One of the many issues that needs addressing about chiropractic is its safety. On this blog, we have had dozens of posts and debates on this topic. Today, I want to try and summarise them by providing a fictitious dialogue between a critic and a chiropractor.
Here we go:
Critic (CR): It seems to me that most of the chiros I talk to are convinced that their hallmark therapy, spinal manipulation, is risk-free.
Chiro (CH): Hallmark therapy? Not true! Osteopaths, physios, doctors they all use spinal manipulation.
CR: I know, but name me a profession that employs it more regularly than you chiros.
CH: In any case, it is as good as risk-free; nothing is totally devoid of risk, but chiropractic spinal manipulation (CSMT) is generally very safe, because we are better trained at it than the others.
CR: Do you say that because you believe it or because you know it?
CH: I know it.
CR: That means you have the evidence to prove it?
CH: Yes, of course. Over the years, I have treated over a thousand patients and never heard of any problems.
CR: Without a monitoring system of adverse events that occur after chiropractic spinal manipulation, this is pretty meaningless.
CH: Monitoring systems do not establish causality.
CR: No, but they are a start and can tell you whether there is a problem that requires looking into.
CH: Let me remind you please that the question of safety is foremost an issue for conventional medicine; this is why a monitoring system is useful for drugs. We actually do not need one, because CSMT is safe.
CR: Are you sure?
CR: The much-cited paper by Dabbs and Lauretti is out-dated, poor quality, and heavily biased. It provides no sound basis for an evidence-based judgement on the relative risks of cervical manipulation and NSAIDs. The notion that cervical manipulations are safer than NSAIDs is therefore not based on reliable data. Thus, it is misleading and irresponsible to repeat this claim. Is there not a better comparison for supporting your point?
CH: Not as far as I know. But you can trust our collective experience: CSMT is safe!
CR: Don’t you think that the issue is too important to rely purely on experience? Your collective experience can be very misleading, you know.
CH: Then tell me why chiros pay only a fraction of the insurance premium compared to doctors.
CR: Yes, that is the argument many chiros love. But it also is a very poor one: doctors treat patients who are often very ill, while chiros treat mostly sore backs. Don’t you think that explains a lot about the difference in insurance premiums?
CH: Perhaps, but if you claim CSMT to be harmful, how about you supporting your claim with evidence?
CR: Sure, the best is to review systematically all prospective studies on the topic; and if you do this, the conclusion is that data from prospective studies suggest that minor, transient adverse events occur in approximately half of all patients receiving spinal manipulation. The most common serious adverse events are vertebrobasilar accidents, disk herniation, and cauda equina syndrome. Estimates of the incidence of serious complications range from 1 per 2 million manipulations to 1 per 400,000. Given the popularity of spinal manipulation, its safety requires rigorous investigation.
CH: I bet these are studies done by people who are against chiropractic.
CR: No, actually the primary studies were all done by chiropractors.
CH: Minor transient problems! These are merely what we expect; things often need to get worse before they get better.
CR: Imagine that a drug company claims such BS about the side-effects of a new drug.
CH: But that’s different!
CR: In what way?
CH: Big Pharma is only out to make money.
CR: And chiros?
CH: That’s different too.
CR: What about the serious adverse events like vertebrobasilar accidents, disk herniation, and cauda equina syndrome? Are you going to deny they exist?
CH: Some of those serious complications, while rare, are conditions that existed prior to CSMT being performed with the practitioner missing it upon initial examination.
CR: How do you know?
CH: I know this from experience.
CR: I already told you that experience is unreliable.
CH: Then show me the evidence that I am wrong.
CR: No, you have to come up with the evidence; the burden of proof is evidently on your shoulders.
CH: Whatever! As long as there is no good evidence, I cannot accept that serious complications are a real problem.
CR: That’s just fine: you say “as long as there is no good evidence…” and, at the same time, you prevent good evidence from emerging by preventing a decent AE monitoring system.
CH: I always knew that one cannot have a reasonable discussion with you. I consider that I have won this debate; this issue is now closed.
On this blog, I have discussed the adverse events (AEs) of spinal manipulative therapy (SMT) with some regularity, and we have seen that ~ 50% of patients who receive SMT from a chiropractor experience some kind of AE. In addition there are many serious complications. In my book, I discuss, apart from the better-known vascular accidents followed by a stroke or death, the following:
- atlantoaxial dislocation,
- cauda equina syndrome,
- cervical radiculopathy,
- diaphragmatic paralysis,
- disrupted fracture healing,
- dural sleeve injury,
- haemorrhagic cysts,
- muscle abscess,
- muscle abscess,
- neurologic compromise,
- oesophageal rupture
- soft tissue trauma,
- spinal cord injury,
- vertebral disc herniation,
- vertebral fracture,
- central retinal artery occlusion,
- Wallenberg syndrome,
- loss of vision,
- Horner’s syndrome.
Considering this long list, we currently have far too little reliable information. A recent publication offers further information on this important topic.
The aim of this study was to identify beliefs, perceptions and practices of chiropractors and patients regarding benign AEs post-SMT and potential strategies to mitigate them. Clinicians and patients from two chiropractic teaching clinics were invited to respond to an 11-question survey exploring their beliefs, perceptions and practices regarding benign AEs post-SMT and strategies to mitigate them.
A total of 39 clinicians (67% response rate) and 203 patients (82.9% response rate) completed the survey. The results show that:
- 97% of the chiropractors believed benign AEs occur.
- 82% reported their own patients have experienced an AE.
- 55% of the patients reported experiencing benign AEs post-SMT, with the most common symptoms being pain/soreness, headache and stiffness.
- 61.5% of the chiropractors reported trying a mitigation strategy with their patients.
- Yet only 21.2% of patients perceived their clinicians had tried any mitigation strategy.
- Chiropractors perceived that patient education is most likely to mitigate benign AEs, followed by soft tissue therapy and/or icing after SMT.
- Patients perceived stretching was most likely to mitigate benign AEs, followed by education and/or massage
The authors concluded that this is the first study comparing beliefs, perceptions and practices from clinicians and patients regarding benign AEs post-SMT and strategies to mitigate them. This study provides an important step towards identifying the best strategies to improve patient safety and improve quality of care.
The question that I have often asked before, and I am bound to ask again after seeing such results, is this:
If there were a drug that causes temporary pain/soreness, headache and stiffness in 55% of all patients (plus an unknown frequency of a long list of serious complications), while being of uncertain benefit, do you think it would still be on the market?
My new book has just been published. Allow me to try and whet your appetite by showing you the book’s introduction:
“There is no alternative medicine. There is only scientifically proven, evidence-based medicine supported by solid data or unproven medicine, for which scientific evidence is lacking.” These words of Fontanarosa and Lundberg were published 22 years ago. Today, they are as relevant as ever, particularly to the type of healthcare I often call ‘so-called alternative medicine’ (SCAM), and they certainly are relevant to chiropractic.
Invented more than 120 years ago by the magnetic healer DD Palmer, chiropractic has had a colourful history. It has now grown into one of the most popular of all SCAMs. Its general acceptance might give the impression that chiropractic, the art of adjusting by hand all subluxations of the three hundred articulations of the human skeletal frame, is solidly based on evidence. It is therefore easy to forget that a plethora of fundamental questions about chiropractic remain unanswered.
I wrote this book because I feel that the amount of misinformation on chiropractic is scandalous and demands a critical evaluation of the evidence. The book deals with many questions that consumers often ask:
- How well-established is chiropractic?
- What treatments do chiropractors use?
- What conditions do they treat?
- What claims do they make?
- Are their assumptions reasonable?
- Are chiropractic spinal manipulations effective?
- Are these manipulations safe?
- Do chiropractors behave professionally and ethically?
Am I up to this task, and can you trust my assessments? These are justified questions; let me try to answer them by giving you a brief summary of my professional background.
I grew up in Germany where SCAM is hugely popular. I studied medicine and, as a young doctor, was enthusiastic about SCAM. After several years in basic research, I returned to clinical medicine, became professor of rehabilitation medicine first in Hanover, Germany, and then in Vienna, Austria. In 1993, I was appointed as Chair in Complementary Medicine at the University of Exeter. In this capacity, I built up a multidisciplinary team of scientists conducting research into all sorts of SCAM with one focus on chiropractic. I retired in 2012 and am now an emeritus professor. I have published many peer-reviewed articles on the subject, and I have no conflicts of interest. If my long career has taught me anything, it is this: in the best interest of consumers and patients, we must insist on sound evidence; not opinion, not wishful thinking; evidence.
In critically assessing the issues related to chiropractic, I am guided by the most reliable and up-to-date scientific evidence. The conclusions I reach often suggest that chiropractic is not what it is often cracked up to be. Hundreds of books have been published that disagree. If you are in doubt who to trust, the promoter or the critic of chiropractic, I suggest you ask yourself a simple question: who is more likely to provide impartial information, the chiropractor who makes a living by his trade, or the academic who has researched the subject for the last 30 years?
This book offers an easy to understand, concise and dependable evaluation of chiropractic. It enables you to make up your own mind. I want you to take therapeutic decisions that are reasonable and based on solid evidence. My book should empower you to do just that.
Tasuki is a sort of sash for holding up the sleeves on a kimono. It also retracts the shoulders and keeps the head straight up. By correcting the wearer’s posture, it might even prevent or treat neck pain. The greater the forward head posture, for example, the more frequent are neck problems. However, there is little clinical evidence to support or refute this hypothesis.
This study was conducted to determine whether Tasuki-style posture supporter improves neck pain compared to waiting-list. It was designed as an individually-randomized, open-label, waiting-list-controlled study. Adults with non-specific chronic neck pain who reported 10 points or more on modified Neck Disability Index (mNDI: range, 0-50; higher points indicate worse condition) were enrolled. Participants were randomly assigned 1:1 to the intervention group or to a waiting-list control group. The primary outcome was the change in mNDI at 1 week.
In total, 50 participants were enrolled. Of these participants, 26 (52%) were randomly assigned to the intervention group and 24 to the waiting-list. Attrition rate was low in both groups (1/50). The mean mNDI change score at 1 week was more favourable for Tasuki than waiting-list (between-group difference, -3.5 points (95% confidence interval (CI), -5.3 to -1.8); P = .0002). More participants (58%) had moderate benefit (at least 30% improvement) with Tasuki than with waiting-list (13%) (relative risk 4.6 (95% CI 1.5 to 14); risk difference 0.45 (0.22 to 0.68)).
The author concluded that this trial suggests that wearing Tasuki might moderately improve neck pain. With its low-cost, low-risk, and easy-to-use nature, Tasuki could be an option for those who suffer from neck pain.
In the previous two posts, we discussed how lamentably weak the evidence for acupuncture and spinal manipulation is regarding the management of pain such as ‘mechanical’ neck pain. Here we have a well-reported study with a poor design (no control for non-specific effects) which seems to suggest that simply wearing a Tasuki is just as effective as acupuncture or spinal manipulation.
What is the lesson from this collective evidence?
Is it that we should forget about acupuncture and spinal manipulation for chronic neck pain?
Or is it that poor trial designs generate unreliable evidence?
Or is it that any treatment, however daft, will generate positive outcomes, if the researchers are sufficiently convinced of its benefit?
Yes, I think so.
If you had chronic neck pain, would you rather have your neck manipulated, needles stuck into your body, or get a Tasuki? (Spoiler: Tasuki is risk-free, the other two treatments are not!)
Non-specific chronic neck pain is a common condition. There is hardly a so-called alternative medicine (SCAM) that is not advocated for it. Amongst the most common approaches are manual therapy and therapeutic exercise. But which is more effective?
This study was aimed at answering the question by comparing the effects of manual therapy and therapeutic exercise. The short-term and mid-term effects produced by the two therapies on subjects with non-specific chronic neck pain were studied. The sample was randomized into three groups:
- spinal manipulation (n=22),
- therapeutic exercise (n=23),
- sham treatment (n=20).
The therapists were physiotherapists. Patients were not allowed any other treatments that the ones they were allocated to. Pain quantified by visual analogue scale, the pressure pain threshold, and cervical disability quantified by the Neck Disability Index (NDI) were the outcome measures. They were registered on week 1, week 4, and week 12.
No statistically significant differences were obtained between the experimental groups. Spinal manipulation improved perceived pain quicker than therapeutic exercise. Therapeutic exercise reduced cervical disability quicker than spinal manipulation. Effect size showed medium and large effects for both experimental treatments.
The authors concluded that there are no differences between groups in short and medium terms. Manual therapy achieves a faster reduction in pain perception than therapeutic exercise. Therapeutic exercise reduces disability faster than manual therapy. Clinical improvement could potentially be influenced by central processes.
The paper is poorly written (why do editors accept this?) but it laudably includes detailed descriptions of the three different interventions:
Group 1: Manual therapy
“Manual therapy” protocol was composed of three techniques based on scientific evidence for the treatment of neck pain. This protocol was applied in the three treatment sessions, one per week.
- 1.High thoracic manipulation on T4. Patients are positioned supine with their arms crossed in a “V” shape over the chest. The therapist makes contact with the fist at the level of the spinous process of T4 and blocks the patient’s elbows with his chest. Following this, he introduces flexion of the cervical spine until a slight tension is felt in the tissues at the point of contact. Downward and cranial manipulation is applied. If cavitation is not achieved on the first attempt, the therapist repositions the patient and performs a second manipulation. A maximum of two attempts will be allowed in each patient.
- 2.Cervical articular mobilization (2 Hz, 2 min × 3 series). The patient is placed on the stretcher in a prone position, placing both hands under his forehead. The therapist makes contact with his two thumbs on the spinous process of the patient’s C2 vertebra and performs grade III posteroanterior impulses at a speed of 2 Hz and for 2 min. There are 3 mobilization intervals with a minute of rest between each one of them .
- 3.Suboccipital muscle inhibition (3 min). With the patient lying supine, the therapist places both hands under the subject’s head, by contacting their fingers on the lower edge of the occipital bone, and exerts constant and painless pressure in the anterior and cranial direction for 3 min.
Group 2: Therapeutic exercise
“Therapeutic exercise” protocol: this protocol is based on a progression in load composed of different phases: at first, activation and recruitment of deep cervical flexors; secondly, isometric exercise deep and superficial flexors co-contraction, and finally, eccentric recruitment of flexors and extensors. This protocol, as far as we know, has not been studied, but activation of this musculature during similar tasks to those of our protocol has been observed. This protocol was taught to patients in the first session and was performed once a day during the 3 weeks of treatment, 21 sessions in total. It was reinforced by the physiotherapist in each of the three individual sessions.
Week 1: Exercises 1 and 2.
- 1.Cranio-cervical flexion (CCF) in a supine position with a towel in the posterior area of the neck (3 sets, 10 repetitions, 10 s of contraction each repetition with 10 s of rest).
- 2.CCF sitting (3 sets, 10 repetitions, 10 s of contraction each repetition with 10 s of rest)
Week 2: Exercises 1, 2, 3, and 4.
- 3.Co-contraction of deep and superficial neck flexors in supine decubitus (10 repetitions, 10 s of contraction with 10 s of rest).
- 4.Co-contraction of flexors, rotators, and lateral flexors. The patients performed cranio-cervical flexion, while the physiotherapist asked him/her to tilt, rotate, and look towards the same side while he/she opposes a resistance with his/her hand (10 repetitions, 10 s of contraction with 10 s of rest).
Week 3: Exercises 1, 2, 3, 4, 5, and 6.
- 5.Eccentric for extensors. With the patient seated, he/she should perform cervical extension. Then, he/she must realize a CCF and finish doing a cervical flexion (10 repetitions).
- 6.Eccentric for flexors. The patients, placed in a quadrupedal and neutral neck position, should perform neck flexion; then, they must have done a cranio-cervical flexion and, maintaining that posture, extend the neck and then finally lose the CCF (10 repetitions).
Group 3: Sham treatment
For the “control” protocol, the patients were placed in the supine position, while the physiotherapist placed his hands without therapeutic intention on the patient’s neck for 3 min. The physiotherapist simulated the technique of suboccipital inhibition. Later, with the laser pointer off, patients were contacted without exerting pressure for 10 s. Patients assigned to the control group received treatment 1 or 2 after completing the study.
This study has many strengths and several weaknesses (for instance the small sample sizes). Its results are not surprising. They confirm what I have been pointing out repeatedly, namely that, because exercise is cheaper and has less potential for harm, it is by far a better treatment for chronic neck pain than spinal manipulation.
Pisa syndrome (PS) is a condition in which there is sustained involuntary flexion of the body and head to one side and slight rotation of the trunk so the person appears to lean like the Leaning Tower of Pisa. The PS can occur as a complication of Parkinson’s disease (PD). It can also be an adverse effect of some medications. It is characterized by a trunk lateral flexion higher than 10 degrees which is reversible when lying. The underlying pathophysiological mechanisms responsible for the development of PS are poorly understood. One pathophysiological hypothesis is that PS in PD is caused by an altered verticality perception, due to a somatosensory impairment.
The management of PS remains a challenge. Physiotherapy with early rehabilitation emphasising stretching exercises for the external oblique and paraspinal muscles is usually recommended. Therapy is also needed to improve static, dynamic posture and the control of pain symptoms. Osteopathic Manipulative Treatment (OMT) is also sometimes advocated for PS, but does it work?
The aim of the study was to assess OMT efficacy on postural control in PD-PS patients by stabilometry. In this single-blinded trial the investigators studied 24 PD-PS patients, 12 of whom were randomly assigned to receive a multidisciplinary physical therapy protocol (MIRT) and sham OMT, while the other 12 received OMT plus MIRT for one month. The primary endpoint was the eye closed sway area assessment after the intervention. Evaluation of trunk lateral flexion (TLF) was also performed.
At one month, the sway area of the OMT group significantly decreased compared to placebo (mean delta OMT – 326.00±491.24 mm2, p = 0.01). The experimental group TLF showed a mean inclination reduction of 3.33 degrees after treatment (p = 0.044, mean d = 0.54). Moreover, a significant positive association between delta ECSA and delta TLF was observed (p = 0.04, r = 0.46).
The authors concluded that among PD-PS patients, MIRT plus OMT showed preliminary evidence of postural control and TLF improvement, compared to the control group.
The authors entitled their paper ‘Efficacy of Osteopathic Manipulative Treatment on Postural Control in Parkinsonian Patients With Pisa Syndrome: A Pilot Randomized Placebo-Controlled Trial’. As a pilot study, it should not test efficacy but explore the feasibility of a definitive trial. The fact the authors report outcome data, indicates to me that this is, in fact, not a pilot study, but a hopelessly underpowered clinical trial. This means that the findings could be due merely to chance alone. And this, in turn, means that the researchers owe it to their patients to conduct a properly powered RCT.
During my almost 30 years of research into so-called alternative medicine (SCAM), I have published many papers which must have been severe disappointments to those who advocate SCAM or earn their living through it. Many SCAM proponents thus reacted with open hostility. Others tried to find flaws in those articles which they found most upsetting with a view of discrediting my work. The 2012 article entitled ‘A Replication of the Study ‘Adverse Effects of Spinal Manipulation: A Systematic Review‘ by the Australian chiropractor, Peter Tuchin, seems to be an example of the latter phenomenon (used recently by Jens Behnke in an attempt to defame me).
Here is the abstract of the Tuchin paper:
Objective: To assess the significance of adverse events after spinal manipulation therapy (SMT) by replicating and critically reviewing a paper commonly cited when reviewing adverse events of SMT as reported by Ernst (J Roy Soc Med 100:330-338, 2007).
Method: Replication of a 2007 Ernst paper to compare the details recorded in this paper to the original source material. Specific items that were assessed included the time lapse between treatment and the adverse event, and the recording of other significant risk factors such as diabetes, hyperhomocysteinemia, use of oral contraceptive pill, any history of hypertension, atherosclerosis and migraine.
Results: The review of the 32 papers discussed by Ernst found numerous errors or inconsistencies from the original case reports and case series. These errors included alteration of the age or sex of the patient, and omission or misrepresentation of the long term response of the patient to the adverse event. Other errors included incorrectly assigning spinal manipulation therapy (SMT) as chiropractic treatment when it had been reported in the original paper as delivered by a non-chiropractic provider (e.g. Physician).The original case reports often omitted to record the time lapse between treatment and the adverse event, and other significant clinical or risk factors. The country of origin of the original paper was also overlooked, which is significant as chiropractic is not legislated in many countries. In 21 of the cases reported by Ernst to be chiropractic treatment, 11 were from countries where chiropractic is not legislated.
Conclusion: The number of errors or omissions in the 2007 Ernst paper, reduce the validity of the study and the reported conclusions. The omissions of potential risk factors and the timeline between the adverse event and SMT could be significant confounding factors. Greater care is also needed to distinguish between chiropractors and other health practitioners when reviewing the application of SMT and related adverse effects.
The author of this ‘replication study’ claims to have identified several errors in my 2007 review of adverse effects of spinal manipulation. Here is the abstract of my article:
Objective: To identify adverse effects of spinal manipulation.
Design: Systematic review of papers published since 2001.
Setting: Six electronic databases.
Main outcome measures: Reports of adverse effects published between January 2001 and June 2006. There were no restrictions according to language of publication or research design of the reports.
Results: The searches identified 32 case reports, four case series, two prospective series, three case-control studies and three surveys. In case reports or case series, more than 200 patients were suspected to have been seriously harmed. The most common serious adverse effects were due to vertebral artery dissections. The two prospective reports suggested that relatively mild adverse effects occur in 30% to 61% of all patients. The case-control studies suggested a causal relationship between spinal manipulation and the adverse effect. The survey data indicated that even serious adverse effects are rarely reported in the medical literature.
Conclusions: Spinal manipulation, particularly when performed on the upper spine, is frequently associated with mild to moderate adverse effects. It can also result in serious complications such as vertebral artery dissection followed by stroke. Currently, the incidence of such events is not known. In the interest of patient safety we should reconsider our policy towards the routine use of spinal manipulation.
In my view, there are several things that are strange here:
- Tuchin published his paper 5 years after mine.
- He did not publish it in the same journal as my original, but in an obscure chiro journal that hardly any non-chiropractor would ever read.
- Tuchin never contacted me and never alerted me to his publication.
- The journal that Tuchin chose was not Medline-listed in 2012; consequently, I never got to know about the Tuchin article in a timely fashion. (Therefore, I did never respond to it.)
- A ‘replication study’ is a study that repeats the methodology of a previous study.
- Tuchin’s paper is therefore NOT a replication study. Firstly, mine was a review and not a study. Secondly, and crucially, Tuchin never repeated my methodology but used an entirely different one.
But arguably, these points are trivial. They should not distract from the fact that I might have made mistakes. So, let’s look at the substance of Tuchin’s claim, namely that I made errors or omissions in my review.
As to ‘omissions’, one could argue that a review such as mine will always have to omit some details in order to generate a concise summary. The only way to not omit any details is to re-publish all the primary papers in one large volume. Yet, this can hardly be the purpose of a systematic review.
As to the ‘errors’, it seems that the ages and sex of three patients were wrong (I have not checked this against the primary publications but, for the moment, I believe Tuchin). This is, of course, lamentable and – even though I have no idea whether the errors happened at the data extraction phase, during the typing, the revising, or the publishing of the paper – it is entirely my responsibility. I also seem to have mistaken a non-chiropractor for a chiropractor. This too is regrettable but, as the review was about spinal manipulation and not about chiropractic, the error is perhaps not so grave.
Be that as it may, these errors are unquestionably not good, and I can only apologise for them. If Tuchin had dealt with them in the usual way – by publishing in a timely fashion a ‘letter to the editor’ of the JRSM – I could have easily corrected them for everyone to see.
But I think there is a more important point to be made here:
Tuchin concludes his paper stating that it is unwise to make conclusions regarding causality from any case study or multiple case studies. The number of errors or omissions in the 2007 Ernst paper significantly limit any reported conclusions. I believe that both sentences are unjustified. The safety of any intervention in routine use has to be examined on the basis of published case studies. This is particularly true for chiropractic where no post-marketing surveillance similar to that for drugs exists.
The conclusions based on such evidence can, of course, never be firm, but they provide valuable signals that can prompt more rigorous investigations in the interest of patient safety. In view of such considerations, my own conclusions in my 2007 paper were, I think, correct and are NOT invalidated by my relatively trivial mistakes: spinal manipulation, particularly when performed on the upper spine, has repeatedly been associated with serious adverse events. Currently the incidence of such events is unknown. Adherence to informed consent, which currently seems less than rigorous, should therefore be mandatory to all therapists using this treatment. Considering that spinal manipulation is used mostly for self-limiting conditions and that its effectiveness is not well established, we should adopt a cautious attitude towards using it in routine health care.
And my conclusions in the abstract have now, I believe, become established wisdom. They are thus even less in jeopardy through my calamitous lapsus or Tuchin’s ‘replication study’: Spinal manipulation, particularly when performed on the upper spine, is frequently associated with mild to moderate adverse effects. It can also result in serious complications such as vertebral artery dissection followed by stroke. Currently, the incidence of such events is not known. In the interest of patient safety we should reconsider our policy towards the routine use of spinal manipulation.
A team of chiropractic researchers conducted a review of the safety of spinal manipulative therapy (SMT) in children under 10 years. They aimed to:
1) describe adverse events;
2) report the incidence of adverse events;
3) determine whether SMT increases the risk of adverse events compared to other interventions.
They searched MEDLINE, CINAHL, and Index to Chiropractic Literature from January 1, 1990 to August 1, 2019. Eligible studies were case reports/series, cohort studies and randomized controlled trials. Studies of high and acceptable methodological quality were included.
Most adverse events are mild (e.g., increased crying, soreness). One case report describes a severe adverse event (rib fracture in a 21-day-old) and another an indirect harm in a 4-month-old. The incidence of mild adverse events ranges from 0.3% (95% CI: 0.06, 1.82) to 22.22% (95% CI: 6.32, 54.74). Whether SMT increases the risk of adverse events in children is unknown.
The authors concluded that the risk of moderate and severe adverse events is unknown in children treated with SMT. It is unclear whether SMT increases the risk of adverse events in children < 10 years.
Thanks to their ingenious methodology, the authors managed to miss 11 of the 13 studies included in the review by Vohra et al which reported 9 serious adverse events and 20 cases of delayed diagnosis associated with SMT. Another review reported 15 serious adverse events and 775 mild to moderate adverse events following manual therapy. As far as I can see, the authors of the new review make just one reasonable point:
We recommend the implementation of a population-based active surveillance program to measure the incidence of severe and serious adverse events following SMT treatment in this population.
In the absence of such a surveillance system, any incidence figures are not just guess-work but also a depiction of the tip of a much bigger iceberg. So, why do the authors of this review not make this point clearly and powerfully? Why does the review read mostly like an attempt to white-wash a thorny subject? Why do they not provide a breakdown of the adverse events according to profession? The answer to these questions can be found at the very end of the paper:
This study was supported by the College of Chiropractors of British Columbia to Ontario Tech University. The College of Chiropractors of British Columbia was not involved in the design, conduct or interpretation of the research that informed the research. This research was undertaken, in part, thanks to funding from the Canada Research Chairs program to Pierre Côté who holds the Canada Research Chair in Disability Prevention and Rehabilitation at Ontario Tech University, and from the Canadian Chiropractic Research Foundation to Carol Cancelliere who holds a Research Chair in Knowledge Translation in the Faculty of Health Sciences at Ontario Tech University.
This study was supported by the College of Chiropractors of British Columbia to Ontario Tech University. The College of Chiropractors of British Columbia was not involved in the design, conduct or interpretation of the research that informed the research. This research was undertaken, in part, thanks to funding from the Canada Research Chairs program to Pierre Côté who holds the Canada Research Chair in Disability Prevention and Rehabilitation at Ontario Tech University, and funding from the Canadian Chiropractic Research Foundation to Carol Cancelliere who holds a Research Chair in Knowledge Translation in the Faculty of Health Sciences at Ontario Tech University.
I have often felt that chiropractic is similar to a cult. An investigation by cult members into the dealings of a cult is not the most productive of concepts, I guess.
Many chiropractors claim that spinal manipulation (SM) has an effect on the pain threshold even in asymptomatic subjects, but SM has never been compared in studies to a validated sham procedure. Now a chiropractic research team has published a study investigating the effect of SM on the pressure pain threshold (PPT) when measured in
ii) an area remote from the intervention.
In addition, the researchers measured the size and duration of the effect.
In this randomized cross-over trial, 50 asymptomatic chiropractic students had their PPT measured at baseline, immediately after and every 12 min after intervention, over a period of 45 min, comparing values after SM and a previously validated sham. The trial was conducted during two sessions, separated by 48 h. PPT was measured both regionally and remotely from the ‘treated’ thoracic segment. Blinding of study subjects was tested with a post-intervention questionnaire.
The results show that the study subjects had been successfully blinded. No statistically significant differences were found between SM and sham estimates, at any time or anatomical location.
The authors concluded that, when compared to a valid sham procedure and with successfully blinded subjects, there is no regional or remote effect of spinal manipulation of the thoracic spine on the pressure pain threshold in a young pain-free population.
Reduced pain sensitivity following SM (often also called ‘manipulation-induced hypoalgesia’ (MIH)) turns out to be little more than a myth promoted by chiropractors for the obvious reason of boosting their business (6 further myths are summarised in the over-optimistic chiropractic advertisement above).
A recent review of the evidence found that systemic MIH (for pressure pain threshold) does occur in musculoskeletal pain populations, though there was low quality evidence of no significant difference compared to sham manipulation. Future research should focus on the clinical relevance of MIH, and different types of quantitative sensory tests.
The aim of this study was to determine the short-term effectiveness of thoracic manipulation when compared to sham manipulation for individuals with low back pain (LBP).
Patients with LBP were stratified based on symptom duration and randomly assigned to a thoracic manipulation or sham manipulation treatment group. Groups received 3 visits that included manipulation or sham manipulation, core stabilization exercises, and patient education. Three physical therapists with an average of 6 years’ experience administered the treatments according to a standardised protocol. Factorial repeated-measures analysis of variance and multiple regression were performed for pain, disability, and fear avoidance.
Ninety participants completed the study. The overall group-by-time interaction was not significant for the Modified Oswestry Disability Questionnaire, numeric pain-rating scale, and Fear-Avoidance Beliefs Questionnaire outcomes. The global rating of change scale was not significantly different between groups.
The authors concluded that three sessions of thoracic manipulation, education, and exercise did not result in improved outcomes when compared to a sham manipulation, education, and exercise in individuals with chronic LBP. Future studies are needed to identify the most effective management strategies for the treatment of LBP.
This study has many features that are praiseworthy. However, others are of concern. Lumping together chronic and acute back problems might be not ideal. And why study only short-term effects?
But foremost I do wonder why manipulations were carried out on the thoracic and not the lumbar spine, the region where the pain was located. The physiotherapist authors state that the effects of thoracic manipulation on adjacent regions have been widely studied, and the majority of authors cite regional interdependence as an explanation for its success. To some degree, this might make sense. Yet, most chiropractors and osteopaths will dismiss the trial and its findings arguing that they would manipulate at the site of subluxations.