Comparing Allografts to Autografts for Maintenance of Cervical Sagittal Parameters and Clinical Outcomes Following Anterior Cervical Discectomy and Fusion With Anterior Cervical Plating

OBJECTIVE: Current literature has not shown if using either allograft or autograft differentially affects postoperative cervical sagittal parameters. The goal of this study was to compare sagittal alignment and patient-reported outcomes following anterior cervical discectomy and fusion (ACDF) with allograft versus autograft. METHODS: A retrospective cohort analysis of patients who underwent single-level ACDF was conducted. Preoperative, immediate postoperative, and final follow-up radiographic assessments were conducted and included: change in C2–7 lordosis, T1 slope, levels fused, sagittal vertical axis (SVA), fusion mass lordosis, and proximal and distal adjacent segment degeneration (ASD). Patient-reported outcomes were obtained using the Neck Disability Index and visual analogue scale scores for neck and arm. RESULTS: A total of 404 patients were assessed; 353 using allograft and 51 using autograft. No significant differences existed in demographics. Cervical lordosis improved in both groups without significant changes in SVA. Autograft group had a significantly greater amount of lordosis at the proximal segment on immediate postoperative radiographs and less overall cervical lordosis at final follow-up. Sagittal parameters were similar at each time point without significant changes between the 3-time points. No significant differences existed in radiographic ASD or reoperation rates. Fusion rates exceeded 96% in both groups. No significant differences existed between preoperative, postoperative, or change in patient-reported outcomes between the 2 groups. CONCLUSION: Sagittal alignment is maintained following ACDF when using either allograft or autograft. Radiographic evidence of ASD is present in both groups; however, this was not considered clinically significant, given low rates of pseudarthrosis or reoperation. No significant differences exist between groups in terms of patient-reported outcomes.