A Systematic Review of the Effectiveness of Low Back Surgeries for Pain and Disability, Written for Patients and their Families

It’s common to believe that treatments recommended and performed by healthcare providers are effective. It’s generally understood, for instance, that governmental institutions hold medications to a certain level of scientific scrutiny and, as such, medications have been shown to be effective before healthcare providers are allowed to prescribe them to their patients. Most people think the same is true for procedures that are performed in healthcare. It’s common, for instance, for people to assume that surgeries have undergone governmental-level scientific scrutiny and have been shown to be effective before they are allowed to be performed on patients. 

Surgeries and other procedures, however, are not held to the same level of scrutiny as medications.

In the United States, for example, there is an office of the federal government called the Federal Drug Administration (FDA) that reviews the research on medication effectiveness and holds the research to certain standards before greenlighting them for use in the healthcare system. There is no FDA equivalent, however, for surgeries or other procedures. 

As a result, the healthcare system in the US (at least) relies on both the healthcare providers' knowledge of the effectiveness of surgeries and the professionalism of those providers to do the right thing by their patients. For surgeries and other procedures, in other words, there is no other policing or enforcing agency beyond a healthcare provider’s knowledge of the research and their professionalism to do what they know works for their patients. 

Trust in healthcare providers by their patients is thus paramount. As a patient who is recommended to undergo a surgery or procedure for a health condition, there is no governmental seal of approval, as it were, to be assured that the recommended surgery or procedure has undergone rigorous scrutiny demonstrating its effectiveness. You just have to trust your healthcare provider that they know what they're doing, and that they wouldn’t do anything that’s been demonstrated to be ineffective. 

For some folks, such trust is enough. For after all, you’d have to call into question the whole healthcare community: wouldn’t they be policing themselves, as it were, and not allowing colleagues to perform surgeries that they know are ineffective? You’d also have to call into question the academic institutions that train and mentor healthcare providers both at the beginning of their careers and throughout their careers in terms of continuing education. Wouldn’t such institutions hold themselves and their students to a high standard of care, as defined by only doing surgeries and procedures that have been scientifically proven to work? As such, no one would fault patients and their families when trusting their individual healthcare provider’s recommendations to undergo a surgery or procedure.

With that said, though, some folks might want to know the degree to which a recommended surgery has been proven to be effective. Some patients and their families, in other words, might want to know for themselves whether a surgery or procedure is effective and, if so, how effective. 

This article attempts to help patients and their families do just that when it comes to surgeries for low back pain. Specifically, the goal of this article is to allow patients with low back pain to understand the degree to which surgeries for low back pain have been scientifically proven to be effective. 

The first thing we’ll do is go over how the scientific community determines the effectiveness of a treatment, whether it is a pill, a therapy or a surgical procedure. This involves commonly accepted scientific methods of putting treatments to the test and then publishing those results in professional journals. Armed with this knowledge of how surgeries are scientifically tested for their effectiveness, the second thing we’ll do is review the published research itself to understand a) have surgeries for low back pain been shown to be effective, and b), if so, how effective are they? 

Both of the above-noted questions are important. You probably wouldn’t want to undergo a surgery or procedure if it hasn’t been shown to be effective. Moreover, there’s times where you’d also want to know how effective a treatment is. It’s an important part of informed consent to know whether a surgery or procedure will help just a little bit or a whole lot. It’s especially true when a surgery or procedure comes with risks in terms of making things worse, or costs in terms of duration of recovery and being out of work, or financial costs. A 4-6-week recovery period of being out of work, for instance, could be viewed very differently if you know the procedure will reduce back pain by 10% or 75%. Surgical risks or a large out-of-pocket expense may or may not be worth it if the procedure leads to an 8-point reduction or 1-point reduction on the usual 0-to-10 rating scale. 

So, let’s look at whether surgeries for low back pain are effective and, if so, how effective they are.

How is effectiveness proven in scientific research?

First, we need to know something about how the healthcare community answers these questions. Such understanding will help to have faith in the scientific findings.

For our purposes, there are two broadly defined types of healthcare effectiveness research. The first is what are referred to as observational studies. An observational study is one in which researchers simply keep track of outcomes of a treatment that’s provided within the routine care of patients. The treatment is typically provided in the usual course of patient care within the setting of a clinic and hospital, and the researchers piggyback on it by tracking the outcomes of such care. Commonly, these outcomes of the treatment under consideration are compared to outcomes of a different treatment or treatments. In the case of observational studies related to surgery for low back pain, the outcomes of surgical patients would be compared to outcomes of patients who decided against surgery and received other types of care instead. The latter care is typically referred to as non-operative care. The second type of research is referred to as clinical trials. In clinical trials, the research is the primary reason for providing the treatment under consideration, (whereas with observational studies, the research is more after the fact). In a clinical trial, patients who are candidates for a treatment are randomly selected for either the treatment or a comparison treatment. The comparison treatment in clinical trials for low back surgeries is typically standard, non-operative care. The random selection of which treatments patients receive is a way to reduce patient bias. Patients might believe that a certain treatment is better than another treatment, and such beliefs can influence outcomes. The researchers who assess the outcomes of the different types of treatments also don’t know which treatment the patients received. This practice reduces the risk of bias on the part of the researchers, who may unconsciously want one treatment to be better than the other. 

Clinical trials are generally thought of as more rigorous and valid than observational studies. In other words, the scientific community trusts the results of clinical trials more than observational studies.

To increase this trust in the validity of the results, the scientific community repeats clinical trials with different researchers and patients. One clinical trial testing the effectiveness of a surgery for low back pain, for instance, isn’t enough to really know if the surgery is effective or not. Other groups of researchers need to do their own clinical trials to see if they get the same results or not. If they do, then it is safer to conclude that the results of the research are accurate and true. 

The most scientifically accepted way to look at the results of all the different clinical trials testing a given treatment is called a meta-analysis. A meta-analysis is when an independent group of researchers collect all the outcomes of all the clinical trials of a given treatment, and combines them together to make one gigantic study. With these pooled results, they run the statistics to see if the results, in our case surgery for low back pain, are better than the comparison treatment, in our case, non-operative care. Meta-analyses are commonly thought to produce the most valid, or trustworthy, results.

In what follows, we will systematically review all published meta-analyses of studies comparing surgeries for low back pain with standard, non-operative care for low back pain. A systematic review is a standard way to report on all published studies by identifying them in various databases of published research. 

The present systematic review searched PubMed, Google Scholar, and Cochrane Database of Systematic Reviews. The time frame for database search was from 2012 to 2022 in order to achieve the most up-to-date research. 

There are different types of surgeries for low back pain. The surgeries include: 

• discectomies for disc herniation
• decompression surgeries for spinal stenosis
• fusion for low back pain 

Sometimes, of course, these procedures can be combined when doing surgery. For our purposes, though, we will report on the scientific findings of research on the effectiveness of each individual type.

As a way to have the most faith in the findings, this review reports on only meta-analyses. 

With that said, a few caveats are in order. Some of the meta-analyses combined both observational studies and clinical trials, whereas some combined only clinical trials. Combining both is sometimes necessary when there aren’t a lot of clinical trials to pool, such as in the case with clinical trials of surgeries for low back pain. Many readers might be surprised to learn that research comparing surgeries and non-operative care for low back pain is uncommon. Simply put, there just isn’t a lot of such research studies looking at whether surgery for low back pain is effective or not. As such, the different meta-analyses tended to combine some of the same previously published studies. Another important point is that the authors from all meta-analyses commented that the quality of studies on spine surgery is low. Many of the studies that went into the meta-analyses were observational studies where risk of bias on the part of patients or researchers were high. They noted other flaws in the research too, for which we don’t need to go into detail for our purposes. Suffice it to say, though, that the overall body of research on the effectiveness of surgery for low back pain is marked by a small number of research studies the quality of which is low.

The criteria for effectiveness that we will use in this review are pain reduction and reduction in disability. In general, researchers looking at surgery effectiveness are also interested in complication rates, re-operation rates, and rates of full fusion for fusion surgeries, in addition to reductions in pain and disability. However, in this systematic review for patients and their families, we will only report on reductions of pain and disability.

Effectiveness in healthcare research is measured statistically, with what is called a test of statistical significance. It’s a complex statistical calculation that shows that the effect of a treatment is unlikely to have been produced by random chance. When we say that the effect of a treatment is statistically significant or that one treatment is statistically more effective than another treatment, we can be reasonably confident that it was the treatment that produced the result and not just sheer luck. 

We also want to know how effective a treatment is and for that issue the criterion we use is what’s called clinical significance. Clinical significance attempts to measure the degree to which patients would notice the (statistically significant) result of a treatment. Sometimes a treatment effect might be so small it’s hardly noticeable. Other times, the results of a treatment might be moderately noticeable and still other times the effect would be so great that you feel great afterwards. The size of the effect of a treatment can thus be measured:

• Less than 10% improvement in symptoms is thought to be a small improvement and not clinically significant
• 10-20% improvement is thought to be a medium improvement and is considered clinically significant
• Greater than 20% improvement is thought to be a large improvement and is also considered clinically significant.¹

With this understanding, let’s look at what the research tells us about the effectiveness of surgery.

Is surgery for low back pain effective? If so, how effective is surgery for low back pain?

• Discectomy for disc herniation

Arts, et al.,² combined studies that compared two types of lumbar discectomies for disc herniation against each other as well as against non-operative care. The two types of surgeries were discectomy or discectomy plus the insertion of a mesh anchored to the bone. When comparing the effectiveness of these surgeries to non-operative care, the non-operative care consisted of physical therapy, chiropractic care, interventional procedures, medications, pain psychology interventions, and the like. 

The meta-analysis of only clinical trials showed that discectomy alone was statistically more effective than non-operative care, but only minimally. Specifically, discectomy alone reduced leg pain associated with disc herniation by 1-point more, on a 0-10 point pain rating scale, than non-operative care. For back pain, it reduced pain by approximately 0.7 points on the 0-10 scale. These differences wouldn’t be considered clinically significant, as they aren’t large enough to be noticed by most people with low back pain. In other words, the surgery does produce a difference in terms of pain reduction, but it isn't a large enough difference to actually make a difference in the lives of people with low back pain.*

Chen, et al.,³ identified and pooled studies of surgery outcomes when compared to non-operative care and found statistically significant differences in the amount of pain reduction between the two types of care at 3-month and 6-month follow-up periods, but not at 1-year. However, again, the differences were small and unlikely to be clinically significant. For studies utilizing the Oswestry Disability Index, a standard measure of disability, the combined results showed statistically significant differences in the functioning of those receiving surgery when compared to those receiving non-operative care at 6-months and 1-year follow-up periods. However, the differences in improved functioning were small and unlikely to be clinically significant. For studies using the Roland-Morris Disability Questionnaire, another standard measure of perceived disability, there was no difference in the degree of functional improvement between those receiving surgery versus those receiving non-operative care. 

In an interesting take on the question of the effectiveness of surgery for low back pain, Reiman, et al.,⁴ looked at the outcome variable of athletes returning to their chosen sport following surgery for lumbar disc herniation. The comparison treatment was non-operative care. They found no difference in the rate of returning to sport based on surgery or non-operative care for disc herniation. Moreover, most athletes returned to playing their sport regardless of whether they had surgery or not. 

• Decompression for spinal stenosis

Ma, et al.,⁵ performed a meta-analysis that combined the results of all surgery types for lumbar stenosis and compared their effectiveness to non-operative care. Noting the variability in types of surgeries for lumbar stenosis, the study involved decompression, laminectomy with- or without fusion, among others. Non-operative care consisted of mostly physical therapy, but also some studies that included interventional procedures. Oddly, despite the study being a meta-analysis, the researchers did not report combined outcomes for pain even though early in the article they stated that their intention was to report pooled results for pain reduction at 6-months, 1-year and 2-year post treatment. Instead, they reported only that the results of the combined studies comparing lumbar surgeries for stenosis with non-operative were “contradictory” and listed the studies individually. Presumably, the pooled analysis did not yield a statistically significant difference between surgery and non-operative care at any of the follow-up periods. The researchers did, however, report on their combined analysis results at 6-months post-treatment on the Oswestry Disability Index, a commonly used measure of disability. The findings showed no difference between surgery and non-operative care. Looking at results further out, meta-analysis showed a very small statistically significant difference and an even smaller statistically significant difference on the measure of disability, both in favor of surgery, at 1-year and 2-year follow-up, respectively. The small size of these differences were not clinically significant, in that they’d unlikely be noticeable to people with low back pain.

In their meta-analysis, Zaina, et al.,⁶ also attempted to combine outcomes from studies involving surgical interventions versus non-operative care for lumbar spinal stenosis. Similar to the study above, they found that meta-analysis wasn’t possible for the variable of pain reduction, presumably for lack of data from multiple studies. As a result, they reported on one individual study regarding pain as an outcome, which showed no difference between decompression surgery and non-operative care at 3-months, 4-years and 10-years follow-up periods.

Meta-analysis was, however, possible for the outcome of disability. Their study showed no difference between surgery and non-operative care for lumbar stenosis at 6-months and 1-year follow-up. They found a small significant difference in favor of surgery at 2-years, in terms of reduced disability, but it’s unlikely to be clinically relevant as the reduction was less than a 10% reduction on the disability rating scale. 

The researchers concluded that there was insufficient evidence to show that surgery for lumbar stenosis was more effective than usual non-operative care. 

• Fusion for low back pain

In their meta-analysis, Yavin, et al.,⁷ compared fusion for low back pain with non-operative care. Combining outcomes from observational studies, they found no difference between those receiving fusion versus those receiving non-operative care. When they isolated and combined only the randomized clinical trials (studies which are generally considered more rigorus than observational studies), they found a small, statistically significant difference in pain reduction for fusion surgeries over non-operative care. This small difference would not be considered clinically significant in the sense that it is too small of a difference to make a difference in the lived experience of people with back pain.

Conclusion in Plain Language

This systematic review looked at all published meta-analyses on the effectiveness of surgery for low back pain. These surgeries were discectomies for disc herniation, decompression for spinal stenosis, and fusion. Discectomies were the only type of surgery that had demonstrated effectiveness, though effectiveness is only minimal.

Specifically, for discectomies, the research shows that surgery for disc herniations produces a demonstrable result in terms of reductions in pain and disability, but the results are so small that it wouldn’t generally be considered clinically relevant to the lives of people with low back pain. At most, surgery for disc herniation reduces pain and disability by about 10%. 

The research for decompression surgery shows that it is no more effective than not having surgery and pursuing standard non-operative care instead. In other words, decompression surgery for low back pain adds no value to the usual care of physical therapy and interventional procedures. 

Fusion surgery shows a small reduction in low back pain when compared to usual, non-operative care. However, this small reduction is apt to be clinically insignificant. In other words, the difference that fusion makes is so small that it is unlikely to be noticable in the lived experience of people with low back pain.  

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*Interestingly, the abstract concludes that lumbar discectomy “...is more effective than [non-operative care] in alleviating symptoms of lumbar disc herniation…”, but doesn’t specify that it is only minimally so.

References

1. Higgins J.P. & Green, S. (Eds). (2011). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration.

2. Arts, M. P., Kuršumović, A., Miller, L. E., Wolfs, J. F. C., Perrin, J. M., Van de Kelft, E., & Heidecke, V. (2019). Comparison of treatments for lumbar disc herniation: Systematic review with network meta-analysis. Medicine, 98(7):e14410. doi: 10.1097/MD.0000000000014410. PMID: 30762743; PMCID: PMC6408089.

3. Chen, B., Guo, J., Zhang, H., Zhang, Y., Zhu, Y., Zhang, J., Hu, H., Zheng, Y., & Wang, X. (2017). Surgical versus non-operative treatment for lumbar disc herniations: A systematic review and meta-analysis. Clinical Rehabilitation, 32(2). doi: 10.1177/0269215517719952

4. Reiman, M. P., Sylvain, J., Loudon, J. K., & Goode, A. (2016). Return to sport after open and microdiscectomy surgery versus conservative treatment for lumbar disc herniation: A systematic review with meta-analysis. British Journal of Sports Medicine, 50, 221-230.

5. Ma, X., Zhao, X., Ma, J., Li, F., Wang, Y., & Wu, B. (2017). Effectiveness of surgery versus conservative treatment for lumbar spinal stenosis: A system review and meta-analysis of randomized controlled trials. International Journal of Surgery, 44, 329-338. doi: 10.1016/ijsu.2017.07.032

6. Zaina, F., Tomkins-Lane, C., Carragee, E., Negrini, S.& Cochrane Back and Neck Group. (2016). Surgical vs. non-surgical treatment for lumbar spinal stenosis. The Cochrane database of systematic reviews, 2016(1), CD010264. doi.org/10.1002/14651858.CD010264.pub2

7. Yavin, D., Casha, S., Wiebe, S., Feasby, T. E., Clark, C., Isaacs, A… & Jette, N. (2017). Lumbar fusion for degenerative disease: A systematic review and meta-analysis. Neurosurgery, 80(5), 701-715. doi: 10.1093/neuros/nyw162

Date of publication: 11-22-2022

Date of last modification: 11-22-2022

About the author: Murray J. McAllister, PsyD, is a pain psychologist and consults to clinics and health systems on improving pain care. He is the founder and editor of the Institute for Chronic Pain. The Institute for Chronic Pain provides academic quality information that is approachable to all.