https://immattersacp.org/weekly/archives/2017/03/21/1.htm

Glucocorticoid injection provides only short-term relief from chronic low back pain

Patients who received a single intradiscal glucocorticoid injection reported positive effects on pain at one month compared with the control group, but the groups did not differ in low back pain intensity at 12 months and in most secondary outcomes at one and 12 months.


A single intradiscal glucocorticoid injection reduces low back pain associated with active discopathy at one month for patients in whom first-line conservative treatments had failed, a study found. However, the effect decreased over time, with no differences in low back pain intensity between groups at 12 months.

Researchers at three tertiary care centers in France randomly assigned 135 patients with chronic low back pain with active discopathy on magnetic resonance imaging (MRI) to a single intradiscal glucocorticoid injection during discography (n=67) or discography alone (n=68).

The primary outcome was the percentage of patients with low back pain intensity less than 40 on an 11-point numerical rating scale (0 [no pain] to 100 [maximum pain] in 10-point increments) in the previous 48 hours, measured at one month after the intervention. The main secondary outcomes were low back pain intensity and persistent active discopathy on MRI at 12 months and spine-specific limitations in activities, health-related quality of life, anxiety and depression, employment status, and use of analgesics and NSAIDs at one and 12 months.

Results were published online March 21 by Annals of Internal Medicine.

Patients who received a single intradiscal glucocorticoid injection reported positive effects on pain at one month compared with the control group; the percentage of responders with low back pain intensity less than 40 was 55.4% compared to 33% in the control group (absolute risk difference, 22.1 percentage points; 95% CI, 5.5 to 38.7 percentage points; P=0.009). The groups did not differ in low back pain intensity at 12 months and in most secondary outcomes at one and 12 months.

At one month, the percentage of patients reporting improvement in low back pain-related limitations in activities was also higher in the treatment group: 84.6% versus 54.0% (absolute risk difference, 30.5 percentage points; 95% CI, 15.7 to 45.2 percentage points; P<0.001), but no differences were seen at 12 months. Starting at three months, pain scores increased in the treatment group and were higher than in the control group. By 12 months, the groups did not differ in pain intensity.

At 12 months, the mean reduction from baseline in the depression score was slightly smaller in the treatment group (−0.1; 95% CI, −1.2 to 1.0) than in the control group (−1.7; 95% CI, −2.7 to −0.6) (absolute difference, 1.6; 95% CI, 0.1 to 3.0; P=0.035). The groups did not differ in employment status at 12 months or in other secondary outcomes at one and 12 months. Patients rated the predicted usefulness of the intervention in reducing their symptoms at 6.9 (SD, 1.9) on a scale of 1 (not useful) to 9 (very useful).

An editorial noted that glucocorticoid intradiscal injection may be an option for short-term pain relief. “However, in patients with chronic pain, glucocorticoid injection clearly is not effective over the long term,” the editorial stated. “The question then arises about the utility of using an invasive treatment for short-term relief in the setting of an acute condition with a favorable natural history or for an acute flare of a chronic condition.”