Disorders of the inert structures: ligamentous instability

If the knee becomes unstable after a ligamentous injury, permanent problems may result, especially if the patient is an athlete with high functional demand. If the history indicates that there is possibly instability, an examination to detect the exact location and degree of this is performed. It is important to make this supplementary examination only when symptoms and signs found in the routine clinical assessment indicate ligamentous instability to be the cause of disability. Indeed, it is important to realize that not every lengthened ligament leads to problems. If the athlete’s muscles are strong enough to provide dynamic stability, a slightly unstable knee will not cause trouble. Conversely, it is quite possible that an athlete with slight laxity of one or more ligaments has a chronic painful lesion as well. If the diagnosis of the latter is missed because the routine functional examination is not performed, it may well be that the patient is sent for surgery, which will solve the slight instability but does not cure the main problem.