Halberd-shaped pelvis An anomalous radiographic appearance of the developing pelvis, in which the greater ischiadic noth (incisura ischiadica major) is shallow and the pelvis takes on the appearance said to resemble a halberd (a weapon especially of the 15th and 16th centuries consisting typically of a battle-ax and pike mounted on a handle). HP:0002826 Halberd-shaped pelvis bone UMLS:C3277119 Abnormal pelvis bone morphology