Trigger Point Injections

Trigger point injections (TPI) are used to detect if hardware implanted in the low back is the source of pain and should be removed. Trigger points are tight knots of muscle that form when muscle fails to relax. Trigger point injections are commonly performed to treat painful areas.

Procedure preparation

A technologist or nurse will contact you 24-48 hours prior to your appointment to review medications you are currently taking, especially pain medications and blood thinners, discuss known allergies and your medical history, as well as answer your questions.

Contact your doctor before you stop taking any medication.

Please bring previous imaging study results (MRI, CT, x-rays) such as films, reports, or CD-ROMs, if available.

You will need a driver for your appointment. If you are unable to drive or arrange transportation, call us for assistance.

Please notify a member of our staff if you are nursing or if there is a chance you may be pregnant.

What to expect during the procedure

Injections are administered by a radiologist and takes approximately 30 minutes.

A small needle is inserted into the trigger point using x-ray-guidance (fluoroscopy), and a local anesthetic (numbing medication) with or without a steroid (anti-inflammatory) is injected.

Injection of medication numbs the trigger point and thus alleviates pain.

Sustained relief usually is achieved with a brief course of treatment. The injection may cause a twitch or pain that lasts a few seconds to a few minutes.

What to expect after the procedure

Numbness from the anesthetic may last about an hour and a bruise may form at the injection site.

Pain can be relieved by alternately applying moist heat and ice for a day or two.

In most cases, stretching exercises and physical therapy are performed following TPI.

Potential side effects

Steroid medications may cause facial flushing, occasional low-grade fevers, hiccups, insomnia, headaches, water retention, increased appetite, increased heart rate, and abdominal cramping or bloating.

These side effects are bothersome in only about 5% of patients and commonly disappear within 1-3 days after the injection.