Acute Lower Back Problems in Adults - Injection Therapy

Symptom Control: Injection Therapy
Trigger Point and Ligamentous Injections

Panel findings and recommendations:

• Trigger point injections are invasive and not recommended in the treatment of patients with acute low back problems. (Strength of Evidence = C.)
  
• Ligamentous and sclerosant injections are invasive and not recommended in the treatment of patients with acute low back problems. (Strength of Evidence = C.)

Trigger point injections involve the injection of local anesthetic into soft tissues (muscles) near localized tender points in the paravertebral area. [189] <http://text.nlm.nih.gov> The theory that such trigger points are responsible for causing or perpetuating low back pain is controversial and disputed by many experts. Other articles reviewed for this topic involve the injection of various substances (especially sclerosing agents) into interspinal ligaments and ligamentous muscle attachments in the low back. The theory behind such treatment is that this stimulates formation of scar tissue in ligaments. The therapeutic objective of both trigger point injections and ligamentous injections is to reduce low back pain.

Literature Reviewed.

Of 14 articles screened for the topics of trigger point and ligamentous injections, 6 RCTs met criteria for review. Three of these evaluated trigger point injections into muscle. [183] <http://text.nlm.nih.gov>– [185] <http://text.nlm.nih.gov> Three evaluated injections into ligamentous structures in the back. [186] <http://text.nlm.nih.gov>– [188] <http://text.nlm.nih.gov> Other articles contained information used by the panel, but did not meet article selection criteria. [189] <http://text.nlm.nih.gov>– [190] <http://text.nlm.nih.gov>

Evidence on Efficacy.

Of the articles evaluating trigger point injections, only Frost, Jessen, and Siggaard–Andersen [184] <http://text.nlm.nih.gov> evaluated patients with acute low back problems. The study population, however, included patients with acute neck or shoulder pain, and data were not given separately for the patients with low back problems. For the other two RCTs on trigger point injections, either the patients evaluated had chronic low back problems [183] <http://text.nlm.nih.gov> or the duration of symptoms was not reported. [185] <http://text.nlm.nih.gov>

Various medications were used for trigger point injections. Frost, Jessen, and Siggaard–Andersen [184] <http://text.nlm.nih.gov> had two groups receiving either local anesthetic or saline. Bourne [183] <http://text.nlm.nih.gov> had three groups receiving methylprednisolone and lignocaine, or triamcinolone and lignocaine, or lignocaine alone. Garvey, Marks, and Wiesel [185] <http://text.nlm.nih.gov> had four groups receiving lidocaine alone, or lidocaine combined with a steroid, or needle acupuncture (with no injection of material), or vapocoolant spray to the skin followed by acupressure (using a plastic needle guard). Two studies included control groups who had no medication injected into muscles, [184] <http://text.nlm.nih.gov>, [185] <http://text.nlm.nih.gov> but none of the three studies included a group with no intervention.

Frost, Jessen, and Siggaard–Andersen [184] <http://text.nlm.nih.gov> and Garvey, Marks, and Wiesel [185] <http://text.nlm.nih.gov> found no differences between groups in pain relief or other outcome measures on followup at 1 and 2 weeks posttreatment, respectively. Bourne[183] <http://text.nlm.nih.gov> found significantly greater pain relief at 3 months followup for the two groups receiving steroid injections than for the group receiving injections of local anesthetic alone.

Of the three articles evaluating injections into ligamentous structures, two studies evaluated patient groups including some patients with acute low back problems. [186] <http://text.nlm.nih.gov>, [188] <http://text.nlm.nih.gov> One study evaluated a subgroup of patients with acute low back problems, all with pain over the medial iliac crest. [186] <http://text.nlm.nih.gov> In the other study, patients were only described as having low back problems for greater than 1 month's duration without specifying how many patients had either acute or chronic symptoms. [188] <http://text.nlm.nih.gov> The third article evaluating ligamentous injections evaluated only patients with chronic low back problems. [187] <http://text.nlm.nih.gov>

Various substances were injected into different ligamentous structures of the low back. Collée, Dijkmans, Vandenbroucke, et al. [186] <http://text.nlm.nih.gov> studied groups receiving injections of either local anesthetic or saline into an area of tenderness over the medial iliac crest (not specified if into muscle or ligamentous attachments). Ongley, Klein, Dorman, et al. [187] <http://text.nlm.nih.gov> evaluated groups receiving injections of either a dilute phenol solution (sclerosing agent) or saline into the lumbar interspinal ligament. Sonne, Christensen, Hansen, et al. [188] <http://text.nlm.nih.gov> evaluated groups receiving injections of either a combination of local anesthetic and steroid or saline alone into the iliolumbar ligament.

Collée, Dijkmans, Vandenbroucke, et al. [186] <http://text.nlm.nih.gov> found that for patients with acute low back pain, there was no significant difference in pain relief between the saline or anesthetic groups, either immediately postinjection or at 1 or 2 weeks followup. Ongley, Klein, Dorman, et al. [187] <http://text.nlm.nih.gov>found greater improvement in pain and disability scores for the patients receiving phenol injections (intended to induce scar) as compared with saline. Sonne, Christensen, Hansen, et al. [188] <http://text.nlm.nih.gov> found that the group receiving injections with a combination of steroid and local anesthetic had significantly greater improvement in symptoms at 2 weeks followup than did the group receiving injections with saline.

Potential Harms and Costs.

The potential risks of trigger point injections include damage to nerves or other tissues, infection, and hemorrhage. [190] <http://text.nlm.nih.gov> The cost for this treatment is considered low to moderate.

Summary of Findings.

Based on limited research evidence in studies that included patients with chronic problems, the efficacy of trigger point or ligamentous injections for treating acute low back problems appears equivocal. The injections can expose patients to serious potential complications.


Bigos S, Bowyer O, Braen G, et al. Acute Low Back Problems in Adults.
Clinical Practice Guideline No. 14. AHCPR Publication No. 95–0642.
Rockville, MD: Agency for Health Care Policy and Research, Public Health
Service, U.S. Department of Health and Human Services. December 1994.