Comparison of adjacent segment degeneration in patients using cervical cage and disc prosthesis in anterior cervical surgery

Aim: To examine the prevalence of adjacent segment degeneration associated with the use of cages and disc prostheses in patients who underwent cervical disc surgery via an anterior cervical approach. Methods: We retrospectively reviewed the medical records of 60 patients who underwent cervical disc surgery via an anterior cervical approach at our clinic between 2018 and 2023. The patients were divided into two groups based on the type of implant used: those with a cervical cage (Group 1) and those with a cervical disc prosthesis (Group 2). Patients' demographic and clinical details, including age, gender, smoking habits, follow-up durations, and any additional comorbid diseases, were recorded. Radiological evaluations focused on degeneration rates in the segments adjacent to where either the cage or disc prosthesis was implanted. Results: In the study comparing two groups, participants' average ages were 48.9 in Group 1 and 48.1 in Group 2 (p=0.720). Group 1 had a higher proportion of smokers (p=0.052) and more discopathy (p=0.196). In terms of disc degenerations, variations existed but were not statistically significant (p=0.259). Utilizing the Pfirrmann grading, Group 1 had more Grade III degeneration (p=0.088) and a significantly higher presence of ossification or osteophytes (p=0.038). Both groups showed high rates of adjacent segment degeneration, yet Group 1 had notably more proximal degeneration (p=0.012). Stenosis and facet hypertrophy differences were not significant (p=0.417, p=0.071). Follow-up duration averaged around 38 months for both groups (p=0.929). Conclusions: No substantial difference in the overall incidence of adjacent segment degeneration between the two procedures. Nevertheless, further large-scale and long-term studies are essential to draw comprehensive conclusions regarding the optimal surgical intervention for cervical disc ailments.