Nonoperatively treated isolated posterior cruciate ligament injuries

To evaluate the theory that isolated posterior cruciate ligament injuries do well when treated nonoperatively, we reviewed 40 patients (mean age, 33 years at followup; average interval from injury, 6 years) who completed a modified Noyes knee questionnaire and were reevaluated by physical examination, radiographs, and isokinetic testing. Thirty of the injuries to the posterior cruciate ligament were sports-related. On the questionnaire, 65% of the patients revealed that their activity level after injury was limited and 49% stated that the involved knee had not recovered fully despite rehabilitation. Ninety percent complained of knee pain with activity and 43% complained of problems with walking. The longer the interval between injury and this followup, the lower the knee questionnaire score and the greater the radiographic degenerative changes. The patients as a group exhibited excellent muscular strength with a mean isokinetic score of 99% of the contralateral extremity. There was no correlation between isokinetic testing and knee questionnaire score. Patients with greater posterior laxity, as measured by the posterior drawer examination, appeared to have greater subjective complaints. Our study suggests that patients with isolated posterior cruciate ligament injuries treated nonoperatively may maintain excellent muscle strength, but significant symptoms and degenerative changes increase with increasing interval from injury.