Ilioinguinal approach to the acetabulum

Introduction

Indications

• Exposure of the inner surface of the pelvis from the sacroiliac joint to the pubic symphysis.
• Exposure of the anterior and medial surfaces of the acetabulum, which exposes anterior column fractures.

Disadvantages

• Difficult approach as the dissection involves isolating and mobilizing the femoral vessels and nerve, as well as the spermatic cord in the male and the round ligaments in the female.
• May need to operate in conjunction with a general surgeon.

Position of patient

• Supine with the greater trochanter at the edge of table.
• Insert catheter to empty bladder as it will obscure vision.

Landmarks and incision

Landmarks

• Palpate the anterior superior iliac spine.
• Palpate the pubic tubercle by moving your thumbs medially along the inguinal creases and obliquely downward.

Incision

• Make a curved incision from 5cm above ASIS to 1 cm above the pubic tubercle to end in the midline.

Internervous plane

No true internervous plane.

Superficial dissection

• Dissect through subcutaneous fat to expose the aponeuroses of the external oblique muscle.
• Divide the aponeurosis of the external oblique muscle in the line of its fibers from the superficial inguinal ring to the anterior superior iliac spine (will often have to sacrifice lateral cutaneous nerve of the thigh).
• Isolate the spermatic cord in the male and the round ligament in the female.
• Dissect medially, dividing the anterior part of the rectus sheath to expose the underlying rectus abdominis muscle.
• Strip the iliacus from the inside wing of the ileum (start with sharp dissection, but once inside the pelvis, use blunt dissection).

Deep dissection

• Divide the rectus abdominal muscle 1 cm proximal to its insertion into the symphysis pubis.
• Develop a plane by bluntly dissecting with the fingers between the symphysis pubis and the bladder (Cave of Retzius).
• Cut though the posterior wall of the inguinal canal (internal oblique and transversus abdominus).
• The inferior epigastric artery crosses the posterior wall of the canal at the medial edge of the deep inguinal ring and must be ligated at that point.
• Visualize the peritoneum covered with extraperitoneal fat and push upward to expose the femoral vessels, nerve, and ileopsoas tendon.
• Isolate the femoral artery and vein in the femoral sheath with a rubber sling.
• Isolate the ileopsoas tendon and femoral nerve lying on top of it with another rubber sling.
• Retract these structures either medially or laterally to gain access to the underlying medial surface of the acetabulum and superior pubic.

Dangers

Femoral nerve

• Beneath the inguinal canal lying on the iliopsoas muscle; take care to avoid vigorous retraction, as stretching the nerve will result in a paralysis of the quadriceps muscle.

Femoral vessels

• Beneath the inguinal ligament, surrounded by the femoral sheath; protect the vessels by leaving in the femoral sheath.
• Care should be taken on retraction of these structures to minimize the risk of deep vein thrombosis.

Lateral cutaneous nerve of thigh

• Usually have to sacrifice leaving numbness on the outer side of the thigh.

Inferior epigastic artery

• Crosses the operative field passing medial to the deep inguinal ring and must be ligated.

Spermatic cord

• Contains the vas deferens and testicular artery; must be treated gently during the approach and the closure to avoid ischemic damage to the testicle.

Bladder

• Use a urinary catheter to empty the urinary bladder.
• Mobilized off the back of the symphysis pubis.
• Fractures of the lower half of the anterior column may have caused bladder damage and adhesions.

How to enlarge the approach

• Proximally, extend the skin incision posteriorly, following the iliac crest. Using sharp dissection, cut down onto the bone. Then strip off the origins of the iliacus from the inside of the ilium using blunt dissection. Retract the iliacus medially to expose the inner wall of the ilium and the sacroiliac joint.
• Distally, the approach cannot be extended.

Figures