Function
The plica infrapatellaris and the other two mucosal folds are created in the embryonic period and often recede into adulthood. The mucosal folds do not have a direct specific function. When the plica infrapatellaris is created, it forms a reinforcing fibrous strand that extends from the underside of the patella through the fatty body into the bony depression. Occasionally, movement may even be restricted. It can swell and block the knee joint, so that no sliding movement can take place.
Rupture
The plica infrapatellaris can also tear in rare cases. A rupture is often caused by overstraining the knee joint. Muscle weakness or an imbalance of the balance can promote a tearing of various ligaments of the joint or the mucous membrane folds.
In most cases, however, the mediopatellar plica is also affected. A rupture can be accompanied by pain, swelling of the plica and the entire joint. MRI images often show a thickening of the mucosal fold. Depending on the severity of the injury, surgery to remove the mucosal folds may be necessary.
MRI
Magnetic resonance imaging of the knee joint is very well suited for imaging soft tissue such as muscles and organs. This also makes it possible to detect the plica infrapatellaris. As a rule, it is presented as a very narrow line with little signal. Low-signal means that the structure appears darker in comparison to the surrounding tissue. Since it is often only visible when there is a simultaneous accumulation of fluid in the joint space (effusion), it is difficult to diagnose by MRI.
OP
The different mucous membrane folds can be differently pronounced in the knee. So it can occasionally happen that a wrinkle is thicker than normal. This can cause friction during movement, which can also lead to entrapment.
The consequence is often a painful inflammation that spreads to the entire knee joint and is often accompanied by swelling and effusion. Typically, the mediopatellar plica causes this plica syndrome. If conservative therapy is not sufficient, surgery is often necessary.
The operation is often performed under general anesthesia and keyhole technique in the context of a knee arthroscopy.Only small incisions are made, through which the necessary instruments with integrated camera are then advanced into the knee joint. This gives the physician a very good overview of the inflammatory processes in the joint. The mucosal folds as well as the inflammatory tissue are removed while protecting the joint cartilage.
With this very gentle method, the patient can return his knee to normal after one to four weeks. In most cases, the operation is very successful and has few complications. The typical complaints such as the feeling that the knee joint is blocked usually disappear completely afterwards. After four to six weeks, light sports activities can also be resumed.
