I was criticised for not referencing this article in a recent post on adverse effects of spinal manipulation. In fact the commentator wrote: Shame on you Prof. Ernst. You get an “E” for effort and I hope you can do better next time. The paper was published in a third-class journal, but I will nevertheless quote the ‘key messages’ from this paper, because they are in many ways remarkable.
- Adverse events from manual therapy are few, mild, and transient. Common AEs include local tenderness, tiredness, and headache. Other moderate and severe adverse events (AEs) are rare, while serious AEs are very rare.
- Serious AEs can include spinal cord injuries with severe neurological consequences and cervical artery dissection (CAD), but the rarity of such events makes the provision of epidemiological evidence challenging.
- Sports-related practice is often time sensitive; thus, the manual therapist needs to be aware of common and rare AEs specifically associated with spinal manipulative therapy (SMT) to fully evaluate the risk-benefit ratio.
The author of this paper is Aleksander Chaibi, PT, DC, PhD who holds several positions in the Norwegian Chiropractors’ Association, and currently holds a position as an expert advisor in the field of biomedical brain research for the Brain Foundation of the Netherlands. I feel that he might benefit from reading some more critical texts on the subject. In fact, I recommend my own 2020 book. Here are a few passages dealing with the safety of SMT:
Relatively minor AEs after SMT are extremely common. Our own systematic review of 2002 found that they occur in approximately half of all patients receiving SMT. A more recent study of 771 Finish patients having chiropractic SMT showed an even higher rate; AEs were reported in 81% of women and 66% of men, and a total of 178 AEs were rated as moderate to severe. Two further studies reported that such AEs occur in 61% and 30% of patients. Local or radiating pain, headache, and tiredness are the most frequent adverse effects…
A 2017 systematic review identified the characteristics of AEs occurring after cervical spinal manipulation or cervical mobilization. A total of 227 cases were found; 66% of them had been treated by chiropractors. Manipulation was reported in 95% of the cases, and neck pain was the most frequent indication for the treatment. Cervical arterial dissection (CAD) was reported in 57%, and 46% had immediate onset symptoms. The authors of this review concluded that there seems to be under-reporting of cases. Further research should focus on a more uniform and complete registration of AEs using standardized terminology…
In 2005, I published a systematic review of ophthalmic AEs after SMT. At the time, there were 14 published case reports. Clinical symptoms and signs included:
- central retinal artery occlusion,
- Wallenberg syndrome,
- loss of vision,
- Horner’s syndrome…
Vascular accidents are the most frequent serious AEs after chiropractic SMT, but they are certainly not the only complications that have been reported. Other AEs include:
- 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…
In 2010, I reviewed all the reports of deaths after chiropractic treatments published in the medical literature. My article covered 26 fatalities but it is important to stress that many more might have remained unpublished. The cause usually was a vascular accident involving the dissection of a vertebral artery (see above). The review also makes the following important points:
- … numerous deaths have been associated with chiropractic. Usually high-velocity, short-lever thrusts of the upper spine with rotation are implicated. They are believed to cause vertebral arterial dissection in predisposed individuals which, in turn, can lead to a chain of events including stroke and death. Many chiropractors claim that, because arterial dissection can also occur spontaneously, causality between the chiropractic intervention and arterial dissection is not proven. However, when carefully evaluating the known facts, one does arrive at the conclusion that causality is at least likely. Even if it were merely a remote possibility, the precautionary principle in healthcare would mean that neck manipulations should be considered unsafe until proven otherwise. Moreover, there is no good evidence for assuming that neck manipulation is an effective therapy for any medical condition. Thus, the risk-benefit balance for chiropractic neck manipulation fails to be positive.
- Reliable estimates of the frequency of vascular accidents are prevented by the fact that underreporting is known to be substantial. In a survey of UK neurologists, for instance, under-reporting of serious complications was 100%. Those cases which are published often turn out to be incomplete. Of 40 case reports of serious adverse effects associated with spinal manipulation, nine failed to provide any information about the clinical outcome. Incomplete reporting of outcomes might therefore further increase the true number of fatalities.
- This review is focussed on deaths after chiropractic, yet neck manipulations are, of course, used by other healthcare professionals as well. The reason for this focus is simple: chiropractors are more frequently associated with serious manipulation-related adverse effects than osteopaths, physiotherapists, doctors or other professionals. Of the 40 cases of serious adverse effects mentioned above, 28 can be traced back to a chiropractor and none to a osteopath. A review of complications after spinal manipulations by any type of healthcare professional included three deaths related to osteopaths, nine to medical practitioners, none to a physiotherapist, one to a naturopath and 17 to chiropractors. This article also summarised a total of 265 vascular accidents of which 142 were linked to chiropractors. Another review of complications after neck manipulations published by 1997 included 177 vascular accidents, 32 of which were fatal. The vast majority of these cases were associated with chiropractic and none with physiotherapy. The most obvious explanation for the dominance of chiropractic is that chiropractors routinely employ high-velocity, short-lever thrusts on the upper spine with a rotational element, while the other healthcare professionals use them much more sparingly.
Another review summarised published cases of injuries associated with cervical manipulation in China. A total of 156 cases were found. They included the following problems:
- syncope (45 cases),
- mild spinal cord injury or compression (34 cases),
- nerve root injury (24 cases),
- ineffective treatment/symptom increased (11 cases),
- cervical spine fracture (11 cases),
- dislocation or semi-luxation (6 cases),
- soft tissue injury (3 cases),
- serious accident (22 cases) including paralysis, deaths and cerebrovascular accidents.
Manipulation including rotation was involved in 42% of all cases. In total, 5 patients died…
To sum up … chiropractic SMT can cause a wide range of very serious complications which occasionally can even be fatal. As there is no AE reporting system of such events, we nobody can be sure how frequently they occur.[references from my text can be found in the book]