| Popis: |
Unicompartmental knee arthroplasty (UKA) has been gaining popularity in recent years due to its perceived benefits over total knee arthroplasty (TKA), such as greater bone preservation, reduced operating-room time, better post-operative range of motion and improved gait. However there have been failures associated with UKA caused by misalignment of the implants. To improve the implant alignment a robotic guidance system called the RIO Robotic Arm has been developed by MAKO Surgical Corp (Ft. Lauderdale, FL). This robotic system provides real-time tactile feedback to the surgeon during bone cutting, designed to give improved accuracy compared to traditional UKA using cutting jigs and other manual instrumentation. The University of Strathclyde in association with Glasgow Royal Infirmary has undertaken the first independent randomised controlled trial of the MAKO system against the Oxford unicompartmental knee arthroplasty - the most common manual UKA used in the UK. This thesis investigates the results from a total of 51 patients (23 Mako, 28 Oxford) that underwent a one year post-operative biomechanical assessment. The assessment analysed the biomechanics of these patients performing walking tasks, stair navigation, sit to stand and deep knee lunges using a 3-dimensional, 12 camera motion analysis system (Vicon Motion Systems, Oxford, UK). 3 month post-operative X-rays confirmed that the implant alignment in the Mako group were significantly more accurate than the implants in the Oxford group. Motion analysis showed that during level walking the Mako group achieved a higher knee excursion during the highest flexion portion of the weight bearing stage of the gait cycle (18.6°) compared to the Oxford group (15.8°). This difference was statistically significant (p-value = 0.03). When compared to normal patients the Mako group's knee excursion values were comparable with normal healthy knees, however the Oxford group had significantly lower knee excursion angles at this point. Even though there were some differences seen in the two groups with motion analysis, these factors did not necessarily correlate with better perceived patient function when the knee function scores were compared against the knee excursions. Therefore it is still unclear if improved implant alignment and better knee motion directly correlate with improved function. |
