Anterior cruciate reconstruction in the chronically unstable knee using an expanded polytetrafluoroethylene (PTFE) prosthetic ligament.

The purpose of this study is to review 30 patients with failed, multiply operated knees, or knees with gross instability which were reconstructed using the expanded polytetrafluoroethylene (PTFE) prosthetic ligament as a substitute for the ACL. The results were then compared with our experience with the proplast ligament used in a previous clinical series. This prospective review evaluated the patients preoperatively and at regular intervals during the postoperative period. The average followup was 24 months postoperation. Eighty-three percent of the patients had a satisfactory result, scoring greater than 140 points on a 200 point knee grading scale. Objectively, the anterior instability pattern was improved in 87% of the knees. Subjectively, pain of at least a mild degree persisted in 70% of the patients postoperatively. This pain seemed to correlate with articular cartilage changes documented intraoperatively. Major complications occurred in two patients. In conclusion, the PTFE prosthetic ligament was an improvement over the proplast ligament in the reconstruction of the multiply operated, unstable knee. The 83% satisfactory rate with the PTFE was promising compared to a 52% satisfactory rate using the proplast ligament. However, we encourage future long term studies of the PTFE prosthetic ligament in the reconstruction of the ACL in the chronically unstable knee.