385 - Clinical Outcomes for a Novel Compressible Core Cervical Total Disc Re...

#385 Clinical Outcomes for a Novel Compressible Core Cervical Total Disc Replacement: 3.5 Year Follow-up

Oral Posters: Cervical Arthroplasty

Presented by: C. Lauryssen

Author(s):

C. Lauryssen (1)
D. Coric (2)
T.A. Dimmig (3)

(1) Institute of Advanced Spinal Research of California/Tower Orthopaedics, Beverly Hills, CA, USA
(2) Carolina Neurosurgery and Spine Associates, Charlotte, NC, USA
(3) Triangle Orthopaedic Associates, Durham, NC, USA

Abstract

Purpose: Cervical total disc replacement (cTDR) has emerged over the last two decades as an acceptable treatment for cervical radiculopathy in appropriate patient population. Patients suffering from severe pain caused by degenerative disc disease have been historically treated by conservative care or anterior cervical fusion. Unlike fusion, cTDR has been associated with motion preservation at the index level and less adjacent level degeneration. The purpose of this study is to assess the long term safety and effectiveness of cTDR in patients suffering from symptomatic cervical radiculopathy.

Methods: This is a prospective, non-randomized FDA-regulated pilot study conducted at 3 sites in the United States of the Spinal Kinetics M6®-C cTDR. Thirty patients were enrolled. Safety evaluations consisted of review of adverse events and effectiveness evaluations consisted of neurological assessment, radiographic analysis, Neck Disability Index (NDI) and neck and arm pain visual analogue scales. Overall subject success was determined using a composite measure of safety and effectiveness that included maintenance or improvement of neurological function, improvement in NDI of at least 15 percentage points, no serious device/procedure related adverse events and no removals, revision or supplemental fixation. Quantitative radiographic assessment included global and index level range of motion (ROM) and disc height.

Results: Twenty seven (27) patients have returned for follow-up at 3.5 years post implant. Seventeen (17) were males and 10 were females. Twelve (12) patients were treated at single level cervical disc between C3-C7 and 15 were implanted at 2 levels. At the 3.5 year follow-up, patients demonstrated a significant reduction in neck pain VAS (pre-op: 7.6 ± 2.2; 3.5 years: 2.1 ± 2.6; p< 0.001). Similarly right and left arm pain VAS decreased from 6.2 to 1.6 and 6.5 to 1.4, respectively. All 27 patients showed a greater than 15 percentage points improvement in NDI with a mean improvement of 48.8 ± 14.9 percentage points at 3.5 years compared to baseline (p<0.001). Overall subject success as defined was observed in 25 of the 27 subjects or in 93% of the cohort. Two (2) patients reported a decline in neurological function which consisted of a slight decrease in sensation. There were no serious device or procedure related adverse events and no removals, revisions or supplemental fixation reported. Mean disc height, index level and global range of motion were restored and maintained through the 3.5 year follow-up.

Conclusions: Results from the M6-C cTDR US IDE pilot study indicate acceptable safety and effectiveness as demonstrated by overall subject success and radiographic outcomes through 3.5 years. Patients will return for planned 5 year follow-up for further clinical assessment.