The knee radiographs of 77 patients were examined by two physicians not involved in the operation a mean of 41.2 months after implantation of a synthetic ligament (Trevira hochfest). They evaluated the increase of degenerative osteoarthritis on a five-grade scale (0-4) by Jonasch and Mohing as modified by Holz, and using the IKDC score. Fifty patients with acute rupture had the synthetic ligament implanted for protection of anterior cruciate repair. Twenty-seven patients had a salvage procedure with the alloplastic ligament functioning as a prosthesis. Both examiners found a statistically significant increase of degenerative arthritis. Patients with acute anterior cruciate tears had a lower degree of osteoarthritis on the day of surgery compared to the patients with chronic insufficiency, but the postoperative increase was identical in both groups. Statistical analysis revealed correlations between osteoarthric changes and several factors such as concomitant meniscus or posterior cruciate injury and demonstrated no correlation to the grade of postoperative stability or injuries to the medial or lateral collateral ligaments or capsule.