Anatomy of the pelvis

The term pelvis as used in this article denotes the irregular but complete bony ring made up of the right and left hip bones (ossa coxae) anteriorly and at the sides, and by the sacrococcygeal part of the vertebral column, posteriorly. It is massively constructed. The two hip bones are firmly united anteriorly at the pubic symphysis, and together constitute the pelvic girdle. The pelvic girdle articulates with the femoral heads and thereby connects the vertebral column (axial skeleton) to the two femora (appendicular skeleton). The main functions of the pelvic girdle are to transmit weight from the upper body to the lower limbs during locomotion and while standing, and to support the weight of the upper body when seated or stationary. Another important function of the bony pelvis is to provide attachment for the powerful muscles (e.g. gluteal muscles) that act on the lower limb and those muscles that support the abdominal wall. The bony pelvis also provides ample protection to the many delicate viscera, vessels and nerves that lie within the pelvic cavity. Fractures of the bony pelvis are relatively uncommon injuries. Most pelvic fractures are caused by high-energy traumatic events such as forceful collisions in road traffic accidents or major crush injuries as may be caused by falling masonry. Successful orthopaedic management of disruptions of the bony pelvis and management of associated injuries to intrapelvic viscera require a sound appreciation of the anatomy of the pelvic ring and pelvic cavity.