Effects of surgical treatment and immobilization on the healing of the medial collateral ligament: a long-term multidisciplinary study.

The long-term effects of surgical repair and immobilization on the healing of the transected medial collateral ligament (MCL) were studied biomechanically, biochemically and histologically in a canine model. Twelve adult canines were divided into two experimental groups and studied at 48 weeks postoperatively. For Group I, the transected MCL of the left knee was not repaired, and the joint was not immobilized. For Group II, the MCL was repaired and the joint was immobilized for six weeks. The right knee of each canine was sham-operated and served as the control. Histologically, the collagen fibers were less aligned in both of the experimental groups than in the controls. Furthermore, there were minimal differences in collagen and fibroblast alignment between the groups, although poorer alignment was observed for Group I at 12 weeks.16 Biochemically, the levels of types I and III collagen, reducible collagen cross-links and total collagen concentration for both groups returned to normal levels. Biomechanic...