The length of the femur varies from person to person and is about 1/4 of one’s height. The femur is the longest and strongest long bone in the human body, and can be divided into the femoral body and the two ends of the femur. The upper end has the femoral head facing inward and upward, and the thinner part of the femoral head slightly below it is called the neck of the femur, and the part where the neck of the femur connects with the body of the femur is called the femoral inter-rotary area, which is susceptible to fracture in the elderly patients. The distal femur has medial and lateral condyles, which form the knee joint with the tibial plateau respectively. The femoral trochanter is formed anteriorly between the medial and lateral condyles, and forms the patellofemoral joint with the articular surface of the patella, which is prone to localized injuries when going up and down the stairs, and forms the patellofemoral joint degeneration, leading to patellofemoral osteoarthritis, and the patient may have symptoms such as pain and limited activity. The femoral stem is prone to fracture under strenuous violence, resulting in displacement, which usually requires surgical incision and reduction and internal fixation treatment for recovery.