Interaction of Mechanical and Biological Factors in Knee Osteoarthritis

Principal Investigator: Thomas P. Andriacchi, PhD

Project Category: Arthritis - 2005

Description: This is a study to identify possible mechanisms by which OA develops and progresses by examining the interaction of in vivo functional mechanical and biological factors in patients with medial compartmental knee OA and healthy subjects.

Our primary long-term goal is to identify possible mechanisms by which OA develops and progresses by examining the interaction of in vivo functional mechanical and biological factors in patients with medial compartmental knee OA and healthy subjects. The key question of the proposed research is whether serum COMP concentration is related to functional in vivo loading of the healthy and osteoarthritis human knee. The specific aims of this investigation are:

Specific Aim 1: To determine if temporal increases in serum biomarker concentration are related to cyclic in vivo loading of the knee. The following hypothesis will be tested:

Hypothesis 1: Serum COMP concentration will show two temporal increases, one immediately after and a second increase five hours after a moderate walking exercise. While these two increases will be of similar magnitudes in control subjects, it is possible that the second increase will be higher in patients with medial compartment knee OA.

Specific Aim 2: To evaluate the relationship between in vivo load at the major joints of the lower extremity during normal gait and serum biomarker concentration.

Hypothesis 2: The change in serum concentration of COMP due to moderate walking exercise correlates with the maximum extrinsic knee adduction moment times number of steps taken during normal gait but not with the extrinsic hip flexion, hip adduction, knee flexion and ankle flexion moments. It is possible that there will be a negative correlation in asymptomatic subjects and a positive correlation in patients with medial compartmental knee OA.

Expected Outcome: The results of this study will help to interpret the relationships between changes in biomarkers and the loading environment of cartilage.

Funding Source: Department of Veterans Affairs

Funding Status: Active