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 development of this syndrome. People with this syndrome are likely to experience pain and swelling, a clicking sensation, and locking and weakness of the knee. Because the symptoms are similar to symptoms of some other knee problems, plica syndrome is often misdiagnosed.
Diagnosis usually depends on the exclusion of other conditions that cause similar symptoms.
The goal of treatment is to reduce inflammation of the synovium and thickening of the plicae. The doctor usually prescribes medicine such as ibuprofen to reduce inflammation. If this treatment program fails to relieve symptoms within 3 months, the doctor may recommend arthroscopic or open surgery to remove the plicae. A cortisone injection into the region of the plica folds helps about half of the patients treated. The doctor can also use arthroscopy to confirm the diagnosis and treat the problem.