Bones of the Pelvis

Question 1

What are the three parts of the hip bone?

What occurs at the point where they fuse?

Answer 1

Ilium (superior large aspect)
Ischium(posterior medium aspect)
Pubis (medial border)

Triadriate cartilage holds them together to form the acetabulum

Question 2

What are the three main articulations of the hip bones?

Answer 2

Sacroiliac joint-articulation with the sacrum
Pubic symphysis-articulation between left and right hip bones
Hip joint- articulation with the head of femur

Question 3

How do the hip bones sit in living human being

Answer 3

Anteflexed- tipped forward with pubic bones angling downwards, not sitting perpendicular to the floor.

Question 4

What is the ala (wing) of the ilium

What are it’s two surfaces

Answer 4

The superior aspect of the ilium, above the body of the ilium which articulates to form the acetabulum

Inner surface- concave medio-anterior side of the ala, produces iliac fossa. Origin of the iliacus muscle

External surface- convex latero-posterior side of the ilium. Provides attatchemnt of the gluteal muscles

Question 5

What is the iliac crest?

What is the greater sciatic notch?

Answer 5

Thickening of the superior margin of the iliac fossa. It extends form the ASIS to the PSIS.

Indentation on the posterior aspect of the ilium

Question 6

What are the three components of the pubis?

Answer 6

Pubic body- medial, articulates with opposite pubic body forming pubic symphysis. Superior aspect is marked by a round thickening pubic tubercle

Superior pubic ramus- extends laterally to form part of the acetabulum

Interior pubic ramus- projects towards ischium

Question 7

What is obturator foramen?

Answer 7

A large hole in the hips formed by the superior and inferior pubic ramus as well as the ischium. The obturator nerve, artery and vein pass through here.

Question 8

What are the three components of the ischium?

Answer 8

Ischial body

Superior ischial ramus- extends upwards to form acetabulum, also forms ischial spine on the posterior aspect

Inferior ischial ramus- forms ischial tuberosites, the bit of the body that takes body weight when sitting

Question 9

What are the two important ligaments of the ischium?

Answer 9

Sacrospinous ligament- runs from ischial spine to sacrum, creates greater sciatic nerve foramen.

Sacrotuberous ligament- runs from the sacrificial, to the ischial tuberosity forming the lesser sciatic foramen.