Anatomy of the Hip Bone

Overview

• The hip bone is a large, irregular flat bone.
• Located in the pelvic region.
• Comprised of two hip bones, sacrum, and coccyx which form the bony pelvis.
• Has a lateral cavity known as the acetabulum.
• Articulates with the femur to form the hip joint.

Composition

• Consists of three parts: ilium, pubis, ischium.
• Initially separated by Y-shaped cartilage, which ossifies later.

Ilium

• Flat, expanded part above the acetabular cavity.
• Parts:
  • Ends: Upper (Iliac crest) and Lower
  • Borders: Anterior, Posterior, Medial
  • Surfaces: Gluteal, Iliac fossa, Pelvic

Upper End (Iliac Crest)

• Elongated and expanded.
• Highest point between the third and fourth lumbar vertebrae.

Anterior Border

• Extends from the anterior superior iliac spine to the acetabulum.
• Notable feature: small notch for lateral cutaneous nerve.

Posterior Border

• Extends from posterior superior iliac spine.

Gluteal Surface

• Outer surface, convex anteriorly and concave posteriorly.
• Bounded by the iliac crest above and acetabulum below.

Iliac Fossa

• Located between the anterior and medial borders.
• Contains the nutrient foramen.

Sacral Pelvic Surface

• Divided into sacral and pelvic parts.

Pubis

• Forms anterior part of the hip bone.
• Consists of body, superior ramus, inferior ramus.

Body

• Connects superior and inferior ramus.
• Contains pubic crest and pubic tubercle.

Superior Ramus

• Triangular in cross-section.
• Has obturator crest and pectineal line.

Ischium

• Forms posterior and lower parts of the hip bone.
• Parts: Body and Ramus.

Body

• Consists of two ends, three surfaces, three borders.
• Ischial tuberosity is divided into upper and lower areas.

Ramus

• Extends upwards, forwards, and medially from the body.

Acetabular Cavity

• Deep hollow facing laterally.
• Formed by contributions from all three hip bones.
• Contains acetabular notch and fossa.

Obturator Foramen

• Large opening between the pubis and ischium.
• Covered by obturator membrane in the living.

Ossification

• Ossifies from three primary centers and five secondary centers.
• Primary centers appear at different stages of intrauterine life.
• Secondary centers appear at puberty and fuse by age 25.