It was studied the arrangement of the collagen fibrils of the medial collateral ligament of the canine elbow joint and evaluated its diameter, when it was isolated or associated to the oblique ligament and loaded in tension until failure. Eighteen joints were divided in three groups. The first group had the medial collateral ligament collected and not loaded, the second group had the medial collateral ligament tested separately and the third group had both ligaments associately tested. Medial collateral ligament not submitted to strain presented a wavy and reticular pattern of the collagen fibers, which was not totally destroyed when it was loaded associated to the oblique ligament, and totally loses the reticular pattern when stretched separately. When the medial collateral ligament was loaded in tension separately, the mean collagen fibrils diameter increased in relation to the group not submitted to the tensile strain. Associated to the oblique ligament, the mean collagen fibrils diameter was the largest in the insertion area and the smallest in the mid-substance, in relation to the other groups. It was concluded that the oblique ligament could favor the integrity of the medial collateral ligament insertion area, facilitating its reconstruction after lesion with larger efficiency.
dog; medial collateral ligament; oblique ligament; elbow; collagen fibrils
