Perennial knee pain includes the following reasons: First, osteoarthritis of the knee, knee joint long-term excessive weight bearing and wear and tear, resulting in degenerative changes in the knee joint, manifested as joint pain, activity restrictions, joint flexion and extension activities can be smelled friction sound or friction sensation, the patient is usually not able to walk long distances, the condition of the advanced stage of the knee can be inversion deformity or valgus deformity and knee flexion deformity, night and rest also have pain symptoms. At night and when resting, the knee joint also has pain symptoms. Second, patellofemoral arthropathy, the patella running track is not correct and repeatedly going up and down the stairs, can lead to degenerative changes in the patellofemoral joint, the clinical manifestation of joint pain when squatting, walking on a flat road with less pain or no pain, when going up and down the stairs the pain symptoms worsened, the pressure on the patellar test and the patellar grinding test is positive.