The pain in the tendon on the side of the knee may be caused by trauma, synovitis, degenerative joint disease of the knee, etc. The treatment mainly includes physical therapy, medication and surgery. 1. Trauma: due to strenuous exercise or exertion can cause ligament strain, meniscus injury, etc., the acute stage should be given rest, braking, ice and other treatments, oral non-steroidal drugs such as ibuprofen and other pain relief, serious injury can choose surgical treatment. 2. Synovitis: caused by trauma, infection, tuberculosis and other factors, oral non-steroidal drugs such as meloxicam tablets, ibuprofen, etc. to relieve pain, choose hot compresses, ultra-short-wave, infrared and other physical therapy to promote local blood circulation, promote the absorption of inflammation, daily attention to rest, avoiding exertion. 3. Knee degenerative joints: with age, the aging and wear of joint cartilage can lead to joint degeneration, should pay attention to rest, avoid walking and climbing for a long time, avoid weight-bearing, pay attention to the knee joints to keep warm, when the lesion is serious and affects the joints activities, you can choose surgical treatment. If the pain of the tendon on the side of the knee is not relieved, or is accompanied by other symptoms, the patient should go to the hospital in time, and give targeted treatment after clarifying the cause.