Patient Information Sheet

The purpose of this test is to determine whether or not pain is arising from one of the sacroiliac joints. The sacroiliac joints are large joints which bear the weight from the upper body and spinal cord onto the hips. Unfortunately there are no specific physical findings or x-ray changes, which identify the sacroiliac joint as a source of pain and therefore the only way to determine whether the sacroiliac joint is painful is to anaesthetize it temporarily by injecting local anesthetic into the joint. The sacroiliac joint can radiate pain into the lower back, buttock, groin or leg.

Before the Procedure

If you think you are pregnant or if you are pregnant you must inform the Doctor before the procedure as the procedure does involve exposure to X-rays. However, the X-ray dose is within recommended limits for adults but could be hazardous for a developing fetus.

You must have your usual pain on the day of the procedure. You many need to withhold your usual medications or even aggravate your pain so that there is sufficient pain at the time of your appointment. If there is insufficient pain please telephone Southern Cross Radiology, 03 379 0770 and cancel your appointment. The procedure can be performed at a later date when there is sufficient pain.

Could you please be accompanied by a friend or relative to drive you home after the procedure as you may feel a little unsteady and so advise you not to drive.


The Procedure

During the procedure you will lie on the X-ray table facing down with a pillow supporting your abdomen. You will be awake and will be able to listen and talk during the procedure. If for any reason you wish a procedure to stop this is possible, however this is unlikely to be required.

Before the procedure, antiseptic is applied to the area of the lumbar spine and a drape is placed over the area to maintain an aseptic area. The X-ray machine is then moved into position and adjusted so there is a good X-Ray of the lumbar spine.

A fine needle is placed on the surface of your skin and its position is checked using the X-ray. Just prior to the needle insertion you will be informed and there is likely to be a stinging sensation as the needle penetrates. As the needle passes through muscles there will also be some discomfort and you may feel an electric shock sensation in your leg when the tip of the needle is close to the nerve root. When the needle is at the target point a small point of contrast is injected slowly to confirm the needle’s position and once this is correct local anesthetic and steroid will be injected. Occasionally as the fluid is injected there is a pressure sensation, which may be uncomfortable but this settles quickly.

This joint is very narrow and irregular and is sometimes difficult to get a needle into. It is accepted internationally that the procedure cannot be completed because of these difficulties in up to 30% of cases. If there is difficulty getting into the joint we will usually book you in to repeat the procedure on another day.


After the Procedure

The procedure usually takes 30 minutes.

If the block has been successful you will note a significant difference in your pain shortly after the procedure. If however the pain is not relieved don’t be afraid to say so and if only part of the pain is relieved then it is important that you let us know which part has been relieved. You need to contact the Christchurch Clinic to make a follow up appointment 3 weeks after the procedure.

Please remember not to drive following the procedure – arrange for someone to drive you home.

Risks of Procedure

Allergic reactions to local anesthetics and to antiseptics. You must tell us before the procedure starts if you have any allergies.

  • Rarely our patients feel faint during the procedure and if you do please tell the doctor as the procedure can be interrupted or postponed until you are feeling better. 
  • As the local an aesthetic can numb muscles this may affect your sensation of balance and this may last half an hour, or rarely until the local anesthetic has worn off. If you do develop this side effect it is best to focus on the horizon while walking and turn slowly with your eyes looking straight ahead.
  • There may be a sensation of stinging or soreness where the needles pierce the skin but this is usually short-lived.
  • Infection where the needle pierced the skin is rare but possible – this procedure is carried out under hospital operating theatre conditions where strict sterile conditions apply – if there was redness, tenderness or any concern about infection please contact me (Dr McLaughlin) as soon as possible.
  • Occasionally following a block there is an initial worsening to occur very rarely as a complication of this procedure but this is more likely when used in the cervical spine and occurs if the steroid is injected into an artery rather than around the nerve. To avoid this the injection of a contrast prior to the injection of local anesthetic and steroid confirms that the needle is not within an artery.



If you have any questions about the procedure please contact Dr Mark McLaughlin, 03 337 4839