Finite Element Analysis of Full Range of Motion Walking and Sitting Down in Patient-Specific Models with Cam Deformities

Cam impingement occurs in 15% of the population and is strongly associated with the development of osteoarthritis. Current clinical measurements do not predict the risk for asymptomatic hips and their risk of developing osteoarthritis adequately. Thus, developing FE analyses of cam-deformed hips that combine accurate material models, patient-specific morphology and kinematics to emphasize the dynamic quality of impingement is the objective of this study. Such models were developed for control, asymptomatic and symptomatic hips through CT segmentation and generation of 3D models of cartilage and the labrum. Forces and rotations during walking and sitting down were applied, where the Asymptomatic hip experienced the highest first principal stresses (0.32 MPa and 0.61 MPa, respectively). The contrast between the cam-affected hips highlighted the importance of morphology and kinematics when examining impingement. These findings emphasized the shortcomings of current measurements of cam deformities and the need to consider impingement as a dynamic problem.