The Uptake of New Knee Replacement Implants in the UK: Analysis of the National Joint Registry for England and Wales

Knee replacement (KR) surgery is one of the most common elective procedures in the UK. A large number of different KR implant brands are in use in the UK, which may contribute to variation in uptake and patient outcomes.

A cohort of 722,178 primary KRs performed for osteoarthritis (with or without other indications) by 2675 consultant surgeons between 2008 and 2017 in England and Wales from the National Joint Registry was examined. We described the uptake of new (first use >2008) KR implant brands, and variation in uptake by consultant surgeons (primary objectives). We explored consultant-level/patient-level factors associated with use/receipt of new implant brands with multilevel logistic regression models (secondary objectives).

Sixty-five new KR implant brands were used in 22,134 KRs (3.1%) by 759 consultants (28.4%) between 2008 and 2017. Consultants used a median of 1 new brand (interquartile range = 1-2, max = 8) in 4.1% (interquartile range = 1.1%-12.3%) of their KRs. Younger patients (<55 vs 55-80, odds ratio [OR] = 1.63, 95% confidence interval [CI] = 1.54-1.72) and women (OR = 1.17, 95% CI = 1.13-1.22) had higher odds of receiving a new rather than established brand. Consultants who used more different implant brands had higher odds of using new brands (OR/additional implant/year = 2.57, 95% CI = 2.37-2.79).

A large number of new KR implant brands have been introduced in the National Joint Registry since 2008. A quarter of consultants have tried a new implant brand but have used them in only a small proportion of primary KRs in this period. Younger, healthier patients are more likely to receive new implant brands, and they are more likely to be used by surgeons who use many different implant brands.