If the patient has pain in the knee fossa, the causes are as follows: a. Ligament and joint capsule injury: injury to the ligaments and joint capsule in the popliteal fossa area, the patient is prone to have pain in the knee fossa. Second, popliteal cysts: popliteal cysts can lead to pain in the knee fossa area, and cystic swelling can be palpable in the knee fossa area. Knee degeneration and osteoarthritis: Knee degeneration and osteoarthritis may also cause pain in the knee fossa. Meniscal posterior horn injury: Meniscal posterior horn injury inside the knee joint can also easily stimulate pain in the knee socket. When a patient has pain in the knee socket, it is important to consult a doctor to see what is causing it and treat the cause to promote pain reduction and recovery. It is important to avoid standing for long periods of time, squatting, running and jumping when pain is evident to avoid aggravating the pain. In the event of pain, non-steroidal anti-inflammatory drugs can be applied temporarily to reduce the pain.