Acupuncture for Chronic Low Back Pain

This narrative review published in the New England Journal of Medicine examines the efficacy of acupuncture in the treatment of chronic low back pain, a condition that affects up to 70% of people in industrialized countries and represents an annual cost of more than 90 billion dollars in the United States alone. Chronic low back pain develops in up to 7% of patients with acute episodes, with most cases classified as 'nonspecific' or 'idiopathic,' without a clear identifiable structural cause. The pathophysiology of chronic low back pain is complex and multifactorial, involving not only structural spine changes but also changes in the central nervous system and psychological and behavioral factors. Neuroimaging studies have demonstrated changes in brain activation and changes in volume and density of specific brain regions in patients with chronic pain.

Acupuncture, an ancient technique that involves inserting fine needles at specific points of the body, has been increasingly studied as a therapeutic alternative. According to traditional Chinese medicine, the technique aims to restore the flow of vital energy (qi, 氣) along bodily meridians. From the Western medicine perspective, studies demonstrate that acupuncture activates peripheral nerve fibers, induces release of endogenous opioids in the central nervous system, and produces anti-inflammatory effects through release of hormones such as cortisol. A 2008 meta-analysis including 6,359 patients revealed intriguing results: although true acupuncture was not significantly superior to sham acupuncture (placebo), both were more effective than conventional treatment alone.

In the largest German study included, with 1,162 patients with chronic low back pain for 8 years on average, response rates were 47.6% for true acupuncture, 44.2% for sham, and 27.4% for conventional therapy. In another German study with 3,093 patients, acupuncture provided an additional functional improvement of 9.4 points on the functionality scale compared with usual care. Typical treatment involves 15-30 minute sessions, with needles inserted at specific points such as BL-23 (shenshu, 腎俞), BL-25 (dachangshu, 大腸俞), GV-3 (yaoyangguan, 腰陽關), BL-40 (weizhong, 委中), and GB-30 (huantiao, 環跳), located in the lumbar region and lower limbs. Insertion depth ranges from 6.4 to 38.1 mm, using 4 to 20 needles per session.

Treatment generally consists of 12 sessions over 8 weeks, starting with two weekly sessions. Adverse effects are rare, with prospective studies involving more than 60,000 sessions reporting no serious adverse events. Minor events include needle-site pain (3%), hematoma (3%), and bleeding (1%). The main medical guidelines, including those of the American College of Physicians and the North American Spine Society, recommend considering acupuncture as a therapeutic option for patients with chronic low back pain who do not respond to self-care.

Interpretation of results generates debate in the medical community about the role of placebo effect, since sham acupuncture proved as effective as true acupuncture. This suggests that benefits may be attributed to contextual and psychosocial factors, such as patient expectations, therapist attention, and therapeutic environment. However, animal studies and human neuroimaging show specific changes in limbic structures after true acupuncture, distinct from sham, indicating that it is difficult to create a truly inactive control. The clinical implications suggest that acupuncture may be a valuable option in the multidisciplinary management of chronic low back pain, particularly for patients who prefer non-pharmacologic approaches or when conventional treatments have failed.

The cost ranges from $65-125 per session, with growing coverage by private health plans.