Does Insert Type Affect Clinical and Functional Outcome in Total Knee Arthroplasty? A Randomised Controlled Clinical Trial With 5-Year Follow-Up

J Arthroplasty. 2015 Nov;30(11):1931-7. doi: 10.1016/j.arth.2015.05.018. Epub 2015 May 20.


New insert types have been developed to improve clinical and functional outcome in mobile bearing (MB-TKA) and fixed bearing total knee arthroplasty (FB-TKA). A prospective single blinded randomised controlled clinical trial was performed to evaluate 2 types of MB-TKA inserts and 2 types of FB-TKA inserts of the Genesis II prosthesis (Smith & Nephew) in 146 patients with 5-years follow-up. A significant difference (P=.042) between the MB-TKA inserts was found in KSS function scores, but clinical significance is expected to be limited. Goniometry, temporal gait parameters and QoL were similar in all groups. Survival was significantly better (P=.047) for FB-TKA. The comparable outcome and higher revision rate in MB-TKA indicate that FB-TKA may be preferential for the Genesis II implant system.

Keywords: fixed bearing; insert; mobile bearing; reoperation; total knee replacement.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee / instrumentation*
  • Female
  • Follow-Up Studies
  • Gait
  • Humans
  • Knee Prosthesis / statistics & numerical data*
  • Male
  • Middle Aged
  • Prospective Studies
  • Prosthesis Design*
  • Quality of Life
  • Reoperation / statistics & numerical data
  • Treatment Outcome