458 - Randomized Controlled Trial between Two Different Cervical Disc Arthro...

Oral Posters: Cervical

Presented by: P. Karpe - View Audio/Video Presentation (Members Only)


A.J. Berg(1,2), M.-C. Killen(1), P. Karpe(1), C.D. Jensen(3), S. Khan(1), R.P. Jeavons(1), G.R. Reddy(1), T. Friesem(1)

(1) University Hospital of North Tees, Spinal Unit, Stockton-on-Tees, United Kingdom
(2) Health Education North West, Manchester, United Kingdom
(3) Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, 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 four 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-three 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. Pre-operative and post-operative Neck Disability Index (NDI) and Visual Analogue Scale (VAS) for Arm and Neck Pain have been compared for significance and comparison of outcomes between the implants compared. Surgical time, blood loss and complications have also been reviewed.

Results: Data for fifty-one patients is reported (one withdrawal, one death). 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.
There was no statistically significant difference in the pre-operative outcome scores or demographics between the groups. NDI, VAS arm and VAS neck improved by statistically significant amounts in both groups.
There was however no statistically significant difference in the post operative outcomes, which are shown in Table 2, between the groups (NDI p=0.825, VAS Neck p=0.548, VAS Arms p=0.410)
No implant specific complications were found. There were no re-operations.

Conclusions: The Four 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. As a result further studies should assess the benefits of newer implant design features such as MRI compatibility, wear profiles and implantation techniques.

Table 1: Distribution of implant type by level

Table 2: Outcome scores