title: No long-term difference between fixed and mobile medial unicompartmental arthroplasty.
abstract: BACKGROUND
  Early studies in the literature reported relatively high early minor reintervention rate for the mobile-bearing unilateral knee arthroplasty (UKA) compared with short- and midterm survivorship after fixed- or mobile-bearing UKA. However, whether the long-term function and survivorship are similar is unclear.
  
  
  OBJECTIVE
  We therefore asked whether (1) mobile- or fixed-bearing UKAs have comparable function (as measured by the Knee Society scores); (2) mobile- and fixed-bearing UKA have comparable Knee Society radiographic scores; and (3) the long-term survivorship is comparable.
  
  
  METHODS
  We retrospectively reviewed 75 patients (79 knees) with a fixed-bearing UKA and 72 patients (77 knees) with a mobile-bearing UKA operated on between 1989 and 1992. Mean age of the patients was 63 years; gender and body mass index (26 kg/m(2)) were comparable in the two groups. We obtained Knee Society function and radiographic scores and determined survival. The minimum followup was 15 years (mean, 17.2 ± 4.8 years; range, 15-21.2 years).
  
  
  RESULTS
  The mean Knee Society function and knee scores were comparable in the two groups. Radiographically, the number of overcorrections and the number of radiolucencies were statistically higher in the mobile-bearing group (69% versus 24%). At final followup, considering revision for any reason, 12 of 77 (15%) UKAs were revised (for aseptic loosening, dislocation, and arthritis progression) in the mobile-bearing group and 10 of 79 (12%) in the fixed-bearing group (for wear and arthritis progression).
  
  
  CONCLUSIONS
  This long-term study did not demonstrate any difference in survivorship between fixed and mobile-bearing but pointed out specific modes of failure.
authors: Center for Arthritis Surgery, Hôpital Sainte-Marguerite, Aix-Marseille University, Marseille, France.
authors: Sebastien
authors: S
authors: Parratte
authors: Vanessa
authors: V
authors: Pauly
authors: Jean-Manuel
authors: JM
authors: Aubaniac
authors: Jean-Noel A
authors: JN
authors: Argenson
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D005602:France; D006801:Humans; D053208:Kaplan-Meier Estimate; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000601:surgery*; D011183:Postoperative Complications / Q000503:physiopathology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D016474:Weight-Bearing