Two-level total disc replacement with Mobi-C cervical artificial disc versus anterior discectomy and fusion: a prospective, randomized, controlled multicenter clinical trial with 4-year follow-up results.
OBJECTIVE
The purpose of this study was to evaluate the safety and effectiveness of 2-level total disc replacement (TDR) using a Mobi-C cervical artificial disc at 48 months' follow-up.


METHODS
A prospective randomized, US FDA investigational device exemption pivotal trial of the Mobi-C cervical artificial disc was conducted at 24 centers in the U.S. Three hundred thirty patients with degenerative disc disease were randomized and treated with cervical total disc replacement (225 patients) or the control treatment, anterior cervical discectomy and fusion (ACDF) (105 patients). Patients were followed up at regular intervals for 4 years after surgery.


RESULTS
At 48 months, both groups demonstrated improvement in clinical outcome measures and a comparable safety profile. Data were available for 202 TDR patients and 89 ACDF patients in calculation of the primary endpoint. TDR patients had statistically significantly greater improvement than ACDF patients for the following outcome measures compared with baseline: Neck Disability Index scores, 12-Item Short Form Health Survey Physical Component Summary scores, patient satisfaction, and overall success. ACDF patients experienced higher subsequent surgery rates and displayed a higher rate of adjacent-segment degeneration as seen on radiographs. Overall, TDR patients maintained segmental range of motion through 48 months with no device failure.


CONCLUSIONS
Four-year results from this study continue to support TDR as a safe, effective, and statistically superior alternative to ACDF for the treatment of degenerative disc disease at 2 contiguous cervical levels. Clinical trial registration no.: NCT00389597 ( clinicaltrials.gov ).
Greater Baltimore Neurosurgical Associates, Baltimore, Maryland;
Reginald J
RJ
Davis
Pierce Dalton
PD
Nunley
Kee D
KD
Kim
Michael S
MS
Hisey
Robert J
RJ
Jackson
Hyun W
HW
Bae
Gregory A
GA
Hoffman
Steven E
SE
Gaede
Guy O
GO
Danielson
Charles
C
Gordon
Marcus B
MB
Stone
D000328:Adult; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D004185:Disability Evaluation; D017586:Diskectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular; D013123:Spinal Fusion / Q000379:methods*; D059145:Total Disc Replacement / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome
ACDF = anterior cervical discectomy and fusion; AE = adverse event; CEC = clinical events committee; HO = heterotopic ossification; IDE = investigational device exemption; MCS = Mental Component Summary; Mobi-C; NDI = Neck Disability Index; NSAID = nonsteroidal antiinflammatory drug; PCS = Physical Component Summary; ROM = range of motion; SEM = standard error of the mean; SF-12 = 12-Item Short Form Health Survey; TDR = total disc replacement; VAS = visual analog scale; anterior cervical discectomy and fusion; artificial disc; cervical arthroplasty; degenerative disc disease; multilevel