The University of Chicago Journal Club
Participating Faculty: Brown, Lam, Hekmat-Panah, Roitberg
Participating Residents: Ferguson, Hobbs, Bhansali, Shakur, Stamates
Topic: How strong is the evidence for non-operative management of degenerative spine disease?
1) Walker B., French S., Grant W., Green S. A Cochrane Review of Combined Chiropractic Interventions for Low-Back Pain. Spine (Phila Pa 1976). 2011 Feb 1;36(3):230-42.
Hobbs: This article is a Cochrane systematic review of randomized control trials evaluating the effects of combined chiropractic interventions on pain, disability, back-related function, overall improvement, and patient satisfaction in adults with low-back pain (LBP). The combined interventions were compared to other therapies, none of which were surgical. A total of 12 studies were included, only 3 of which were found to have a low risk of bias. Pragmatic trials were selected to analyze the degree of benefit of therapies, as they would be implemented in actual practice. Patient pain was categorized as acute (<6 weeks), subacute (6-12 weeks), or chronic (>12 weeks). Important inclusion/exclusion criteria: studies examining patients with non-specific low back pain were included; studies that include examination of pathological causes, patient’s with low back pain with radiculopathy, or trials with singular therapy were excluded. Duration of pain did not affect inclusion/exclusion.
Patients were evaluated at time intervals defined as short-term (<1 month), medium term (1 month – 6 months) and long-term (6 months or greater). Results of the meta-analysis suggested that combined chiropractic therapeutics provided short-term and medium-term relief for pain and disability in patients with acute and sub-acute LBP, though the effects were small and significantly significant, they were not clinically relevant and did not extend to long-term follow-up.
The paper had several points of contention. Only 3 of 12 papers had low risk of bias, decreasing the validity of results reported. Additionally, when talking of comparing chiropractic therapies to other therapies, the studies actually had the same interventions in the comparative arms, they were merely performed by someone other than a chiropractor, and thus no true comparisons were analyzed. Also, there was no null-hypothesis, so chiropractic interventions could not be compared the natural history of nonspecific LBP, so it is unknown if the interventions actually provide any improvement from what would naturally occur. In conclusion, this is a flawed analysis with questionable, minimal results and more rigorous, valid analysis needs to be performed to truly analyze what benefit these interventions may provide.
Lam: Cochrane reviews are an important educational resource. The message here is not surprising; this review highlights the lack of quality information. Even the interventions to which chiropractic is compared do not have strong evidence to support them. The outcomes of all patients could represent a regression to the mean. Sometimes Cochrane reviews are more proscriptive and directly useful, but not in this case.
Brown: Non-operative interventions, including spinal manipulative therapy (SMT) are viewed as cheaper alternatives in the care of patients with spine problems. There is a complex political pressure, from many directions, to act as if SMT and chiropractic in general, are effective for back pain. Actually it was quite brave for a chiropractor to come out as first author on this review.
Hekmat-Panah: NIH has a section for Alternative Medicine. Politicians dedicated years to promoting such a section. In the end it is not clear that any treatment is cheaper than an operation, in properly selected cases. Nevertheless, the movement to support “Alternative medicine” has a life of its own, despite the lack of scientific evidence. There is even a student group here at The University of Chicago supporting alternative medicine, you can take courses, read testimonials.
Stamates: I would have liked to see the imaging of the patients in the studies summarized here. Without clear pathology we would not offer surgery, and yet people need something, they are asking for some treatment for their suffering.
Roitberg: The authors make a distinction between pragmatic and explanatory trials. “Pragmatic” is defined as studies that evaluate interventions as they would be practiced in real life, whereas ‘explanatory” trials attempt to isolate the studied intervention in a more controlled situation. This review focuses on pragmatic studies. As such, no comparison exists to natural history. We do not know if the lack of efficacy of chiropractic compared to other non-operative intervention is due to both being equally effective, or equally ineffective. If interventions are similar in nature, the result may be similar (for better or worse) regardless of the title of the practitioner doing the intervention. We should also pay attention to the limitation of any meta-analysis – it shoehorns different data into the same scales. This specific analysis also defines short medium and long term outcomes in a way that differs from many other studies. Even the long-term is quite short compared with what would be considered long term in a surgical outcome study (typically two years). However, the Cochrane collaboration reviews are probably the most consistently thorough and rigorous in the literature today.
Chiropractic interventions are paid for and recognized by the government. But as you have seen here – there is not much data to support it for LBP. This is not to say that surgical interventions are automatically preferred. A useless back operation is clearly even worse than a useless non-invasive treatment. Maybe that is the problem – we clearly need real data about efficacy and cost effectiveness of everything we do, with long term prospective and objective follow up. On the other hand – we should not complain too loudly because we often have no effective surgical treatment to offer our patients. In those cases we are happy to refer the patient to non-operative management, even without rigorous proof of efficacy of the latter. Patients come asking for a solution to their pain, and doctors really want to do something or at least recommend something. This has always been the case, even before any effective treatment has been invented.
2) Ammendolia C, Stuber K, de Bruin LK, Furlan AD, Kennedy CA, Rampersaud YR, Steenstra IA, Pennick V. Nonoperative Treatment of Lumbar Spinal Stenosis with Neurogenic Claudication: A systematic review; SPINE, 37 (10) ppE609-616. 2012.
Stamates: This article focuses on the elderly population suffering neurogenic claudication, with “a significant impact on functional ability, quality of life and independence in the elderly.” The authors note that these patients have greater walking limitations when compared to others diagnosed with knee or hip osteoarthritis. Patients with neurogenic claudication are often recommended to undergo conservative treatment, with insufficient evidence for the effectiveness of conservative or non-operative treatment.
“Claudication” in this review was defined as “buttock or leg pain or aching, numbness, tingling, weakness or fatigue with or without back pain, precipitated by standing or walking.” Two independent reviewers screened randomized controlled trials from the largest group of US database collections over the last 20 years. Patient outcomes were measured in the immediate (1 week), short term (1 week-3mo), intermediate (3m-1 yr) and long-term (1 year or greater). Data was assessed by the GRADE and Cochrane Back Review Group scales. The reviewed RCTs and their treatment recommendations were graded as very low evidence, low-quality, moderate-quality or high-quality evidence; 21 total RCTs were selected for full review.
The group of 21 RCTs was limited by a highly diverse patient population whose symptoms varied from 12wk-15yr and with non-uniform follow-up. Thus, only 4 of the studies evaluated were considered low risk of bias; Bias in most studies was attributed to high crossover rates, failure to blind patients and/or health care providers & selective reporting. As for the quality of evidence for interventions, all interventions reviewed had low quality evidence when the studies were reviewed. No conclusions were able to be made about calcitonin, medications (NSAIDs, gabapentin, etc), epidural steroid injections or physical therapy. Although the study was successful in narrowing a large amount of literature into an analyzable section by clearly defining the diagnosis of claudication, there were no clear conclusions to draw. It was not helpful for physicians trying to determine if patients should spend time undergoing conservative, well-known treatments or if surgery should begin to be considered much earlier in the course of the disease. More study into these common methods is needed.
Roitberg: Again we see a dramatic lack of evidence for medical management of a common degenerative spine condition. This time it is not the diffuse “lower back pain” which may have no surgically treatable lesion causing it. Neurogenic claudication typically has a clear pathological correlate - lumbar spinal stenosis, and is mostly treatable with surgical intervention; often quite minimally invasive with low risk and limited cost. The stenosis itself is a mechanical problem that does not resolve with medical management. Surgical treatment for severely symptomatic lumbar spinal stenosis is widely accepted. So why is the medical treatment of this condition so common? Should it be? Although it is tempting as surgeons to answer in the affirmative, we do not know exactly when to recommend an operation for spinal stenosis. Should we do it for all patients with any symptom of neurogenic claudication, even mild? In order to better define the indications we need to study outcomes in a systematic way, using a variety of tools – get patient rated outcomes, measure minimal clinically important difference (MCID) and even grapple with advanced concepts underlying the study of cost effectiveness. We must lead as neurosurgeons, as a profession dedicated to our patients.
Lam: This review demonstrates that it is difficult to perform uniform large scales studies. A more restrictive and centralized medical care system, like the one in Canada or the United Kingdom may allow for more standardized study of efficacy of particular interventions. Regarding the need for better study of outcomes - recently, many attempts have been made to compare the true cost effectiveness of treatments by their effect on quality of life – the metric known as Quality Adjusted Life Years (QALY). The idea is to presume that a year of perfect health equal one, and a year of poor health is worth less, in proportion to the severity of illness or disability. Cost-effectiveness of intervention can be gauged by the amount of QALYs added for a particular cost. However, designing formal intrubments to evaluate QALY is difficult.
Hekmat-Panah: This QALY appears to me a very hypothetical construct. If it is based on questionnaires to healthy people, then it really needs to be validated by asking patients with a disability what their life if worth to them now. Giving a precise numerical value to quality of life is problematic.
3) Manchikanti L, Cash KA, McManus CD, Pampati V, Fellows B. Results of 2-Year Follow-Up of a Randomized, Double-Blind, Controlled Trial of Fluoroscopic Caudal Epidural Injections In Central Spinal Stenosis. Pain Physician 2012; 15:371-384.
Bhansali: This journal article presents the results of a study down to evaluate short- and long-term outcomes of fluoroscopic caudal epidural steroid injections on chronic low back pain related to lumbar stenosis. The study was a double-blind, randomized control trial that evaluated 100 patients, randomized to one of two groups – caudal injections with lidocaine (I), or caudal injections with lidocaine plus betamethasone (II). The patients had to demonstrate long-term pain that was function-limiting, had a radicular component, and they could not have allergies to the agents used, uncontrolled medical or psychiatric conditions, or unstable opioid use. The primary outcome was pain relief and improvement in disability scores of 50% or more. Overall results at the end of 2 years showed attainment of the primary outcome in 38% of Group I members and 44% of Group II members. A further subset of patients, defined as ‘successful’ by achieving 3 or more weeks of relief after the first 2 injections, showed greater improvement, with 51% in the Group I subset achieving the primary outcome and 57% in the Group II subset. The average length of improvement in this Group I subset was 60 weeks, and 54 weeks for the Group II subset.
Discussion: The paper’s authors provide some background to their study design, noting that previous studies have shown improvement of LBP symptoms with injection of saline or lidocaine alone that had comparable benefits to ESIs. However, the authors point out that those studies often did not use fluoroscopy for guidance, and did not consistently look at long-term outcomes, when the effects of lidocaine would be expected to have worn off. The authors use the same argument in regards to the absence of a true placebo group; they acknowledge that epidural saline has provided symptomatic benefit, but it would not be expected to last two years.
The patients were all selected from the same practice group, and the same physician performed all of the injections, providing consistency but limiting the generalizability of the results. There was a low drop-out rate that contrasts with many of the previous LBP intervention studies that suffer from low retention and high cross-over rates. Because this study was performed by pain specialists rather than spine surgeons, it’s not clear what kind of counseling or other interventions these patients had, other than a general sense of ‘conservative’ management, so extrapolating the results and the time course of these patients to a neurosurgical practice must be done with caution.
Dividing the groups into ‘successful’ and ‘failed’ groups based on response to the first 2 injections provided another layer of data to analyze, but it’s not clear how useful those results are. It is not surprising that the group that benefited the most from the injections would show overall better results at 2 years than those who had ‘failed.’ The authors summarize this by saying “the response is only modest in approximately half of the patients feeling significant improvement half of the time.”
Stamates: the study does not have a high value, and is not very reliable. One reason – the authors report a decrease use of narcotic medication at three months, but this being the pain clinic, they are also the ones who prescribe the drugs.
Hobbs: The study demonstrates that steroids have no additional benefit over local anesthetic. However, the side effects of the injections are often related to the steroids. Why use them?
Hekmat-Panah: The symptoms of spinal stenosis fluctuate. Wait for a few weeks and the pain is better. In the cases when an epidural injection has been done, the benefit is ascribed to the injection.
Roitberg: The comparison lacks a formal placebo, and thus can be criticized for comparing interventions that are too much alike. On the other hand, a local injection of anesthetic is supposed to wear off within a few hours. Any longer term effect is ascribed to the steroids. Also, without local anesthetic the patient will clearly feel that the injection is different. So, the steroid free injection was the proper control if we want to study steroids as the active ingredient. Here the results are clear – no added benefit to steroids.
Then what explains those cases where the benefit of the clearly temporary local anesthetic appeared to last? This may be the result of random changes in symptom severity, and surgical placebo effect. A good placebo controlled trial is not easy to design, but this study provides enough material to doubt the efficacy of epidural steroid injections for lumbar spinal stenosis.