title: Rotating-platform TKA no different from fixed-bearing TKA regarding survivorship or performance: a meta-analysis.
abstract: BACKGROUND
  Mobile bearings have been compared with fixed bearings used in TKA. However, rotating platforms, a specific type of mobile bearing, have not been compared with fixed-bearings using meta-analysis.
  
  
  OBJECTIVE
  We asked whether the performance of a rotating-platform bearing is superior to, comparable to, or worse than a fixed bearing. Four areas were investigated: clinical performance, component alignment, adverse event rates, and revision rates.
  
  
  METHODS
  Searches of Medline, EMBASE, Google Scholar, and the Cochrane databases, combined with reference lists from published meta-analyses and systematic reviews of mobile-bearing versus fixed-bearing prostheses used in TKAs, provided 17 nonlanguage-restricted studies consisting of 1910 TKAs (966 rotating platform versus 944 fixed bearing). Random-effect modeling was used for all meta-analyses, thereby mitigating possible effects of heterogeneity among studies. All meta-analyses were examined for publication bias using funnel plots; publication bias was not detected for any meta-analysis.
  
  
  RESULTS
  There were no statistically or clinically significant differences in clinical performance (clinical scores, ROM, and radiographic evaluation), component alignment, revision rates, or adverse event rates except for tibial component alignment in the AP plane, which favored TKA with fixed-bearings (p = 0.020; standardized mean difference, 0.229; 95% CI, 0.035-0.422), but the effect size was small enough that it was not considered clinically important.
  
  
  CONCLUSIONS
  Based on our findings, which agree substantially with those of prior systematic reviews of TKAs with mobile-bearing versus fixed-bearing prostheses, there is no compelling case for either rotating-platform or fixed-bearing implant design in terms of clinical performance, component alignment, adverse event frequencies, or survivorship. This dataset, which was limited to a maximum 6 years followup, is insufficient to address questions related to wear or late revisions. We therefore suggest that implant choice should be made on the basis of other factors, perhaps including cost or surgeon experience.
authors.affiliation: Virginia Tech Carilion School of Medicine, Roanoke, VA, USA.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Moskal
authors.forename: Susan G
authors.initials: SG
authors.lastname: Capps
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D016017:Odds Ratio; D011183:Postoperative Complications / Q000601:surgery; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012086:Reoperation; D012307:Risk Factors; D012399:Rotation; D013314:Stress, Mechanical; D013997:Time Factors; D016896:Treatment Outcome