Comparison of multilevel anterior cervical discectomy and fusion utilizing zero-profile self-locking cages versus the cage-with-plate system: a 5-year-minimum follow-up study.

Abstract

Study design: Retrospective study.

Purpose: To compare the clinical and radiological outcomes of self-locking cage (SC) and cage-with-plate (PC) systems in three-level anterior cervical discectomy and fusion (ACDF) over a 5-year follow-up period.

Overview of literature: The durability of SCs in maintaining cervical alignment and preventing complications over an extended period of time remains uncertain.

Methods: Sixty-two patients (2014-2019) were divided into the SC (n=32) and PC (n=30) groups. Clinical outcomes were evaluated using the Visual Analog Scale (VAS), modified Japanese Orthopedic Association (mJOA) score, and Neck Disability Index (NDI). Radiological parameters, including cervical lordosis (CL), fused segment angle (FSA), and disc height (DH), were assessed. Cage subsidence, adjacent segment degeneration (ASD), and other complications were also documented. The relationship between postoperative radiological changes and symptoms was also analyzed.

Results: Both groups showed significant improvement in symptoms, with fusion achieved in all surgical segments. The SC group had a shorter operative time and reduced intraoperative blood loss. However, the SC group had a higher subsidence rate (16.7% vs. 5.6%, p=0.017). The PC group maintained better cervical alignment in terms of CL, FSA, and DH (p<0.05), with an increased incidence of dysphagia and ASD (p<0.05). Spearman correlation analyses showed that neither CL nor FSA loss at the 5-year follow-up was significantly associated with improvements in the mJOA, VAS, and NDI scores (p>0.05) in either group. Regression analyses indicated that subsidence or loss of lordosis did not correlate with the degree of postoperative symptoms (p<0.05).

Conclusions: Both SC and PC achieved sustained pain relief, neurological improvement, and solid fusion in three-level ACDF at the 5-year follow-up. SC demonstrated significant advantages in reducing dysphagia and ASD, while PC better maintained cervical alignment and segmental stability. Patient-specific factors should be used to guide implant selection. Further multicenter studies are required to validate these findings.