title: Prospective clinical and radiographic results of CHARITÉ III artificial total disc arthroplasty at 2- to 7-year follow-up: a Canadian experience.
abstract: BACKGROUND
  Early and intermediate results have shown that the SB CHARITÉ III total disc arthroplasty (TDA) favourably compares to spinal fusion, but is associated with fewer complications and higher levels of satisfaction. We sought to prospectively report the clinical and radiographic results of the CHARITÉ III TDA after an average of 55 months follow-up.
  
  
  METHODS
  We conducted a prospective study of patients receiving the CHARITÉ TDA at either L4-5 or L5-S1 between April 2001 and November 2006. The primary indication for surgery was discogenic low-back pain confirmed by provocative discography. Assessment included pre- and postoperative (3, 6 and 12 mo and yearly thereafter) validated patient outcome measures and radiographic review.
  
  
  RESULTS
  Fifty-seven of the potential 64 (89%) patients were available for complete follow-up. Their mean age was 39 (range 21-59) years. A statistically significant improvement was demonstrated between all the mean pre- and postoperative intervals for the Oswestry Disability Index, visual analogue scale for back and leg pain, and Short Form-36 health survey (p < 0.001). The mean sagittal rotation was 6.5° (range 0.5°-22.4°), and the mean intervertebral translation was 1.1 mm (range 0-2.4 mm). Subsidence of the implant was present in 44 of 53 (83%) patients with an L5-S1 disc arthroplasty. The mean subsidence was 1.7 mm (range 0-4.8 mm).
  
  
  CONCLUSIONS
  The 2- to 7-year follow-up of this cohort of patients demonstrated satisfactory clinical and radiographic results in a carefully selected patient population. The radiographic assessment confirmed preservation and maintenance of motion at the replaced disc during the period of follow-up.
authors.affiliation: The Division of Orthopaedics, Department of Surgery, University of Western Ontario, London, ON.
authors.forename: Michael
authors.initials: M
authors.lastname: Katsimihas
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Bailey
authors.forename: Khalil
authors.initials: K
authors.lastname: Issa
authors.forename: Jennifer
authors.initials: J
authors.lastname: Fleming
authors.forename: Patricia
authors.initials: P
authors.lastname: Rosas-Arellano
authors.forename: Stewart I
authors.initials: SI
authors.lastname: Bailey
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Gurr
mesh_terms: D000328:Adult; D019643:Arthroplasty, Replacement / Q000295:instrumentation*; D002170:Canada; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging* / Q000601:surgery*; D055959:Intervertebral Disc Degeneration / Q000601:surgery; D007595:Joint Prosthesis; D017116:Low Back Pain / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D011859:Radiography