Minor muscle tears consequent to injury, unaccustomed activity, or repetitive use may cause a painful irritative focus in a muscle, commonly referred to as a "trigger point." This is the most common cause of nonarticular rheumatic pain; it presents as a regional musculoskeletal pain Many patients who have myofascial pain are initially misdiagnosed as having bursitis, tendinitis, a radiculopathy, or a nerve entrapment syndrome. Trigger points are not visualized on Thus, these patients may have significant dysfunction that cannot be substantiated by routine tests, and they may be erroneously labeled as malingering or having a "functional syndrome." Many patients with a primary arthritis or tendinitis and/or bursitis develop biomechanical imbalance, which leads to a secondary myofascial pain syndrome. Failure to recognize the evolution of such a myofascial pain syndrome results in apparent treatment failures. The finding of a single or several trigger points should suggest the diagnosis of a myofascial pain syndrome and myofasitis.
Symptoms of regional musculoskeletal pain. Local pain on pressure of the trigger point, often with centrifugal referral. Pain on stretching the involved muscle. Pain on contraction of the involved muscle. Functional shortening of the involved muscle. Increased consistency of muscle on palpation of the trigger point area. Temporary relief of pain by the precise injection of 1 to 3 mL of 1% procaine hydrochloride into the trigger point area.
The essential prerequisites of myofascial therapy are as follows:
In most patients, this treatment regimen needs to be repeated for a period of several weeks and occasionally several months. Recalcitrant cases are usually due to failure to eliminate.
The technique for performing trigger point injection is as follows. After the skin is cleaned, a 24- to 26-gauge needle is inserted only as far as the deep dermis. The needle is then slowly advanced into the area of the trigger point, and the patient is instructed to tell the physician when an acute increase of pain is noted. There are two reliable signs that a trigger point has been entered: (1) the patient's experience of a sudden pain, often with a centrifugal pattern of referral, and (2) a feeling of increased resistance to the progression of the needle tip.
Patients should be informed that they may experience an immediate relief of the pain from the effects of the local anesthetic, but there may be a temporary increase in pain for a few days. There are often several trigger points responsible for myofascial pain syndrome; hence more than one trigger point may need to be injected at the same time. Because large volumes of local anesthetic (more than 15 mL) may cause dizziness, tinnitus, muscle fasciculations, bradycardia, hypertension, and rarely convulsions.
The efficacy of trigger point injections is often enhanced by performing "myofascial spray and stretch" immediately after the injections. Spray and stretch consists of an application of a vapocoolant spray, such as dichlorodifluoromethane-trichloromonofluoromethane (Fluori-Methane) over the muscle with simultaneous passive stretching.
The technique for performing trigger point injection is as follows. After the skin is cleaned, a 24- to 26-gauge needle is inserted only as far as the deep dermis. The needle is then slowly advanced into the area of the trigger point, and the patient is instructed to tell the physician when an acute increase of pain is noted. There are two reliable signs that a trigger point has been entered: (1) the patient's experience of a sudden pain, often with a centrifugal pattern of referral, and (2) a feeling of increased resistance to the progression of the needle tip.
Patients should be informed that they may experience an immediate relief of the pain from the effects of the local anesthetic, but there may be a temporary increase in pain for a few days. There are often several trigger points responsible for myofascial pain syndrome; hence more than one trigger point may need to be injected at the same time. Because large volumes of local anesthetic (more than 15 mL) may cause dizziness, tinnitus, muscle fasciculations, bradycardia, hypertension, and rarely convulsions.
The efficacy of trigger point injections is often enhanced by performing "myofascial spray and stretch" immediately after the injections. Spray and stretch consists of an application of a vapocoolant spray, such as dichlorodifluoromethane-trichloromonofluoromethane (Fluori-Methane) over the muscle with simultaneous passive stretching.