Master of Science

thesisCam femoroacetabular impingement syndrome (FAIS) is a hip condition characterized by motion or position-related pain arising from morphological abnormalities of the proximal femur. Cam morphology is theorized to alter the mechanical environment of the joint, causing conflict between the acetabular labrum and proximal femur. Soft tissue damage in the anterosuperior labrum is often observed clinically, and research suggests that cam FAIS is major underlying cause for many cases of hip osteoarthritis (OA), formally deemed idiopathic. Improving our understanding of impingement and its relationship to joint morphology and motion may improve patient care for those with cam FAIS. Computational models are frequently used to study the pathomechanisms of impingement, otherwise impossible to study in vivo, but many models apply assumptions or simplifications that are not appropriate for describing the complex interaction of morphology and motion in cam FAIS. Models with patient-specific inputs address this limitation but require time-intensive setup and optimizations, rendering them less feasible for clinical applications. To balance patient-specificity and computational simplicity, we adapted a modeling technique, used by several research groups to study knee and ankle mechanics, which we refer to as "soft tissue overlap" (STO) modeling. In the first portion of this thesis, we used STO modeling to investigate how labral contact mechanics may be altered in cam FAIS compared to healthy controls in the acetabular labrum during four activities of daily living (internal/external pivots, level/inclined walking). No statistically significant differences were found during pivoting activities, but trends suggesting greater contact area and strain in the acetabular labrum of the cam FAIS cohort were found during the walking activities. In the second portion of this thesis, we investigated the sensitivity of STO model predictions by introducing perturbations in mesh geometry and kinematics and comparing an STO model to a finite element model (herein considered a reference standard for modeling of hip contact mechanics). With both portions of this thesis, we hope to offer new insight into the mechanical iv mysteries surrounding cam FAIS and provide a framework for a new computational methodology for future studies to improve upon