Hamilton DF, Burnett R, Patton JT, et al. - Longitudinal analytical techniques were applied to analyze mid-term outcomes of an existing implant trial cohort to document changing patient function over time following total knee arthroplasty and to ascertain whether implant design chosen at time of surgery influenced these outcomes. Researchers included a mid-term follow-up of the remaining 125 patients [the mean follow-up of the patients was 8.12 years (7.3 to 9.4)] from a randomized cohort of total knee arthroplasty patients (initially comprising 212 recruited patients), comparing modern (Triathlon) and traditional (Kinemax) prostheses. They evaluated functional outcomes with the Oxford Knee Score, knee range of movement, pain numerical rating scales, lower limb power output, timed functional assessment battery, and satisfaction survey.  This mid-term follow-up of a randomized controlled trial cohort, at a mean 8.12 years, indicates a general reduction in measures of patient function with patient age and follow-up duration, and a comparative preservation of function based on implant received at time of surgery.