What is a piriformis injection?

A piriformis injection is an injection into the buttock. The piriformis muscle is a muscle in the buttock area that goes from the side of the base of the spine/tailbone to the side of the thighbone. The piriformis muscle can become inflamed, tight or go into spasm which can cause pain in the buttock and leg area.

Why do I need to have the injection?

The piriformis muscle can be injected with local anaesthetic, with or without steroid. The local anaesthetic can help reduce the pain by blocking the pain signals to the brain and help the muscle fibres relax and the steroid can help to relieve inflammation in the area.

Who does the procedure?

The injection is usually carried out by a Pain Specialist Consultant in the Injection Room in the Outpatients Department (OPD). They may use an ultrasound machine or X-ray to guide the injection.

What is injected?

The injection will consist of a local anaesthetic with or without steroid.

Important information

Before your injection you must inform the clinician if you are

• pregnant or may be pregnant,
• diabetic,
• feel unwell,
• have an infection, cold or persistent cough,
• have any allergies,
• taking any of the following medication: Antibiotics, Aspirin, Warfarin or Clopidogrel or other tablets taken to thin the blood (some of these may need to be stopped some days before).

Failure to do so may result in procedure being cancelled on the day.

How effective is the injection?

For many people the injection can produce noticeable improvements in symptoms. However, their effectiveness cannot be guaranteed or predicted. The effects can last for weeks, months or even years and the injection can be repeated if symptoms return.    

What are the risks of the procedure?

• Infection
• Damage to small veins when the needle is inserted
• Bleeding causing local bruising or bleeding around the nerve
  Nerve damage
• Adverse reaction to injection which may be mild or life threatening (anaphylaxis)
• If you are diabetic, then the injection may raise your glucose levels. Glucose levels should be monitored for up to 1 month after your injection. If there are any changes in diabetic symptoms, then you should consult their GP.
• Facial flushing for a few days
• Temporary discomfort for a few days after your injection
• For females - temporary alteration of your menstrual cycle

The risk of complications with this procedure are small, please discuss any concerns with the clinician looking after you.

On the day of your procedure 

• Please arrive to the Outpatients Department no more than 10 minutes before your appointment time.
• Take any medication as normal unless advised otherwise, bring a list of your tablets with you.
• You can eat and drink normally before arriving. Food and drink will not be offered before the procedure, this is to aid your comfort during the procedure and is an additional safety measure in case of complications.
• You will be admitted to the Outpatients Department Injection Suite and assessed by a nurse. This is to make sure you are fit and ready for the injection. You will have the opportunity to ask any questions at this stage.
• The Doctor carrying out your injection will also see you before you have the procedure.

As your piriformis injection is being carried out as a day case you will normally be admitted for 30 minutes after the procedure. You may be asked to stay overnight but this is unusual.

What will happen after the piriformis injection?

You will be asked to rest in the chair or trolley/bed after the procedure during which time you will be monitored by the nursing staff who will check your:

• Blood pressure
• Injection site

Once you have passed urine you will be able to make arrangements for going home.

You must not drive yourself home or use public transport. For your own well-being we advise that you are collected by a relative or friend. Hospital transport can only be booked if there is a medical need and you meet the set criteria.

Back at home

• It is important that you take things easy for the rest of the day.
• Do not do any excessive exercise or heavy work for the first few days.
• If a dressing is in place, remove the dressing the morning following your procedure.
• Continue to take your pain relief tablets until you notice an improvement in your symptoms.

Who do I contact if I have any problems following the procedure?

From 9am – 4pm you can either speak to a nurse from the Outpatient Injection Suite on 0121 685 4000 extension 55814 or you can contact the Secretary for the clinician you are under. Outside these hours contact the bleep holder through switchboard at the ROH: 0121 685 4000.

Follow up appointment

Need for a follow up appointment will be discussed before you are discharged.

Can’t make your appointment?

If for any reason you cannot make your appointment you must let the Scheduled Care Coordinators know as soon as possible. You can contact the department on 0121 827 3835, Mon-Fri 8.30am to 4.00pm. Your appointment will not be automatically re-booked unless you call to tell us that you are unable to attend.

Useful contact numbers
PALS - 0121 685 4128
Scheduled Care Coordinator - 0121 827 3835
Injection Suite - 0121 685 4000 extension 55814