Interstitial tears of the posterior cruciate ligament of the knee.

We reviewed the records of 10 patients who suffered complete interstitial tears of their posterior cruciate ligaments. Five patients had isolated posterior cruciate tears, confirmed at arthrotomy. The most reliable clinical findings for posterior cruciate disruption were a posterior drawer sign and a posterior sag. All patients underwent surgical repair, with reinforcement using the tendon of the medial head of the gastrocnemius. Seven of the 10 patients were seen at followup examinations an average of 22 months after surgery. Each had a posterior drawer sign, but none had a posterior sag or recurvatum. The results do not approach the uniform good results of posterior cruciate avulsion injuries, but do show improvement over the results of nontreatment.