Development of 3 Dimensional subject specific dynamic models for the ankle and its assessment against in vitro cadaveric experimental data using distance mapping and kinematic evaluation

Abstract

Currently osteoarthritis is the leading joint disease which in turn leads to major socio-economic losses in terms of physical pain and inability to work leading to losses of over $60 Billion to the US economy alone (Buckwalter et al, 2004). Current treatment methods include Total Ankle Replacement (TAR) or arthrodesis. Since arthrodesis leads to major loss in mobility, TAR comes across as a better alternative. Recent research by Siegler et al (2016) proposes patient specific models, which would help, recreate kinematics closest to regular. Previous experimental studies conducted to understand and validate the effect of morphological variations to kinematics involved invasive surgical procedures and hence could only be conducted in cadaveric foot. Hence a need for a dynamic model which could predict and recreate the kinematics of an ankle using only CT and, or MRI data was realized. Such a model could help in development and non-invasive testing of subject specific TAR. This study involves the development of five 3D patient specific dynamic models in MSC ADAMSTM to simulate the motion of the talus and the calcaneus on application of different moments. The simulation has been conducted on 3D models which have been developed using CT and MRI data of five cadaveric legs, which have already undergone studies for the subchondral bones using distance mapping, which is a tool in Geomagic ControlTM. The ADAMSTM model has been used to simulate moments like the experiment and to acquire kinematic data and study surface-to-surface interaction between the bones using distance mapping techniques.%%%%M.S., Mechanical Engineering and Mechanics – Drexel University, 2017