Hip surgery tools covered in blood. These are used to remove bone from a patient's diseased hip. Bone is removed from both the femur (upper leg bone) and the pelvis parts of the hip joint, allowing an artificial hip joint to be inserted. The tool at centre, which has the most blood on it, is called a reamer. This tool is used to gradually enlarge a hole and smooth edges, for instance when gouging out a hole in the femur (upper leg bone) for the implantation of the pin part of an artificial hip.