The patient: on April 22, 07 from the high can fall right foot can not stand walking, admission CT scan is: right tibial plateau medial part visible bone continuity interruption, visible linear bone translucent lines, its alignment is clear, sharp, right knee joint capsule visible uniform density shadow, the average CT value is 52.6Hu, the boundary is clear, so that the iliofemoral joint gap significantly widened, the rest did not see obvious abnormalities. Physician’s opinion: right tibial plateau fracture combined with blood accumulation in the joint cavity. x-radiographs were: orthopantomogram of the chest showed no significant abnormalities in the heart, lungs and diaphragm. The bone structure was intact and clear, and there were no obvious signs of fracture. The right knee frontal and lateral radiographs showed discontinuity of the bone edge of the right tibial medial condyle, disorganized bone trabeculae, and fair alignment of the broken ends. He was hospitalized in a plaster cast for nearly 3 months and was supported by crutches for a period of time after discharge. The joint moves freely, but he has been suffering from the following problems: the right joint hurts vaguely when he does not exercise at all, and he wakes up in the middle of the night with pain when he sleeps at night without a blanket (low temperature), and he needs to cover his right joint with sweat to reduce the pain; he feels pain when he puts weight on it (including his own weight), and the pain is sharp when he walks about 500 meters (the symptoms are worse when he walks up and down stairs and when he puts weight on it). Sometimes, when walking, the right knee joint rings with a “da” sound and the pain is so severe that it brings tears to my eyes, and I have to shake my right foot hard to relieve the pain. If I walk and exercise a little more despite the pain, my right knee will become stiff and difficult to lift, and my right joint will swell up a little. This had a great impact on normal work and life. On October 7, 2008, he went to a higher level hospital for examination and MRI. No small amount of fluid was found in the joint cavity, no abnormality was found in the meniscus, no abnormality was found in the ligaments and muscles, and the physician’s opinion: sequelae of old fracture. He was discharged from the hospital for 10 days with physical therapy, and no significant effect was seen. I can’t find the specific cause of the fracture, so I can’t treat it symptomatically. I would like to ask what could be the cause of this condition and how to treat it to be effective. Thank you! Doctor: Since there is sometimes a popping sound in the right knee when walking, you can consider knee arthroscopy, which is a minimally invasive technique that can diagnose and treat intra-articular diseases simultaneously.