Chronic lower back pain, with its very high incidence across the country, is the subject of very many studies and different treatment trials. Many times, a treatment will seem like the perfect solution, only for patients and doctors to realize that the treatment isn’t as effective as they’d hoped or not as available, either cost-wise or practicality-wise.
The authors of this article wanted to see if one treatment that is gaining popularity to treat subacute or chronic low back pain, injections into the back, is helpful or not. The authors undertook to review studies that had been done and see what the general consensus was. The researchers did have to take into account that several of the studies have variations that could result in different findings, such as some studies looked at injections that went directly into the facet joints, others into the epidural space (space around the spinal cord), and yet others in different areas. There were also differences between the different medications used to inject: the corticosteroids tht would reduce inflammation or swelling, analgesics to numb the pain, and antibiotics to fight or reduce the risk of infection. Finally, a third difference is why the injections were done. Were they done for diagnosis or for treatment?
The researchers looked only at randomized, controlled trials. Patients ranged in age from 18 to 70 years and had to have had back pain for at least one month to be considered subacute and four months to be considered chronic back pain.The patients had all received injection therapy for their back pain, in the fact joint sites, epidural sites, and local sites (right where the pain was located). Pain was measured by pain scales, overall improvement, number of patients who were considered recovered, and patient reports of improvement in symptoms.
Eighteen trials were reviewed in all, with a total of 1179 patients. Ten of the trials were considered to be of high quality. Among studies that compared epidural corticosteroids with placebo injections, two studies compared the short-term effects and one of the studies as a high quality study, the second low quality. Both found there wasn’t any significant differences between the patients who received the corticosteroids and those who had placebos. There was a small difference in the corticosteroid group for better short-term movement and moderate evidence for pain relief.
Epidural injections were compared to other treatments for low back pain, such as using medications like NSAIDs (nonsteroidal anti-inflammatory drugs). Three studies looked at NSAIDs with the injections and none showed any increased benefit for either. In a high-quality study, morphine was compared with the injection but that study also didn’t find any significant differences.
Epidural injections with anesthetics were also compared with other treatments. There were no differences in either the low-quality or the moderate-quality studies. When facet joint injections with corticosteroids were compared with placebo injections, two studies (one high quality, one low) found no significant differences in how the patients reported their pain and any improvement when they were evaluated at one and three months after the injections, but at six months, those who had the corticosteroid injections did have better pain relief and function. Three other trials, considered moderate quality, didn’t find any differences in short-term relief and, in fact, two trials contradicted each other.
When the facet joint injections were compared with other treatments, the results were the same again: no significant differences. One small trial (only 84 patients) tried using a medication called sarapin along with the anesthetics and those researchers reported better pain relief, function, and return-to-work rates. Comparing fact joint injections with local anesthetics and other treatments, one high-quality study compared lidocaine with a placebo and the lidocaine group did do better with pain relief. A moderate-evidence trial also found a bit of improvement.
Local injections with corticosteroids compared with placebos, in high-quality and low-quality studies,found that there wasn’t much a difference after, although the high-quality study did report that more patients who had treatment reported improvements two weeks later. Local injections with anesthetics compared with placebos had similar results.
A low-quality study looked at injecting vitamin B12 into the muscles compared with placebo injections in treating the pain. The small study (60 patients) seemed to show that the patients receiving the vitamin did significantly better than those who didn’t, over the short term.
Overall, the evidence showed that there wasn’t a big difference – no increased relief from pain, no improvement in disability, no quicker or higher number of patients returning to work, and little improvement in self-reported pain – among any of the injection treatments.The authors of the article do, however, point out that even though there doesn’t seem to be any added benefit, that doesn’t necessarily mean that the treatment won’t work for individual patients.