Groin Pain of Neural Origin

Groin pain of neural origin is a debilitating condition in which one or more nerves in the inguinal (groin) region become damaged, compressed, or entrapped — causing chronic pain that significantly impacts daily life. This condition most commonly occurs after hernia repair surgery, but can also arise spontaneously from nerve entrapment.

Nerves Involved

Three major nerves traverse the inguinal region and are susceptible to injury or entrapment:

Ilioinguinal Nerve

The ilioinguinal nerve (originating from L1) travels along the inguinal canal and provides sensation to the medial thigh, mons pubis, and parts of the genitalia. It runs between the internal oblique and transversus abdominis muscles before entering the inguinal canal. This nerve is the most commonly injured during open inguinal hernia repair.

Iliohypogastric Nerve

The iliohypogastric nerve (also from L1) runs parallel to and above the ilioinguinal nerve. It supplies sensation to the skin over the lower abdomen (hypogastric region) and the lateral gluteal area. It is vulnerable during lower abdominal incisions and laparoscopic port placement.

Genitofemoral Nerve

The genitofemoral nerve (L1–L2) splits into a genital branch (which travels through the inguinal canal alongside the spermatic cord or round ligament) and a femoral branch (which supplies the skin of the upper anterior thigh). It can be injured during both open and laparoscopic hernia repairs and is particularly vulnerable to mesh-related entrapment.

Causes

Post-Hernia Repair Pain (CPIP)

Chronic post-herniorrhaphy inguinal pain (CPIP) is defined as inguinal pain persisting more than 3 months after hernia surgery. It affects an estimated 10–15% of patients undergoing inguinal hernia repair and is the most common cause of neuropathic groin pain seen in referral practices. The mechanisms include:

• Mesh entrapment: Synthetic mesh used to reinforce the repair can incorporate or compress nearby nerves, particularly as scar tissue forms around the mesh
• Suture entrapment: Fixation sutures or tacks can directly injure or entrap a nerve
• Neuroma formation: When a nerve is transected during surgery, it may form a painful neuroma at the cut end
• Scar tissue: Post-operative fibrosis can gradually constrict nerves in the inguinal region

Idiopathic Nerve Entrapment

In some cases, inguinal nerve entrapment occurs without prior surgery. Causes may include anatomical variants, repetitive strain (common in athletes), or compression from fascial structures. This is sometimes called "sportsman's hernia" or athletic pubalgia, though the nerve component is distinct from the musculoskeletal injury.

Symptoms

• Groin pain: Burning, stabbing, or electric-shock-like pain in the groin crease
• Radiation: Pain may radiate to the inner thigh, scrotum or labia, or lower abdomen depending on the nerve involved
• Activity-related worsening: Walking, bending, lifting, or physical exertion often exacerbates the pain
• Hyperesthesia: The skin in the groin area may be exquisitely sensitive to light touch or clothing
• Hypoesthesia: Some patients have numbness or decreased sensation in the nerve's territory
• Sexual dysfunction: Pain during sexual activity, especially with genitofemoral nerve involvement

Diagnosis

• Clinical examination: Careful sensory mapping of the groin to identify the territory of the affected nerve, Tinel's sign (tapping over the nerve reproduces radiating pain), and assessment of previous surgical scars
• Diagnostic nerve blocks: Image-guided selective blocks of the ilioinguinal, iliohypogastric, and/or genitofemoral nerves — significant temporary pain relief confirms the nerve involved
• Imaging: MRI to assess for mesh complications, neuroma formation, or masses; MR neurography may help identify swollen or entrapped nerves
• Electrodiagnostic studies: EMG may be helpful in some cases, though inguinal nerves can be technically difficult to study

Treatment

Conservative Management

• Neuropathic pain medications: Gabapentin, pregabalin, amitriptyline, or duloxetine
• Nerve blocks: Serial nerve blocks can provide cumulative relief and also serve as a prognostic indicator for surgery
• Physical therapy: Core stabilization, desensitization techniques, and activity modification

Surgical Treatment: Neurectomy

When conservative management fails, surgical neurectomy — the controlled division of the affected nerve — is the primary treatment. Dr. Lakhiani performs targeted neurectomy with the following approach:

• Selective neurectomy: Based on diagnostic nerve blocks, only the identified offending nerve(s) are addressed
• Triple neurectomy: When all three inguinal nerves are involved, all three may be divided in a single procedure
• Proximal implantation: The cut nerve end is buried in healthy muscle to prevent neuroma recurrence
• Mesh assessment: If mesh is contributing to the problem, it may be partially or completely removed in coordination with a general surgeon

The expected outcome of neurectomy is significant pain reduction. Patients should understand that the procedure trades pain for numbness in the nerve's territory — for most patients with severe CPIP, this is a favorable trade.

Connection to the Pelvic Pain Clinic

Groin pain of neural origin is managed within Dr. Lakhiani's Pelvic Pain Clinic. The multidisciplinary team ensures a thorough evaluation to distinguish neuropathic groin pain from musculoskeletal, urological, or gynecological causes before surgical intervention is recommended.