Anterior Superior Iliac Spine

Anterior superior iliac spine is a bony projection represents the anterior edge of iliac crest, which connects with the lateral point of the inguinal ligament.

The subcutaneous anterior superior iliac spine starts anteriorly and at the anterior end of the iliac crest it can be easily palpated. The iliac crest spreads out posteriorly from the anterior superior iliac spine in order to terminate at the posterior superior iliac spine that is located just superior to the buttocks, directly deep towards the dimples.

Relations with iliac crest

• The iliac crest may be subdivided into
  • A ventral section made up of the anterior two thirds of the crest.
  • A dorsal section made up of the posterior one third.
• The ventral section has a wide middle area confined by inner and outer rims.
• The dorsal section of the iliac crest has medial and lateral surfaces separated by a ridge.
• The anterior boundary of the ilium spreads out from the anterior superior iliac spine towards the acetabulum. Its lowest pan presents a prominence called the anterior inferior iliac spine.
• Most prominent is the outer lip of the iliac crest around 5cm posterior towards the anterior superior iliac spine. This projection is known as the tubercle of the iliac crest.

Anterior Superior Iliac Spine

Clinical Significance

Surgical Technique – Lateral Femoral Cutaneous Nerve Block

Traditional

• The patient is positioned in prostrate stance.
• A skin mark is placed 2 to 3 cm inferior and 2 to 3 cm medial towards it, after examination of the anterior superior iliac spine.
• A 3 to 4-cm needle with syringe attached is afterwards inserted through the mark and perpendicular to the skin surface.
• Afterwards, the firm fascia lata is sensed and while the needle passes through, a swift release is done.
• Then superiorly, as the needle is moved, 10 mL of a local anesthetic solution is released fanwise and inferiorly, releasing solution in the fascia both above and below, while mostly it should be released below.

Alternate

• An alternate technique is to point the needle via the skin mark in a little lateral and to strike the iliac bone cephalad direction, just medially and below towards the anterior superior iliac spine.
• The deposition of 10 ml of local anesthetic solution in a medial fanwise way will also accomplish adequate obstruction of the nerve because the nerve emerges here.

Anterior Superior Iliac Spine Fracture

• Fractures of the anterior superior iliac spine constantly arise as an acute initial injury, but chronic stress fractures, can be influencing elements which represent as iliac apophysitis.
• At the time of the initial presentation stress injuries are often missed, because these injuries are frequently self-diagnosed as distortions or muscle lesions, a doctor is not even consulted by many patients.
• The cause is an instant and forceful tug towards the anterior superior iliac spine on the sartorial as well as tensor fascia lata muscles.
• These lesions can be mistaken for a fracture of the anterior inferior iliac spine due to of this dislocation.