Patella Instability

Patellar (or kneecap) dislocations are common injuries and affect mainly adolescents and young adults. In this condition, the patella moves out of its usual location in the front of the knee to the lateral or outer side of the knee. This can occur because of direct trauma or a twisting injury of the knee.

The risk factors for patella dislocations include generalized ligamentous laxity, a valgus (or knock-knee) deformity of the knee and a shallow trochlea (groove for the patella) in the front of the knee. ​The diagnosis of a patella dislocation is made after a thorough clinical assessment of the knee. MRI scans are done to confirm the diagnosis and to look for concomitant knee injuries and anatomical risk factors. First-time acute patella dislocations are usually treated with a period of immobilization of the knee. Surgery is usually not required unless there is a significant cartilage injury that needs to be addressed.

In patients who have recurrent patella dislocations and symptoms of patella instability, reconstructive surgery is needed to improve patella stability.