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The KAT trial, funded by the NIHR HTA Programme (95/10/501) is the largest randomised trial of knee replacement surgery ever undertaken, in which the effects of patellar resurfacing, mobile bearings and metal backing were investigated. Recruitment was completed in 2003.  A total of 116 surgeons in 34 UK centres participated and 2352 participants were randomised.  At a median of 10 years of follow-up we can be more than 95% confident that patella resurfacing is cost-effective, despite there being no significant difference in clinical outcomes.  We found no definite advantage or disadvantage of mobile bearings in OKS, quality of life, reoperation and revision rates or cost-effectiveness.  We found improved functional results for metal-backed tibias: complication, reoperation and revision rates were similar.  The metal-backed tibia was cost-effective, particularly in the elderly. 

The KAT trial is led by Professor David Murray in collaboration with the University of Aberdeen.

The KAT study has been ongoing since 1999 and currently follow-up to 20 years post-randomisation is being carried out.

For more information please see the KAT Study Website.

research papers

Completed trials