Analysis of the three United States Food and Drug Administration investigational device exemption cervical arthroplasty trials

Clinical article

Restricted access


There are now 3 randomized, multicenter, US FDA investigational device exemption, industry-sponsored studies comparing arthroplasty with anterior cervical discectomy and fusion (ACDF) for single-level cervical disease with 2 years of follow-up. These 3 studies evaluated the Prestige ST, Bryan, and ProDisc-C artificial discs. The authors analyzed the combined results of these trials.


A total of 1213 patients with symptomatic, single-level cervical disc disease were randomized into 2 treatment arms in the 3 randomized trials. Six hundred twenty-one patients received an artificial cervical disc, and 592 patients were treated with ACDF. In the three trials, 94% of the arthroplasty group and 87% of the ACDF group have completed 2 years of follow-up. The authors analyzed the 2-year data from these 3 trials including previously unpublished source data. Statistical analysis was performed with fixed and random effects models.


The authors' analysis revealed that segmental sagittal motion was preserved with arthroplasty (preoperatively 7.26° and postoperatively 8.14°) at the 2-year time point. The fusion rate for ACDF at 2 years was 95%. The Neck Disability Index, 36-Item Short Form Health Survey Mental, and Physical Component Summaries, neck pain, and arm pain scores were not statistically different between the groups at the 24-month follow-up. The arthroplasty group demonstrated superior results at 24 months in neurological success (RR 0.595, I2 = 0%, p = 0.006). The arthroplasty group had a lower rate of secondary surgeries at the 2-year time point (RR 0.44, I2 = 0%, p = 0.004). At the 2-year time point, the reoperation rate for adjacent-level disease was lower for the arthroplasty group when the authors analyzed the combined data set using a fixed effects model (RR 0.460, I2 = 2.9%, p = 0.030), but this finding was not significant using a random effects model. Adverse event reporting was too heterogeneous between the 3 trials to combine for analysis.


Both anterior cervical discectomy and fusion as well as arthroplasty demonstrate excellent 2-year surgical results for the treatment of 1-level cervical disc disease with radiculopathy. Arthroplasty is associated with a lower rate of secondary surgery and a higher rate of neurological success at 2 years. Arthroplasty may be associated with a lower rate of adjacent-level disease at 2 years, but further follow-up and analysis are needed to confirm this finding.

Abbreviations used in this paper: ACDF = anterior cervical discectomy and fusion; BMI = body mass index; IDE = investigational device exemption; MCS = Mental Component Summary; NDI = neck disability index; NNT = number needed to treat; PCS = Physical Component Summary; ROM = range of motion; RR = relative risk; SF-36 = 36-Item Short Form Health Survey; VAS = visual analog scale; WMD = weighted mean difference.

Article Information

* Drs. Upadhyaya and Wu contributed equally to this work

Address correspondence to: Jau-Ching Wu, M.D., Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital Room 509, 17F, No. 201, Shih-Pai Road, Sec. 2, Beitou, Taipei 11217, Taiwan. email:

Please include this information when citing this paper: published online December 23, 2011; DOI: 10.3171/2011.6.SPINE10623.

© AANS, except where prohibited by US copyright law.



  • View in gallery

    Combined results of NDI favored arthroplasty without statistical significance. Fixed effects analysis presented. The random effects model had similar outcomes.

  • View in gallery

    The MCS (upper) and PCS (lower) scores of SF-36 for both arthroplasty and ACDF had no significant differences. Fixed effects analysis presented. The random effects model had similar outcomes.

  • View in gallery

    Neck pain frequency (upper) and intensity (lower) had no significant differences between arthroplasty and ACDF. Fixed effects analysis presented. The random effects model had similar outcomes.

  • View in gallery

    Arm pain frequency (upper) and intensity (lower) had no significant differences between arthroplasty and ACDF. Fixed effects analysis presented. The random effects model had similar outcomes.

  • View in gallery

    The neurological success rate at 24 months postoperatively was better after arthroplasty than after ACDF. Fixed effects analysis presented. The random effects model had similar outcomes.

  • View in gallery

    The overall secondary surgeries, including revision, removal, supplemental fixation, and reoperations, were significantly more likely to happen in the ACDF group at 24 months postoperatively. Fixed effects analysis is presented. The random effects model had similar outcomes.

  • View in gallery

    Adjacent-level surgeries were more likely to happen in the ACDF group at 24 months postoperatively with statistical significance by the fixed effects model. When using the random effects model, there was a trend to favor arthroplasty. p = 0.052.

  • View in gallery

    Examples of maintenance of ROM at the index level for each artificial disc: Prestige ST (A), Bryan (B), and ProDisc-C (C). Extension (left) and flexion (right) dynamic lateral radiographs of the cervical spine obtained during follow-up.



Coric DFinger FBoltes P: Prospective randomized controlled study of the Bryan Cervical Disc: early clinical results from a single investigational site. J Neurosurg Spine 4:31352006


Fraser JFHärtl R: Anterior approaches to fusion of the cervical spine: a metaanalysis of fusion rates. J Neurosurg Spine 6:2983032007


Goffin JCasey AKehr PLiebig KLind BLogroscino C: Preliminary clinical experience with the Bryan Cervical Disc Prosthesis. Neurosurgery 51:8408472002


Goffin JVan Calenbergh Fvan Loon JCasey AKehr PLiebig K: Intermediate follow-up after treatment of degenerative disc disease with the Bryan Cervical Disc Prosthesis: single-level and bi-level. Spine (Phila Pa 1976) 28:267326782003


Heller JGSasso RCPapadopoulos SMAnderson PAFessler RGHacker RJ: Comparison of BRYAN cervical disc arthroplasty with anterior cervical decompression and fusion: clinical and radiographic results of a randomized, controlled, clinical trial. Spine (Phila Pa 1976) 34:1011072009


Hilibrand ASCarlson GDPalumbo MAJones PKBohlman HH: Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis. J Bone Joint Surg Am 81:5195281999


Ioannidis JP: Adverse events in randomized trials: neglected, restricted, distorted, and silenced. Arch Intern Med 169:173717392009


Ioannidis JPMulrow CDGoodman SN: Adverse events: the more you search, the more you find. Ann Intern Med 144:2983002006


Kang HPark PLa Marca FHollister SJLin CY: Analysis of load sharing on uncovertebral and facet joints at the C5–6 level with implantation of the Bryan, Prestige LP, or ProDisc-C cervical disc prosthesis: an in vivo image-based finite element study. Neurosurg Focus 28:6E92010


Liberati AAltman DGTetzlaff JMulrow CGøtzsche PCIoannidis JP: The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ 339:b27002009


Link HDMcAfee PCPimenta L: Choosing a cervical disc replacement. Spine J 4:6 Suppl294S302S2004


Mummaneni PVBurkus JKHaid RWTraynelis VCZdeblick TA: Clinical and radiographic analysis of cervical disc arthroplasty compared with allograft fusion: a randomized controlled clinical trial. J Neurosurg Spine 6:1982092007


Mummaneni PVHaid RW: The future in the care of the cervical spine: interbody fusion and arthroplasty. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004. J Neurosurg Spine 1:1551592004


Mummaneni PVRobinson JCHaid RW Jr: Cervical arthroplasty with the PRESTIGE LP cervical disc. Neurosurgery 60:4 Suppl 23103152007


Murrey DJanssen MDelamarter RGoldstein JZigler JTay B: Results of the prospective, randomized, controlled multicenter Food and Drug Administration investigational device exemption study of the ProDisc-C total disc replacement versus anterior discectomy and fusion for the treatment of 1-level symptomatic cervical disc disease. Spine J 9:2752862009


Nabhan AAhlhelm FShariat KPitzen TSteimer OSteudel WI: The ProDisc-C prosthesis: clinical and radiological experience 1 year after surgery. Spine (Phila Pa 1976) 32:193519412007


Park DHRamakrishnan PCho THLorenz EEck JCHumphreys SC: Effect of lower two-level anterior cervical fusion on the superior adjacent level. J Neurosurg Spine 7:3363402007


Pimenta LMcAfee PCCappuccino ABellera FPLink HD: Clinical experience with the new artificial cervical PCM (Cervitech) disc. Spine J 4:6 Suppl315S321S2004


Porchet FMetcalf NH: Clinical outcomes with the Prestige II cervical disc: preliminary results from a prospective randomized clinical trial. Neurosurg Focus 17:3E62004


Riina JPatel ADietz JWHoskins JSTrammell TRSchwartz DD: Comparison of single-level cervical fusion and a metal-on-metal cervical disc replacement device. Am J Orthop 37:E71E772008


Sekhon LHSears WDuggal N: Cervical arthroplasty after previous surgery: results of treating 24 discs in 15 patients. J Neurosurg Spine 3:3353412005


Tumialán LMPan JRodts GEMummaneni PV: The safety and efficacy of anterior cervical discectomy and fusion with polyetheretherketone spacer and recombinant human bone morphogenetic protein-2: a review of 200 patients. J Neurosurg Spine 8:5295352008


Wang YCai BZhang XSXiao SHWang ZLu N: [Clinical outcomes of single level Bryan cervical disc arthroplasty: a prospective controlled study.]. Zhonghua Wai Ke Za Zhi 46:3283322008. (Chinese)




All Time Past Year Past 30 Days
Abstract Views 720 720 440
Full Text Views 115 115 30
PDF Downloads 122 122 16
EPUB Downloads 0 0 0


Google Scholar