Letters to the Editor.

Causes of Injury From Cervical Manipulation

To the Editor:

I am writing in response to the recent article by Richard Di Fabio.[1] I would first like to commend Dr Di Fabio on his efforts. I feel he delivered the information regarding the risks and benefits of cervical spinal manipulation in a neutral fashion. A topic such as this tempts authors to write with a biased pen.

One related and important area not addressed in the article relates to all the reported causes of vertebral artery dissection. Dr Di Fabio suggests that cervical manipulation is a frequently reported cause of such dissections. If we focus our attention on reported cases of vertebral artery dissection caused by spinal manipulation and do not attempt to determine the incidence from all the causes, we are myopic in our understanding of this problem. We must determine not only the incidence caused by cervical manipulation but the incidence from all causes of vertebral artery dissection.

I performed a MEDLINE abstract literature search on this condition. A database search was made from 1967 to January 1999. I included a publication if it contained the phrase "vertebral artery dissection," if it included an abstract, and if it specified the number of cases being presented. All English and non-English abstracts were included in the review. One hundred twenty-one publications fulfilled the inclusion criteria. All were case studies. There were 837 individual cases reported in the 121 publications. No publications were identified prior to 1985. The most frequently reported cause was "spontaneous" (357 cases). A cause was not reported in 334 cases. Chiropractic manipulation was the reported cause in 10 cases. Seven cases were caused by cervical manipulation by an unknown provider. Sixty-five cases were related to minor head trauma. Various causes such as exercise, motor vehicle accidents, and connective tissue disorders were also reported.

Although there are many metholology cal problems with this abbreviated MEDLINE literature review, it raises many questions. For example, what was the cause of the dissections in the 334 cases where no cause was reported? If there are over 800 cases in the MEDLINE database, how many other cases exist in the literature? What is the cause of spontaneous vertebral artery dissections? Why were there no reported cases in MEDLINE prior to 1985?

The relationship of cervical spinal manipulation and vertebral artery dissections is real. Nobody would argue against this statement. The question I ask is: How prevalent is the relationship to cervical spinal manipulation when compared with other potential causes such as spontaneous dissections? Additional research in this area is needed.

Richard Branson, DC Director of Chiropractic Services Institute for Athletic Medicine Minneapolis, Minn

References

[1] Di Fabio RE Manipulation of the cervical spine: risks and benefits. Phys Ther. 1999;79:50-65.

Author Response:

Dr Branson has not provided the reader with a way to evaluate his claim that only 17 out of 837 cases of vertebral artery dissection were related to manipulation of the cervical spine (MCS). We do not know which references he used to support his statements, nor do we know what method was used to summarize relevant data from each case. In my article, I reported that 19.2% of 177 cases (n=34) with injuries related to MCS had vertebral artery dissections. It is difficult to understand how Dr Branson reviewed 837 cases (including cases that were also covered in my review) and found fewer than 34 incidents of manipulation-related vertebral artery dissection.

Dr Branson seems to imply that vertebral artery dissection is uncommon following cervical manipulation, but as I pointed out in my article, it is possible to have subclinical damage to the arterial walls with high-velocity thrusts to the neck. This means that a patient could receive cumulative injury from repeated manipulations (even successful manipulations) and sustain an unexpected acute arterial dissection. I think that it is important to reiterate that manipulation of the cervical spine has the potential to expose patients to vertebral artery damage. Low-velocity mobilizations of the cervical spine may be just as effective as MCS in reducing neck pain and improving neck motion, but without the risk of damaging the vertebral arteries.

Richard P Di Fabio, PhD, PT Professor Program in Physical Therapy Department of Physical Medicine and Rehabilitation University of Minnesota Minneapolis, MN 55455

Editor-in-Chief Journal of Orthopaedic & Sports Physical Therapy

Letters to the Editor

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