[Alloplastic replacement of the anterior cruciate ligament by a polytetrafluoroethylene ligament. Animal experiment study]

4 sheep knees received an implant of polytetrafluorethylene. 18 month after implantation the clinical and histological investigation showed two cases of anterior instability and rupture of parts of the prosthesis. We sw severe degenerative lesions intraarticular with chronic inflammation characterized by the proliferation of immature fibroblasts, the accumulation of macrophages and the formation of multinucleated giant cells. The transfer of our results to the human knee is discussed.