Definition
The suprapatellar plica is a bulging of the knee capsule mucosa in front of the kneecap. There are various plicae in the area of the knee joint, which are named differently depending on their location in relation to the patella. In addition to the suprapatellar plica, a distinction can be made between infrapatellar, mediopatellar and lateropatellar plica. The plicae are not present in all humans and represent a relic from the human embryonic period. The plica suprapatellaris is the least common in humans.
Anatomy
Like all real joints in the human body, the knee joint also has a capsule. Due to variations in the development of the capsule, some people experience the capsule bulging out in different directions. These sacculations are called plicae.
The plica is named according to its position in relation to the kneecap. According to this principle, the suprapatellar plica is located in front of/above the patella, the infrapatellar plica is located below the patella, the mediopatellar plica is located on the inside of the patella and the lateropatellar plica is located on the outside of the patella. Depending on the extent and location of the plicae, patients may experience problems in the knee joint.
The mediopatellar plica is most often symptomatic. Patients complain of a feeling of pressure and pain when moving the knee. Sometimes the plica is even palpable from the outside. The suprapatellar plica is rather rare and affects only a minority of patients. The suprapatellar plica can also be palpable from the outside.
Function
The suprapatellar plica represents a bulging of the joint capsule in the area of the knee joint. As an embryonic relic, it has no direct function. However, the joint capsule itself is essential for the function of the knee joint.
On the one hand, it acts as a kind of protective mantle against external influences on the knee joint. Furthermore, the capsule forms the so-called synovial fluid, which is important for smooth movement. In addition to the ligaments and muscles of the knee, the joint capsule is an important factor in the stability of the knee joint. Without a joint capsule, the knee would not be functional.
