An elbow joint surgical treatment includes transmitting an ultrasonic vibration to a treating portion of an ultrasonic device to excise the treated object region of the synovial membrane, and bringing the treating portion of the ultrasonic device, used in excising the synovial membrane, to come in contact with an osteophyte positioned in one of a coronoid fossa of a humerus, an olecranon fossa of the humerus, a coronoid process of an ulna, and an olecranon. The surgical treatment includes transmitting an ultrasonic vibration to the treating portion in contact with the osteophyte to remove the osteophyte.