The non-operative management of collateral ligament injuries of the knee joint.

Severe knee ligament injuries are frequently underestimated, and this results in later problems of chronic instability. A history of an appropriate mechanism coupled with immediate reduction in function should arouse suspicion of a major disruption. Examination with the patient under anesthesia may be required to assess the extent of the injury. If the lesion is an isolated collateral tear, the intact cruciate ligaments prevent wide displacement. Such an injury can be managed non-operatively. A long leg plaster at 90 degrees for 2 weeks followed by 4 weeks in a cast brace with motion from 45 degrees to 100 degrees is recommended. The knee is then protected in a brace during athletic activities for approximately 6 months. Thirty collateral ligament tears have been managed in this fashion. Only one has significant residual complaints. It is emphasized that an isolated collateral ligament tear is a positive diagnosis, and associated cruciate lesions must be ruled out. The recovery is faster in those patients managed non-operatively than in those who have surgical repair. There has not been a problem with late instability.