A 58-year-old woman presents to the emergency department with acute-onset severe groin pain and vomiting for 6 hours. On examination, she has a tender, irreducible lump below the inguinal ligament, medial to the femoral vessels. Her abdomen is distended with hyperactive bowel sounds. Plain abdominal X-ray shows small bowel obstruction. What is the most likely diagnosis?

Explanation

## Clinical Presentation **Key Point:** Femoral hernias present as a tender lump **below and medial to the femoral vessels**, distinguishing them from inguinal hernias which lie above the inguinal ligament. **High-Yield:** Femoral hernias account for only 3–5% of all groin hernias but have the **highest risk of strangulation (20–40%)** among all hernias. They are more common in women due to a wider pelvic outlet and larger femoral canal. ## Why This Patient Has Femoral Hernia Strangulation | Feature | Femoral Hernia | Inguinal Hernia | |---------|---|---| | **Location** | Below inguinal ligament, medial to femoral vessels | Above inguinal ligament | | **More common in** | Women | Men | | **Strangulation risk** | 20–40% | 10–15% | | **Typical presentation** | Acute obstruction/strangulation | Chronic bulge, then acute obstruction | | **Anatomical boundary** | Femoral ring (medial: lacunar ligament; lateral: femoral vein) | Hesselbach's triangle | **Clinical Pearl:** The femoral canal is bounded medially by the lacunar ligament (sharp edge) and laterally by the femoral vein. This rigid anatomy makes femoral hernias prone to compression and strangulation, especially when bowel herniates through the narrow femoral ring. ## Mechanism of Strangulation 1. Bowel herniates through the femoral ring (narrow, rigid opening). 2. The lacunar ligament (medial border) compresses the neck of the hernia. 3. Venous return is compromised → edema → arterial compromise. 4. Ischemia and necrosis develop rapidly (within 6–12 hours). **Warning:** Unlike inguinal hernias, femoral hernias often present acutely with strangulation rather than a chronic bulge. Many patients have no prior history of a palpable lump. ## Management **High-Yield:** All femoral hernias require **urgent surgical repair** due to high strangulation risk, even if asymptomatic. In this acute case with obstruction and strangulation signs, **emergency surgery** is indicated. **Mnemonic: FEMORAL hernia red flags** — **F**emale sex, **E**lderly, **M**edial to femoral vessels, **O**bstruction/strangulation, **R**igid boundaries, **A**cute presentation, **L**ow repair rate if delayed. [cite:Sabiston Textbook of Surgery Ch 44]