Plica in the knee


Plica is a fold of the mucous membrane that starts from the inner synovium.
It is formed from collagen fibers and a very thin mucous membrane with a smooth surface (synovial skin), which lines the inner surface of the joint capsule. The synovial skin secretes a liquid mass, the so-called synovial fluid (synovia).

This reduces the resulting friction within the joint cavity and supplies nutrients to supply the joint cartilage.

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Anatomy of the mucosal fold in the knee

The synovial skin forms during the human Embryonic development a layer (membrane) from that knee divides into two separate areas. Often there is one in the course of further development This membrane regresseswhat the Freedom of movement within the joint elevated. However, at approx. 70 % of adults receive a fold of the mucous membrane (plica). This fold of the mucous membrane in the knee takes over no important functions. In most cases, the plica pulls from the inside of the central area of ​​the Knee joint Towards the center.

Since it is either above, below or to the side of the kneecap, it can be divided into Plica suprapatellaris, Infrapatellar plica or Mediopatellar plica.

Read more about the topic here Plica infrapatellaris or plica suprapatellaris

Plica suprapatellaris

In the Plica suprapatellaris it is a fold of the inner synovial membrane that extends above the kneecap in the knee joint.

It starts at the lower end of the thigh bone and moves over to the inner wall of the knee joint. It rarely occurs.

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Infrapatellar plica

The Infrapatellar plica is a Envelope fold, which below the kneecap in the knee joint is located. It extends from a depression of the Bone at the bottom of the Thigh (Fossa intercondylaris femoris) to the anterior joint cavity of the knee, where it is attached to a fat body (Hoffa fat body).

Mediopatellar plica

The Mediopatellar plica occurs most often. It is located between the medial articular process of the thigh bone and the kneecap. The plica extends from the inner Knee joint compartment towards the center. Because of her location, she often comes with a stretched bowstring compared. She represents the most common cause of plica syndrome represent.

Plica syndrome

Problems that occur acutely and are related to a plica are relatively rare. On the other hand, it happens more often painful and inflammatory changes as part of creeping processes. Friction can cause it to Damage to the articular cartilage come.

The Plica Syndrome, or also Shelf Syndrome called, usually arises due to a Overexertion or excessive strain on the knee joint. Possible causes can for example sports how to jog, Ball sports, To dance or Cycle because they create a high load in the form of frequent extension and flexion of the knee joint. Other causes include Injuries , one Instability in the knee joint, inflammatory processes in the area of ​​the synovium, as well as a Muscle imbalance.

As a result of these processes, a Swelling of the folds of the mucous membrane and it evolves inflammatory reactions, as a result of which there is a connective tissue remodeling and thus to a Hardening and thickening of the folds of the mucous membrane can come.

The pain that occurs is often used to Inside knee localized and as load-dependent described. When exercising, a feeling of pressure or tension arises, which is perceived as very unpleasant.

In most cases that is Mediopatellar plica responsible for the complaints. It is pinched between the inner thigh roll and the kneecap when the knee is flexed and can be used as a hardened, painful cord between thigh and kneecap be keyed. As a result of recurrent inflammatory changes and pinching of the plica, it can Movement restrictions and blockages of the knee joint, joint effusions and recurring again and again Pain come. It is also possible that the joint stiffened and that when bending the knee loud cracking can be heard.

To correct a plica syndrome therapy to be able to, it is important to assess the severity. With regard to therapy, a distinction is made between conservative and operational Procedure. At first try the plica syndrome conservative to treat. Here come next to one anti-inflammatory medication also physical conservation, Cooling pads, Massages, such as Exercises to build muscle for use. The most important thing is that to reduce existing overloading of the joint. If one does not achieve improvement with the conservative therapy options, one can consider whether one can achieve pain relief and improvement of the symptoms by surgical removal of the plica. If the articular cartilage has already been damaged too much, there may be no improvement even after the plica has been removed.