FIGURE 7.1 Myofascial trigger point.

Dry needling is an invasive procedure in which a standard hollow hypodermic needle or a solid core acupuncture needle is inserted through the skin and directly into a myofascial trigger point. Proper dry needling of a myofascial trigger point will elicit both referred pain and a local twitch response. This is an involuntary spinal cord reflex in which the muscle fibers in the taut band of muscle quickly contract. The local twitch response indicates the proper placement of the needle in a trigger point. At the site of an active trigger point, there are elevated levels of inflammatory mediators, known to be associated with persistent pain states and myofascial tenderness. This local milieu positively changes with the occurrence of a local twitch response.² Lewit³ demonstrated that the therapeutic effect from passage of a needle is distinct from that of the injected substance.

Several adverse effects associated specifically with dry needling have been reported. These include pain, hematoma, syncopal episodes, and pneumothorax.⁴ Overall, the rate of complications is low, and dry needling/acupuncture provided by experienced physicians is considered a safe treatment.⁵

An examination of the peer-reviewed literature regarding the benefit of dry needling is inconclusive. There are randomized clinical trials indicating both positive effect⁶ and no difference.^7–9 The use of ultrasound may improve the accuracy, clinical response, and safety of the procedure.¹⁰ A systematic review¹¹ indicated no difference in outcomes in patients treated with dry needling for the treatment of myofascial pain syndrome. Another comprehensive review¹² yielded insufficient evidence to make any recommendations about acupuncture or dry needling for acute low back pain. But, for chronic low back pain, results show that acupuncture is more effective for pain relief and improving function than is no treatment or sham treatment in the short term. The technique has a small incremental effect when added to other conventional therapies, but is not more effective than are other conventional and “alternative” treatments.

Several other percutaneous treatments for tendinopathy that include corticosteroid injection, prolotherapy, autologous whole blood injection, and autologous platelet-rich plasma injection are often performed in conjunction with fenestration. It is currently unknown if these other percutaneous procedures have any benefit over dry needling alone.

Most reported studies suffer from significant methodologic limitations and may not be generalizable.^12,13 Furthermore, rigorous evidence regarding the potential physiologic mechanisms of actions and effects of this modality is sparse and incomplete. Studies performed in an acupuncture setting do not necessarily apply to dry needling.¹⁴ Since it appears that significant symptomatic improvement occurs in some patients who are treated with injection of myofascial trigger points, further high-quality research is required to determine the proper place of this intervention in the treatment of myofascial pain syndrome. Areas that need to be addressed include proper study design that include blinding, randomization, use of controls, and sufficient numbers of patients.

PATIENT POSITION

• Lying prone on the examination table.

LANDMARKS