What is the most common cause of femoral hernia?

Explanation

## Etiology of Femoral Hernia **Key Point:** Femoral hernias result from increased intra-abdominal pressure acting on a pre-existing anatomical weakness — the femoral canal. ### Anatomical Basis The femoral canal is the medial compartment of the femoral sheath, bounded by: - Laterally: femoral artery - Medially: lacunar ligament (medial margin of inguinal ligament) - Anteriorly: inguinal ligament - Posteriorly: pectineal ligament This space is naturally narrow and represents a potential weak point. ### Causative Factors | Factor | Role | Frequency | |--------|------|----------| | **Increased IAP** | Primary driver; straining, coughing, constipation, heavy lifting | Most common | | Anatomical predisposition | Laxity of femoral sheath, wide femoral canal | Predisposing | | Obesity | Increases intra-abdominal pressure | Contributing | | Pregnancy | Increased IAP + hormonal laxity | Contributing | | Chronic respiratory disease | Chronic straining from cough | Contributing | | Congenital weakness | Rare; not the primary cause | Rare | | Trauma | Does not cause femoral hernia | Incorrect | | Femoral artery puncture | Complication risk, not cause | Incorrect | **High-Yield:** Femoral hernias are **acquired** lesions, not congenital. They develop when increased intra-abdominal pressure overwhelms the inherent weakness of the femoral canal. This is why they are more common in women (wider pelvis, more lax ligaments) and increase with age. ### Clinical Pearl Femoral hernias account for only 3–5% of all groin hernias but have a **40–45% incidence of incarceration** — the highest among all groin hernias. Early recognition and repair are critical because the narrow femoral ring makes strangulation likely. **Mnemonic: FERN** — **F**emoral canal, **E**nlarged by pressure, **R**esults in hernia, **N**arrowing of ring (high strangulation risk).