The painful protrusion of the ankle joint is mainly seen in the following cases. 1. osteoarthritis of the ankle joint, due to long-term chronic strain, degeneration or injury, causing bone degeneration, hyperplasia and narrowing of the joint space of the ankle joint, resulting in protrusion of the ankle joint and painful symptoms. 2. can also be seen in trauma, acute violent trauma can also lead to ankle joint It can be seen in bone tumors, which are relatively rare, but can often be seen in bone cysts, bone fibrous dysplasia or metastatic tumors, which can also cause local protrusion and pain. 4. Some metabolic diseases or underlying diseases can also cause protrusion and swelling of the ankle joint, such as gouty arthritis.