Orthopedic & Muscular System: Current Research
Open Access

A preliminary study of the kinematics of medial pivot knee arthroplasty in high-flexion

International Conference and Expo on Biomechanics & Implant Design

July 27-29, 2015 Orlando, USA

Zainal Abidin Arsat1,2, A Halim Kadarman2, Amran Ahmed Shokri2, Mohd Ezane Aziz2, Shaifuzain A Rahman2 and Solehuddin Shuib3

Posters-Accepted Abstracts: Orthop Muscular Syst

Abstract :

Introduction: Medial pivot knee arthroplasty is known as prosthesis that has ball-contact joint on the medial side. Reduction number of radius from two to one on the femoral component might change the kinematics implant. Numerous studies have been done for low-flexion, and for high-flexion are still deficient. Two objectives upon this study; 1) how is the kinematics of medial pivot knee arthroplasty in high-flexion? (2) Does pivoting mechanism last until full flexion? Method: Harnessing a 2/3 registration technique, two experiments had been conducted. Firstly empirical study, artificial bones and x-ray machine were used to capture five flexions ranged 100º to 140º with interval 10º. Secondly in-vivo study, nine subjects (3 male: 4 female) were selected to participate and were asked to lay-on-side on the interested leg for x-ray procedure. Result & Conclusion: Empirical study finding shows the jig that holds the artificial bone influenced the kinematics of implant. Differently for in-vivo study, finding shows that the femoral component translated posteriorly on lateral side for about 15 mm from position 100º flexion. The pivoting mechanism on medial side was activated at 120º flexion and beyond. The kinematics of medial pivot knee arhtroplasty shows a positive mimicry knee motion. Further study is needed for weight-bearing position.