Study design: A retrospective study.
Objective: To analyze adjacent segment degeneration (ASD) in 2-level anterior cervical discectomy, comparing fusion with stand-alone cages [anterior cervical discectomy and fusion (ACDF)-CA] and fusion with cage and plate constructs (ACDF-CPC) with respect to clinical outcomes and radiologic changes.
Summary of background data: ACDF using a stand-alone cage or a cage and plate construct is a popular procedure. However, there is lack of knowledge concerning ASD between the 2 procedures.
Methods: A total of 42 consecutive patients who underwent 2-level ACDF-CA or ACDF-CPC for 2-level cervical disk disease and who completed 2 years of follow-up were included in this study. The patients were divided into 2 groups: ACDF-CA group (n=22) and ACDF-CPC group (n=20). The following parameters were assessed using radiographs: disk space narrowing, anterior osteophyte formation, calcification of the anterior longitudinal ligament, and fusion status. Clinical outcomes were assessed using the Robinson criteria.
Results: No difference in clinical outcomes was observed between the 2 groups. Moreover, the ACDF-CPC group showed a similar fusion rate compared with the ACDF-CA group (100% vs. 95%, P=0.335). There was also no statistical significance in anterior osteophyte formation and calcification of the anterior longitudinal ligament. However, mean intervertebral disk height change of an adjacent segment was significantly lower in the ACDF-CA group than the ACDF-CPC group (upper level: 0.08±0.24 vs. 0.49±0.35; lower level: 0.06±0.41 vs. 0.49±0.28; P<0.01).
Conclusions: The use of a cage with or without plate constructs in 2-level ACDF provides similar clinical results and fusion rates. Notwithstanding, ACDF-CPC showed a higher incidence of ASD than ACDF-CA over the 2-year follow-up.