Sacral lateral branch block and sacro-iliac joint injection overview
Identifying pain from the joints
A lateral sacral branch block involves injecting local anaesthetic onto the nerves of the sacro-iliac joints at the base of the spine. It is used as a diagnostic tool to determine whether back pain is arising from these joints.
The procedure temporarily interrupts pain signals from the sacro-iliac joints. If it results in a significant reduction in back pain, this indicates that these joints are likely to be the source of the pain. In the case of a sacro-iliac joint steroid injection, pain relief may last for several weeks.
Sacral lateral branch block and sacro-iliac joint injection preparation
Preparing for your diagnostic procedure
A lateral sacral branch block or sacro-iliac joint injection may be recommended for lower back pain arising from the sacro-iliac joints.
As this is primarily a diagnostic procedure, it is important that your usual pain can be reproduced at the time of the procedure. You should stop taking pain medication around 5-6 hours beforehand.
If you do not have pain on the day of the procedure, we may suggest postponing it to a later date.
You should avoid undergoing any other medical procedures, such as dental treatment or a colonoscopy, within 48 hours before or after a lateral sacral branch block or sacro-iliac joint injection.
Please let us know ahead of the procedure if:
- You are taking any antibiotics.
- You have a pacemaker or defibrillator.
- You are ill, in which case we may need to postpone the procedure.
You should also not drive yourself to or from the appointment, or drive during the 24-hour period after the procedure.
After your sacral lateral branch block or sacro-iliac joint injection
Recovery and monitoring after the procedure
After the procedure you are able to return home (although as explained in the preoperative instructions above, you should not drive yourself. There is no restriction on day-to-day activities. In some (relatively rare) cases there may be some discomfort and/or bruising to the skin at the injection site. Any feeling of numbness in the legs or buttocks generally goes away within a few hours.