Management of Chronic Low Back Pain with Trigger Point Injections
The authors reviewed available literature on the efficacy of trigger point injections in the management of chronic low back pain (CLBP). Trigger points are defined as firm, hyperirritable loci of muscle tissue located within a taut band, in which external pressure causes a local twitch response and jump sign which in turn provokes referred pain to distant structures. Trigger points may be considered active meaning that they cause spontaneous pain; or latent, meaning they cause pain only when compressed.

Trigger points have been injected with local anesthetic, saline, sterile water, steroids, nonsteroidal anti-inflammatory drugs, botulinum toxin, 5-HT3 receptor antagonists. Another technique is dry needling where no medication is used.

The authors found that there are no randomized controlled studies that evaluate the efficacy of trigger point injections or dry needling in patients with chronic low back pain. They note that recent European guidelines and other prominent guidelines for the treatment of CLBP do not support the use of trigger point therapy. In spite of a lack of evidence, the authors of the review support trigger point injection or dry needling in the myofascial pain patient that is resistant to other conservative non-invasive therapies. Studies do not support the use of injected corticosteriods. They also feel that the high costs of botulinum toxin do not support its use, with the possible exception of a highly resistant case of CLBP.
G. Malanga, E. Wolff. Evidence-informed management of chronic low back pain with trigger point injections.The Spine Journal. January/February 2008. Volume 8. Issue 1. Pp. 243-252.