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Show SCHOOL OF MEDICINE AND HEALTH SCIENCES UNDERGRADUATE RESEARCH ABSTRACTS KINEMATICS OF FEMOROACETABULAR IMPINGEMENT DURING CLINICAL EXAMS Michael Kutschke (Andrew Anderson, Ashley Kapron) Department of Orthopaedics University of Utah Femoroacetabular impingement (FAI) is a condition of the hip joint that is characterized by bony abnormalities that decrease clearance between the femoral head and the acetabulum. It is hypothesized that impingement, or premature articulation, between the femoral head and acetabulum causes this damage. While the orthopaedic community has a general idea of h o w impingement occurs in the hip joint as a result of FAI deformities, impingement has never been observed in vivo. Through completion of this study, w e will be the first to accurately quantify impingement in vivo during clinical hip exams, which will greatly improve the understanding of hip impingement and possibly explain the cause of cartilage and labral damage often observed in hips with FAI. W e will achieve this goal by implementing the use of a dual fluoroscopy system (DFS) and model-based tracking. In preparation for this study of comparing the hip motion of FAI patients and normal control subjects, w e have conducted a preliminary study with cadaveric specimens to assess the accuracy of the DFS and model based tracking. To determine the accuracy, hip kinematics from model-based tracking was found to be 0.109 ± 0.082 mm compared to the reference standard (marker-tracking). N o w that our method of data collection and processing has been validified, w e will begin implementing these procedures with unaffected, normal subjects and affected subjects w h o present with FAI. The goal is to recruit a total of five normal subjects and five affected subjects. Data collection and processing has begun on two normal subjects and two affected subjects w h o presented with cam FAI (asphericity of the femoral head). Processing the data will ultimately allow us to understand how measurements of joint angles and bone-to-bone distances compare between the normal subjects and those affected with FAI. Flexion (+) Adduction (+) Internal Rotation (+) Distance Between Bones (mm) 100 so at S 60 ? TJ • 4° Ol c < 20 0< ( 1 2 Tim e(s) 3 Plot of hip joint angles over the course of impingement exam. Anterolateral view of the hip showing Anterior view of the hip showing bone-to-bone distances at t=1.5 seconds bone-to-bone distances at t=1.5 seconds during impingement exam; femur during impingement exam; pelvis transparent. transparent. Michael Kutschke tiaUNflHMSQHMH Andrew Anderson Ashley Kapron 123 |