COMPARISON OF HIGH FLEXION DESIGN AND POSTERIOR STABILIZATION PROSTHESES OF TOTAL KNEE ARTHROPLASTY BY GAIT ANALYSIS

Introduction: The primary goal of total knee arthroplasty (TKA) is to resolve knee destruction and associated problems at the end stages of diseases such as osteoarthritis and rheumatoid arthritis. High satisfactory rate has been reported in terms of pain relief and correction of deformity. However, the method for objective assessment of the outcome, such as range of motion (ROM) and quantitative evaluation of the clinical outcome of TKA, is to be confirmed. The purpose of this study was mandatory to investigate the ROM objectively and the newly designed prostheses. Materials and methods: The study was done in randomly selected patients who received dynamic measurement of knee function. Twenty-six patients participated in the study. They were divided into two groups (13 patients in A and 13 patients in B group), according to the knee prostheses they had received. Basic knee functions were evaluated in various dynamic activities, including nonweight bearing status of knee flexion, level walking, kneeling, and squatting, using computerized gait analysis techniques (Vicon 512 system). Passive knee ROM and static alignment were measured using traditional goniometer. HSS scores, physical, and neural examination were recorded. Results: After comparing patients in almost similar criteria, results have shown that there was no significant difference between two types of knee prostheses in randomly selective patients. Conclusion: Newly designed prostheses for achieving higher flexion angle cannot guarantee to provide better knee flexion for every patient. A patient, who can achieve higher knee flexion in pre-operative status, will have high flexion results in post-operative result. In other words, poor knee flexion function in pre-operation will lead to poor knee flexion function in post-operation status. Minor prosthesis design has little to do with the surgical outcome of knee flexion.