Structural Allograft versus Polyetheretherketone Cage in Anterior Cervical Discectomy and Fusion: A Meta-Analysis

Abstract

Polyetheretherketone (PEEK) cages and structural allografts (SAs) are commonly used in Anterior Cervical Discectomy and Fusion (ACDF), yet their postoperative results remain uncertain. This meta-analysis was conducted to determine whether there were any differences in outcomes between patients who received these two grafts in ACDF. We comprehensively searched electronic databases up to August 2023. Observational studies or randomized controlled trials reported postoperative outcomes, including fusion, subsidence, reoperation rates, and patient-reported outcomes through the Neck Disability Index (NDI), the Visual Analog Scale (VAS) for neck and arm pain, and the Japanese Orthopedic Association (JOA)/modified JOA score following primary ACDF using SA or PEEK cage. The results are presented in odds ratios (ORs) or mean differences with corresponding 95% confidence intervals (CIs). Eleven studies were included, with 1213 patients (788 receiving SAs and 425 receiving PEEK cages). Patients having SA had significantly higher fusion (OR: 1.84, 95% CI: 1.27-2.67, p = 0.001) and lower subsidence (OR: 0.50, 95%CI: 0.30-0.86, p = 0.01) rates when compared with the PEEK cage. There was no difference in revision rate between SA or PEEK cage (p = 0.88). Two grafts demonstrated similar clinical improvements in NDI (p = 0.31), VAS for the neck (p = 0.77) and arm pain (p = 0.22), and JOA/mJOA score (p = 0.99). SA demonstrates better fusion and lower subsidence rates than the PEEK cage in ACDF. Nevertheless, these two cages resulted in equally successful postoperative clinical performances.