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.
Femoral nerve blocks are often used for pain relief. A femoral nerve block may be used to manage pain caused by:
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:
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.
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.
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.
15 to 20 minutes
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.
Blood pressure and heart rate will be monitored.
Activity will be limited until the block wears off.
It is important to monitor your recovery. Alert your doctor to any problems. Call your doctor if any of the following happen:
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
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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.com/topics/dmp~AN~T360995/Total-knee-arthroplasty. 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