Isolated posterior cruciate ligament injuries in athletes.

The literature is divided as to the necessity of an intact posterior cruciate ligament for functional stability. Presented here is a prospective study of isolated posterior cruciate injuries seen in the acute stage in 13 patients, 6 males and 7 females. The diagnosis of posterior cruciate ligament tear was made clinically and confirmed by arthroscopy. The average age at injury was 22 years. The athletic activity at injury was varied. Hyperflexion was the most common mechanism of injury, followed by pretibial trauma in the hyperflexed knee or in the "dashboard" injury. There were seven complete midsubstance tears and five partial tears. Direct visualization of the posterior cruciate ligament was not attained in one patient. All patients were treated nonoperatively on a physiotherapy routine. Average followup was 2.6 years. Patients were clinically examined and subjected to KT-1000 and Cybex testing. All patients were able to return to their previous activity and experienced no limitations with their injured knees. Using Hughston's criteria, subjective and functional ratings were all good. However, only 3 rated good and 10 fair when assessed objectively. We conclude that acceptable functional stability in these patients does not necessarily require absolute static stability. Nonoperative treatment of the isolated posterior cruciate ligament midsubstance injury may be a viable alternative to the difficult repair/reconstruction procedure.