Sacral ribs.
D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D010384:Pelvic Bones / Q000293:injuries; D011859:Radiography; D012272:Ribs / Q000002:abnormalities* / Q000000981:diagnostic imaging; D012447:Sacrum / Q000002:abnormalities* / Q000000981:diagnostic imaging