AN ANALYSIS OF AUTOGRAFT FIXATION AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION IN A RABBIT MODEL

Fixation and incorporation of a tendon implanted within the bone pose theoretical as well as practical concerns for the surgeon who treats i nstability problems of the knee. Understanding the physiology involved in graft-bone incorporation is necessary for the appropriate rehabili tation of patients who undergo anterior cruciate ligament surgery. The purpose of the study was to examine the histologic and biomechanical changes of a semitendinosus autograft reconstruction of the anterior c ruciate ligament in a rabbit model at the graft-bone tunnel interface in the femur. The results indicate that by 3 weeks, failure of the bon e-graft-bone or construction is through the intraarticular portion of the graft, not as a result of pullout from the bone tunnel. Graft fixa tion of the bone tunnel occurs by an intertwining of graft and connect ive tissue and anchoring of connective tissue to bone by collagenous f ibers and bone formation in the tunnels. The collagenous fibers have t he appearance of the Sharpey's fibers seen in an indirect tendon inser tion.