Broken thigh bone. Coloured X-ray image showing a fracture of a child's upper femur (thigh bone). This type of fracture usually occurs when the femur is subjected to extreme force, such as in a road traffic accident. The bone ends in this case are considerably displaced which typically causes severe pain, tenderness and swelling. In most cases the fracture is repaired by a surgical operation performed under general anaesthesia. The bone ends are realigned and fastened together with a long metal pin. After realignment the leg is supported with a splint and put in traction to hold the bone in a correct position for healing.