TRIGGER POINT INJECTIONSTechniques, Pitfalls, and Alternatives

30 Practical PAIN MANAGEMENT, November/December 2008©2008 PPM Communications, Inc. Reprinted with permission.

Amyofascial trigger point is defined as a hyperirritablespot, usually within a taut band of skeletal muscle that ispainful on precise compression, and that can give rise to

characteristic referred pain, tenderness, and autonomic or otherepiphenomena. They can be active, latent, primary, secondary,or satellite. Twitch responses are usual. They are found at areaswith high concentrations of endplate.1,2 An illustration of adysfunctional endplate region is shown in Figure 1 and repre-sents a site at which either a trigger point injection or inactiva-tion with a low-level laser would be effective.

Myofascial Pain Syndrome vs FibromyalgiaMyofascial pain syndrome is defined as pain at the site of activetrigger points and referred pain to predictable areas along withassociated muscle dysfunction. It is a regional syndrome that mayinvolve many regions.1,2 It is clear to me, based on nearly 20 yearsexperience, that the sympathetic nervous system is involved inthe referred pain patterns. In a clinical setting, this can be clearlydemonstrated in patients with cervical or thoracic syringomyeliawhen there is no sympathetic innervations of one arm.

Fibromyalgia, on the other hand, is a very different condition.While, in my experience, all fibromyalgia patients have myofas-cial pain with associated trigger points, not all myofascial painpatients have fibromyalgia. The fibromyalgia syndrome involvescentral sensitization at the caudate nuclei of the thalamus in themid brain. This central sensitization results in widespreadallodynia (the perception of pain in response to a normally non-painful stimulus). These patients also demonstrate numerousneuroendocrine abnormalities, primarily involving thehypothalamo-pituitary–adrenal axis. An injury can develop into

a chronic process of either myofascial pain syndrome, fibromyal-gia, or CRPS as illustrated in Figure 2.

In the treatment of chronic pain, we all know that thepatient’s symptom of pain is very subjective. However, triggerpoints and their referred pain are objective, and can be consis-tently demonstrated by a trained clinician. What is most impor-tant in the treatment of chronic pain is making the properdiagnosis. Without the proper diagnosis, treatments arefrequently unsuccessful and may, in fact, lead to a far morecomplicated problem.

Tips on practicing good technique for inactivating trigger points while avoidingpitfalls and minimizing complications.

By Bernard E. Filner, MD

sensitizingsubstances

energy crisis

decreased energysupply

increased energydemand

nociceptivenerve fibers

autonomicnerve fibers

motornerve terminal

excess acetylcholine

release

depolarization

SR

calcium release

sacromere contracture

compression of vessels

muscle

fiber

FIGURE 1. Illustration of a dysfunctional endplate region. After Travelland Simons.1,2

Dysfunctional Endplate Region

Editor’s note: This article is adapted from Dr. Filner’spresentation titled “Techniques of Trigger Point Injections”at the American Academy of Pain Management annualmeeting in Nashville, Tennessee in September, 2008.

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Trigger Point InactivationTrigger point inactivation can be achieved a number of ways.These techniques can include injection, ischemic pressure,acupuncture, heat, stretching, massage therapy, body work, lowlevel laser therapy, as well as the use of microcurrent. For the first15 years of my practice, trigger point injections were the primarymodality in the treatment of myofascial pain—as described inmy guest editorial in the October 2006 issue of Practical PainManagement.3 In the past six years, I have gradually begun to uselow level laser therapy as the primary modality for inactivatingtrigger points in my practice. It is extremely important not tojust simply inactivate the trigger point and do nothing else. It isvery important to use heat and gentle stretching immediatelyafter inactivating the trigger points and having the patient followup with home stretching and application of heat.

In terms of discussing trigger point injections, there arenumber of areas that need to be covered:

• Solution makeup• Tools• Treatment sequence• Quantity and frequency• Post-treatment• Pitfalls and complications

Solution MakeupIn my practice, I use a 50-50 solution of 1% lidocaine and 0.9%saline. The fact is that the local anesthetic used is not the mostcritical item. What one should remember, however, is thatbupivacaine and some of the other longer-acting local anesthet-ics, can have a significant myo-toxic effect. In addition, it is myopinion that steroids should never be used in a trigger pointinjection. There has never been any evidence that a trigger pointis an inflammatory lesion and therefore there is no reason toinject an anti-inflammatory. Additionally, the Depo prepara-tions used can be severely myo-toxic. Likewise, use of epineph-rine must be avoided since decreased arteriolar circulation isalready present at the site of a trigger point (see Figure 1). Asfar as the mechanism of a trigger point injection is concerned,it is presumed to involve the depolarization of the taut band toallow increased circulation and a decrease in the “soup “ thathas sensitized the nociceptors in the area. The net result shouldbe turning off the pain.

ToolsWhile others may disagree, I think it is quite important to usethe smallest needle consistent with your ability to reach thetrigger point. For most injections, I use a 27-gauge, 1.25-inchneedle. This is attached to a 3cc Luer-Lock syringe. This sizesyringe is easy to hold, manipulate, aspirate (to detect blood orspinal fluid) and inject—all with one hand. For deeper injec-tions, I use a 25-gauge, 2.5-inch needle. Rarely, for a very deeptrigger point, I used a 22-gauge, 3-inch needle. The purpose ofusing small needles is to get a much better feel for the tissueinto which you’re placing the needle and, the smaller the needle,the less pain and discomfort the patient will feel. Larger needlesare more painful, and can make feeling the taut band and triggerpoint much more difficult.

Treatment SequenceIf the upper body is also to be treated at the same visit, trigger

points in the lower portion of the body should be done first.This avoids the tightening of the upper body muscles when thelower body trigger points are injected and thus undoing of yourtreatment. The iliocostalis lumborum and quadratus lumborummuscles should be treated first, as satellite and secondary triggerpoints may disappear without treatment. When treating theupper body, the upper trapezius muscles should also be treatedfirst for the same reason (this was a personal communicationfrom Dr. Janet Travell and has proven invaluable over the years).

Quantity and FrequencyQuantity and frequency is often challenged by the health insur-ance carriers. My answer, based on the years I spent workingwith Dr. Travell, is that all active and latent trigger points withinany functional unit must be inactivated within the patient’s toler-ance. Based on my own 20 years of experience in treating chronicmyofascial pain, I conclude that the frequency of injectionshould be primarily determined by the patient’s medical condi-tion and symptoms and the physician’s judgment—rather thandetermined by a carrier’s arbitrary limitations.

Post-TreatmentA concern of the clinician who injects the trigger points—and thepatient who receives the injection(s)—is post-injection soreness.This is not noted in all patients but is a fairly frequent occurrence.The major causes of this soreness are (in no particular order):

• Not enough heat or stretching post-injection • Too much of the wrong activities after the injection(s) • The clinician either missed the trigger point or left a rem-

nant behind • Significant bleeding at the site of the injection (muscular

or subperiosteal) which may be related to the use of a largeneedle, the patient being on ASA, warfarin, clopidogrel,St. John’s wort, or excess vitamin E

• Post-injection spasm, particularly of the sternocleidomas-toid muscle, the external oblique muscle, or the gastrocne-mius muscle

Additionally, if there are very active and multiple twitchresponses during injection, the soreness—much like after charleyhorse releases—is often increased. While post-injection sorenessis relatively common, it can be minimized by a number of hours

T r i g g e r P o i n t I n j e c t i o n s

31Practical PAIN MANAGEMENT, November/December 2008©2008 PPM Communications, Inc. Reprinted with permission.

“Injury”

MFPS

CMFPS

Surgery

Scar Tissue

Neuropathic Pain

Ligament Tears

FMS CRPS

FIGURE 1. Cascade of chronic pain stemming from an injury.

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of application of hot packs (at home) aswell as gentle stretching.

Pitfalls and ComplicationsThe clinician must be aware of the pitfallsand complications of trigger point injec-tions. These include persistent pain,scarring (which may occur after bleedingor the use of a steroid), toxicity of theinjectate (possible local anestheticreaction from too much local anesthetichaving been in injected), as well as a nerveblock occurring at the time of triggerpoint injection. If the clinician knowshis/her anatomy, the possibility of a nerveblock from the spread of the dilute localanesthetic should be anticipated and thepatient warned that this may occur for ashort period of time. Of course, oneshould never inject when a paresthesia isencountered, as significant nerve damagemay occur. Obviously, aspiration of thesyringe should always be done prior toinjection, in order to assure that the injec-tion will not be intra-arterial or subdural.These are of particular concern wheninjecting trigger points in the neck. Caremust be taken to avoid injection into avertebral artery or into the subarachnoid

space. One of the ways to minimize thisis to use short needles having a length thatis just adequate to reach the muscles inthe neck. While rare, infection is a possi-bility. To minimize this, avoid injectingtoo close to any area that may lookinfected, and use an adequate amount ofalcohol that is allowed to dry on the skin.

The patient may also demonstratepersistent pain after the clinician has

injected multipletrigger points. Thismay be due eitherto the entiretrigger point notbeing inactivated,or the clinician nottreating all of thetrigger pointspresent. Anotherpotential causemay be that an areaof pain in the refer-ence zone wasinjected — ratherthan the appropri-ate trigger point.Another possibilityis that the entiretarget was missed!Another distinctpossibility is thatthe patient hasfibromyalgia re-sulting in persist-ent pain from thatcondition eventhough the myofas-cial pain compo-nent has beeninactivated. Lastly,

the clinician may be proceeding to treatthe wrong diagnosis!

Low Level Laser for InactivatingTrigger PointsIn my practice, over the past five years, myprimary method of inactivating triggerpoints has become the infra-red low levellaser. It is effective, essentially risk free,and less expensive for the patient. Inaddition, as the energy compounds (cyclicAMP, primarily) produced in themitochondria and distributed around thecell are increased, the muscle cells will healfaster thus shortening the overall timeuntil symptoms are relieved. The unit I useis illustrated in Figure 3. It has three 30mwlaser beams that slightly converge andcover approximately one square centime-ter at a depth of 2.5-3.0 centimeters fromthe skin surface. The unit delivers ninejoules/square centimeter over 96 seconds.It is a Class IIIb laser and non-heating tothe tissues—unlike a Class IV laser that canburn tissue. Aside from having to wearappropriate glasses to protect the eyes, theunit is otherwise risk-free. n

Bernard E. Filner, MD has practiced painmedicine in Rockville, Maryland since 1987.He is certified by the American Board ofAnesthesiology and by the American Academyof Pain Management (AAPM). He is a memberof the AAPM (and has served on its Technol-ogy and Education Committees), the AmericanPain Society, International Association for theStudy of Pain, the American Society of PainEducators , and the International MyopainSociety. He is on the Board of Advisors of theNational Fibromyalgia Partnership, Inc. andthe National Fibromyalgia Association.

As a clinician specializing in pain manage-ment, Dr. Filner has lectured extensively on thetreatment of the myofascial pain syndrome andfibromyalgia as well as techniques of triggerpoint injections—including presentations withDr. Janet Travell (the Travell Seminars) earlyin his career. At the present time, Dr. Filner alsoconducts training courses in the use of the coldlaser for pain treatment. Dr. Filner’s e-mailaddress is drfilner@thepaincenter.us.

References1. Travell JG, Simons DG. Myofascial Pain andDysfunction: The Trigger Point Manual. Volume 1. 1stEdition. Williams & Wilkins. Baltimore. 1983.2. Simons DG, Travell JG, and Simons L. Travell &Simons’ Myofascial Pain and Dysfunction: The TriggerPoint Manual, Volume 1. 2nd Edition. Williams &Wilkins. Baltimore.1999. 3. Filner BE. Low Level Laser Therapy: A Clinician’sView. Pract Pain Mgmt. October 2006. 6(7): 34-39.

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32 Practical PAIN MANAGEMENT, November/December 2008©2008 PPM Communications, Inc. Reprinted with permission.

FIGURE 1. Illustration of infra-red low levellaser application to muscle tissue.

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