Trigger point injection (TPI) are used to treat intense pain in the muscles containing trigger points. Trigger points are tight bands or knots that are formed when the muscle fails to relax after the contraction. A trigger point may also cause referred pain (pain in another part of the body) by irritating the adjacent nerves.
Trigger point injections can be used to relieve pain in conditions such as myofascial pain syndrome when other treatments are a failure, fibromyalgia, and tension headaches.
During this procedure, nerve block will be administered by the orthopaedist or pain specialist to numb the area of needle penetration and keep you comfortable during the procedure. Further, a small needle containing local anesthetic (lidocaine, procaine) which may or may not containing corticosteroid is directly injected to the trigger point. This makes the trigger point inactive and the pain is relieved.
This is a short procedure and may just take a few minutes. The injection may cause mild pain for a short time. If you are allergic to the local anesthetic medication, a dry-needle technique (without medications) is used.
Numbness at the site of injection may persist for about an hour after the procedure. A bruise may even form at the site of injection. Applying moist heat and ice alternatively to the area for two days relieve the pain. Your physician may also recommend stretching exercises and physical therapy after trigger point injections.