Halberd pelvis

A halberd pelvis refers to a pathognomonic appearance of the pelvis seen in metatropic dysplasia, a rare form of spondyloepimetaphyseal dysplasia.

• hypoplastic ilia with narrow sacrosciatic notches
• horizontal acetabular roofs with small associated notches superior to their lateral borders
• prominent flaring of crescentic iliac wings

History and etymology

The appearance is thought to resemble a halberd, a two-handed pole weapon that was in popular use in central Europe from the 14th to 16th centuries. The halberd comprises an almost 2 meter long shaft, ending in a lengthened spiked head. Before the spike is the blade of an ax, with an opposed hook-like pick. It remains the ceremonial weapon of the Swiss Guard in the Vatican, the pope's bodyguard .