Trigger Point Injection

Trigger point injections help with pain management.

• Trigger points are focal areas of muscle spasm, often located in the upper back and shoulder areas.
• A trigger point injection involves the injection of medication directly into the trigger point.
• Trigger point injections can be used to treat a number of conditions including fibromyalgia, tension headache, and myofascial pain syndrome.

Trigger points are focal areas of spasm and inflammation in skeletal muscle. The rhomboid and trapezius back muscles, located in the upper back and behind the shoulder areas, are a common site of trigger points. Trigger points in these areas can cause neck pain, shoulder pain, and headache. In addition to the upper spine, trigger points can also occur in the low back or less commonly in the extremities.

Often there is a palpable nodule in the muscle where the trigger point is located. The area is tender, and frequently when pushed, pain radiates from the trigger point itself to an area around the trigger point. Trigger points commonly accompany chronic musculoskeletal disorders such as fibromyalgia, myofascial pain syndrome, neck pain, and low back pain. They may also occur with tension headache and temporomandibular pain. Acute trauma or repetitive minor injury can lead to the development of trigger points.

A trigger point injection (TPI) is an injection that is given directly into the trigger point for pain management. The injection may be an anesthetic such as lidocaine (Xylocaine) or bupivacaine (Marcaine), a mixture of anesthetics, or a corticosteroid (cortisone medication) alone or mixed with lidocaine. Sometimes, a needle alone is inserted into the trigger point, and no medication is injected. This may be helpful and is referred to as "dry needling." With the injection, the trigger point is made inactive and the pain is relieved.

Trigger point injections are frequently administered by rheumatologists, pain-management doctors, and physical medicine and rehabilitation doctors. Some internists, family practice doctors, generalists, and neurologists perform trigger point injections.

The trigger point injection is performed in the health care professional's office, usually with the patient either lying on the exam table on the stomach or sitting on the exam table. The exact technique varies. The health care professional performing the procedure locates the trigger point by manual palpation and marks the site. Ultrasound guidance is not generally necessary. The injection site is then cleaned. Alcohol or another skin cleanser such as betadine is commonly used to clean the injection site. Frequently, a numbing spray such as ethyl chloride is used to anesthetize the skin and make the actual injection less painful. The needle is then inserted into the trigger point and the medication is injected. After the injection, a simple adhesive bandage may be applied. If the area is painful after the injection, ice, heat, acetaminophen (Tylenol), or over-the-counter nonsteroidal anti-inflammatory medications such as ibuprofen (Advil) or naproxen sodium may be used.

Trigger point injection is used when a patient has a painful trigger point, especially when pain radiates from the trigger point to the surrounding area. Trigger point injections may be used as a treatment for conditions such as fibromyalgia and myofascial pain syndrome. However, the trigger points commonly recur with chronic pain syndromes.

A potential complication from the trigger point injection procedure is post-injection pain. This is relatively uncommon, but it can occur. This pain usually resolves by itself after a few days. It is more common when no medication is injected into the trigger point (dry needling). Ice, heat, or over-the-counter medications such as acetaminophen, ibuprofen, or naproxen sodium may be useful for post-injection pain.

If a steroid medication is injected into the trigger point, there is a risk of shrinkage of the fat under the skin, leaving a dent in the skin. This does not occur when only anesthetic is injected without any steroid medication. Other side effects are rare with trigger point injections but can occur anytime a needle punctures the skin, including infection and bleeding.

Optimally, a trigger point resolves after one injection. This may happen when a patient has one isolated trigger point, especially if the cause of the trigger point has been removed (such as a trigger point caused by a repetitive minor trauma or movement that will no longer be performed). Trigger points caused by chronic conditions such as fibromyalgia and myofascial pain syndrome tend to recur due the underlying problem. In these cases, trigger point injections may be administered on a regular or as needed basis. The frequency of trigger point injections depends on the medication being injected. If only lidocaine or a mixture of anesthetics is injected, then the injections can be administered as ongoing therapy as frequently as monthly. If a steroid medication is injected, TPIs should be administered much less frequently, at the discretion of the treating health care professional, because of the risk of tissue damage or shrinkage from the steroid medication.