Innominate bones

The innominate bones, also known as the hip bones or os coxae, are the fused bones of the pelvis either side of the sacrum. The bone comprises the ischium, pubis and ilium which are fused to each other in the acetabulum and are part of the appendicular skeleton.

The innominate bone contributes to two bilateral joints and one midline joint:

• sacroiliac joint
• hip joint
• pubic symphysis

See bony pelvis.