The synovial plica is the inward folds of the synovial lining present in the knee joint capsule. The common region where the plica is present is the inside border of kneecap.
About Synovial Plica
The synovial membrane secretes synovial fluid into the joint which helps in lubrication of the joints, shock absorption, and nutrient and waste transportation. The synovial folds found along the medial border of the knee cap are known as synovial plica. The synovial fluid is produced by the synovial sheath which may also become inflamed resulting in knee synovitis.
The medial suprapatellar plica of the knee is one of the commonest causes of knee pain. About 50% of the patients presenting with knee pain have some amount of irritation of their patellofemoral joint. Medial plica syndrome is present in both young and old patients who are physically very active. The symptoms may wax and wane over periods of time. Prolonged flexion can increase the pain and extension may relieve the pain. Synovial plica irritation may be caused by direct trauma or overuse of the joint leading to inflammation. A proper rehabilitation program is required in order to recover from the symptoms associated with synovial plica irritation.
Symptoms of Synovial Plica Irritation
- Unpredictable, sharp pain present anteriorly, medially or posteriorly in the patella.
- Squatting causes sharp pain.
- The plica at times can feel like thick band on the inside of patella.
Causes of Synovial Plica Irritation
- Dysfunction of the patellofemoral joint due to overuse, injury or abnormal mechanics.
- Direct trauma to the knee such as dashboard injuries or falling onto a flexed knee or twisting injuries and overuse of the joint may cause irritation.
- Other knee joint conditions such as a meniscal tear or arthritis could also result in plica irritation.
- Anything that causes bleeding in the joint or synovitis can also lead to plica irritation.
Prevention and Treatment of Synovial Plica Irritation
- Activities which aggravate plica irritation should be avoided.
- The root cause of synovial irritation should be identified and treated.
- When a patient does not benefit with treatment of patellofemoral pain syndrome, then synovial or patellar plica is considered to cause the pain.
- X-rays, MRI help in the diagnosis.
- Physical therapy (PT) should be undertaken.
- NSAIDs help in relieving pain and inflammation.
- Local anesthetic and corticosteroid injections help in decreasing inflammation.
- Surgery may be done via arthroscopy to look for a plica and if present to remove the plica.
- A routine exercise program should be followed to prevent recurrence of knee pain.