The recent statement published by the American Heart Association on the risk of cervical artery dissection (CD) with cervical manipulative therapy (CMT) and the responses to this statement by the APTA and AAOMPT have gotten me thinking about this issue again. One of my biggest concerns is that our profession (namely the manual therapists) are too biased in favor of CMT to objectively assess the risk benefit ratio laid out in the literature. It is very easy to be influenced by anecdotes of successful treatment with CMT and to lose sight of the overall benefits in proportion with the potential risks. It is also easy to cherry pick articles which support our bias by showing positive outcomes with CMT while down playing or calling into question the association with CD risk. In light of this inherent bias within our profession (and within me personally), I find statements from an external stake holder such as AHA very compelling. Just like surgeons should heed our concerns about excessive and unwarranted surgeries, we should take very seriously the opinions of other intelligent, well meaning experts on the issue of CMT and CD. It is important that we fight the reflexive urge to be defensive and look at this statement by the AHA as an opportunity to challenge our biases and take a fresh look at the issue. For even more outside perspective here are some other opinions on the topic.
I was not surprised when I read the response of the APTA and AAOMPT to this article. I think they both highlight the bias and protectionism that our profession has towards cervical thrust manipulation. In this post I am going to examine the arguments put forth by the APTA and AAOMPT in defense of CMT. This is a complex issue and I look forward to hearing the opinions of others on the topic.
When I started to read the statements by the APTA and AAOMPT (which are very similar) I was encouraged that both letters acknowledged the likely connection between CD and CMT.
AAOMPT-“The orthopaedic manual physical therapist community recognizes the rare but significant risks associated with cervical manipulation”
APTA-“The physical therapy community recognizes the rare but significant risks associated with cervical manipulation”
Although arguments can be made against the correlation of CD and CMT, it does seem highly plausible that they are related. Case reports (such as this, this, this, this, and this) also suggest that CMT can cause CD (smoking gun), however this cannot be determined with certainty from these case reports and the case controlled studies we have on the topic.
After acknowledging the correlation between CMT and CD both statements go on to make some pretty weak arguments in defense of CMT. For example, both statements make comments about mitigating the risk of CD.
Quote from Tim Flynn: APTA“In fact, physical therapists in the United States, along with our international colleagues, have developed a clear framework designed to mitigate this risk”
AAOMPT:” In fact, the AAOMPT, in collaboration with the International Federation of Orthopaedic Manual Physical Therapists (IFOMPT) has studied this issue in great detail and previously provided an international framework for mitigating risk associated with these techniques. This framework is reflective of best practice, intending to place risk in an appropriate context that is informed by the available evidence.”
They have developed a framework to mitigate risk, however I have seen no convincing evidence that this framework is effective at reducing risk. The current evidence does not provide us with a way of predicting who will suffer a CD from CMT. Many of the reported cases of CD after CMT occur in young healthy subjects with no major risk factors for arterial disease. In fact, later on in the APTA statement they say
“In a 2002 review12 of 64 cases of cerebrovascular ischemia, or lack of blood flow to the brain, associated with cervical spine manipulation, researchers concluded that strokes after manipulation appear to be unpredictable and should be considered a rare complication of this treatment approach.”
So they appear to be unpredictable yet we have a framework which can mitigate the risk? Are we fooling ourselves? I guess if we are going to continue with CMT we need to show that we are putting forth an effort; however, we are far from proving that any measures other than abstinence can reduce the risk of CD with CMT. At best, the framework developed by the IFOMPT will help to identify patients who are already having an ischemic event prior to CMT.
Both statements then make a Tu quoque argument, under the guise of context. They bring up the fact that commonly used interventions such as medications, injections and surgery also have significant risks. I agree that these treatments have risk (even a greater risk than CMT) however this argument is one sided and may be seen as an erroneous argument because it is irrelevant to the safety/efficacy of CMT. I would suggest however, that context is not totally irrelevant, although the APTA and AAOMPT articles did not present a balanced view of the context. Both statements mentioned interventions with greater risk but they did not address the effectiveness of those interventions and they did not address the effectiveness of interventions with a lower risk than CMT. Bringing up this issue, in this way, simply points out that we need to perform a well thought-out risk/benefit analysis of all the interventions available for a given condition. If an intervention’s potential benefit is not worth the risk of the procedure then its use should be questioned, irrespective of context.
My next concern with these statements pertains to their framing of the potential benefits of CMT. It took me a few reads before I noticed that all three articles cite the same systematic review but make very different points. All three articles spoke about a 2007 systematic review in the Journal of Rheumatology from Gross et al which looked at conservative management of mechanical neck pain. The AHA stated this about the article:
“Data on the effectiveness of CMT for neck pain are sparse and questionable. The most recent Cochrane review consisting of some low-quality trials found that the effect of cervical manipulation was comparable to that of mobilization, which does not include a thrust”
Both the statements from the APTA and AAOMPT paint a different picture.
AAOMPT-“ To date, many scientific studies support cervical manipulation for the treatment of head and neck pain of mechanical origin. One systematic review in the Journal of Rheumatology3 from 2007 reviewed 88 randomized controlled trials and concluded that exercise combined with manipulation or mobilization demonstrated both pain relief and functional improvement in adults with acute, subacute, or chronic mechanical neck disorders.”
So despite their critique of the AHA article as being “limited in its scope and context” the AHA paper was the only one of three which pointed out the important difference between thrust and non-thrust CMT techniques. Given CDs relationship to trauma and force, the most defensible position is to assume that thrust techniques are more likely to result in CD than non-thrust. There are also several case reports documenting CD after thrust and a lack of case reports documenting CD after mobilization. I do realize that I am making an assumption by saying thrust is more dangerous than non-thrust CMT. There is no direct evidence which proves this, however it seems to be a reasonable position given the indirect evidence which is currently available.
Ignoring this difference between thrust and non-thrust CMT is a big flaw in the APTA and AAOMPT’s statements. I am sure that most stakeholders looking at this issue are thinking about thrust techniques, not non-thrust. As the AHA statement rightfully points out, there is no convincing evidence that thrust techniques to the cervical spine are more effective than the, likely much safer, mobilization techniques.
As stated above I am not surprised by the statements from the APTA and AAOMPT. Both of these organizations represent practitioners not patients. Most of the time their mission to represent PTs is in line with the best interest of the patient. However, in this case I question whether they are sacrificing (probably unintentionally due to bias) the best interest of patients for the benefit of the clinicians they represent. I see no reason why the AHA has any interest in the topic other than to promote safety and efficacy for patients. I feel that the AHA’s statement was well constructed, well supported, and I strongly disagree with the statement that the AHA’s position “may place unnecessary fear in the public of an effective low risk treatment intervention.”
I feel very strongly that patients should be educated about the risks involved in any procedure they may undertake and the AHA’s statement provides a well balanced resource for this education. When offering thrust manipulation to the cervical spine as a treatment option it is important that we discuss the risks and benefits with our patient. How we frame that conversation can have a large impact on the “informed” part of the consent. For those of you who perform cervical thrusts, what do you tell patients about the risks and potential benefits of the technique?