Fractures of the femoral stem do not show obvious internal and external rotation, but may be displaced differently depending on the location of the fracture and the pulling of the muscles. 1. Upper 1/3 femur fracture: the proximal end of the fracture is displaced in the direction of forward and outward rotation by the pull of iliopsoas and gluteus muscles, etc. The distal end of the fracture is displaced inwardly and posteriorly by the pull of the adductor muscles and is displaced proximally by the quadriceps muscle. 2. Fracture of the middle 1/3 of the femur: the pull of the adductor muscle group makes the fracture site angle outward. 3. Lower 1/3 femur fracture: the distal end of the fracture is displaced backward by the traction of gastrocnemius muscle, which may injure the popliteal vessels and popliteal nerves posteriorly; the proximal end of the fracture is displaced forward by the traction of the muscle; the distal and proximal ends of the fracture will show a shortening deformity. Unlike femoral stem fracture, femoral neck fracture and intertrochanteric fracture will show obvious external rotation deformity, and posterior dislocation of the hip joint will show internal rotation deformity.