femoral nerve

{{Short description|Long nerve down the thigh and inner leg}}

{{Infobox nerve

| Name = Femoral nerve

| Latin = nervus femoralis

| Image = Gray823.png

| Caption = The lumbar plexus and its branches. (Femoral labeled at bottom left.)

| Image2 = Gray545.png

| Caption2 = Femoral sheath laid open to show its three compartments. (Femoral nerve visible in yellow.)

| Innervates = Anterior compartment of thigh

| BranchFrom = L2

| BranchTo = L4

}}

The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee. It is the largest branch of the lumbar plexus.

Structure

The femoral nerve is the major nerve supplying the anterior compartment of the thigh. It is the largest branch of the lumbar plexus, and arises from the dorsal divisions of the ventral rami of the second, third, and fourth lumbar nerves (L2, L3, and L4).{{cite book|last1=Krishna|first1=Garg|title=BD Chaurasia's Human Anatomy (Regional and Applied Dissection and Clinical) Volume 2 - Lower limb, abdomen, and pelvis|date=2010|publisher=CBS Publishers and Distributors Pvt Ltd|location=India|isbn=978-81-239-1864-8|page=55|edition=Fifth|chapter = Front of the thigh (Chapter 3)}}{{Citation|last1=Massey|first1=E. Wayne|title=Chapter 8 - Mononeuropathies in pregnancy|date=2020-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780444642400000088|journal=Handbook of Clinical Neurology|volume=172|pages=145–151|editor-last=Steegers|editor-first=Eric A. P.|series=Neurology and Pregnancy: Neuro-Obstetric Disorders|publisher=Elsevier|language=en|access-date=2021-01-17|last2=Massey|first2=Janice M.|doi=10.1016/B978-0-444-64240-0.00008-8 |pmid=32768085 |isbn=9780444642400 |editor2-last=Cipolla|editor2-first=Marilyn J.|editor3-last=Miller|editor3-first=Eliza C.}}

The nerve enters Scarpa's triangle by passing beneath the inguinal ligament, just lateral to the femoral artery. In the thigh, the nerve lies in a groove between iliacus muscle and psoas major muscle, outside the femoral sheath, and lateral to the femoral artery. After a short course of about 4 cm in the thigh, the nerve is divided into anterior and posterior divisions, separated by lateral femoral circumflex artery. The branches are shown below:

=Muscular branches=

=Cutaneous branches=

=Articular branches=

  • Hip joint is supplied by the nerve to the rectus femoris.
  • Knee joint is supplied by the nerves to the three vastus muscles. The nerve to vastus medialis is particularly thick because it contains the proprioceptive fibres from the knee joint. This is in accordance to the Hilton's law.

=Vascular branches=

  • Branches to the femoral artery and its branches.

Clinical significance

Signals from the femoral nerve and its branches can be blocked to interrupt the transmission of pain signals from the innervation area. Some of the nerve blocks that work by affecting the femoral nerve are the femoral nerve block, the fascia iliac block and the 3-in-1 nerve block. Femoral nerve blocks are very effective.{{Citation|last1=Candido|first1=Kenneth D.|title=Chapter 76 - Lumbar Plexus, Femoral, Lateral Femoral Cutaneous, Obturator, Saphenous, and Fascia Iliaca Blocks|date=2005-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780443066511500800|work=Essentials of Pain Medicine and Regional Anesthesia (Second Edition)|pages=645–658|editor-last=Benzon|editor-first=Honorio T.|place=Philadelphia|publisher=Churchill Livingstone|language=en|isbn=978-0-443-06651-1|access-date=2021-01-06|last2=Benzon|first2=Honorio T.|editor2-last=Raja|editor2-first=Srinivasa N.|editor3-last=Molloy|editor3-first=Robert E.|editor4-last=Liu|editor4-first=Spencer S.}}

During pelvic surgery and abdominal surgery, the femoral nerve must be identified early on to protect it from iatrogenic nerve injury.{{Citation|last1=Cheema|first1=Zahid F.|title=Femoral Nerve|date=2003|url=https://www.sciencedirect.com/science/article/pii/B0122268709008686|encyclopedia=Encyclopedia of the Neurological Sciences|pages=366–367|publisher=Elsevier|language=en|doi=10.1016/B0-12-226870-9/00868-6|isbn=978-0-12-226870-0|access-date=2021-01-06|last2=Robbie|first2=Ahmad}}

The femoral nerve stretch test can be performed to identify the compression of spinal nerve roots.{{Citation|last=Fritz|first=Julie|title=17 - Low Back Rehabilitation|date=2012-01-01|url=http://www.sciencedirect.com/science/article/pii/B9781437724110000174|work=Physical Rehabilitation of the Injured Athlete (Fourth Edition)|pages=333–356|editor-last=Andrews|editor-first=James R.|place=Philadelphia|publisher=W.B. Saunders|language=en|isbn=978-1-4377-2411-0|access-date=2021-01-06|editor2-last=Harrelson|editor2-first=Gary L.|editor3-last=Wilk|editor3-first=Kevin E.}} The test is positive if thigh pain increases.

Additional images

File:Gray546.png|Structures passing behind the right inguinal ligament

File:Gray827.png|Nerves of the right leg.

File:Slide6888.JPG|Femoral nerve.Deep dissection.

File:Slide8AAA.JPG|Femoral nerve.Deep dissection.

See also

References

{{Gray's}}

{{Reflist}}