Plica syndrome is a fairly common cause of knee pain and instability. It occurs when folds of joint tissue called plica become irritated, inflamed, and swollen. A person can develop plica syndrome following a direct injury or as the result of chronic overuse of the joint. Most cases are mild and temporary, and people are able to return to normal activity levels after about four weeks of rest. If plica tissue is severely damaged, however, surgery and a lengthy rehabilitation program may be necessary to fully recover.
Plica tissue plays a major role in the development of knee structures while a fetus is in the womb. Most plica tissue deteriorates to make room for tendons, cartilage, and bone in the second trimester, and remnants of plica form four small folds in the knee. The fold closest to the inside of the knee joint is usually the one that is implicated in plica syndrome. Problems occur when a person puts excess pressure on the knee, either from excessive running and bending or from a sudden twist or impact. Athletes, very active people, and car accident victims are the most likely to experience plica syndrome.
The symptoms of plica syndrome depend on the severity and nature of the injury. Irritated tissue can cause the inside part of the joint to become tender, achy, and stiff. It may be possible to hear a snapping or clicking noise when bending the knee. If major damage has occurred, it may be very painful to bear weight on the affected leg. Occasionally, redness and swelling accompany other symptoms.
It is important to visit a doctor whenever painful symptoms develop to gain an accurate diagnosis. A doctor can perform a physical exam to determine if pain is being caused by inflamed plica tissue or a more serious problem, such as a bone fracture or a torn tendon. Magnetic resonance imaging scans are often taken to confirm soft tissue inflammation in the knee.
Most patients with relatively minor symptoms are instructed to rest and ice their knees for several weeks. Over-the-counter painkillers and anti-inflammatory drugs can also help reduce symptoms. If pain is severe at the time of examination, the doctor may decide to inject a corticosteroid solution directly into the joint. It is important to give the knee ample time to recover before returning to activity to avoid further injuries.
Arthroscopic surgery is only needed if a person fails to get better with conservative treatment. A skilled orthopedic surgeon can remove or reinforce damaged plica tissue from the joint. It may take up to six months to recover from surgery, during which time a person needs plenty of rest and guided physical therapy. Surgery for plica syndrome is usually very effective, and the majority of patients are eventually able to return to normal activity levels.