American Board of Surgical Assistants (ABSA) Orthopedic Practice Test

The hip bone is formed by the fusion of which three bones?

1. Ilium, Ischium, Pubis

2. Ilium, Sacrum, Coccyx

3. Femur, Tibia, Fibula

4. Pelvis, Lumbar, Sacrum

The correct answer is: Ilium, Ischium, Pubis

The hip bone, also known as the acetabulum or os coxae, is indeed formed by the fusion of three specific bones: the ilium, ischium, and pubis. These bones unite to create a robust structure that supports weight during both standing and locomotion. The ilium is the largest of the three, forming the upper part of the hip bone and contributing to the pelvic brim. The ischium forms the lower and back part of the hip bone, providing structural integrity and support when sitting. The pubis is located at the front and contributes to the formation of the pubic symphysis, which is the joint between the left and right pubic bones. This fusion is crucial for the overall stability and function of the pelvis, enabling it to support the spine and connect the legs to the trunk. The hip bone's anatomical design allows for a wide range of motion in the hip joint while accommodating the forces exerted by activities such as walking and running. Other options include bones or structures that do not contribute to the formation of the hip bone. For instance, the sacrum and coccyx are part of the vertebral column and are not involved in forming the hip bone. The femur, tib