Arcuate Line Aponeurosis

linea arcuata (aponeurosis)

The arcuate line (linea semicircularis of Douglas) is the curved tendinous border marking the lower limit of the posterior rectus sheath, approximately one-third of the way between the umbilicus and pubis. Below the arcuate line the aponeuroses of all three abdominal muscles pass anterior to the rectus, leaving the posterior rectus sheath absent and the rectus covered only by transversalis fascia posteriorly.

Region: Abdomen

Clinical Relevance

Clinical Notes

The arcuate line is a key anatomical landmark in laparoscopic hernia repair where the transition from posterior sheath to transversalis fascia marks the inferior limit of safe fascial dissection. Arcuate line hernias and weaknesses inferior to the line are repaired differently from supra-arcuate defects. The inferior epigastric vessels emerge from the posterior to the anterior rectus plane at the arcuate line level.

Pathology

Common Injuries & Conditions

Arcuate Line Hernia

Abdominal wall herniation at the arcuate line where the posterior rectus sheath is absent, producing a palpable epigastric mass at the lower rectus border managed by laparoscopic or open fascial repair.