Introduction: The role of interbody cages in anterior cervical discectomy and fusion (ACDF) with anterior plate remains controversial, with prior literature associating interbody cage use with higher pseudoarthrosis and reoperation rates. Conflicting evidence has been impacting surgical decision-making and reimbursement authorization. We aimed to summarize the literature on the use of interbody cages in ACDF and compare interbody cages versus structural bone grafts on radiographic and clinical outcomes.
Methods: A systematic review of the literature was performed to identify studies on ACDF with anterior plate directly comparing the use of an interbody cage with structural bone graft. Radiographic outcomes of interest included fusion, change in disc height, and change in cervical and segmental Cobb angles. Clinical outcomes examined were Visual Analogue Scale (VAS) for neck and arm pain, Neck Disability Index (NDI), and reoperation rates.
Results: A total of 17 studies were identified. 810 (44.8%) patients underwent ACDF with interbody cage, and 997 (55.2%) patients underwent ACDF with structural bone graft. Cage interbodies were associated with greater increase from baseline disc height at final follow-up (MD:0.59mm,p < 0.01). At final follow-up, structural bone grafts were associated with greater loss of segmental Cobb angle (MD:0.46o,p=0.046), compared to first postoperative follow-up. Reoperations were lower in the cage group (2.5% vs. 4.4%,p=0.24), with a number needed to treat equal to 53. Pseudoarthrosis rates (5.3% cage vs. 8.9% bone,p=0.41) were similar between the two groups and did not reach statistical significance. Cervical Cobb angles and patient-reported outcomes were not statistically significant between the two groups.
Conclusion : In a comprehensive synthesis of the literature, the use of interbody cages in ACDF with anterior plate fixation offered greater preservation of disc height and segmental Cobb angle at long-term follow-up. Contrary to prior evidence, interbody cages does not increase the risk of pseudoarthrosis and might be associated with a lower reoperation risk.
