07/2 Validation and medical applications

		Three-dimension whole-joint computational models are being developed to validate our functional simulation and to address specific clinical questions about e.g. femero-acetabular impingement.

Model Validation

Validation of our functional simulation models, using pre-operative and post-operative data, will verify the correctness of methods chosen and establish the credibility of computer-aided simulation results for medical diagnosis. To provide functional simulation to the surgeon in a time-efficient manner, model simplifications are required to reduce computational time to an acceptable level. A robust cross-validation of functional simulation results against the predictions from more highly-detailed, but time consuming, computational models is critical to establish the accuracy of such whole-limb functional models. Parameters for computationally-efficient linear elastic material descriptions of cartilage, ligament and other soft-tissues of the hip joint will be obtained by systematic reduction of the solutions derived from highly non-linear, multi-phasic material models.

Medical Applications

The ability of the functional models to accurately simulate pre-operative mechanical response and post-operative outcome will be validated through the construction of three-dimensional reference finite element models to study pre- and post-operative joint mechanics, i.e. the redistribution of contact pressures and local cartilage stresses following surgical intervention. The clinical relevance of mechanical joint responses predicted by the functional model will be verified by in-depth evaluation of the more complex reference finite element models, and the appropriate output parameters from the functional simulation will be defined. Evaluation of functional simulation results will be guided by established biomechanical principals and sound clinical hypotheses. For example, local acetabular rim overload, as predicted by the functional model, corresponding to high levels of local cartilage stress within the joint, as predicted by a reference finite model, will be evaluated in the context of the clinical hypothesis of femoro-acetabular impingement as a precursor to osteoarthritis.