Femoroacetabular impingement (FAI) is a reduction in hip joint clearance that causes hip pain and may predispose the hip joint to osteoarthritis (OA). Altered biomechanics are considered the key initiator of OA. Patients with FAI often present with chondrolabral damage and restrictions in range of motion, suggesting that FAI alters cartilage/labrum contact mechanics and hip kinematics. Recent studies suggest that FAI may also cause primary or adaptive changes to muscle activation and force. Previous clinical and basic biomechanics studies have failed to elucidate the link between FAI, altered biomechanics and OA due to oversimplified approaches or inaccurate testing equipment. Our long term goal is to improve the diagnosis and treatment of FAI by quantifying hip biomechanics. To support this goal, we propose a R21-level research study to demonstrate the feasibility of using a combined experimental and computational protocol to quantify joint kinematics, muscle forces/activations, and cartilage/labrum contact mechanics in the human hip. We will use a combination of dual fluoroscopy and camera-based marker tracking to quantify lower limb kinematics during activities of daily living. Musculoskeletal (MS) models will estimate muscle forces/activations and finite element (FE) models will predict chondrolabral mechanics. In the past, our MS models assumed a static hip joint center and pre-defined muscle attachments and our FE models assumed boundary and loading conditions from the literature. In this R21, we will compare MS model (Aim 1) and FE model (Aim 2) predictions between models that are subject-specific with those that assume pre-defined or literature-based inputs. After determining the required level of model complexity and after conducting power analyses with the pilot data from this R21, we will pursue R01 level funding extending our computational and experimental protocols to further investigate the biomechanics of FAI.

Public Health Relevance

Femoroacetabular impingement (FAI) is a reduction in clearance in the hip joint and may be the primary cause of osteoarthritis in young adults. This study will use motion capture and computer models to evaluate how the abnormal bone geometry of FAI alters the mechanics of the hip joint. This may help explain how FAI leads to osteoarthritis, and improve diagnosis and treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AR063844-02
Application #
8629695
Study Section
Musculoskeletal Rehabilitation Sciences Study Section (MRS)
Program Officer
Lester, Gayle E
Project Start
2013-05-01
Project End
2015-04-30
Budget Start
2014-05-01
Budget End
2015-04-30
Support Year
2
Fiscal Year
2014
Total Cost
$158,313
Indirect Cost
$52,063
Name
University of Utah
Department
Orthopedics
Type
Schools of Medicine
DUNS #
009095365
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112