Purpose: In this ongoing trial we are analysing the performance of both a fixed bearing total knee replacement and a mobile bearing total knee replacement using gait analysis and a patient-based questionnaire. We aim to find out if there is a difference in the functional performance of the two types of prosthesis.

Method: Patients are taken from the in-patient waiting list of three consultants and introduced to the trial if deemed suitable. Each patient is analysed once pre-operatively and on three occasions post-operatively (6 weeks, 3 months and 1 year) at the university gait analysis laboratory. At each visit various anthropological measurements are recorded and the patient fills in an “Activities of Daily Living” questionnaire. After calibration and measurement of the passive range of motion of both knees each patient has their gait analysed over a series of six walks using a standard 5 camera system with skin marker clusters, the kinematic data from this is supplemented with force-plate recordings and video analysis of each set of walks. Data is recorded for both of the patient’s knees. The staff in the gait analysis laboratory are blinded as to which prosthesis has been used for each patient in an effort to eliminate bias.

We present our methodology and some preliminary results.