A study of 500 consecutive Attune knee implants, assessing early outcomes and failure rates, a single surgeon, non-design centre study.

Abstract

The Attune knee system was released in 2011 aiming to improving patient satisfaction rates following total knee arthroplasty. There have been few large non-design centre studies published to date. The aim of this study is to assess failure rates and patient-reported outcome measures(PROM) of the Attune knee implant in a non-design centre. We retrospectively analysed a prospectively collected database of consecutive series of the first 500 primary, cemented, posterior stabilised, fixed bearing, Attune total knee arthroplasty cases performed by a single non-design surgeon, at one hospital. PROMs were measured as Oxford Knee Scores(OKS) and Patient's Knee Implant Performance(PKIP) questionnaires pre-operatively, 3-months post-operatively and at an average of 5.44 years (minimum 2 years) post-operatively. We recorded failure rates and examined the learning curve by comparing outcomes per 100 cases over time. The majority of cases (n = 445) were performed with the 1st generation Legacy™ tray. No patients were lost to follow-up. Of the 500 knees, mean age was 72 years. Mean follow up was 5.44 years (SD 1.62, range 2-8.9 years). The mean OKS increased post-operatively from 18.26/48 to 45.61/48. The mean PKIP increased post-operatively from 19.01/100 to 88.37/100. Both PROMs were maintained at medium-term follow up (2 years). In total there were 11 (2.2%) revisions of which three (0.6%) were revised for tibial tray loosening, two (0.4% were revised for infection, one (0.2%) for unexplained pain and five (1%) patients underwent a polyethylene liner upsizing due to instability. This prospective study shows favourable early post-operative results of the Attune knee with just three patients (0.6%) being revised for tibial tray loosening. The strengths of this study include the large consecutive cohort in a non-design centre with no loss to follow-up. Further long-term follow-up is required however, this is the largest non-design centre study to our knowledge to date.