Mid- to long-term rates of symptomatic adjacent-level disease requiring surgery after cervical total disc replacement compared with anterior cervical discectomy and fusion: a meta-analysis of prospective randomized clinical trials.

Abstract

Thus far, no meta-analysis focusing on the mid- to long-term incidence of adjacent segment disease requiring surgery after cervical total disc replacement and anterior cervical discectomy and fusion has been published yet. This study aimed to compare mid- to long-term rates of symptomatic adjacent-level disease requiring surgery after cervical disc replacement and anterior cervical fusion. A meta-analysis was performed, and only randomized controlled trials with a follow-up period of more than 48 months reporting rates of symptomatic adjacent-level disease requiring surgery after cervical total disc replacement and anterior cervical discectomy and fusion were included. The analysis revealed that the overall rate of symptomatic adjacent-level disease requiring surgery in the cervical disc replacement group was significantly lower than that of the anterior cervical fusion group at 48-120 months' follow-up. The subgroup analysis of different follow-up periods also yielded the same results. The rate of symptomatic adjacent-level disease requiring surgery in the cervical disc replacement group using unrestricted prosthesis was significantly lower than that of the anterior cervical fusion group (p < 0.001); however, the cervical disc replacement group using semi-restricted prosthesis showed no statistical difference compared with the fusion group. Our review suggests that cervical disc replacement is preferable to anterior cervical fusion in reducing the incidence of symptomatic adjacent-level disease requiring surgery at mid- to long-term follow-up. A review of the literature also demonstrated that randomized controlled trials investigating the rate of symptomatic adjacent-level disease requiring surgery were insufficient; therefore, studies focusing on this subject with longer-term follow-up are warranted.