Short greater sciatic notch HP:0008815 UMLS:C1866689 Shortened sacroiliac notches HP:0003185 Small sacroiliac notch Short sacroiliac notch The sacroiliac joint in the bony pelvis connects the sacrum and the ilium of the pelvis, which are joined by strong ligaments. The notch is located directly superior to the joint. This term refers to a reduction in the height of the notch. Abnormal greater sciatic notch morphology