This is an important variant that we as radiologists have to take into consideration. The ischiopubic synchondrosis (IPS) is the junction between the inferior ischial and pubic rami and is principally composed of hyaline cartilage. It is a temporal joint occurring in childhood prior to fusion of the ischium and pubic bones. With skeletal maturation, like all synchondroses, it becomes thinner and then obliterates, either due to bony union or synostosis.