Anterior-Only Stabilization of Traumatic Subaxial Cervical Spine Injuries: Why Constructs Fail and Why Most Survive—A Systematic Review

Study Design Systematic review. Objectives To characterize mechanical failure rates and candidate risk signals for failure after anterior-only stabilization for traumatic subaxial cervical spine injuries. Methods We searched MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception to June 1, 2026 for studies evaluating mechanical construct failure or candidate risk signals after anterior-only stabilization for subaxial fractures. Narrative synthesis reported crude event fractions and study-specific odds ratios without pooling. Risk of bias and evidence certainty were assessed using ROBINS-I and GRADE (PROSPERO CRD420261420216). Results Six studies were included: five retrospective clinical cohorts (659 patients) and one nationwide registry (1,486 patients). Crude failure fractions were 5.8% (38/659) overall and 8.1% (33/405) in a morphology-focused descriptive subset, excluding separable stiff-spine cases. The separately analyzed registry recorded implant failure in 0.9% (14/1,486), implant malposition in 1.0% (15/1,486). Candidate risk signals included posterior tension-band injury (bilateral facet dislocation, posterior longitudinal ligament [PLL] injury, and facet fracture), compression endplate fracture, older age, and C7–T1 involvement; AO Spine Type C morphology was associated with registry implant failure. Compression endplate fracture and older age were each associated with failure in two cohorts; the remaining signals in one. In three cohorts with specific timing, failures were identified within seven postoperative weeks. Evidence certainty was very low. Conclusions Mechanical failure appears uncommon in selected anterior plate-based cohorts. Each candidate risk signal was supported by one or two studies; effects may depend on patient selection and surgical technique. We propose a hypothesis-generating construct-survival framework balancing mechanical demand against construct capacity until fusion and requiring prospective validation.