Study design: This is a prospective randomized and controlled study, approved by the local ethical committee of Saarland (Germany).
Objective: The aim of the current study was to analyze segmental motion following artificial disc replacement using disc prosthesis over 1 year. A second aim was to compare both segmental motion as well as clinical result to the current gold standard (anterior cervical discectomy and fusion [ACDF]).
Summary of background data: ACDF may be considered to be the gold standard for treatment of symptomatic degenerative disc disease within the cervical spine. However, fusion may result in progressive degeneration of the adjacent segments. Therefore, disc arthroplasty has been introduced. Among these, artificial disc replacement seems to be promising. However, segmental motion should be preserved. This, again, is very difficult to judge and has not yet been proven.
Methods: A total of 49 patients with cervical disc herniation were enrolled and assigned to either study group (receiving a disc prosthesis) or control group (receiving ACDF, using a cage with bone graft and an anterior plate). Roentgen stereometric analysis (RSA) was used to quantify intervertebral motion immediately as well as 3, 6, 12, 24, and 52 weeks after surgery. Also, clinical results were judged using visual analog scale and neuro-examination at even RSA follow-up.
Results: Cervical spine segmental motion decreased over time in the presence of disc prosthesis or fusion device. However, the loss segmental motion is significantly higher in the fusion group, when looked at 3, 6, 12, 24, and 52 weeks after surgery. We observed significant pain reduction in neck and arm after surgery, without significant difference between both groups.
Conclusion: Cervical spine disc prosthesis remains cervical spine segmental motion within the first 1 year after surgery. The clinical results are the same when compared with the early results following ACDF.