Synovial membrane is located inside the joint capsule, so it is present in all joints. The synovium is located where the joint capsule meets the bone, at the border of the joint cavity. The synovial membrane is often not particularly visible here. The synovial membrane’s main function is to secrete synovial fluid, which is effective in relieving friction and vibration within the joint. In some pathological cases, the synovial membrane may become hyperplastic due to cold, trauma, inflammation, infection, etc., which may cause damage to the interior of the joint. For example, it may cause some soft tissue obstruction or damage to the cartilage and subchondral bone inside the joint. This may result in significant joint pain, swelling, joint effusion, and limited joint motion. Treatment of this condition requires the use of nonsteroidal medications to suppress synovial inflammation and hyperplasia. In some cases of particularly severe synovial hyperplasia, surgical debridement is required.