Construct Failure in Anterior Cervical Discectomy and Fusion: Incidence, Mode, and Time of Failure Within 2 Years.

Abstract

Despite progress in surgical approach and instrumentation, the risk of construct failure (CF) in anterior cervical discectomy and fusion (ACDF) remains. This study aims to report the time of failure, mode of failure, and reoperation rates in ACDF CFs. A systematic search was conducted through PubMed, Scopus, Embase, and Cochrane for articles relevant to ACDF CF. After stratifying CF (cage-related or screw-related), Welch's t-test, Mann-Whitney U test, and Levene's test of equal variance compared temporal (minimum endpoint, maximum endpoint, and range of failure) averages and variances. Spearman and Pearson correlation assessed relationships between surgical characteristics and outcomes with temporal characteristics. Multivariate linear regression was conducted evaluating the relationship among cage material, osteoporosis, plated versus standalone ACDF, and single-level versus multilevel ACDF with temporal characteristics. From the 978 included patients, 132 (13.5%) presented with CF within 2 years, of which 9 (6.8%) required a secondary surgery. Screw-related failures occurred within 18 months, while cage-related failures occurred within 24 months. Compared to screw-related failures, cage-related failures had greater variability in the time range of failure (P = 0.004). Multivariate regression found that polyetheretherketone cages were associated with a later minimum endpoint of failure when compared to bioabsorbable grafts (r = 0.776; P = 0.045) among screw-related failures. Among all CF patients, patients with cage-related failures are more likely to occur over a more spread-out time. Spine surgeons should be aware of these trends to determine if continued clinical observation or reoperation is necessary for CFs.