Pelves

Pelves is the plural form of pelvis, the basin-shaped bony structure at the base of the spine. It consists of two hip bones (ossa coxae), the sacrum, and the coccyx, forming the bony pelvis. Each hip bone is composed of three fused parts: the ilium, ischium, and pubis. The two pelvic bones meet at the pubic symphysis anteriorly and with the sacrum at the sacroiliac joints posteriorly. The pelvic space is divided by the pelvic brim into the greater (false) pelvis and the lesser (true) pelvis, with the latter enclosing the pelvic cavity and its organs.

The pelvis functions to support the upper body and transmit weight to the lower limbs. It provides attachment points for muscles of the abdomen, back, and thighs, and it protects pelvic organs, including the urinary bladder, reproductive organs, and portions of the digestive tract. The pelvic cavity houses the pelvic viscera, and in females it relates to pregnancy and childbirth. The perineum lies inferior to the pelvic outlet.

Sex differences in pelves are clinically significant. The female pelvis is generally broader and shallower, with a wider true pelvis, pelvic inlet, and pelvic outlet to aid childbirth, and a wider subpubic angle. The male pelvis tends to be taller and narrower, with a more acute subpubic angle and a heart-shaped pelvic inlet. The sacrum and coccyx also show sex-related variation.

Clinical relevance includes pelvic injuries and fractures that can disrupt the pelvic ring and cause substantial bleeding. Pelvic morphology influences obstetric, urologic, and gynecologic considerations, and imaging modalities such as X-ray, CT, and MRI are used to assess the bones and surrounding tissues. Individual pelves vary in size and shape as part of normal human variation.