Summary
A plica is a fold of skin that exists in some organ systems and which gradually recedes over time. In the area of the knee a so-called mediopatellar plica is sometimes found. It forms on the inner side of the knee joint and then moves in the middle.
If this skin fold has not completely receded, it can cause corresponding complaints. In chronic cases, there is increasing friction between the plica and the cartilage, which stretches the inside of the joint. The friction can cause irritation and inflammation, but also thinning of the cartilage.
As soon as the cartilage has worn away, it clears the way to the bone. If the plica starts to rub against it, this can lead to severe pain. The chronic conditions are often triggered by overloading in the knee joint, but also by incorrect loading.
Acute complaints can always be triggered by the plica becoming trapped in the joint space. This leads to severe symptoms and makes immediate treatment necessary. The diagnosis of a plica syndrome is not easy and is often made as an exclusion diagnosis when no other cause for the complaints has been found.
An MRI examination is often used as an imaging technique. Acute constrictions can be seen here but less the friction of the plica against the cartilage when the cartilage is still complete and undamaged. Knee arthroscopy is particularly useful here, since the patient’s knee can also be moved during the examination and it can be seen whether the plica is trapped in the joint space.
Conservative treatment options include sparing the knee as well as medication to reduce inflammation and pain using ibuprofen or diclofenac. If these treatments are not sufficient, or if the condition is acute, the plica should be surgically removed.
