title: Cervical disc arthroplasty with the Prestige LP disc versus anterior cervical discectomy and fusion, at 2 levels: results of a prospective, multicenter randomized controlled clinical trial at 24 months.
abstract: OBJECTIVE The authors compared the efficacy and safety of arthroplasty using the Prestige LP cervical disc with those of anterior cervical discectomy and fusion (ACDF) for the treatment of degenerative disc disease (DDD) at 2 adjacent levels. METHODS Patients from 30 investigational sites were randomized to 1 of 2 groups: investigational patients (209) underwent arthroplasty using a Prestige LP artificial disc, and control patients (188) underwent ACDF with a cortical ring allograft and anterior cervical plate. Patients were evaluated preoperatively, intraoperatively, and at 1.5, 3, 6, 12, and 24 months postoperatively. Efficacy and safety outcomes were measured according to the Neck Disability Index (NDI), Numeric Rating Scales for neck and arm pain, 36-Item Short-Form Health Survey (SF-36), gait abnormality, disc height, range of motion (investigational) or fusion (control), adverse events (AEs), additional surgeries, and neurological status. Treatment was considered an overall success when all 4 of the following criteria were met: 1) NDI score improvement of ≥ 15 points over the preoperative score, 2) maintenance or improvement in neurological status compared with preoperatively, 3) no serious AE caused by the implant or by the implant and surgical procedure, and 4) no additional surgery (supplemental fixation, revision, or nonelective implant removal). Independent statisticians performed Bayesian statistical analyses. RESULTS The 24-month rates of overall success were 81.4% for the investigational group and 69.4% for the control group. The posterior mean for overall success in the investigational group exceeded that in the control group by 0.112 (95% highest posterior density interval = 0.023 to 0.201) with a posterior probability of 1 for noninferiority and 0.993 for superiority, demonstrating the superiority of the investigational group for overall success. Noninferiority of the investigational group was demonstrated for all individual components of overall success and individual effectiveness end points, except for the SF-36 Mental Component Summary. The investigational group was superior to the control group for NDI success. The proportion of patients experiencing any AE was 93.3% (195/209) in the investigational group and 92.0% (173/188) in the control group, which were not statistically different. The rate of patients who reported any serious AE (Grade 3 or 4) was significantly higher in the control group (90 [47.9%] of 188) than in the investigational group (72 [34.4%] of 209) with a posterior probability of superiority of 0.996. Radiographic success was achieved in 51.0% (100/196) of the investigational patients (maintenance of motion without evidence of bridging bone) and 82.1% (119/145) of the control patients (fusion). At 24 months, heterotopic ossification was identified in 27.8% (55/198) of the superior levels and 36.4% (72/198) of the inferior levels of investigational patients. CONCLUSIONS Arthroplasty with the Prestige LP cervical disc is as effective and safe as ACDF for the treatment of cervical DDD at 2 contiguous levels and is an alternative treatment for intractable radiculopathy or myelopathy at 2 adjacent levels. Clinical trial registration no.: NCT00637156 ( clinicaltrials.gov ).
authors.affiliation: The Orthopedic Center of St. Louis.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Gornet
authors.affiliation: California Spine Group, Century City Hospital, Los Angeles, California.
authors.forename: Todd H
authors.initials: TH
authors.lastname: Lanman
authors.affiliation: Wilderness Spine Services, The Hughston Clinic, Columbus, Georgia.
authors.forename: J Kenneth
authors.initials: JK
authors.lastname: Burkus
authors.affiliation: Center for Sports Medicine and Orthopaedics, Chattanooga.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Hodges
authors.affiliation: Orthopaedic Associates of Allentown, Pennsylvania; and.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: McConnell
authors.affiliation: Central Texas Spine Institute, Austin, Texas.
authors.forename: Randall F
authors.initials: RF
authors.lastname: Dryer
authors.affiliation: SPIRITT Research, St. Louis, Missouri.
authors.forename: Anne G
authors.initials: AG
authors.lastname: Copay
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Hui
authors.initials: H
authors.lastname: Nian
authors.affiliation: Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Frank E
authors.initials: FE
authors.lastname: Harrell
mesh_terms: D064591:Allografts; D001860:Bone Plates; D016025:Bone Transplantation; D002574:Cervical Vertebrae / Q000601:surgery*; D017586:Diskectomy; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011183:Postoperative Complications; D019736:Prostheses and Implants; D062707:Return to Work; D012720:Severity of Illness Index; D013123:Spinal Fusion; D013997:Time Factors; D059145:Total Disc Replacement; D016896:Treatment Outcome
keywords: ACDF = anterior cervical discectomy and fusion; AE = adverse event; ASD = adjacent segment degeneration; CAC = Clinical Adjudication Committee; CDA = cervical disc arthroplasty; DDD = degenerative disc disease; FDA = Food and Drug Administration; FSU = functional spinal unit; HO = heterotopic ossification; HPD = highest posterior density; IDE = investigational device exemption; MCS = Mental Component Summary; NDI = Neck Disability Index; NRS = Numeric Rating Scale; PCS = Physical Component Summary; SF-36 = 36-Item Short-Form Health Survey; adjacent segment disease; anterior cervical discectomy and fusion; artificial cervical disc; cervical disc arthroplasty