PATELLOFEMORAL INSTABILITY

The kneecap (patella) sits in a groove (trochlea) on the front of the thighbone (femur). Normally it is held in place by the shape of the groove and the surrounding ligaments. Some people are prone to instability because of variations in the shape of the patella or its groove. Individuals with normal anatomy may sustain instability due to twisting injuries. A patellar subluxation occurs when the kneecap briefly slides out of place and back in again. A dislocation occurs when the patella comes completely out of the groove and becomes locked there.

Prevention

It is important to maintain good quadriceps muscle tone and flexibility when participating in jumping and twisting sports. Individuals who are prone to instability can help prevent this through exercises, specialized patellar tracking braces and sometimes taping.

Treatment

Nonoperative treatment involves the same strategies outlined in the prevention section above. For recurrent problems, there are surgical techniques to realign and stabilize the patella. Rehabilitation exercises to strengthen and balance the musculature are very important after surgery.