TOTAL CERVICAL DISC REPLACEMENT WITH THE DISCOCERV® CERVIDISC EVOLUTION CERVICAL PROSTHESIS: INTERMEDIATE RESULTS

Abstract

Background: Long-term results after fusion for cervical disc disease show evidence of adjacent segment disease, mainly in young and active population. This led to the development of new techniques, i.e. cervical mobile prostheses. 8yr-follow-up of Cervidisc^® semi-constrained prosthesis documented motion preservation, but its design required minor adjustments to assess optimal outcome leading to an optimized version – Discocerv^® Cervidisc Evolution.

Purpose: To evaluate the intermediate outcome in patients operated with Discocerv^®.

Study design: Multicenter prospective non comparative study.

Patient sample: Since April 2006, 77 consecutive patients (41m/36w: mean age 45.2[27–65]) were enrolled in the study so far in 7 centers in France and Switzerland. Mean follow up was 6(0–12) months.

Outcome measures: Clinical evaluation criteria: VAS 1 to 100mm self-reported cervical and radicular pain, NDI (1–50 scale), symptoms evolution (ODOM score), work status, patient satisfaction were recorded pre–and post-operatively. Radiographic criteria: operated levels’ flexion-extension mobility.

Methods: Patients underwent one (C3C4 n=2, C4C5 n= 7, C5C6 n=37, C6C7 n= 28) or multiple level (C5C6/ C6C7 n=2; C4C5/C5C6/C6C7 n=1) cervical arthroplasty with Discocerv for degenerative disc diseases (disc hernia, stenosis, discopathy).

Results: Per-operative complications occurred in 4 patients (5%) without further consequences. No post operative complications were reported. 67% of active patients resumed their previous work within the first 6 months after surgery. The ODOM score showed 100% excellent and good results at 6 to 12mths follow-up.

Mean cervical and radicular VAS-reported pain decreased from 60 [4–84] and 65 [2–96] pre-operatively to 21[0–45] and 21[0–36] at 0–6 months and to 15 [0–40] and 16 [0–40] respectively at 6–12 months. Similarly mean NDI decreased from 25 [9–45] to 10 [0–35] at 0–6 months and to 6[0–36] at 6–12mths. All patients were satisfied with the results so far.

Quantitative radiographic analysis showed satisfactory restoration of cervical mobility at the operated levels with mean flexion-extension mobility 6.4°[1–11°] at 0–3mths and 7.1°[4–12°] at 6–12mths respectively. The adjacent level mobility was found within normal ranges at 6–12mths post-operatively. At the same follow-up period, the regional lordosis was within physiological ranges for 65% of patients at the last follow-up.

Discusssion and conclusion: Our results with Discocerv^® Cervidisc Evolution prosthesis confirm the long term 96% mobility obtained at 7 years follow-up with the first generation of the device, i.e. Cervidisc^®.

Both clinical and radiological findings in this study support the effectiveness of the Discocerv^® Cervidisc Evolution prosthesis at mid-term. However further follow-up at long term is necessary in order to confirm these findings.