Sacroiliac Radiofrequency Ablation

The sacroiliac joint has been shown to be a source of pain in 10% to 27% of suspected cases with chronic low back pain utilizing controlled comparative local anaesthetic blocks. A radiofrequency denervation of the sacroiliac joint is an outpatient procedure for treating low back and buttock pain.

What are sacroiliac joints?

Sacroiliac joints connect your spine to your hip bone. They connect the bottom of the spine, called the sacrum, to the outer part of the hip bone, called the ilium. You have two sacroiliac joints. One is found on each side of the sacrum.

Sacroiliac joints help control your hip area when you move. They help transfer forces from your lower body to your upper body. Each sacroiliac joint has several ligaments to help strengthen it.

What is sacroiliac joint pain?

You may feel pain if a sacroiliac joint is injured. At times it may feel like simple muscle tension, but at other times the pain can be severe. Sometimes cartilage inside the joint is injured, but at other times only ligaments around the joint are affected.

You usually feel sacroiliac joint pain in an area from your low back down to your buttocks. But sometimes, if a joint is very inflamed, pain may even extend down the back of the leg. The diagram shows where sacroiliac joint pain is usually felt.

How do I know if I have sacroiliac joint pain?

If you have pain in one or more of these areas on the diagram you may have sacroiliac joint pain. Common tests such as x-rays or MRIs may not always show if a sacroiliac joint is causing pain. Your pain doctor can do other tests to find out if you have sacroiliac joint pain.

What is a radiofrequency denervation of the sacroiliac joint injection?

Radiofrequency ablation (RFA) is a minimally invasive procedure to provide long-term relief from lower back pain if you had a positive diagnostic injection to the sacroiliac joint.

RFA uses radiofrequency energy to disrupt nerve function. When this is applied to the nerves that take sensation from the SI joint to the spinal cord, the nerve can no longer transmit pain from an injured SI joint.

What happens during an injection?

The procedure is performed in the operation theatre. You will be sedated and local anaesthesia will be used to numb your skin. The doctor will then insert a small needle near the lateral branch nerve that take sensation from the SI Joint. Fluoroscopy, a type of x-ray, will be used to ensure the safe and proper position of the needle. Once the doctor is sure the needle is correctly placed, the medicine will be injected. Radiofrequency energy will then be used to disrupt the lateral branch nerve. This is often repeated at more than one level of the sacrum.

What happens after an injection?

You will be monitored for up to monitored closely in the recovery room for 30 minutes after the injection. When you are ready to leave, the staff will give you discharge instructions. You will need to keep a pain diary. It is important to maintain a diary to help the doctor ascertain the success of the RFA.

You may feel sore for one to four days. It may be due to muscle and nerve irritation. Your back may feel numb, weak, or itchy for a couple weeks. Maximum pain relief normally comes in two to three weeks, but can take as long as six to eight weeks.

How long can I expect pain relief?

Nerves regenerate after an RFA, but how long this takes varies. Your pain may or may not return when the nerves regenerate which can range from 9 to 18 months. If it does, another RFA can be done.

How do I prepare for the procedure?

Please advise staff if you are:

  1. Taking blood thinners (especially warfarin and clopidogrel)
  2. Diabetic
  3. Pregnant (or any chance of you being pregnant).
  4. Allergic to iodine, betadine, shellfish, local anaesthetics, or steroids.
  5. Unwell (especially if you have an infection)

Operating department staff may advise you to:

  1. Fast
  2. Take your usual medications (apart from those mentioned above)
  3. Arrange for someone to accompany you home

When do I seek medical attention after the procedure?

Contact us, your GP or Local Emergency department , if you experience the following:

  1. Loss of bowel or bladder control
  2. Weakness in your limbs
  3. Fever: temperature above 38℃ that does not improve

This pamphlet is for general education only. Specific questions or concerns should always be directed to your doctor. Your doctor can explain possible risks or side effects.