A-Extra-articular
21-A-1 #ulna,radius intact
21-A-2 #radius,ulna intact
21-A-3 both bones

B-Articular

21-B-1#ulna,radius intact
21-B-2 #radius, ulna intact
21-B-3 one intra-artic + other extra-articular

C-Articular # of both bones

21-C-1 simple articular
21-C-2 one simple + one comminuted
21-C-3 both comminuted