title: Total ankle arthroplasty in inflammatory joint disease with use of two mobile-bearing designs.
abstract: BACKGROUND
  Interest in mobile-bearing total ankle arthroplasty has increased in recent years. However, to our knowledge, no study has focused exclusively on patients with the diagnosis of inflammatory joint disease or has provided a detailed analysis of the risk factors for failure.
  
  
  METHODS
  A prospective observational study of the results of cementless mobile-bearing total ankle arthroplasty in patients with inflammatory joint disease (mainly rheumatoid arthritis) was conducted at two centers. Ninety-three total ankle arthroplasties were performed. The LCS (low contact stress) prosthesis was used initially, in nineteen ankles, between 1988 and 1992, and a modification of the LCS prosthesis, the Buechel-Pappas design, was used in seventy-four ankles between 1993 and 1999. Clinical and radiographic follow-up was performed at yearly intervals. Three clinical scoring systems were used, and any complication was recorded throughout follow-up. Actuarial survival (with revision as the end point), multivariate analysis, and a competing risk approach were used to describe the long-term outcome.
  
  
  RESULTS
  The clinical result at one year after surgery showed a significant improvement in the scores on all three scoring systems (p < 0.05). Ankle dorsiflexion (mean, 7 degrees ) also improved significantly (p < 0.05) compared with the preoperative state. The most frequent complication was a malleolar fracture, which occurred in twenty ankles. Only when it occurred in combination with a deformity in the frontal plane did this complication have an adverse effect on the end result. At a mean follow-up of eight years, seventeen patients (twenty-one ankles) had died and fifteen ankles had been revised because of aseptic loosening (six ankles), primary or secondary axial deformity with edge-loading (six ankles), deep infection (two ankles), and a severe wound-healing problem (one ankle), leaving fifty-seven ankles (61%) that were evaluated. The mean overall survival rate at eight years was 84%. An increased failure rate was encountered in ankles with a preoperative deformity in the frontal plane of >10 degrees (p = 0.03) and in ankles in which an undersized tibial component had been implanted (p = 0.02).
  
  
  CONCLUSIONS
  Mobile-bearing total ankle arthroplasty is a valid treatment option for the rheumatoid ankle if proper indications are used. Aseptic loosening and persistent deformity are the most important modes of failure.
authors.affiliation: Department of Orthopaedic Surgery, Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands. orkdo@slz.nl
authors.forename: H Cornelis
authors.initials: HC
authors.lastname: Doets
authors.forename: Ronald
authors.initials: R
authors.lastname: Brand
authors.forename: Rob G H H
authors.initials: RG
authors.lastname: Nelissen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000601:surgery*; D019643:Arthroplasty, Replacement / Q000009:adverse effects; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis / Q000009:adverse effects; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D016896:Treatment Outcome