Relation of ligament damage with site specific cartilage loss and osteophyte formation in collagenase induced osteoarthritis in mice.

OBJECTIVE To investigate the correlation between initial ligament damage and development of subsequent osteoarthritic changes. METHODS Collagenase was injected intraarticularly into the knee joint of mice of strain C57B16 or C57B110. After 3 days, ligament damage was evaluated by measurements of knee laxity in the anterior-posterior direction as a measure of cruciate ligament function, and in the varus-valgus direction as a measure of collateral ligament function. The amount and location of cartilage loss and osteophyte formation were determined at Day 42. RESULTS Significant correlations between the amount of laxity changes and the severity of cartilage loss (r = 0.78), the amount of laxity changes and the size of osteophytes (r = 0.87), and between the severity of cartilage loss and osteophyte size (r = 0.94) were demonstrated. The amount of cartilage loss and the degree of osteophyte formation at the medial side of the joint depended mainly on the severity of cruciate ligament damage. This is contrast to changes at the lateral side of the joint, which appeared not to be associated with the severity of ligament damage. CONCLUSION A strong relationship exists between the severity of cruciate ligament damage and the severity of osteoarthritic changes on the medial side of the joint. In the lateral joint compartment, prone to spontaneous osteoarthritis in the mouse strain studied, this relation is absent.