Femoral Nerve Block


The femoral nerve starts at a nerve bundle in the lower back. It passes through the pelvic area and branches off as it travels down the leg to the foot. The nerve affects feeling and movement of the thigh, hip, and knee. A femoral nerve block decreases sensation in these areas.

The Nervous System

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Reasons for Procedure

Femoral nerve blocks are generally used for pain relief. You may also be given a femoral nerve block for:

  • Femoral neck or shaft fracture
  • Surgery on your leg

Possible Complications

There is a higher risk of falls after having a femoral nerve block because of decreased sensation in the leg. Falls can cause or worsen injury.

Other problems from the procedure are rare, but all procedures have some risk. The doctor will review potential problems, like:

What to Expect

Prior to Procedure

Before the procedure, the doctor may request the following:

  • Physical exam
  • Blood tests
  • Urine tests
  • Imaging tests, which may include x-rays, or an MRI or CT scan

Current medications should be discussed with the doctor before surgery. Certain medications need to be stopped up to a week before your procedure.


A local anesthetic will be used at the injection site before the block is delivered. It will numb the area. A sedative may also be give to encourage relaxation.

Description of the Procedure

This procedure may be done as treatment by itself or as part of your treatment.

You will be asked to lie on your back. The doctor will locate the femoral nerve by feeling of the pulse from the femoral artery just below your pelvic area. The femoral nerve is located next to this blood vessel. An ultrasound machine may also be used to help guide the needle. The needle will then be inserted into the femoral nerve. More than one injection may be needed to get the needle into the correct position. You may feel your thigh muscle twitch when the nerve is stimulated by the needle. Once the needle is in the correct place, the anesthetic medication will be injected into the nerve.

How Long Will It Take?

15-20 minutes

Will It Hurt?

Local anesthesia will prevent pain at the injection site during the femoral nerve block. You may have some discomfort at the insertion site after the nerve block wears off.

Post-procedure Care

At the Hospital

After the procedure, the hospital staff will monitor blood pressure and heart rate.

At Home

Transportation home and assistance at home will be needed until the anesthesia wears off.

Call Your Doctor

It is important to monitor your recovery. Alert your doctor to any problems. If any of the following occur, call your doctor:

  • Signs of infection, including fever and chills
  • Redness, swelling, pain, or discharge from the insertion site
  • Pain that does not go away with the medication you were given
  • Excess bleeding from the insertion site
  • Falls, especially if they result in injury
  • Residual tingling, numbness, weakness or shooting pain in your leg
  • Cough, shortness of breath, or chest pain

If you think you have an emergency, call for emergency medical services right away.


American Society of Anesthesiologist
Ortho Info—American Academy of Orthopaedic Surgeons


Canadian Anesthesiologists' Society
When it Hurts to Move—Canadian Orthopaedic Foundation


Anesthesia for hip and knee surgery. Ortho Info—American Association of Orthopaedic Surgeons website. Available at:
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Updated March 2014. Accessed October 2, 2017.
Femoral nerve block. New York School of Regional Anesthesia website. Available at:
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Accessed October 2, 2017.
Sharma S, Iorio R, Specht LM, Davies-Lepie S, Healy WL. Complications of femoral nerve block for total knee arthroplasty. Clin Orthop Relat Res. 2010;468(1):135-140.
Szucs S, Morau D. Femoral nerve blockade. Med Ultrason. 2010;12(2):139-144.
Total knee arthroplasty. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated July 17, 2017. Accessed October 2, 2017.
Wright I. Peripheral nerve blocks in the outpatient setting. AORN J. 2011;94(1):59-74.
Last reviewed September 2018 by EBSCO Medical Review Board Marcin Chwistek, MD
Last Updated: 7/1/2014

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