Overuse knee injuries are common and painful problems that can affect athletes and the layman alike. Synovial Plica Syndrome is one of the less known culprits, but painful non the less. A plica is thin fibrous tissue and they are extensions of the synovial capsule of the knee. The synovial capsule is what surrounds the joint and provides a frictionless surface for the knee to move on. The plica form early on, as a fetus the knee is divided into three compartments, as as it develops they merge together. Most people have remnants of these cavities and they are the plica.
Here is a picture showing the three plica. Book: Overuse Injuries of the Musculoskeletal System.
Normally the plica will not cause any problems, however with certain events they can cause quite painful symptoms. When the knee is irritated inflammation can occur. This could be from repetitive stress, single trauma, loose bodies in the knee, meniscus tears and other knee pathologies. The plica can get thicker, or it is chronically changed (enlarged, fibrotic, calcified), and this is where problems will start to occur. For example, when the knee is flexed the plica can rub on the medial condyle of the femur, which is basically at the end of the femur on the medial side of the knee. It turns into a viscous cycle as the inflammation doesn’t subside and the plica get’s thicker and more painful. The medial plica tends to be the most common offender and can result in many other problems such as chondromalacia when it rubs against the surfaces inside the knee.
This condition may be missed in an examination which can lead to an ineffective rehabilitation plan. The symptoms presented can mimic other knee conditions and a rehab plan given may actually cause further problems to the plica. Thus it is very important that it is considered in knee pain examinations.
How To Treat Plica Syndrome
Non operative measures can be employed to help plica syndrome. Rest from the aggravating activity is the first thing that needs to occur, as you need to control the inflammation. Anti inflammatory drugs can help in most cases in cycles, knee taping and knee braces to ensure that the plica does not come into contact with the articular surfaces of the knee are often also useful. Once the inflammation has subsided and the pain is at least under control rehab exercises should be started. It is important that the quadriceps are kept exceptionally strong as it can help to take the pressure of the knee joint. Likewise in regard to the glutes, calves and hamstrings… as we have discussed before here this will take a lot of pressure off the knee.
In cases where the pain is very persistent and activity can’t be undertaken, surgery can help and cure the problem. An arthroscope is performed and the plica is removed/ altered. This usually fixes the problem and no more pain is experienced, unless of course other areas of the knee are aggravated chronically. In patellofemoral disorders this procedure along side a release of the lateral retinaculum (extension of the ITD close to the knee which can get very tight and cause tracking problems) are often recommended by surgeons.