Piriformis injection

Patient Information Leaflet

Introduction

Welcome to The Dudley Group NHS Foundation Trust. This leaflet will provide you and your relatives with information about a piriformis injection. It includes information on what this is, the risks and benefits of it and what the procedure involves.

What is a piriformis injection?

It is an injection into the buttocks. The piriformis is a muscle in the buttock area that goes from the side of the tailbone to the side of the thighbone. The muscle can become inflamed, tight or go into spasm, causing pain in the buttock and leg.

To help with pain, the muscle can be injected with local anaesthetic, with or without steroid. The local anaesthetic can help the muscle fibre relax and the steroid can relieve inflammation.

Steroids have been used for decades for their beneficial effects. Although steroids are not licensed for this specific procedure, their use is endorsed by the British Pain Society. The steroids we use act locally and so minimise any side effects.

The injection is not a cure for the cause of your pain but it is used to help reduce the level of your pain.

What are the benefits?

The purpose of the injection is to:

• diagnose whether or not the piriformis muscle is involved in causing your pain and
• to provide pain relief

The injection contains a mixture of local anaesthetic and steroid. It is thought to have the following beneficial effects:

• Local anaesthetics numb the area for a period of hours giving short-term relief.
• Local steroid has a long-term effect of reducing inflammation in the area of the injection.

The injection can help to relieve pain for several hours, weeks, months or possibly longer. You may get a period of pain relief that will enable you to increase activity levels.

What are the possible risks?

Steroids given by injection to a specific area minimise the side effects on the rest of the body. Overall, these injections are very safe and serious side effects or complications are rare. However, like all injection procedures, there are some risks:

Common risks

• Bruise at the site of injection.
• Numbness or weakness in your leg – this should stop in three to four hours.
• There is a very slight chance of getting an infection where the needle is placed. Every effort is made to avoid this by using a sterile technique.
• The injection may take up to six weeks to relieve your pain and for some people, it may not help at all.
• Your pain may be worse for a few days. In some cases, this can take up to two weeks to return to normal levels.

Rare risks

• Anaphylaxis – severe allergic reaction to drugs.
• In a very small number of patients, there is a risk of damage to tissues in the area of the injection and, very rarely, a permanent increase in pain.

If you experience any of these rare risks, please contact the Pain Management Helpline on 01384 244735, your GP or in an emergency dial 999.

Steroid-related risks

Compared to regular steroid use, the steroid injection used for pain procedures is associated with very few side effects, however:

• If you have diabetes – you may experience a slight rise in blood sugar for up to two weeks so you should monitor your blood sugar very carefully. Contact your GP or diabetic nurse if you have any problems.
• If you have heart failure – you may experience increased shortness of breath due to salt and water retention. Contact your GP or nurse if you have any problems.

X-ray precautions:

• The procedure uses X-rays and these use a small amount of radiation which may add slightly to the normal risk of cancer.

Female patients – you must tell us if you are or might be pregnant. If you are not sure, we will offer you a pregnancy test.

What are the alternatives?

Your pain specialist will have discussed alternatives with you in your consultation. These could be medicines, different injections or physical therapies. Every patient is unique and; therefore, specific alternatives cannot be given on an information leaflet as not all treatments are suitable for everyone.

What do I do about medication?

• You should take all your regular medications except blood thinning medication such as clopidogrel, warfarin, dipyridamole, rivaroxaban. We will give you instructions about what to do about these drugs when you are given your appointment for the injection.
• Please bring a repeat prescription document with you if you are taking any regular medications.

Can I eat and drink?

You can eat and drink as normal unless your pain consultant advises you otherwise.

How long will I be in hospital?

Although the procedure itself takes 15 to 20 minutes, you will be given a time to come in for either a morning or afternoon procedure. Due to the way the theatre lists are organised, you may have to wait for your injection, so please come prepared for this.

Can I drive home?

For safety reasons, you are asked not to drive on the day of your procedure, so you will need someone to collect you from the hospital. Please arrange to have someone with you overnight.

What does the treatment involve?

• The injection is performed as a day case procedure meaning you will only need to be in hospital for the day.
• Your treatment will be at Russells Hall Hospital or Corbett Outpatient Centre as an outpatient in the Day Surgery Unit (either a morning or an afternoon appointment). This will be confirmed at your clinic appointment.
• You will be at the appointment for between two to four hours.
• On the day of treatment, please take all your routine medications.
• One of the pain doctors will explain the treatment and answer any questions that you may have. They will then ask you to sign a consent form for the treatment if you still want to go ahead with it.
• Shortly before the injection, you will need to change into a hospital gown.

During the procedure

• This is carried out in theatre while you are awake.
• You will need to lie flat on your stomach to allow the doctor to do the procedure. If you have any difficulty in getting into this position, a member of staff will be there to help you.
• The skin over the area of your injection will be cleaned with antiseptic.
• The doctor will give you a local anaesthetic to numb the skin around the area for injection.
• The doctor will then give you the injection (usually a combination of local anaesthetic and a steroid drug).
• X-ray pictures may be taken throughout the procedure, or the consultant may use ultrasound to ensure the needle is in exactly the right place.
• It may be uncomfortable but it should not be too painful.
• You will have a small plaster covering the injection site which may be removed after 24 hours but do not worry if it falls off sooner.

After the procedure

• In the recovery area, we will observe you for 30 minutes as you might feel a little drowsy and sleepy.
• We will offer you light refreshments and after this you can go home.
• You must not drive or use public transport; you must have a lift home.

What do I need to do when I get home?

When you get home, please continue to take any regular medication. It may be necessary for you to take painkillers for a day or two. You might need someone at home to help you but you do not have to stay in bed. You can remove the plaster the next day.

Do not drive or operate heavy machinery until the next day. Avoid alcohol for 24 hours. You can eat and drink normally unless you have been told otherwise.

You should gradually increase your level of activity. However, do not take up new exercises until your muscles have had time to adapt. Build up your exercise levels by increasing your physical activity (for example, walking, swimming, housework) gradually every few days. The eventual aim is to get back to a level of activity that is normal for you.

By gradually increasing your physical activity, you will allow your muscles to regain some of their lost strength. If you do not strengthen your muscles, any benefit from the injections will be very short term, as the injection is not a cure in itself, it just relieves pain.

What happens after having the injection?

Some patients will experience immediate pain relief. However, it usually takes 24 to 72 hours for the effects of the steroid medication to take effect and it may be up to one week before the maximum benefits are felt.

Some patients will experience mild pain from the procedure that will ease in a very short amount of time. On rare occasions, patients have experienced a prolonged increase in pain after the procedure.

How you respond to the injection will be monitored by you on a pain monitoring chart which we will give you to take home. Your further treatment plans will be based on this.

If you have any questions, or if there is anything you do not understand, please contact the Russells Hall Hospital switchboard number on 01384 456111 and ask for the relevant department who issued this leaflet.

If you have any feedback on this patient information leaflet please email dgft.patient.information@nhs.net

This leaflet can be made available in large print, audio version and in other languages, please call 0800 073 0510.

Originator:  Ruth Carter, Alifia Tameem. Date originated: December 2017. Date reviewed: January 2024. Next review date: October 2026. Version: 3. DGH ref: DGH/PIL/01374.