Preoperative Neurological Severity and Clinically Meaningful Recovery After Anterior Cervical Decompression and Fusion

STUDY DESIGN: Multicenter retrospective cohort study. OBJECTIVE: To determine how preoperative neurological severity influences postoperative recovery and achievement of clinically meaningful improvement following anterior cervical decompression and fusion (ACDF/ACCF) for degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: Anterior cervical decompression procedures are widely used for DCM, including ossification of the posterior longitudinal ligament, with favorable outcomes reported over decades. However, the impact of preoperative neurological severity on recovery after anterior surgery remains insufficiently defined. Large anterior-only cohorts evaluating severity-adjusted minimal clinically important difference (MCID) are lacking. METHODS: We retrospectively analyzed 1,024 patients who underwent anterior cervical decompression and fusion at three spine centers between 2011 and 2021. Patients were stratified by preoperative JOA score into a severe group (JOA <10; n=320) and a mild-moderate group (JOA ≥10; n=704). Neurological outcomes were assessed using the JOA score, JOA recovery rate, and severity-specific MCID thresholds (≥3-point improvement for severe and ≥2-point improvement for mild-moderate myelopathy). Perioperative complications, including dysphagia, segmental motor deficit, and graft-related events, were recorded. RESULTS: Preoperative JOA scores were significantly lower in the severe group (7.4 ± 2.2) than in the mild-moderate group (12.4 ± 1.6; P<0.001). Both groups showed substantial improvement at 1 year (11.7 ± 3.1 vs. 14.6 ± 1.8; P<0.001). Recovery rates were similar (44.6% vs. 48.2%; P=0.74). MCID achievement was significantly higher in the severe group (66.9%) than in the mild-moderate group (49.0%; P<0.001). Excellent recovery (JOA recovery rate ≥80%) was more frequent in the mild-moderate group (23.4% vs. 12.5%; P<0.01). Complication rates did not differ significantly. CONCLUSION: In this large multicenter cohort, patients with severe preoperative myelopathy achieved meaningful neurological improvement and high rates of severity-adjusted MCID after anterior cervical decompression and fusion. These findings provide practical, severity-based prognostic information for preoperative counseling in DCM surgery.