The hemorrhagic crescent sign of acute synovial rupture.
D001172:Arthritis, Rheumatoid / Q000150:complications; D003937:Diagnosis, Differential; D005260:Female; D006470:Hemorrhage; D006801:Humans; D008297:Male; D008875:Middle Aged; D012422:Rupture, Spontaneous; D013581:Synovial Cyst / Q000175:diagnosis* / Q000209:etiology; D013924:Thrombophlebitis / Q000175:diagnosis