title: Implant design influences patient outcome after total knee arthroplasty: a prospective double-blind randomised controlled trial.
abstract: Total knee arthroplasty (TKA) is an established and successful procedure. However, the design of prostheses continues to be modified in an attempt to optimise the functional outcome of the patient. The aim of this study was to determine if patient outcome after TKA was influenced by the design of the prosthesis used. A total of 212 patients (mean age 69; 43 to 92; 131 female (62%), 81 male (32%)) were enrolled in a single centre double-blind trial and randomised to receive either a Kinemax (group 1) or a Triathlon (group 2) TKA. Patients were assessed pre-operatively, at six weeks, six months, one year and three years after surgery. The outcome assessments used were the Oxford Knee Score; range of movement; pain numerical rating scales; lower limb power output; timed functional assessment battery and a satisfaction survey. Data were assessed incorporating change over all assessment time points, using repeated measures analysis of variance longitudinal mixed models. Implant group 2 showed a significantly greater range of movement (p = 0.009), greater lower limb power output (p = 0.026) and reduced report of 'worst daily pain' (p = 0.003) over the three years of follow-up. Differences in Oxford Knee Score (p = 0.09), report of 'average daily pain' (p = 0.57) and timed functional performance tasks (p = 0.23) did not reach statistical significance. Satisfaction with outcome was significantly better in group 2 (p = 0.001). These results suggest that patient outcome after TKA can be influenced by the prosthesis used.
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: D F
authors.initials: DF
authors.lastname: Hamilton
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: R
authors.initials: R
authors.lastname: Burnett
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: J T
authors.initials: JT
authors.lastname: Patton
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: C R
authors.initials: CR
authors.lastname: Howie
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: M
authors.initials: M
authors.lastname: Moran
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: A H R W
authors.initials: AH
authors.lastname: Simpson
authors.affiliation: University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
authors.forename: P
authors.initials: P
authors.lastname: Gaston
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D016001:Confidence Intervals; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D020127:Recovery of Function; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome
keywords: Knee arthroplasty; randomised trial; outcomes; implant design