title: Sagittal alignment comparison of Bryan disc arthroplasty with ProDisc-C arthroplasty: a prospective, randomized controlled clinical trial.
abstract: METHODS
  A prospective, randomized study of the radiographic outcomes in patients undergoing single-level cervical arthroplasty with Bryan disc and ProDisc-C prosthesis.
  
  
  OBJECTIVE
  The purpose of this trial was to compare the alignment changes of Bryan disc arthroplasty (modified techniques) with ProDisc-C arthroplasty.
  
  
  BACKGROUND
  Aggravation of kyphosis is the known challenge after Bryan disc arthroplasty. Both Bryan disc arthroplasty with modified techniques and ProDisc-C arthroplasty were reported to avoid the postoperative local kyphosis. There have been no studies comparing the alignment changes after Bryan disc arthroplasty with ProDisc-C arthroplasty.
  
  
  METHODS
  We conducted a randomized controlled clinical trial enrolling patients with cervical disc disease. Ultimately 20 patients received Bryan disc arthroplasty with modified surgical techniques and 26 patients received ProDisc-C arthroplasty. Functional spinal unit (FSU) and overall cervical alignment (Cobb angle of C2/7) were compared at final follow-up.
  
  
  RESULTS
  (1) FSU angle: the FSU angle was maintained for the Bryan disc group (from 0.8 to 0.6 degrees) without statistical significance; the FSU angle increased 2.9 degrees for the ProDisc-C group (from -0.3 to 2.6 degrees) with statistical significance. (2) Overall alignment: the overall alignments did not change for both Bryan disc and ProDisc-C groups.
  
  
  CONCLUSIONS
  Bryan disc arthroplasty with modified techniques can maintain the lordosis of FSU, whereas ProDisc-C arthroplasty can restore the lordosis of FSU. For the patients with preoperative FSU kyphosis, ProDisc-C arthroplasty may be a better choice to restore the lordosis.
authors.affiliation: Department of Orthopedic Surgery, Peking University Third Hospital, Beijing, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yanbin
authors.forename: Sun
authors.initials: S
authors.lastname: Yu
authors.forename: Chen
authors.initials: C
authors.lastname: Zhongqiang
authors.forename: Liu
authors.initials: L
authors.lastname: Zhongjun
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D017586:Diskectomy / Q000379:methods*; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011843:Radiculopathy / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D055009:Spondylosis / Q000000981:diagnostic imaging / Q000601:surgery; D059145:Total Disc Replacement / Q000379:methods*; D016896:Treatment Outcome