Trigger Point Injection Vs. SI Injection

Both trigger point and SI (sacroiliac) injections are used to treat back or other muscular or joint pain. However, they are used in different situations and yield different types of results. Trigger point and SI injections have different risks associated with them as well.

Significance

• SI injections are primarily a diagnostic tool. Pain relief from the injection indicates a problem with the SI joint, as opposed to other possible causes for the back pain. Trigger point injections may confirm a diagnosis, but are used primarily to help provide pain relief as part of a treatment plan involving other therapies and exercise.

Function

• The procedure for an SI injection requires an IV and the use of a fluoroscope (an x-ray machine that shows the image during the procedure). Anesthetic and cortisone are injected, and then the patient is taken to a recovery area. For trigger point injections, the process is much simpler. There are antiseptic precautions, but no IVs or recovery room procedures are required. And no more than three injections are administered per trigger point.

Benefits

• The potential benefits for SI injections include obtaining a diagnosis of problems with the SI joint (the joint at the lower back where the sacrum and the iliac bone join--seen as the dimples in the lower back under the belt line), and perhaps some pain relief for up to several weeks when cortisone is used. The potential benefit for trigger point injections includes confirmation of a diagnosis, and pain relief to aid in beginning exercise and therapy for the affected region.

Risks

• The risks of SI injections include allergic reactions to drugs injected, infection at the injection site, and increased pain. The risks of trigger point injections include muscle damage and scarring after repeated injections, as well as infections and nerve injuries.

Follow Up

• Follow up for SI injections is generally simple. There are no restrictions on diet or activity, and you can resume physical therapy immediately. Follow up for trigger point injections is maintaining exercise and rehabilitation therapy.