Evaluation of Dacron-covered and plain bovine xenografts as replacements for the anterior cruciate ligament.

Surgical repair of the anterior cruciate ligament often involves the use of a suitable autograft. As alternatives to sacrificing these normal structures, various allografts, xenografts, and synthetic materials have been investigated as ligament replacement materials. This study investigates Dacron fabric-covered and plain bovine xenograft tendon as such materials in the canine knee. The implants were tested to failure in an MTS machine following 13 weeks of implantation in a canine knee. Dacron woven fabric-covered implants became more firmly attached than those covered by Dacron mesh fabric or plain xenografts. The implants were also analyzed according to their method of attachment (fixation staples or sutures). Overall, the sutured implants failed at slightly higher forces than did the stapled ones. Histologically, limited vascular invasion of the xenograft was observed. No host fibrous or osseous tissue could be identified within the graft. Fibrous tissues did form between the bone and xenograft. The implants exhibited extreme intraarticular wear, which suggests a low potential for intraarticular ligament replacement