Femoral Nerve Block

by Michael Jubinville, MPH

Definition

The femoral nerve starts at a nerve bundle in the lower back. It passes through the pelvic area and runs 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

Reasons for Procedure

Femoral nerve blocks are often used for pain relief. A femoral nerve block may be used to manage pain caused by:

Fracture of hip or thigh bone
Surgery on your leg

Possible Complications

The block dulls sensation in the leg. This increases the risk of falls, which can cause or worsen injury.

Other problems are rare, but all procedures have some risk. The doctor will review possible problems such as:

Blood clots
A local pocket of blood outside of the blood vessels—hematoma
Infection
Nerve or blood vessel damage
Atrial fibrillation
Pneumonia
Kidney failure

What to Expect

Prior to Procedure

The doctor may review tests that were already done. Other steps will depend on the reason a block is needed.

The doctor needs to know about any medicine that you are currently taking. Certain medicine will need to be stopped up to 1 week before your procedure.

Anesthesia

Local anesthesia will be used. It will numb the area where the injection will be made. A sedative may also be given. It will improve 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 feel. An ultrasound machine may also be used to help guide the needle. The needle will be inserted through the skin and into the femoral nerve. More than 1 injection may be needed to get the needle into the correct place. You may feel your thigh muscle twitch when the nerve is touched by the needle. The medicine will be injected into the nerve and the needle will be removed.

How Long Will It Take?

15 to 20 minutes

Will It Hurt?

There may be some pressure when the needle is place. Medicine will block pain. The area may be sore after the nerve block wears off.

Post-procedure Care

At the Hospital

Blood pressure and heart rate will be monitored.

At Home

Activity will be limited until the block wears off.

Call Your Doctor

It is important to monitor your recovery. Alert your doctor to any problems. Call your doctor if any of the following happen:

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.

RESOURCES:

American Society of Anesthesiologist
https://www.asahq.org

Ortho Info—American Academy of Orthopaedic Surgeons
http://orthoinfo.org

CANADIAN RESOURCES:

Canadian Anesthesiologists' Society
http://www.cas.ca

When it Hurts to Move—Canadian Orthopaedic Foundation
http://whenithurtstomove.org

References:

Anesthesia for hip and knee surgery. Ortho Info—American Association of Orthopaedic Surgeons website. Available at:
...(Click grey area to select URL)
Updated March 2014. Accessed February 12, 2020.

Femoral nerve block. New York School of Regional Anesthesia website. Available at:
...(Click grey area to select URL)
Accessed February 12, 2020.

Femoral Shaft Fracture - Emergency Management. EBSCO DynaMed website. Available at: https://www.dyname.... Accessed February 12, 2020.

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 website. Available at: http://www.dynamed.... Updated July 17, 2017. Accessed February 12, 2020.

Wright I. Peripheral nerve blocks in the outpatient setting. AORN J. 2011;94(1):59-74.

Last reviewed September 2019 by EBSCO Medical Review Board Marcin Chwistek, MD
Last Updated: 9/11/2020

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