General Session: Cervical-2
Presented by: A.J. Berg - View Audio/Video Presentation (Members Only)
A.J. Berg(1,2), M-C. Killen(1), C.D. Jensen(3), P. Karpe(1), S. Khan(1), R. Malgatil(1), G.R. Reddy(1), T. Friesem(1)
(1) North Tees and Hartlepool NHS Foundation Trust, Spinal Unit, Stockton on Tees, United Kingdom
(2) Pennine Acute Hospitals NHS Trust, Manchester, United Kingdom
(3) Northumbria Healthcare NHS Foundation Trust, Trauma and Orthopaedics, Northumberland, United Kingdom
Introduction and Purpose: Motion preservation with cervical disc arthroplasty has consistently been shown, in numerous randomised controlled trials (RCT), to produce equivalent or superior clinical outcomes to fusion. It is hypothesised that different implants could produce different surgical, clinical and radiographic results and therefore there has been a call to compare outcomes. We report the results, at three years, of the only RCT comparing two different arthroplasty implants - the NuNEC™ Cervical Arthroplasty System (RTI Surgical, Inc., USA), a PEEK on PEEK articulating device with inferior ball and superior trough secured by cam-lock screws and the PRESTIGE® LP Cervical Disc System (Medtronic, USA), a titanium ceramic composite articulating device with superior ball and inferior trough secured by keels. While of different construction the implants share some characteristics such as allowing a degree of translation.
Methods: A review of fifty-two patients with degenerative disc disease causing cervical radiculopathy and/or myelopathy enrolled in this United Kingdom National Health Service Research Ethics Committee approved study has been performed. Pre-operatively patients were randomized into the two groups (surgery with NuNEC™ Cervical Arthroplasty System or PRESTIGE® LP Cervical Disc System) and blinded until after surgery. Neck Disability Index (NDI), Visual Analogue Scale (VAS) for Arm and Neck Pain and Hospital Anxiety and Depression Scale were collected pre-operatively and at follow-up. Surgical time, blood loss and complications have also been reviewed. Outcomes have been compared between groups.
Results: Data for forty-seven patients is reported (one withdrawal due to relocation, four non-attendance at follow-up excluded). The distribution of patients according to implant type and number of levels treated is shown in Table 1. There was no statistically significant difference in the distribution of the number of operated levels between the two implant groups and therefore analysis has been performed using the means for each group. There was no statistically significant difference in the pre-operative outcome scores or demographics between the groups. There was no statistically significant difference in the post operative outcomes, which are shown in Table 2, between the groups. VAS arm and VAS neck improved by statistically significant amounts in both groups. The improvement in NDI only achieved statistical significance in PRESTIGE® LP group. No implant specific complications were found. There were no re-operations.
Conclusions: The three year results of the only RCT comparing two different cervical arthroplasty implants - the NuNEC™ Cervical Arthroplasty System and the PRESTIGE® LP Cervical Disc System - suggest little difference in the clinical outcomes between the implants. Further studies comparing implants with significantly different mechanics is needed.
Table 1- Distribution of implant type by level
Table 2- Outcome Scores