Injections for back pain: The evidence is weak

It’s been a while since I did a cycling topic.

As I was skimming thorough the Journal of the American Medical Association recently, I came across this review article on spinal injection therapy for low back pain. It was a shocker.

Two factors brought my attention to the article. First, almost all the cyclists or runners I know have been beset with either back pain or sciatica (referred pain or weakness down the leg). In fact, in some cases, back issues have ended their competitive careers. I too have been flattened with low back pain. It was awful. The other reason to pay attention to the review is the huge numbers of requests I receive from atrial fibrillation (AF) patients who are asking to stop their anticoagulant (blood thinner) for a spinal injection.

Background

Low back issues are even more common than AF. In the US, low back pain accounts for 2% of all doctor’s visits and is the fifth most common reason for visits to primary care. That makes perfect sense, doesn’t it? The same risk factors for heart disease, not moving enough and eating too much, also increase the risk of skeletal issues in the low back. The waiting room of the orthopedist looks very similar to the cardiologist.

Since I am no expert in orthopedics, I will write most of this post from a journalistic standpoint. The facts in the review are striking enough; they don’t need much editorial. My comments will be at the end.

5 facts from the review article

1. There is substantial variation in the use of injections. One study found relatively few providers are responsible for a disproportionately high percentage of injections. The authors of the study called it a“pattern of marked [overuse] by a minority of providers.” There is no data on whether high use rates associate with better outcomes.

2. Not all injections are the same. There are different targets (epidural, facet, discs, and ligaments for example), and different drugs injected. (local anesthetics, steroids, pain meds etc.). Injections are performed in different stages of disease: acute, subacute and chronic. All this variation makes it a tough topic to review.

3. One of the best tools for evaluating the benefits of a treatment is to do a systematic review of all the world’s literature. The Cochrane Collaboration did such a study for spinal injections in 2008. The researchers found that only 6 of 18 trials showed significant results for at least one outcome in favor of the injection. No clear pattern of benefit emerged. The researchers concluded: “There is insufficient evidence to support the use of injection therapy in subacute and chronic low-back pain. However, it cannot be ruled out that specific subgroups of patients may respond to a specific type of injection.”

4. A more recent pooled analysis of 25 studies looked specifically at epidural injections for sciatica. Here, at least there was a very small (6-point on a scale of 0-100) improvement in the short-term. No long-term benefit was noted. The authors concluded: “The small size of the treatment effects raises questions about the utility of this procedure in the target population.”

5. Review of guidelines show only one country (Belgium) recommends spinal injections. The US, UK, and Europe simply do not recommend injection therapy for low back pain. Rather, the guidelines start with education, “back schools,” NSAIDs (editorial comment – be careful), opioid analgesics, back exercises, spinal manipulation, rehabilitation, and behavioral therapy.

The review article concludes:

Patients with low back pain differ in their clinical presentation and may respond differently to treatments. Injection therapy of any kind may be beneficial in individual cases or subgroups. Nevertheless, given the weak scientific evidence base and the availability of noninvasive and more effective alternatives, physicians and policy makers should not recommend the use of injection therapy for patients with low back pain and sciatica.

My comments

This was very surprising. I had no idea that the evidence base for spinal injections was so weak. The concept of putting anti-inflammatory drug right on the source of inflammation makes perfect sense. It hits the problem area without exposing the patient to the risk of systemic exposure to steroids or non-steroidal drugs. You would have thought comparison studies would have strongly favored local injections. But that’s the thing with evidence-based medicine: just because something makes sense, and smart doctors think it so, does not mean it is so.

Spinal injection therapy is an important topic because many of the patients referred for injections are older folks on anticoagulant drugs. Recent studies in the AF literature make it clear that interrupting anticoagulant drugs can be risky. We also know “bridging” patients with (lovenox) shots carries risk. Again we get into net clinical benefit: you don’t mind taking the risk of being off anticoagulation if the benefit is great. This review of the literature on spinal injections suggests otherwise.

The wide-angle overriding view of the matter is always the same in medicine. It’s best to avoid the need for treatment. Human disease is never 100% avoidable, but a healthy and balanced (emphasis especially on balanced) lifestyle reduces the risk of facing tough decisions. And when disease strikes, if it is safe to wait, taking a conservative approach, giving the body time to heal itself, is often just as good as having a sharp object stuck into you.

A final caveat on the JAMA review article. The authors are PhD researchers from a quality healthcare institute. They are not orthopedists. That might have resulted in a biased selection of the literature. An orthopedist/pain interventionalist perspective might have been different.

John Mandrola is a cardiologist who blogs at Dr John M.

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  • ninguem

    I for one am not surprised the data is so weak.

    “…..The concept of putting anti-inflammatory drug right on the source of inflammation makes perfect sense……”

    There in may be the problem. The assumption that we know the anatomic source of the problem.

    • Adiemusfree

      I couldn’t agree more ninguem. And I did do a wee chuckle at a cardiologist suggesting selection bias because the “authors are PhD researchers from a quality healthcare institute”. I’d have thought unbiased reviewers who have no vested interest in the outcome would have been a good thing!

      People seek treatment for back pain because it interferes with daily life, not just pain intensity (Ferriera, et al., 2010) – and psychosocial issues don’t get addressed in biomedical treatment. Back pain is a multifactorial problem – thinking that injecting something, cutting something, burning something or whatever will “fix it” makes little sense when the reasons people are bothered by their pain are related more to psychosocial factors like attitudes, beliefs, fears, social reinforcement and the like. Maybe if we thought about back pain as part of normal human experience, we’d have fewer people looking for help for what is largely a manageable experience.

      Fordyce (1988) said this: We should distinguish pain from suffering. Equally important, we should distinguish suffering from disability. Suffering belongs to the person. Disability is a legal or social judgment, based in part on medical judgments. Whether suffering warrants a person’s designation as disabled and requiring assistance is not a simple question.

      He quotes Waddell (who is an orthopaedic surgeon) saying this:

      “Newly introduced orthopaedic services in a rapidly developing
      country such as Oman are inundated with patients looking for
      treatment for low back pain.., low back pain appears to be
      almost universal. The striking observation in Oman is that al-
      though low back pain is so common, there is very little actual
      disability before the introduction of western medicine. Patients
      are crippled by polio or tuberculosis or thoraco-lumbar fractures but virtually no one goes to bed, no one stays off work, and no one is permanently disabled by simple low back pain. (Waddell,1987, p. 632)
      Would that this approach could be spread more broadly.

  • Suzi Q 38

    Don’t you want to find out why the patient has back pain?
    What if the patient was in so much pain that he had to rest every day for 3 hours, in bed and not get up?
    If the pain is persistent and escalating, at what point do you quit the Advil and Vicodin and move on to an MRI of the entire back and more tests?
    Is 6 months a long time to experience excruciating back pain?

    I am describing the patient scenario of my brother in law,
    who was admitted to the E.R. with severe back pain that started over 6 months prior. He was 52 when he died within 3 months of his diagnosis of pancreatic cancer.

    Back pain. That’s it.

  • drll

    Ninguem’s pithy statement is right on. It is not always easy to diagnose where the pain generator is coming from. Also the technique of the physician can vary and miss the mark as well.

  • ninguem

    The poster is a cardiologist it appears. Not trying to give anyone a hard time, really not.

    Maybe to use a cardiology comparison, we might (just a suggestion), be approaching most back pain, as though we were researching angina pectoris trying to find out what’s wrong with the left arm.

    • drll

      it’s so true. there is so much referred pain it can be hard to diagnose correctly, The biggest problem is it can take a lot of time and thought which often seems to be missing.

  • Ray Foster

    The presumption that “putting anti-inflammatory drug right on the source of inflammation makes perfect sense” is the source of the author’s confusion. First, it assumes that the pain is generated by inflammation. There is no basis for that assumption, although it may be true in some occasions. Second, it presumes that the injected medication, usually an anti-inflammatory depot steroid, actually “stays” at the site of injection. It does not. Although the depot is local, the effect is systemic, similar to the allergist injecting kenalog into one’s backside to treat nasal allergies. There is no logic to the assumption when it is subjected to critical thought. Thus, there are no legitimate studies that show consistent substantial benefit to injection of a steroid that lasts a maximum of 8 days. Do not even get me started on the complete absence of scientific evidence for serial injections.

  • marysue15

    I had sharp, needling low back came that gradually came on after I was hit by a car while riding my bike. I went through a year a physical therapy to no avail. The orthopedic doctors I saw said I must have some type of disk injury, and one even performed cortisone injections in the facet joints. Nothing helped. I was still in a lot of pain. Finally my injury lawyer mentioned a doctor who had helped another client with back pain. This family practice MD in the SF Bay Area said I might have strained ligaments running from the low back to the sacroiliac joint, and did an initial injection of cortisone (using fluoroscopy to direct the needle) in low back ligaments. Bingo. My pain disappeared. He then performed a series of prolotherapy injections in those ligaments, over several months. This was 30 years ago, and I haven’t had a recurrence. I was shocked when I tried telling my previous orthopedic doctors about the prolotherapy–they were not interested and did not want to hear about it. I guess they would rather stick to a prognosis that was incorrect, in my case, instead of learning something.

  • Marvin Israel

    I had two episodes of sciatica. The first was so severe that my left leg collapsed under me as I was walking on my country road and had it not been for a neighbor who saw me in front of his house, I would have had to crawl on all fours back to my house. An epidural got rid of the pain.

    Three years later came another extremely debilitating episode. Again, an epidural got rid of the pain. Ten years later I have had no further severe episodes of sciatica, although a few times I had mild symptoms. I don’t know what I would have done had it not been for the epidural injections.

  • Angel Discoveries

    I received a tainted epidural steroid shot during last year’s national outbreak. I developed severe meningitis, had a stroke and an aneurism and barely survived. I am now permanently in severe chronic pain due to arachnoiditis. I will never get another ESI.

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