Femoral Hernia
Summary
Femoral hernia is protrusion of abdominal contents through the femoral canal, located below and lateral to the pubic tubercle. It is the second most common groin hernia (5-10%) but has the highest strangulation risk of all external hernias (40% present as emergencies). The narrow, rigid femoral ring makes incarceration and strangulation common. Femoral hernias are more common in women (3:1 F:M) due to wider pelves. All femoral hernias should be repaired surgically, even if asymptomatic, because of the high strangulation risk.
Key Facts
- Anatomy: Below and lateral to pubic tubercle (differs from inguinal)
- Demographics: F:M = 3:1 (wide pelvis)
- Strangulation Risk: 40% (highest of external hernias)
- Classic Finding: Small, non-reducible lump below inguinal ligament
- Management: ALWAYS surgical (elective or emergency) - never watchful waiting
- Emergency Rate: 40% present as surgical emergencies
Clinical Pearls
"Below and Lateral = Femoral": The pubic tubercle is your landmark. Inguinal hernias are above and medial; femoral are below and lateral.
"All Femoral Hernias Need Surgery": Unlike inguinal hernias, there is NO role for watchful waiting. The strangulation risk is too high.
"Strangulated Until Proven Otherwise": If a femoral hernia is tender, irreducible, or associated with vomiting - assume strangulation and prepare for urgent surgery.
"Richter's Hernia is Sneaky": A Richter's hernia (only part of bowel wall) can strangulate without causing complete obstruction. Maintain high suspicion.
Incidence
- 5-10% of all groin hernias
- Much less common than inguinal (90%)
- 40% present as emergencies
Demographics
- F:M = 3:1 (wider female pelvis)
- Rare in children
- Peak incidence: 50-70 years
- Often multiparous women
Risk Factors
| Factor | Mechanism |
|---|---|
| Female sex | Wider pelvis, larger femoral canal |
| Multiparity | Ligamentous laxity |
| Increased abdominal pressure | Chronic cough, constipation, obesity |
| Previous inguinal hernia repair | May enlarge femoral canal |
| Age | Tissue weakness |
| Connective tissue disorders | Collagen abnormalities |
Anatomy of Femoral Canal
The femoral canal is a potential space medial to the femoral vein:
Boundaries:
- Anterior: Inguinal ligament
- Posterior: Pectineal ligament (Cooper's)
- Medial: Lacunar ligament (Gimbernat's)
- Lateral: Femoral vein
Contents normally: Fat, lymph node (of Cloquet)
Why Strangulation is Common
- Femoral ring is tight and rigid
- Lacunar ligament forms sharp, unyielding medial border
- Once incarcerated, bowel swells → Venous obstruction → Arterial compromise → Necrosis
Richter's Hernia
- Only antimesenteric border of bowel herniates
- May strangulate without complete obstruction
- Can present with strangulation but no obstruction signs
Symptoms
| Feature | Description |
|---|---|
| Lump in groin | Small, may be intermittent |
| Pain | Local aching, worse on standing/straining |
| Often asymptomatic | Found incidentally |
Signs of Strangulation (EMERGENCY)
| Sign | Significance |
|---|---|
| Tender, irreducible lump | Incarceration with possible strangulation |
| Vomiting | Bowel obstruction |
| Absolute constipation | Complete obstruction |
| Abdominal distension | Proximal bowel dilation |
| Peritonism | Perforation |
Inspection
- Small bulge below inguinal ligament
- Often small and easily missed
- May only appear on standing/coughing
Palpation
- Relationship to pubic tubercle is KEY:
- Femoral: Below and lateral
- Inguinal: Above and medial
- Often irreducible at presentation
- Cough impulse may be absent (incarcerated)
Key Examination Points
┌──────────────────────────────────────────────────────────┐
│ INGUINAL VS FEMORAL HERNIA │
├──────────────────────────────────────────────────────────┤
│ │
│ PUBIC TUBERCLE (landmark) │
│ ● │
│ ↗ ↘ │
│ INGUINAL ↗ ↘ FEMORAL │
│ (above and (below and │
│ medial) lateral) │
│ │
└──────────────────────────────────────────────────────────┘
Differential Diagnosis
| Condition | Distinguishing Features |
|---|---|
| Inguinal hernia | Above and medial to pubic tubercle |
| Saphena varix | Disappears on lying, cough impulse, venous hum |
| Lymph node | Usually multiple, non-cough impulse |
| Lipoma | Soft, non-tender, no cough impulse |
| Femoral artery aneurysm | Pulsatile |
| Psoas abscess | Fluctuant, fever, TB history |
Clinical Diagnosis
- Often clinical diagnosis based on examination
- Imaging helpful if diagnosis uncertain
Imaging
| Modality | Indication |
|---|---|
| Ultrasound | First-line if diagnosis uncertain |
| CT abdomen | If strangulation suspected or diagnostic difficulty |
| Herniography | Rarely used |
Preoperative (Elective)
- Bloods: FBC, U&E, coagulation
- ECG and CXR if indicated
- Anaesthetic assessment
Emergency (Strangulation)
- FBC (raised WCC)
- U&E (dehydration, AKI)
- Lactate (bowel ischaemia)
- Group and Save
- ABG if unwell
Key Principle
ALL FEMORAL HERNIAS SHOULD BE REPAIRED SURGICALLY There is NO role for watchful waiting.
Elective Repair
Approaches:
| Approach | Description | Advantages |
|---|---|---|
| Low (Lockwood) | Below inguinal ligament | Direct access, simple |
| High (Lotheissen) | Through inguinal canal | Better for tight repairs |
| Laparoscopic (TEP/TAPP) | Preperitoneal mesh | Faster recovery, bilateral repair |
Repair:
- Mesh placement (synthetic) is standard
- Suture repair (McVay) if mesh contraindicated
Emergency Repair (Strangulation)
┌──────────────────────────────────────────────────────────┐
│ STRANGULATED FEMORAL HERNIA │
├──────────────────────────────────────────────────────────┤
│ 1. RESUSCITATE │
│ - IV fluids, analgesia, NG tube if obstructed │
│ - Antibiotics (Gram-negative cover) │
│ │
│ 2. URGENT SURGERY │
│ - McEvedy approach (high incision) │
│ - Allows bowel assessment and resection if needed │
│ │
│ 3. INTRAOPERATIVE │
│ - Assess bowel viability │
│ - Warm, wait 3-5 minutes, look for colour/peristalsis│
│ - Resect if non-viable │
│ - Repair hernia (may avoid mesh if contaminated) │
└──────────────────────────────────────────────────────────┘
Of Untreated Femoral Hernia
- Incarceration (40%)
- Strangulation (30%)
- Bowel obstruction
- Bowel necrosis and perforation
- Peritonitis
- Death
Of Surgery
- Recurrence (1-5%)
- Wound infection
- Chronic pain (less common than inguinal repair)
- Femoral vein injury
- Bladder injury (rare)
- Mesh complications (rare)
Natural History Without Repair
- 40% strangulation rate (very high)
- Emergency surgery carries 10x mortality of elective repair
- Watchful waiting is NOT acceptable
Surgical Outcomes
| Scenario | Outcomes |
|---|---|
| Elective mesh repair | Recurrence <2%, mortality <0.1% |
| Emergency (viable bowel) | Mortality 2-5% |
| Emergency with bowel resection | Mortality 10-15% |
Prognosis
- Excellent if repaired electively
- Significantly worse if emergency (especially if bowel necrosis)
Key Guidelines
- EHS Guidelines on Femoral Hernia (2020)
- NICE Guidance on Hernia Surgery
- International Guidelines for Groin Hernia Management
Key Evidence
Strangulation Risk
- Studies show 40% emergency presentation rate
- Highest of all external hernias
- Strongly supports early surgical repair for all femoral hernias
Mesh vs Suture
- Mesh repair has lower recurrence
- Consider suture repair in contaminated field
What is a Femoral Hernia?
A femoral hernia is a bulge in the upper inner thigh, just below the groin crease. It happens when part of your bowel or fatty tissue pushes through a weak spot (the femoral canal).
Who Gets It?
Femoral hernias are more common in women, especially those who have had children. They're also more likely in older adults.
Why is it Serious?
Femoral hernias have a high risk of becoming "strangulated" - this means the bowel gets trapped and its blood supply is cut off. This is a surgical emergency. For this reason, ALL femoral hernias should be repaired with surgery, even if they're not causing symptoms.
What Are the Symptoms?
- A small lump in the upper thigh/groin area
- Discomfort or aching (especially when straining or lifting)
- Sometimes no symptoms at all
When to Seek Emergency Care
Call 999 or go to A&E immediately if you have:
- A painful, tender lump that won't go back in
- Vomiting
- Unable to pass wind or stool
- Severe abdominal pain
These may indicate strangulation requiring emergency surgery.
Primary Guidelines
- HerniaSurge Group. International guidelines for groin hernia management. Hernia. 2018;22(1):1-165. PMID: 29330835
- European Hernia Society. Guidelines on Femoral Hernia. 2020.
Key Studies
- Nilsson H, et al. Mortality after groin hernia surgery. Ann Surg. 2007;245(4):656-660. PMID: 17414617