156 - Early Experience with the M6-C Artificial Cervical Disc: A Report from...

Oral Posters: Cervical

Presented by: R. Sasso - View Audio/Video Presentation (Members Only)


R. Sasso(1), J. Smucker(1), S. Blumenthal(2), R. Guyer(2), J. Zigler(2)

(1) Indiana Spine Group, Carmel, IN, United States
(2) Texas Back Institute, Plano, TX, United States


Introduction: Cervical disc replacement design continues to evolve progressing from variations of ball and socket design to viscoelastic designs that mimic normal kinematics. The purpose of this study is to evaluate the early clinical and radiographic results of a one piece viscoelastic cervical disc (M6-C, Spinal Kinetics, Sunnyvale, CA) for treatment of single-level cervical radiculopathy at two investigational sites participating in a FDA approved IDE Study.

Methods: Thirty-nine skeletally mature patients with single-level (C3-C7) cervical radiculopathy were enrolled in a clinical trial at two investigational centers according to a US FDA approved IDE protocol. Specific inclusion and exclusion criteria were used to determine eligibility for participation in the study (preoperative NDI ≥ 30%, neck or arm pain ≥ VAS 4 out of 10 cm, six-weeks of prior unsuccessful conservative care, no previous anterior cervical spine surgery, etc.). Patients provided written informed consent prior to their enrollment in the IRB approved investigation. Patients were assessed clinically and radiographically at 1 year via Neck Disability Index (NDI), neck and arm visual analog scale (VAS) pain scores, and independent radiographic analyses. Safety information was collected.

Results: Thirty-nine patients (17 males and 22 females) were treated with the arthroplasty device with a mean age of 45 years and BMI of 27.6 kg/m2. Patients were noted to have an average of a 21-month history of neck pain. Mean surgical time (incision-to-skin closure) was 81 minutes with average blood loss of less than 20 cc. Mean hospital stay was 0.3 days. Mean NDI scores decreased from 57 preoperatively to 9 at 1 year follow-up. Mean VAS neck pain scores decreased from 7.4 to 1.0. Preoperative predominant arm VAS pain was reduced from 8.1 to 0.7. Median scores indicated that half of the patient population had a NDI score below 2 and VAS neck pain scores below 0.08 at 1 year. There were no neurological deficits or serious adverse events deemed to be device or procedure-related in this cohort as adjudicated by an independent panel of surgeons.

Conclusions: The M6-C is currently being investigated in an FDA approved IDE study in the US. The early experience of two investigational centers suggests that the device performs as intended both clinically and radiographically for the treatment of symptomatic cervical radiculopathy. There has been no revision, removal, subsidence, or migration in this population. There were no serious adverse events related to the device or procedure. Additional follow-up of the population through two years at our centers as well as in the entire study will further elucidate safety and effectiveness outcomes.