title: No difference in joint awareness after mobile- and fixed-bearing total knee arthroplasty: 3-year follow-up of a randomized controlled trial.
abstract: OBJECTIVE
  To compare the patients ability to forget the artificial knee joint in everyday life who were randomized to be operated for mobile- or fixed-bearing total knee arthroplasty (TKA).
  
  
  METHODS
  This single-center randomized controlled trial evaluated the 3-year follow-up of the cemented mobile- and fixed-bearing TKA from the same brand in a series of 41 patients. Clinical examination was during the pre-, 6-week, 6-month, 1-, 2- and 3-year follow-up containing multiple patient-reported outcome measures (PROMs) including the 12-item Forgotten Joint Score (FJS-12) at 3 years. Effect size was calculated for each PROM at 3-year follow-up to quantify the size of the difference between both bearings.
  
  
  RESULTS
  At 3-year follow-up, general linear mixed model analysis showed that there were no significant or clinically relevant differences between the two groups for all outcome measures. Calculated effect sizes were small (<0.3) for all the PROMs except for the FJS-12; these were moderate (0.5).
  
  
  CONCLUSIONS
  The results of this study demonstrate that joint awareness was slightly lower in patients operated with the MB TKA with comparable improved clinical outcome and PROMs at 3-year follow-up. Measuring joint awareness with the FJS-12 is useful and provides more stringent information at 3-year follow-up compared to other PROMs and should be the PROM of choice at each follow-up after TKA.
  
  
  METHODS
  Level I, randomized controlled trial.
authors.affiliation: Department of Orthopaedic Surgery, Zuyderland Medical Centre, Location Sittard-Geleen, The Netherlands. martijnschotanus@hotmail.com.
authors.forename: M G M
authors.identifier: http://orcid.org/0000-0002-3975-6337
authors.initials: MGM
authors.lastname: Schotanus
authors.affiliation: Department of Orthopaedic Surgery, Reinier de Graaf Hospital, Delft, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Pilot
authors.affiliation: Department of Methodology and Statistics, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Vos
authors.affiliation: Department of Orthopaedic Surgery, Zuyderland Medical Centre, Location Sittard-Geleen, The Netherlands.
authors.forename: N P
authors.initials: NP
authors.lastname: Kort
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D001364:Awareness; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint; D007720:Knee Prosthesis / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D000071066:Patient Reported Outcome Measures; D011184:Postoperative Period; D011474:Prosthesis Design / Q000523:psychology*
keywords: Effect size; Fixed-bearing; Forgotten Joint Score; Joint awareness; Mobile-bearing; PROMs; Randomized controlled trial; Total knee arthroplasty