Effect of anterior cruciate ligament reconstruction with patellar tendon or prosthetic ligament on the morphology of the other ligaments of the knee joint. An experimental study in dogs.

The effect of anterior cruciate ligament replacement on the other ligaments of the knee, including the medial or lateral collateral and posterior cruciate ligaments, was studied histologically in the canine knee. The anterior cruciate ligament was replaced either with the medial third of the patellar tendon or with a prosthetic ligament. Histologic analysis was performed 3 months after prosthetic ligament implantation and 1 year after patellar ligament reconstruction. In all ligaments, numerous pathologic alterations were found. Degenerative changes such as glycosaminoglycan accumulation, metachromasia, collagenolysis, collagen necrosis, and lipomatosis were similar after 3 months and after 1 year. Granulation tissue, a sign that characterizes tissue repair, was seen only in those ligaments taken 3 months after anterior cruciate ligament surgery. Similar degenerative changes also were found in the ligaments of the knees with only a large medial arthrotomy (sham). In the contralateral control knees, the pathologic alterations were rare. Thus, open arthrotomy alone or with anterior cruciate ligament reconstruction seems to result in longstanding degenerative changes in all ligaments of the canine knee joint.