Thigh fracture is also called femoral stem fracture, usually 3~4 weeks can be knee exercise. 1. After the fracture of the femoral stem, you need to take a strict bed rest in the early stage, because although the fracture has been internally fixed after the surgery, the fracture has been well, if you exercise too early, it will cause the fracture not to heal or the internal fixation breaks. 2. Generally 3~4 weeks, you can exercise the knee flexion and extension activities, active quadriceps or hamstring muscle contraction exercise, the main purpose of exercise is to prevent muscle atrophy, to prevent the formation of deep veins in the lower limbs. After a period of exercise, generally in a month and a half or so can help crutches, appropriate walking on the ground, appropriate exercise will help the healing of the fracture. 3. Some patients with serious fracture of the femoral stem, poor physical condition and slow recovery may need longer time to do knee exercises after surgery. Generally 4~6 days after surgery, quadriceps muscle contraction exercise is needed, and then knee rehabilitation training is gradually carried out. Patients after femur fracture surgery need to strengthen the rehabilitation training and daily life management, which is conducive to the improvement of the disease.