Anterior Cervical Discectomy and Fusion Using Cages with Different Sized Windows: A Randomized Controlled Trial.

Abstract

Prospective randomized controlled trial. This study aimed to evaluate the subsidence rates of anterior cervical discectomy and fusion (ACDF) using polyetheretherketone (PEEK) cages with different window sizes. PEEK cages used for ACDF procedures typically come with windows designed for filling with bone graft material. However, the impact of window size on subsidence rates remains unexplored. The enrolled patients were randomly assigned to three parallel treatment groups based on cage window size: large, middle, and small. Subsidence was assessed at 1 and 12 months postoperatively. At 12 months postoperatively, fusion outcomes were evaluated using three-dimensional computed tomography (CT), including the extra-cage bridging bone (ExCBB) score, intra-cage bridging bone (InCBB) score, and successful fusion rate. Clinical outcomes included the Neck Disability Index (NDI) score, Japanese Orthopaedic Association (JOA) score, and visual analog scale (VAS) scores for neck and arm pain. A total of 95 patients with 153 levels were included in the final analysis. The subsidence rate was significantly higher in the large window group than in the middle and small window groups. While the small window group had a lower subsidence rate than the middle window group, the difference was not statistically significant. There was no significant difference in the fusion results among the three groups. All three groups showed significant improvements in clinical outcomes at 12 months postoperatively compared to preoperatively. However, no significant differences were found among the groups in clinical outcomes. Using cages with large windows in ACDF increased the risk of cage subsidence. Cages with different sized windows seemed to achieve similar fusion and clinical outcomes.