Dry Needling Offers Relief From Chronic Low Back Pain
More than one in four Americans has a musculoskeletal condition that requires medical attention. In fact, musculoskeletal disorders and diseases are the leading cause of disability in the United States and account for more than half of all chronic conditions in people older than 50 years of age.1 Chronic back pain accounts for most of the common musculoskeletal pain conditions treated in the United States. It can be treated nonoperatively or surgically, depending on the acuity of the problem, neurologic symptoms, and the pain practitioner’s philosophy.
Dry needling (DN) is a unique treatment option for chronic low back pain. DN is a procedure in which filiform needles—needles commonly used in acupuncture—are used to deactivate myofascial trigger points (MTrPs). These trigger points are discrete, focal, hyperirritable spots located in a taut band of skeletal muscle. The spots are painful on compression, and they can produce referred pain, referred tenderness, motor dysfunction, and autonomic phenomena.2
This article describes the use of DN and the success we have experienced using this technique to treat patients with chronic back pain in our medical center.
Traditionally, there are three types of trigger points—active, latent, and satellite. This classification helps us to understand the relationship between the trigger points and the symptoms they elicit. Active trigger points present with pain without any applied pressure (spontaneous pain). Latent trigger points elicit pain with applied pressure. Satellite trigger points occur in the specific area of referred pain that radiates from active trigger points.
DN an MTrP can be most effective when local twitch responses are produced. A local twitch response is defined as a transient visible or palpable contraction or dimpling of the muscle and skin as the tense muscle fibers (taut band) of the trigger point contract when pressure is applied. This response is brought on by a sudden change of pressure on the trigger point by needle penetration into the trigger point or by transverse snapping palpation of the trigger point across the direction of the taut band of muscle fibers (Figure).2
Mechanism of Action
The underlying mechanism of action in DN is still not well understood. However, it appears to allow the sarcomere to resume its resting length3 and activate inhibitory dorsal horn interneurons. This implies that DN causes opioid-mediated pain suppression and also blocks any incoming noxious stimulus into the dorsal horn by activating the serotonergic and noradrenergic descending inhibitory systems.4
In addition, the levels of two biochemicals drop significantly following DN. There is a decrease in local concentrations of substance P and calcitonin gene–related peptide; this development may correlate with the systematic reduction of pain following deep DN.5
Furthermore, there are studies currently under way that are using multiple imaging techniques to visualize the cascade of physiologic changes that are possible with the introduction of filiform needles into an MTrP.
Because DN is considered a physical medicine modality and does not require any specialized equipment, patients do not need to do any type of preparation for this procedure. Typically, patients report immediate pain relief that can last from a few hours to a few weeks, depending on the frequency of treatment. However, it is recommended that repeat DN not be done on the same areas within 72 hours to allow for the tissue to heal. Also, some patients may experience muscle soreness at the area where the procedure was performed.
There are minimal contraindications for this procedure, and patients can drive home or return to work immediately after DN. For maximum results, DN combined with other modalities and exercises are usually done over a 6-week period.
Patients who have had both spinal epidurals and DN have reported either the same amount of pain relief or increased relief following DN. Patients also may prefer DN because it can be done more frequently and with fewer risks than lumbar epidural spinal injections (ESIs).6
A 44-year-old male veteran was injured when he fell from a telephone pole. As a result, he had intermittent pain in his lumbar spine until 3 years ago. At that point, the pain became constant, with right-leg numbness and neuralgia in certain positions. Since 1993, the patient drove a semi-trailer. The pain became so severe and constant that he was forced to sell his vehicle, and he became unemployed. Upon his initial consultation for DN, he had recently finished his third lumbar ESI in a series of three—his second series in a year. The second series of ESIs produced no pain relief.
Physical examination of the lumbosacral region produced multiple active and latent MTrPs: located along the piriformis, iliopsoas attachment, tensor fasciae latae, and gluteal fibers. No neurologic deficits were elicited. Imaging tests did show mild degenerative disk disease of L3-L5 with facet arthritis and ligamentum flavum hypertrophy.
Initially, the patient noted a transient decrease in pain (10% decrease). However, upon completion of the second session of DN, the patient achieved a 30% reduction in pain, which was equal to the most pain relief he experienced with the six ESIs. He ultimately underwent six DN sessions and maintained a 30% decrease in overall pain.
Comparison with Epidural Injections
Although the underlying mechanism of action of epidurally administered steroid and local anesthetic injections is still not well understood, it is believed that the achieved neural blockade alters or interrupts nociceptive input, reflex mechanisms of the afferent fibers, self-sustaining activity of the neurons, and the pattern of central neuronal activities.6
ESIs are performed on an outpatient basis, and most patients are able to return to preinjection activities within a day. The injections can be done in a series of three—each spaced approximately 6 weeks apart. Many patients report minimal pain relief immediately after, which can last from a few hours to a few weeks.
Currently, there is limited evidence to prove the effectiveness of ESIs for chronic lumbar pain. Armon et al reported that “while some pain relief is a positive result in and of itself, the extent of leg and back pain relief from epidural steroid injections, on the average, fell short of the values typically viewed as clinically meaningful.”7
Cost of ESIs at Dayton VA Medical Center
At the Dayton VA Medical Center in Dayton, OH, DN is available 5 days a week by a certified chiropractor, physician, nurse practitioner, and physical therapist. Although patients are seen on a schedule, emergency patients may be accommodated for DN on a walk-in basis. The cost of the visit is comparable with any other physical modality visit, which averages about $45 per session.