title: Prospective, Randomized Comparison of Cervical Total Disk Replacement Versus Anterior Cervical Fusion: Results at 48 Months Follow-up.
abstract: METHODS
  This was a prospective, randomized, controlled multicenter trial.
  
  
  OBJECTIVE
  The purpose of this study was to compare clinical outcomes at 4-year follow-up of patients receiving cervical total disk replacement (TDR) with those receiving anterior cervical discectomy and fusion (ACDF).
  
  
  BACKGROUND
  ACDF has been the traditional treatment for symptomatic disk degeneration. Several studies found single-level TDR to be as safe and effective as ACDF at ≥2 years follow-up.
  
  
  METHODS
  Patients from 23 centers were randomized in a 2:1 ratio with 164 receiving the investigational device (Mobi-C Cervical Disc Prosthesis) and 81 receiving ACDF using an anterior plate and allograft. Patients were evaluated preoperatively and 6 weeks, 3, 6, 12, 18, 24, 36, and 48 months postoperatively. Outcome assessments included a composite success score, Neck Disability Index, visual analog scales assessing neck and arm pain, patient satisfaction, major complications, subsequent surgery, segmental range of motion, and adjacent-segment degeneration.
  
  
  RESULTS
  The composite success rate was similar in the 2 groups at 48-month follow-up. Mean Neck Disability Index, visual analog scale, and SF-12 scores were significantly improved in early follow-up in both groups with improvements maintained throughout 48 months. On some measures, TDR had significantly greater improvement during early follow-up. At no follow-up were TDR scores significantly worse than ACDF scores. Subsequent surgery rate was significantly higher for ACDF compared with TDR (9.9% vs. 3.0%, P<0.05). Range of motion was maintained with TDR having a mean baseline value of 8 degrees compared with 10 degrees at 48 months. The incidence of adjacent-segment degeneration was significantly higher with ACDF at inferior and superior segments compared with TDR (inferior: 50% vs. 30%, P<0.025; superior: 53% vs. 34%, P<0.025).
  
  
  CONCLUSIONS
  Significant improvements were observed in pain and function. TDR patients maintained motion and had significantly lower rates of reoperation and adjacent-segment degeneration compared with ACDF. This study supports the safety and efficacy of TDR in appropriately selected patients.
authors.affiliation: *Texas Back Institute, Denton, TX †The Spine Institute at St John's Health Center, Santa Monica, CA ‡GBMC Healthcare Greater Baltimore Neurosurgical Associates, Baltimore, MD §Oklahoma Spine & Brain Institute, Tulsa, OK ∥Orthopedic North East, Fort Wayne, IN ¶University of California Davis Medical Center, Sacramento, CA #Spine Institute of Louisiana, Shreveport, LA **Neurological Specialists of Austin, Austin ††Texas Back Institute ‡‡Texas Back Institute Research Foundation, Plano, TX.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hisey
authors.forename: Hyun W
authors.initials: HW
authors.lastname: Bae
authors.forename: Reginald J
authors.initials: RJ
authors.lastname: Davis
authors.forename: Steven
authors.initials: S
authors.lastname: Gaede
authors.forename: Greg
authors.initials: G
authors.lastname: Hoffman
authors.forename: Kee D
authors.initials: KD
authors.lastname: Kim
authors.forename: Pierce D
authors.initials: PD
authors.lastname: Nunley
authors.forename: Daniel
authors.initials: D
authors.lastname: Peterson
authors.forename: Ralph F
authors.initials: RF
authors.lastname: Rashbaum
authors.forename: John
authors.initials: J
authors.lastname: Stokes
authors.forename: Donna D
authors.initials: DD
authors.lastname: Ohnmeiss
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004185:Disability Evaluation; D017586:Diskectomy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology; D010147:Pain Measurement; D017060:Patient Satisfaction; D011446:Prospective Studies; D019736:Prostheses and Implants; D011788:Quality of Life; D011859:Radiography; D013123:Spinal Fusion / Q000379:methods*; D059145:Total Disc Replacement / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult