Autologous Iliac Bone Graft With Anterior Plating Is Advantageous Over the Stand-Alone Cage for Segmental Lordosis in Single-Level Cervical Disc Disease

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) with autologous iliac bone graft and plating has been a standard surgical method for single-level cervical disc disease. The stand-alone cage was introduced to reduce graft-related morbidity. However, problems due to focal kyphosis at the operated level have been on the rise. It has been difficult to derive a conclusive answer from previous studies for the indications of each method. OBJECTIVE: An interim analysis of a prospective randomized study was performed to compare the sagittal alignment between a stand-alone cage (ACDF cage) and autologous iliac bone graft and plating (ACDF plate). METHODS: Twenty-nine patients were allocated to the ACDF-cage group (M:F = 17:12) and 23 to the ACDF-plate group (M:F = 14: 9). Cobb angles at the operated segment (segmental angle, SA; lordosis vs kyphosis) were compared at postoperative 12 months and the other confounding factors were explored. RESULTS: Demographic features were not different between groups. The fusion method significantly affected segmental alignment at 12 months (P = .03; odds ratio, 5.52). Preoperatively, the SA was not different between the groups (P = .18) and was similar (P = .22) immediately following the operation. However, the SA was significantly more lordotic (P < .05) in the ACDF-plate group at postoperative 12 months in comparison with the ACDF-cage group. There was no other significant risk factor for segmental kyphosis. CONCLUSION: The stand-alone cage and autologous bone graft with plating had similar clinical outcomes, but stand-alone cage fusion may be disadvantageous from a radiological viewpoint.