1. Cruciate-ligament instability at the knee causes a definite disability and should be prevented if possible.
2. Repair of the cruciate ligaments is surgically feasible and highly successful if it is done early.
3. Cruciate-ligament instability was the primary cause of disability in those athletes who did not return to competition. Of the sixteen athletes who did not return to full competition, fifteen (94 per cent.) gave cruciate-ligament instability as a major cause of their failure to participate. They could tolerate some pain, some stiffness, some weakness, some lateral instability, but they could not tolerate cruciate instability.
4. The time of the repair is vastly more important than the severity of the injury, but the more serious the injury is, the more urgent is ear'y repair.
5. Results in the athletes were markedly better than those in non-athletes, regardless of age.
6. Complete rupture of any ligament of the knee demands early surgical repair to assure best results. In all types of injury early repair (under two weeks) gives much better results than late repair or reconstruction.