Lateral Femoral Cutaneous Nerve | Lateral Cutaneous Nerve of the Thigh

Anatomy

  • Formed from L2 and L3
  • Crosses iliacus and leaves the pelvis under or through the inguinal ligament close to the ASIS
  • Course near the ASIS is variable
  • Enters the thigh superficial to sartorius
  • Can pass several centimetres medial to the ASIS

Sensory Supply

  • Anterolateral thigh
  • No motor supply

Clinical Features

  • Meralgia paraesthetica gives burning pain and numbness of the anterolateral thigh
  • No weakness or reflex change
  • Causes include tight belts, obesity, pregnancy, diabetes and prone positioning
  • Iatrogenic injury follows iliac crest graft harvest and anterior hip and pelvic approaches
  • Prolonged standing and hip extension worsen symptoms

Investigations

Ilioinguinal Approach to Acetabulum, structures passing behind the inguinal ligament
Structures passing behind the inguinal ligament. Image by Henry Gray, Wikimedia Commons, Public domain.
  • Diagnosis is clinical
  • Diagnostic nerve block
  • Nerve conduction studies are unreliable
  • Pelvic imaging to exclude a mass in older patients

Differential Diagnosis

  • L2 or L3 radiculopathy
  • Femoral neuropathy, which causes weakness

Management

  • Remove the cause of compression and encourage weight loss
  • Local anaesthetic and steroid injection
  • Neurolysis or neurectomy for refractory pain
  • Most cases settle with conservative care

Structures at Risk

  • Direct anterior approach to the hip, so enter through the tensor fascia lata sheath and stay lateral
  • Iliac crest graft harvest, so start about 3 cm posterior to the ASIS
  • First window of the ilioinguinal approach
  • Prone positioning on bolsters in spinal surgery

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.