Our lab develops new methods for measuring joint mechanics and applies these methods to
a) identify specific mechanical causes of osteoarthritis and other musculoskeletal conditions and
b) quantify the effects of clinical treatments on mechanics.
A complete and accurate understanding of the biomechanics of the human hip is essential for understanding its function and for designing treatments for disorders that affect this vital joint.
The long-term objectives of this program of research are to develop methods to assess hip mechanics under physiological conditions and to apply these methods to determine comprehensively how the most prevalent hip deformities and injuries change hip mechanics, and which treatment approaches most effectively restore hip mechanics to normal.
Within this program, two short-term objectives are:
In Aim 1, we will develop imaging-based methods for measuring cartilage strain in the hip joint in cadaver specimens loaded to simulate in vivo physiological loads. To make measurements that are more accurate than any that have been made previously, we will use the Canada Light Source synchrotron to perform three dimensional, computed tomography images of hips.
In Aim 2 we will determine the effect of a prevalent type of hip deformity, femoroacetabular impingement (FAI), and acetabular labral damage on cartilage strain in hip specimens at physiological loads and hip positions
Figure 1: Maps of hip cartilage compressive strain (combined femoral and acetabular) from one
specimen determined from synchrotron imaging for 5 different load levels (colourbar legend: strain).
Synchrotron Imaging to Assess Hip Cartilage Strain
CURRENT RESEARCH PROGRAMS
Hip osteoarthritis (OA) is common and disabling. Many cases of hip osteoarthritis may be caused by bony deformities that change joint mechanics. It is not clear, though, what size a deformity has to be to cause problems at the hip. In addition, it is not known whether certain activities people do can result in the development and progression of OA in patients with these deformities. In this project we will look for relationships between the following components:
direct measurements of the hip joint using a special scanner that can detect deformities which can lead to mechanical problems
measurements of hip during activities to see mechanical problems in motion
We will assess which activities cause mechanical problems in the hip, and how these mechanical problems are affected by deformity size. The results will help doctors to determine which patients with these hip deformities will need early activity modification to prevent or delay the onset and progression of OA and which patients might be candidates for surgical intervention.
Postures for direct imaging of impingement using open MRI.
Open MRI for assessing joint biomechanics:
Applications for Osteoarthritis
The overall benefit of this project will be to help explain why people get osteoarthritis, which must be understood to develop ways to prevent and treat the disease.
The aims of this project are:
a) to develop new methods for measuring how knees move and transmit load
b) to develop new methods for measuring early degeneration in cartilage and
c) to assess how the changes in joint movement and load transmission produced by an operation performed for early osteoarthritis are linked to degeneration of cartilage.
To date, these links have not been well-studied because we have not previously been able to make appropriate measurements of joint movement and load transmission and cartilage degeneration in living people.