The common reasons for the formation of osteoarthritis of the knee joint are as follows: 1, osteoarthritic degeneration, with age, physical weakness, coupled with the loss of bone mass, can not be timely supplementation will lead to osteoarthritic degeneration, most commonly seen in the elderly. 2, chronic injury to the knee joint, repeated labor, walking or standing, the muscle repeatedly pulling the bone, resulting in chronic injury to the attachment points of the musculoskeletal, repeated inflammation ultimately caused by calcium salt deposition to form calcification, the formation of labral changes. Calcium salt deposition to form calcification, the formation of lip-like changes.3, knee joint fracture, strenuous exercise or trauma caused by osteoarthritic fracture and avulsion fracture, local hematoma, inflammation, parcel mechanization, the formation of hyperplastic bone, or trauma caused by periosteum peeling, resulting in heterotopic ossification.