Pelvic Bone Anatomy Quiz

The Pelvis

• The cle is a bony projection situated lateral to the pubic crest.

The Pubis

• The pubis consists of the body, superior pubic ramus, and inferior pubic ramus.
• The superior pubic ramus extends laterally from the body and joins the ilium to form part of the acetabulum.
• The inferior pubic ramus meets with the ischial ramus to form the ischiopubic ramus.
• The obturator foramen is formed by the superior pubic ramus and ischiopubic ramus.
• The obturator nerve, artery, and vein pass through the obturator foramen to reach the lower limb.

The Ischium

• The ischium is an L-shaped bone that forms the postero-inferior part of the hip bone.
• The ischium consists of the body, ischial spine, lesser sciatic notch, ischial tuberosity, and ischial ramus.
• The body of the ischium is the upper thick part.
• The ischial spine projects from the posterior border of the body of the ischium and intervenes between the greater and lesser sciatic notches.
• The ischial tuberosity is the thick postero-inferior aspect of the bone.
• The ischial ramus combines with the inferior pubic ramus to form the ischiopubic ramus, which encloses the lower part of the obturator foramen.

The Sacrotuberous and Sacrospinous Ligaments

• The sacrospinous ligament runs from the ischial spine to the sacrum.
• The sacrotuberous ligament runs from the sacrum to the ischial tuberosity.
• These two ligaments convert the greater and lesser sciatic notches into foramina (greater and lesser sciatic foramina).

The Ilium

• The iliac crest is situated at the superior aspect of the ilium.
• The anterior superior iliac spine (ASIS) is situated at the anterior end of the iliac crest.
• The anterior inferior iliac spine (AIIS) is a rounded prominence situated below the ASIS.
• The posterior superior iliac spine (PSIS) is situated at the posterior end of the iliac crest.
• The posterior inferior iliac spine (PIIS) is located below the posterior superior iliac spine.
• The iliac tubercle lies about 5 cm behind the anterior superior spine.
• The greater sciatic notch is an indentation on the posterior aspect of the body of the ilium, above and behind the acetabulum.

The Sacroiliac Joint

• The sacroiliac joint is a synovial plane joint.
• The articular surfaces of the sacroiliac joint are the auricular surface of the ilium and the auricular surface of the sacrum.
• The ligaments of the sacroiliac joint are the anterior sacroiliac ligament, posterior sacroiliac ligament, sacrotuberous ligament, and sacrospinous ligament.
• The sacroiliac joint is innervated by the S1-S2 spinal nerves, superior gluteal nerve, obturator nerve, and lumbosacral trunk.
• The sacroiliac joint allows for slight gliding and rotatory movements.