title: Clinical and radiographic results of Bryan cervical total disc replacement: 4-year outcomes in a prospective study.
abstract: BACKGROUND
  Early results have indicated that the Bryan cervical total disc replacement (TDR) favorably compares to anterior cervical decompression and fusion, while it is associated with fewer complications and higher levels of satisfaction. In this study, we sought to prospectively report the midterm outcomes of the Bryan TDR.
  
  
  METHODS
  A total of 20 patients had performed their 4-year follow-up visit and had been assessed clinically and radiologically. Clinical outcomes (JOA, VAS, NDI, SF-36) and ROM measurements were investigated preoperatively and at 1 and 6 months, and 1, 2 and 4 years after operation. Complications were also investigated. Occurrences of heterotopic ossifications (HOs) and adjacent-level degeneration (ALD) radiographic changes were detected from 4-year follow-up X-rays.
  
  
  RESULTS
  The mean JOA score, VAS score for arm and neck, NDI score and SF-36 score for PCS and MCS were reduced significantly at each postoperative time point when compared with the preoperative condition. The range of movement of the cervical spine, functional spinal unit, treated segment and the adjacent segment temporarily decreased at the early assessment, but all recovered to preoperative levels over a 6-month to 4-year time period. HO was evident in 6 of the 23 operated segments, which did not restrict the movement of the prosthesis. No obvious ALD was found on MRI. There were no cases of prosthesis migration, subsidence, loosening or wear.
  
  
  CONCLUSIONS
  The midterm outcomes demonstrated that the Bryan TDR maintains favorable clinical and radiological results, with preservation of movement and satisfactory clinical outcome. There were no serious complications or cases of prosthetic wear or failure. The long-term benefits are yet to be examined.
authors.affiliation: Orthopedic Department, The Affiliated Taizhou People's Hospital of Nantong University, Taizhou, Jiangsu, 225300, People's Republic of China.
authors.forename: Zhenxiang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Beibei
authors.initials: B
authors.lastname: Gu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.forename: Quanming
authors.initials: Q
authors.lastname: Wang
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011859:Radiography; D013997:Time Factors; D059145:Total Disc Replacement; D016896:Treatment Outcome