Having a nerve block for hip or knee surgery

What is a nerve block?

Pain messages are carried to the brain by nerves. A nerve block is the injection of a local anaesthetic numbing solution around a nerve to stop pain messages reaching the brain. This is generally done in your groin or behind the top of your thigh.

Why do I need a nerve block?

Nerve blocks are used by anaesthetic doctors to make your hip or knee numb to reduce pain after an operation. These are performed in addition to either a spinal or general anaesthetic.

What are the benefits to me of having a nerve block?

You will be awake after the operation and you may experience less pain. It may be possible to give you less strong painkillers and so less side effects from these such as nausea or vomiting.

What does it involve?

Your anaesthetist will tell you what he/she is going to do. You may also choose to have a sedative to make you feel relaxed and sleepy while the block is done.

Are there any risks to me?

You should discuss these with your anaesthetist. Some of the risks with a nerve block are:

  • Nerve damage. This may be result in tingling, numbness or weakness. It is uncommon, but if it does occur, may last several weeks before getting better. Very occasionally it may be permanent.
  • Bruising or bleeding around the injection site (common)
  • The nerve block may not completely remove pain and you may still need some other pain killing drugs (common)
  • Local anaesthetic drugs can cause heart problems or loss of consciousness if accidentally injected into a blood vessel (uncommon)


Source www.youranaesthetic.info

Are there any reasons I may not have a nerve block?

Yes, sometimes a nerve block may be dangerous or undesirable, and your anaesthetist will ask you about any medical conditions you may have.

What will happen after my operation?

After your operation the nerve block will continue to make your leg numb and weak for a certain amount of time – usually between 6 and 24 hours .During this time you should be aware that you could damage your leg without being aware of the damage because it is numb, for example, you may not feel a hot coffee cup burning or you may fall when trying to get up. It is important to take extra care until the block wears off. If your block lasts longer than 48 hours you should contact the hospital for advice.

How can I get more information?

Your anaesthetist will be able to answer any questions you have. You should have been given a copy of our general leaflet ‘Information About Your Anaesthetic’.  Other information can be accessed via the Internet at www.youranaesthetic.info or www.portsmouthanaesthesia.com

Consent- What does this mean?

It is important before giving permission that you understand what you are agreeing to. If you do not understand – ask. More detailed information is available on request.

Information about you- The Data Protection Act 1998

Confidential records are kept about your health and the care you receive. These records are important; helping to make sure you receive the best possible care from us. The information may also be used to plan services and assist in the teaching and training of health professionals.

How to comment on your treatment

We aim to provide the best possible service and staff will be happy to answer any questions that you have.  However, if you have any concerns you can also contact pagwork@msn.com who will be happy to assist.


Author: Drs Marsh, Stedman, Taylor Anaesthetic Dept:  Produced Jan 2010:  Review: Jan 2012:  Ref: Ana/07

Used with permission.

© Portsmouth Hospitals NHS Trust


If you have any questions or concerns please contact us.