A 45-year-old woman has a tender reducible bulge in the left lower abdomen, just above the inguinal ligament and lateral to the rectus abdominis. CT shows herniation through a defect in the linea semilunaris below the umbilicus. The defect occurs where:

• A The external oblique aponeurosis splits to form the superficial ring
• B The posterior rectus sheath ends at the arcuate line ✓
• C The linea alba widens at the umbilicus
• D The inguinal ligament attaches to the ASIS

Explanation

A Spigelian hernia passes through the spigelian fascia along the linea semilunaris, classically at the level of the arcuate line, where the posterior rectus sheath terminates and the abdominal wall loses its strongest support. Below the arcuate line only transversalis fascia backs the muscles, so the defect occurs there. These hernias are often interparietal, lie between the oblique layers, and carry a higher risk of strangulation because of a narrow rigid neck.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.