What is located on either side of the midline complex of the pelvic girdle?

The os coxae, commonly referred to as the hip bones, are located on either side of the midline complex of the pelvic girdle. Each os coxae consists of three fused bones: the ilium, ischium, and pubis. Together, they form the left and right sides of the pelvic structure, providing support for the lower limbs and assisting in functions such as walking and bearing weight.

In the context of human anatomy, the pelvic girdle is defined by the ilium, which is the broad, upper part of the os coxae, and it connects the lower body to the axial skeleton. The midline complex refers to structures that are centrally oriented in the body, and the os coxae flank this midline, thus firmly anchoring themselves to the sacrum at the back, contributing to the stability of the entire pelvic region.

The other options do not fit this anatomical description: the femur is the thigh bone, located further down the leg, the scapula is associated with the upper body and shoulders, and the patella is the kneecap, located in front of the knee joint. Therefore, the os coxae are the only pair of bones positioned symmetrically on either side