Can occur in either superior lumbar triangle of Grynfeltt-Lesshaft or inferior lumbar triangle of Petit
– Superior lumbar triangle of Grynfeltt-Lesshaft defined by 12th rib superiorly, superior border of internal oblique inferiorly, and erector spinae medially
– Inferior lumbar triangle of Petit defined by latissimus dorsi muscle medially, iliac crest inferiorly, and free border of external oblique muscle laterally
PATHOLOGY
• 80% of lumbar hernias are acquired
Can be spontaneous (especially in older patients and patients with excessive weight loss) or secondary to trauma, infection, or previous surgery in flank