Trigger Point Injection


A trigger point injection (TPI) is an injection directly into the fascia to relieve muscle pain. A trigger point is a knot in the muscle that does not relax. These points are very sensitive and painful.

When pressure is applied to a trigger point, the patient will feel a painful sensation there, but also senses pain in another part of the body. Common trigger point areas are the muscles in the upper and lower back, as well as the buttocks. Thetrigger point2se particular trigger points occur due to strain from everyday activities, injury, and certain body position and mechanics.

Why is the trigger point injection done?

A trigger point injection contains an anesthetic, which is often mixed with a long-acting corticosteroid. These medications relieve muscle spasms and feelings of tightness. When combined, they work to provide pain relief and decrease inflammation, which allows the patient to move more easily.

How is the trigger point injection performed?

To perform a trigger point injection, the doctor first feels around the area that is painful to identify the exact trigger point. He/she then will mark the spot with a surgical pen.

The skin is cleansed with an antiseptic first, then the doctor injects a small amount of the medication. Following the injection, the doctor may massage the area to spread the medication around to the muscle and surrounding tissues.

What conditions are treated with trigger point injections?

Approximately 10% of the U.S. population has a chronic disorder of the musculoskeletal system, which is about 23 million persons. These conditions are the main cause of disability for working adults.Trigger point diagram

TPIs are used to treat the pain in these muscle groups, which can include the lower back, neck, arms, and legs. Additionally, a trigger point injection can be used for myofascial pain syndrome.

What are the side effects of a trigger point injection?

Trigger point injections do have certain side effects, though most patients tolerate these treatments well. Adverse reactions include infection, increased pain, swelling and tenderness at the injection site, and bleeding.

A potential complication associated with TPI is post-injection pain. While this is uncommon, it does occur. This pain usually resolves within a few days, and is remedied with ice application and non-steroidal anti-inflammatory medicines, such as ibuprofen.

If a corticosteroid medication is injected into the painful trigger point, there can be shrinkage of the fat under the skin, which leaves a slight dent. This is a rare complication, however.

How frequently do TPIs need to be administered?

The goal of trigger point injection administration is to relieve pain. However, one injection does not work for every patient. Trigger points caused by repetitive movement and/or trauma often resolve after one injection.

Trigger Point InjectionsTrigger points related to chronic conditions tend to recur, and may require additional injections. The frequency of trigger point injection depends on the type of medication injected, the doctor’s preference, and the patient’s condition.

When only lidocaine is administered, the injections can be given as frequently as every month. However, due to the risk of tissue damage from the steroid, TPIs with this drug are not recommended to the same area on a regular basis.

Do trigger point injections work?

Trigger point injections are indicated for patients with symptomatic active trigger points that produce a twitch response with pressure and have a pattern of referred pain. Studies show that trigger point injections are effective for complete relief (58%) and partial relief (40%) of pain. The injection of lidocaine is found to reduce the site soreness.

Resources

Hong CZ. Lidocaine injection versus dry needling to myofascial trigger point. The importance of the local twitch response. Am J Phys Med Rehabil. 1994;73:256–63.

Simons DG, Travell JG, Simons LS. Travell & Simons’ Myofascial pain and dysfunction: the trigger point manual. 2d ed. Baltimore: Williams & Wilkins, 1999:94–173.