Plica (PLI-kah) syndrome occurs when plicae (bands of synovial tissue) are irritated by overuse or injury. Synovial plicae are the remains of tissue pouches found in the early stages of fetal development. As the fetus develops, these pouches normally combine to form one large synovial cavity. If this process is incomplete, plicae remain as four folds or bands of synovial tissue within the knee. Injury, chronic overuse, or inflammatory conditions are associated with this syndrome.

Symptoms

Symptoms of plica syndrome include pain and swelling, a clicking sensation, and locking and weakness of the knee.

Diagnosis

Because the symptoms are similar to those of some other knee problems, plica syndrome is often misdiagnosed. Diagnosis usually depends on excluding other conditions that cause similar symptoms.

Treatment

The goal of treatment is to reduce inflammation of the synovium and thickening of the plicae. The doctor usually prescribes medicine to reduce inflammation. People are also advised to reduce activity, apply ice and an elastic bandage to the knee, and do strengthening exercises. A cortisone injection into the plica folds helps about half of those treated. If treatment fails to relieve symptoms within 3 months, the doctor may recommend arthroscopic or open surgery to remove the plicae.