In his post, Different Cracks, David Butler asked whether anyone was still “cracking” joints. It generated a lot of interest and remains one of the most commented-on posts on noijam. Comments came from a range of different perspectives and the question of risk and cervical manipulation was inevitably raised.
A paper published earlier this month in Stroke and free to access online has raised the question again and sought to review the evidence and provide a scientific statement from the American Heart and Stroke Associations:
Conclusions—CD is an important cause of ischemic stroke in young and middle-aged patients. CD is most prevalent in
the upper cervical spine and can involve the internal carotid artery or vertebral artery. Although current biomechanical
evidence is insufficient to establish the claim that CMT causes CD, clinical reports suggest that mechanical forces play
a role in a considerable number of CDs and most population controlled studies have found an association between CMT
and VAD stroke in young patients. Although the incidence of CMT-associated CD in patients who have previously
received CMT is not well established, and probably low, practitioners should strongly consider the possibility of CD
as a presenting symptom, and patients should be informed of the statistical association between CD and CMT prior to
undergoing manipulation of the cervical spine
But scratching the surface of the cervical-manipulation-safety debate reveals a convoluted story. The paper in Stroke was picked up and published in a post by Steven Novella on the Science-Based Medicine blog. The author of the post on SBM questions the Stroke paper’s treatment of a key study, Cassidy et al (2008) published in Spine, that is often used to support the notion that the correlation between cervical manipulation and cervical arterial dissection is NOT causal – suggesting that cervical manipulation is safe.
Novella links to another SBM post by a Mark Crislip in 2008 that took a very close look at the Cassidy et al (2008) article. Crislip makes a number of very strong points against the Cassidy article questioning their conclusions, methodology and, in his opinion, very selective writing of the abstract.
Both of the SBM posts generated hundreds of comments that became very heated, personal, and at times degenerated into ad hominem attacks and flights of logical fancy. If you have time, a read through the comments is quite interesting.
The Science-Based Medicine blog has been very forthright in its approach to the topic of cervical manipulation, particularly in relationship to it’s use by chiropractors. In this post, Jann Bellamy reports on a hearing of the Connecticut Board of Chiropractic Examiners held in January 2010. The hearing was convened to decide whether chiropractors should warn patients about the risk of stroke following neck manipulation and provide a discharge summary listing the symptoms of stroke.
The hearing occurred because two Connecticut women, Janet Levy and Britt Harwe, suffered strokes resulting from chiropractic cervical manipulation. Bellamy’s post recounts the harassment that these two women faced from some chiropractors, which ended up with the FBI getting involvement and the eventual arrest and conviction of one harasser. There’s a transcript of the Superior Court hearing here if you’re really interested and a timeline of the whole story here.
During the hearing J David Cassidy, (of Cassidy et al 2008) gave evidence as a representative of the International Chiropractors Association, and according to Bellamy, the Board relied heavily on Cassidy’s testimony and article in deciding that chiropractors were not required to inform patients of the risk of stroke prior to performing a cervical manipulation.
Fast forward a few years and the British Medical Journal published a piece by Wand, Heine and O’Connell (2012) (unfortunately behind a paywall here) entitled “Should we abandon cervical spine manipulation for mechanical neck pain? Yes” and a press release. The Wand et al paper was criticised by at least one blogger as manipulative cherry-picking of articles by authors that had no track record on the topic (no link, you’ll have to look that one up yourselves if you want to), and there was also an opposing view published in there BMJ by (no surprise) Cassidy, Bronfort and Hartvigsen (2012). A copy of their response is available here and includes a disclosure of competing interests that makes for interesting reading.
The response from Cassidy et al (2012) cite patient preference as a key point in the discussion, reasoning that cervical manipulation must be preferred by many as 6-12% of the population receives it annually. The idea of patient preference might lead one to speculate whether patient’s would still undergo spinal manipulation in the same numbers if the Connecticut Board had decided in 2010 that chiropractors were required to inform their patients of a potential link between cervical manipulation and stroke.
Coming back full circle, what is to be made of the American Stroke and Heart Associations’ scientific statement? They make four key points that I think every clinician should be aware of:
– Although current biomechanical evidence is insufficient to establish the claim that CMT causes CD, clinical reports suggest that mechanical forces play a role in a considerable number of CDs
– Most population controlled studies have found an association between CMT and VAD stroke in young patients.
– Although the incidence of CMT-associated CD in patients who have previously received CMT is not well established, and probably low, practitioners should strongly consider the possibility of CD as a presenting symptom
– Patients should be informed of the statistical association between CD and CMT prior to undergoing manipulation of the cervical spine
What does this mean for a clinician deciding whether to manipulate a patient’s neck or not? Here are my* thoughts
– There IS a risk. Regardless of the statistical likelihood of cervical arterial dissection occurring after cervical manipulation, the catastrophic potential impact puts this risk in the red in my mind.
– Patients may present as a result of symptoms caused by an already existing cervical arterial dissection – a careful assessment and examination and awareness of red-flags is always essential.
– Informing patients of the risks associated with cervical manipulation (while legally mandated in Australia for physiotherapists anyway) is morally and ethically a must, no question at all.
I’ll admit to bias** here (I’ve never manipulated a neck in a clinic- I never saw the need) but, given the magnitude of the risk, with the potential for stroke or death, and the dubious (at best) benefits, I would find it hard to defend this procedure.
Dissenting thoughts and arguments welcomed!