Healing of the medial collateral ligament in rats. The effects of repair, motion, and secondary stabilizing ligaments
Hart, D.P.; Dahners, L.E.
Journal of Bone and Joint Surgery. American Volume 69(8): 1194-1199
1987
ISSN/ISBN: 0021-9355 PMID: 3667648 Document Number: 298539
The effects of repair, motion, and the integrity of the secondary ligamentous restraints on healing of the medial collateral ligament were studied in a rat model. Healing was assessed by measuring ligamentous laxity and tensile strength. All healing ligaments were weaker and more lax than their controls. Repair did not have a statistically significant effect on the laxity or the strength of the medial collateral ligament. Allowing active motion had a statistically significant beneficial effect on the strength of the medial collateral ligament. Stability was adversely affected by active motion if the secondary restraints had been transected; however, when the secondary ligamentous restraints were intact, active motion was beneficial and immobilization was harmful. Clinical Relevance: Individuals who treat injured knees should be aware that most previously reported laboratory studies have used models in which the secondary restraints were intact. This study provides supporting evidence that treating an isolated injury of the medial collateral ligament with active motion, without an oepration, is beneficial. A more severe injury, with damage to the secondary restraints, may require immobilization to prevent reinjury during the healing process.