Clinical and Radiological Outcome at the 10 Year Follow up of Total Cervical Disc Replacement

Abstract

IntroductionThere is still a lack of facts about long term impacts after implantation of a total cervical disc replacement (cTDR). The aim of this current analysis was to evaluate the long- term clinical results and efficacy, the radiographic findings of the index level as well as the adjacent level in a cohort of cTDR patients treated with ProDisc C (Synthes, Paoli, USA) 10 years after surgery. Material and MethodsClinical outcome scores and patient satisfaction rates were acquired within the framework of an ongoing single center prospective non randomized clinical trial. The patient's employment status, complications, reoperations and further treatments due to symptomatic adjacent segment disease (ASD) were recorded. X-ray evaluation included the incidence of heterotopic ossifications (HO) according as well as the rates and timing of ASD. Follow up was recorded 1, 5 und 10 years after surgery. Results38 patients were available for final FU, resembling a 80,8% FU rate after a mean FU of 122,9 months. The overall results revealed a highly significant improvement from baseline VAS and NDI levels at all postoperative FU stages (p < 0,0001). VAS scores demonstrated a statistically significant improvement (VAS neck 6.4 to 1.9; VAS arm 6.3 to 2.1 at the last FU). The NDI baseline values showed a stable improvement (21/50 to 6/50). Patient satisfaction rates remained stable throughout the postoperative course, with 78.9% of patients reporting a ‘highly statisfactory’ or a ‘satisfactory’ outcome in 21,1%. The radiographic results demonstrated a noteworthy incidence of HO as well as a progression of the HO in process of time. HO Grade I appeared in 10%, Grade II in 10%, Grade III in 32%, and Grade IV in 26%. The overall complication rate (excluding HO) was 12%. The incidence of ASD was 32.3%. 70% of ASD were asymptomatic, none of the ASD patients need further surgery. Within this group of patients with ASD 80% of the patients presented with a high-grade HO with loss or reduced function of the prosthesis in the 5 year FU. ConclusionThe results demonstrate that cTDR is a viable treatment option resulting in improved clinical outcomes and low rates of subsequent surgical procedures. The progression of HO with a high amount of non functional TDR may leads to the high figures of ASD.