title: The new Frenchay artificial cervical joint: results from a two-year pilot study.
abstract: METHODS
  A clinical prospective observational cohort study of 15 patients undergoing cervical intervertebral disc replacement.
  
  
  OBJECTIVE
  To assess the safety, clinical stability, and capacity of a newly designed cervical intervertebral disc replacement for preserving motion in the cervical spine of patients with degenerative disc disease.
  
  
  BACKGROUND
  Anterior cervical discectomy and interbody fusion results in loss of motion segments and there is evidence of accelerated degenerative changes occurring at adjacent levels. Intervertebral disc replacement may be a valid alternative to fusion. There is a need for cervical disc replacement to be evaluated in prospective studies before it can be adopted as an acceptable surgical technique.
  
  
  METHODS
  The study enrolled 15 patients with cervical radiculopathy or myelopathy and radiologically confirmed cervical disc herniation or posterior vertebral body osteophytes. Eligibility for the study required that patients have either a previous adjacent-level surgical or congenital spinal fusion or radiologic evidence of adjacent-level degenerative disc disease. After decompressive surgery via an anterior approach, all 15 patients received the artificial joint. Follow-up visits were at set intervals and included clinical examination, radiologic assessment, and evaluation by patient-completed questionnaires.
  
  
  RESULTS
  In all cases, the artificial joint maintained motion at the operative levels while reestablishing intervertebral height. The procedure was considered safe for experienced spine surgeons to perform, and the device was stable, with no dislocation of components or backing out of screws. Two screws broke, but without any consequence. Improvements in assessment scores were noted.
  
  
  CONCLUSIONS
  Cervical intervertebral motion can be maintained with the new device, which is clinically stable. Meticulous attention must be paid to the surgical technique to maximize the chances of a good result. The pilot study was successful, although it has yet to be determined what conditions will benefit most from this technology.
authors.affiliation: Department of Neurosurgery, The Academic Centre, Frenchay Hospital, Bristol, United Kingdom.
authors.forename: Crispin C
authors.initials: CC
authors.lastname: Wigfield
authors.forename: Steven S
authors.initials: SS
authors.lastname: Gill
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Nelson
authors.forename: Newton H
authors.initials: NH
authors.lastname: Metcalf
authors.forename: James T
authors.initials: JT
authors.lastname: Robertson
mesh_terms: D019643:Arthroplasty, Replacement / Q000009:adverse effects / Q000706:statistics & numerical data*; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000502:physiology / Q000601:surgery; D015331:Cohort Studies; D019299:Decompression, Surgical / Q000009:adverse effects / Q000295:instrumentation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000150:complications / Q000601:surgery*; D007595:Joint Prosthesis / Q000009:adverse effects / Q000706:statistics & numerical data*; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D009333:Neck; D010146:Pain / Q000209:etiology; D010865:Pilot Projects; D011446:Prospective Studies; D011843:Radiculopathy / Q000209:etiology / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology; D013118:Spinal Cord Diseases / Q000209:etiology / Q000601:surgery*; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome