Wear and survival of total joint replacements do not depend on the duration of the implant in situ, but rather on the amount of its use, i.e. the patient's activity level [1]. With this in mind, the present study was driven by two questions: (1) How does total knee replacement (TKR) respond to the simulation of daily highly demanding activities? (2) How does implant size affect wear response of total knee replacement (TKR)? Two sets of the same total knee prosthesis (TKP), different in size (#2 and #6), equal in design, were tested on a three-plus-one knee joint simulator for two million cycles using a highly demanding daily load waveform [2], replicating a stair-climbing movement. The results were compared with two sets of TKP previously tested with the ISO level walking task. Gravimetric and micro-Raman spectroscopic analyses were carried out on the polyethylene inserts. Visual comparison with in vivo explants was carried out and digital microscopy was used to characterize the superficial structure of all the TKPs and explanted components.Introduction
Materials & Methods
