [combining cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion (ACDF)] and three-level ACDF alone in patients with multilevel cervical degenerative disease.MethodsA systematic review and meta-analysis were conducted following PRISMA guidelines. Nine retrospective cohort studies (704 patients: 450 HS, 254 ACDF) were included. Pooled mean differences (MD) with 95% confidence intervals (CI) were calculated for clinical, radiological, perioperative, and complication outcomes.ResultsBoth HS and ACDF significantly improved disability and myelopathy scores, with no differences in NDI or mJOA. HS preserved better the operated-level ROM (MD + 5.79°; 95% CI 2.38 - 9.21; <i>P</i> = 0.0009), while adjacent segment motion did not differ. Arm pain improvement showed a non-significant trend favouring HS (MD -2.63; <i>P</i> = 0.08), and neck pain was similar. Both procedures improved segmental lordosis; global alignment remained stable. Complications differed: instrumentation failure was more common with ACDF (33.3% vs 5.2%, <i>P</i> = 0.02), while HO occurred in 41.2% of hybrid constructs, reflecting loss of arthroplasty motion.ConclusionThree-level HS and ACDF provide comparable clinical outcomes. HS is a promising alternative, providing better motion preservation but at the cost of a higher risk of heterotopic ossification, while ACDF may be associated with a higher rate of instrumentation failure. Long-term prospective studies are still needed to strengthen these conclusions.