Treatment of Unilateral Groin Numbness
For unilateral groin numbness, the primary treatment approach depends on identifying the specific nerve involved through history and physical examination, followed by either nerve decompression (for lateral femoral cutaneous nerve) or surgical neurectomy (for ilioinguinal, iliohypogastric, or genitofemoral nerves), with excellent pain relief achieved in 68-78% of cases. 1
Diagnostic Approach
The diagnosis of groin numbness of neural origin can be established through history and physical examination alone, without requiring elaborate imaging or electrodiagnostic studies 1. The key is determining which of four nerves is responsible:
- Lateral femoral cutaneous (LFC) nerve: Causes numbness over the anterolateral thigh, often extending to the knee 1
- Ilioinguinal (II) nerve: Causes numbness in the groin and medial thigh 1
- Iliohypogastric (IH) nerve: Causes numbness in the groin with potential referred symptoms to pelvic viscera 1
- Genitofemoral (GF) nerve: Causes numbness in the groin with potential referred symptoms to the testicle 1
Treatment Algorithm Based on Nerve Involvement
For Lateral Femoral Cutaneous Nerve Entrapment (Meralgia Paresthetica)
Surgical decompression is the treatment of choice, particularly when the nerve is located above or within the inguinal ligament 1. This approach achieves excellent results in 68% of patients for both pain relief and functional restoration 1.
For Ilioinguinal or Iliohypogastric Nerve Involvement
Surgical neurectomy provides the best outcomes, with excellent results in 78-83% of cases for both pain relief and functional restoration 1. These nerves show the most favorable surgical outcomes among all groin nerve pathologies 1.
- Poor results occur in only 11-17% of cases 1
- Prophylactic ilioinguinal neurectomy during hernia repair significantly decreases chronic groin pain (8% vs 28.6% with nerve preservation) without added morbidities 2
For Genitofemoral Nerve Involvement
Surgical neurectomy is performed, though outcomes are less favorable than with other nerves, achieving excellent results in only 50% of patients with poor results in 25% 1.
Surgical Technique Considerations
Post-Hernia Repair Numbness
If groin numbness follows inguinal hernia repair, a combined laparoscopic and open approach provides optimal results 3:
- Mesh removal (open or laparoscopic depending on original approach) 3
- Neurectomy of the affected nerve(s) 3
- Placement of mesh in the opposite location from the first mesh 3
- This approach results in significant improvement or resolution in 95% of patients (20 of 21) 3
Important Technical Points
- Percutaneous nerve blocks are typically unsuccessful and should not delay definitive surgical management 3
- Complications are minimal and may include bruising or cautery injury to the LFC nerve 1
- The procedure can be performed for unilateral or bilateral symptoms 1
Critical Pitfalls to Avoid
Do not confuse groin numbness with lymphadenopathy-related symptoms. Reactive lymphadenopathy is common and should not be assumed to cause numbness without clear nerve involvement 4, 5. Up to 25% of clinically negative lymph nodes may harbor micrometastases in cancer patients, but this is unrelated to isolated numbness 5.
Do not attribute all groin numbness to hernia. Other causes must be excluded 6:
- Enthesopathy (inflammation at tendon/ligament insertions) accounts for 30 of 49 cases of chronic groin pain 6
- Spinal referred pain 6
- Ureteric stones 6
Recognize that symptoms can be referred beyond the groin: The IH nerve can cause pelvic visceral symptoms, the LFC nerve can cause knee symptoms, and the GF nerve can cause testicular symptoms 1.
Expected Outcomes
For the entire series of surgical management of groin numbness of neural origin 1:
- 68% achieve excellent pain relief
- 72% achieve restoration of function
- 10% have poor results
- Best outcomes: II and IH nerves (78-83% excellent)
- Worst outcomes: GF nerve (50% excellent, 25% poor)