Abstract

In this retrospective comparative study, 42 patients with single-level cervical radiculopathy were operated upon, either with Shell™ cage fusion (23 patients) or with Prestige™ cervical disc arthroplasty (19 patients). The mean follow-up (FU) was 17.5 months (range : 5.6-42.1 months). Both treatments significantly improved all clinical parameters (VAS, ODI, SF36) (p < 0.001), without statistically relevant differences between the two groups. From a radiological viewpoint there was an obvious but statistically non-significant increase in the segmental height for both treatment groups. Segmental angle also increased in both groups, and the increase was significant (p < 0.05).

As expected, range of motion (ROM) decreased significantly (p < 0.05) in the fusion group, while it was preserved in the arthroplasty group. Significantly more (p < 0.05) adjacent level degeneration class 1 to 4 was evident in the fusion group (8/23 or 34.8%) than in the arthroplasty group (3/19 or 15.8%). Two fusion patients (2/23 or 8.7%) developed painful clinical adjacent level disease requiring arthroplasty. The major conclusion was that significant adjacent level degenerative changes occurred in the cage group. Retained motion at the operative site seems to decrease the incidence of adjacent level degeneration. Implant subsidence was recorded at FU in 8 out of 42 patients (19%).

It occurred significantly (p < 0.05) more often in the fusion group (6/23 or 26.1%) than in the arthroplasty group (2/19 or 10.5%)), but it did not cause clinical symptoms. As in other studies, there is no explanation as to why better radiological results did not translate into better clinical outcomes within the time limits of the study.