Key Benefits of Needling, Infiltration, and Trigger Point Injections

• Trigger point injection stops the pain and relieves muscle spasms immediately, allowing active movement (limbering exercises). Trigger point injection accelerates substantially the recovery in both muscle and ligament sprain 

• "Needling" in order to break up mechanically the painful and tender tissue is combined with infiltration by local anesthetic, (trigger point) injections 
• Preinjection blocks (PIB) prevent pain from needle penetration

MOST EFFECTIVE METHODS FOR FAST RELIEF OF MUSCULOSKELETAL PAIN

(from NEW APPROACHES IN TREATMENT OF MYOFASCIAL PAIN by Andrew A. Fischer, MD, PhD  Department of Rehabilitation Medicine, Mount Sinai School of Medicine)

 Needling and Infiltration of Tender Spots and Trigger Points

-- "Needling" in order to break up mechanically the painful and tender tissue is combined with infiltration by local anesthetic, (trigger point) injections

-- Preinjection blocks (PIB) prevent pain from needle penetration to sensitive areas. FIIB itself is effective in relieving pain and relaxing muscle spasm. It relaxes, inactivates instantaneously the neurogenic component of taut bands and trigger points/tender spots. PIB also prevents sensitization of tissues and nerve fibers that occurs after needling. PIB desensitizes hyperalgesic (sensitized) tissues

-- Somatic block to relieve muscle spasm as well as pain caused by it

-- Spray inactivates painful tender spots and TrPs. Spray is followed by movement, which heals and restores function

-- Relaxation exercises relieve muscle tightness, tension. Postural correction, such as restoration of lumbar and cervical lordosis, relieves pain

Basic principle of pain management

The immediate cause of pain has to be established so treatment can be specifically focused on the etiologic factors and not limited to symptomatic relief

CONDITIONS IN WHICH NEEDLING AND INFILTRATION OF TENDER SPOTS OR TRIGGER POINT INJECTIONS ARE EFFECTIVE

Injuries

Chronic trigger points usually in the stage of anatomic pathologic changes (fibrotic tissue); this applies to myofascial, ligamentous, or pericapsular TrPs regardless of the cause of damage

Acute stage of injury immediately after the sprain and/or 1-3 days later. Trigger point injection stops the pain and relieves muscle spasms immediately, allowing active movement (limbering exercises). Trigger point injection accelerates substantially the recovery in both muscle and ligament sprain

Sport injuries caused by acute sprain or repetitive stress (i.e., pitcher's or tennis elbow, golf shoulder, elbow, etc)

Repetitive stress disorders, such as industrial work causing myofascial or ligamentous TrPs

Operation scars and TrPs around the scars, tissues under tension; frequent after spine operations and hip replacement

Inflammation

Bursitis, tendinitis, epicondylitis

Arthritis, including osteoarthritis with TrPs in the pericapsular tissues and sprained, strained ligaments around the degenerated joints

Fibromyalgia/fibromyositis, endocrine (thyroid, estrogen) deficiency, vitamin and metabolic disorders usually develop TrPs from tension or secondarily from local damage of susceptible tissues

Headaches, particularly tension headaches. Also migraine headaches have frequently a tension component inducing TrPs. Injections give considerable relief in both conditions

Nerve fiber irritation inducing spasm and consequently TrPs. Radicular irritation produces a typical rnyotomal distribution of TrPs

TrPs in emotional stress and tension, anxiety, or depression

Advantages of trigger point injections

Immediate relief of pain and spasm caused by pain

Instant improvement or restoration of function, ambulation, or use of upper extremity Needling is the most effective method for complete resolution of TrP in chronic stage once fibrotic tissue has formed

TECHNIQUE OF TRIGGER POINT INJECTIONS, NEEDLING AND INFILTRATION 

Trigger point injection (TI) is a special technique used for the alleviation of pain caused by the TSs/TrPs.* The ideal goal is to break up and eliminate the entire underlying abnormal tissue. Three different commonly used TI techniques are described.

Needling combined with infiltration is the most effective technique of TI.  Infiltration with a local anesthetic such as 1% lidocaine or 0.5% procaine is combined with needling (i.e., repetitive insertion and withdrawal of the needle covering the entire abnormal [painful] tissue in order to break it up). The tenderness (sensitization) usually extends over the myotendinal junction and particularly the enthesopathy at the attach- ment of taut band to the bones (Fig. 1).

This mechanical breakup of abnormal tissue (dysfunctional or pathologic) induces the long-term effect of TI. The technique requires using a sufficiently long needle to reach the entire area of abnormal tissue, if possible, from one single skin penetration. In addition the use of a needle with a larger diameter facilitates the mechanical breakup of the abnormal tissue. The amount of injected fluid is relatively large (2-12 mL), because usually an extensive area has to be infiltrated, ranging from 3 to 25 cm in length and 2 to 10 cm wide. The size of infiltration depends on the extent of the trigger point and on the length of the affected muscle fibers.

The mechanism by which needling and infiltration (N&I) alleviates pain instantaneously and remains effective for a long period of time has been discussed", 14 and can be summarized as follows: N&I breaks up a pocket in which nerve endings are entrapped along with the inflammatory, irritative substances. In the acute stage of injury when N&I is highly effective for immediate relief of pain, and prevents development of symptoms and spasm, taut formation of taut bands or pathologic scar can be explained by breaking up a layer of edema that has formed around the damaged area. In the chronic stage, which occurs probably within 3 or 4 weeks after the injury, a pocket of fibrotic tissue may form, entrapping the nerve endings along with the irritative, inflammatory substances    .14 This concept is based on general knowledge of wound healing by formation of scar tissue and mainly on clinical experience. It was observed that the needle penetration at this chronic stage is hindered by resistance which is characteristically fibrotic (i.e., very hard and nonelastic). In TSs/TrPs there seems to be also a "core" that cannot be relaxed by block of neurogenic impulses and is of hard "fibrotic" consistency. This core reacts best to N&I.

Travell's technique of injecting a small amount of 0.5% procaine into the TrP to desensitize the most tender spots is another TI method.

With steroid injection, a short 1.5-inch, thin needle, usually 25 gauge, is used. Steroids are combined with a small amount (1-3 mL) of local anesthetic, usually lidocaine. Steroids are not necessary for myofascial TrP because the technique of needling with breaking up the abnormal tissue is more effective. In fact, steroids may induce local myopathy; however, steroids may be useful in the treatment of passive tissues such as bursitis, tendinitis, epicondyhtis, or ligament sprain. The disadvantage of steroid injections into ligaments and ten- dons includes loosening and incomplete healing of these tissues, which makes them susceptible to reinjury. The number of steroid injections is limited to 3 to 5 sessions, which leaves the rest of TrPs untreated.

PREINJECTION BLOCKS (PlBs)

This is a new approach that consists of a local anesthetic infiltration of the nerve which supplies the area where a trigger point injection (TPI) or other injection will be administered to a sensitive tender area.

Effects of PIB:

1. Prevents pain caused from TPIs by interrupting the transmission of nociceptive impulses going to the central nervous system (CNS).

2. Prevents postinjection soreness and pain. Allows for more thorough needling over larger areas than without PIB.

3. Makes possible "early mobilization," active limbering (relaxation) exer- cises, which promote healing and functional recovery.

4. Lidocaine silences ectopic neuroma discharges caused by sensitization of neuroma and corresponding dorsal root ganglion. This desensitization is not related to the conduction block."'

5. Applied prior to nerve injury (ligation) FIB prevents pain and (thermal) hyperalgesia as well as reflex sympathetic vasoconstriction.

Nerve Blocks

Diagnostic blocks

Aid differential diagnosis of the site and cause of pain Help determine mechanism of chronic pain syndromes

Therapeutic blocks

Control severe acute postoperative, post-traumatic pain, and pain from self-limiting diseases

Breaking of "vicious cycle" involved in some pain syndromes may provide prolonged relief

Provide temporary relief to permit other therapies, or used in combination with other therapies (physical therapy)

Preinjection block (PIB) administered prior to trigger point injections, paraspinous somatic blocks, or needling and infiltration of sprained, traumatized, or inflamed tissue. The PIB prevents pain caused by needle penetration of sensitive tissue