The (Low) Risk of Manipulation

Are you currently performing spinal thrust manipulation in the clinic? If you answered no, why not? We asked this question at our first OPTIM COMT program two weekends ago. Aside from a lack of experience performing the techniques, a main reason physical therapy clinicians are not manipulating is because of potential complications associated with manipulation. In this post, I will analyze the true risk associated with spinal manipulation and how safe these techniques truly are with appropriate screening. 

Cervical Manipulation Risks
Cervical thrust joint manipulation is often viewed as a danger zone by physical therapists. For whatever reason, physical therapy schools avoid teaching cervical manipulations. In school the negative complications are ingrained in our minds. The greatest risk associated with cervical manipulation is inducing vertebral basilar insufficiency (VBI). VBI is defined as an occlusion or injury to the vertebral artery causing a decrease in bloodflow to the brain stem and posterior cranium. If the vertebral artery is affected, stroke or death could result. In addition to VBI, other adverse reactions can include neck soreness, radiating arm pain, nystagmus, headaches, ringing in the ears, and other less severe complications.

Risk by the Numbers: What the Research Reports
The exact risk of severe complications (VBI or death) is unknown. Rivett and Milburn estimate that 1 in 50,000 to 1 in 5,000,000 manipulations will result in neurovascular compromise (1). DiFabio et al performed an extensive literature review of 177 patients who experienced severe adverse events following cervical manipulation. Of the 177 patients, arterial dissection (VBI) was the primary diagnoses found. Additionally, DiFabio pointed out that only 2% of the severe injuries were performed by physical therapists (2). Others have reported the risk of VBI following cervical manipulation to be as high as 6 in 10,000,000 (3). 

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Lumbar Manipulation Risk and Numbers
Lumbar thrust joint manipulations appear to be even safer than cervical manipulation. With lumbar manipulation, the greatest complication is cauda equina syndrome. Cauda equina syndrome is damage to the cauda equina causing widespread neurological compromise, urinary retention, and fecal incontinence. In an editorial by Tim Flynn titled, "Move it and move on" he estimated the post-lumbar manipulation risk was 1 in 6 million.  An interesting article by Childs et al in 2006 found that there was a greater risk by withholding lumbar manipulation in patients with low back pain (4). In the study there was greater risk to the patient by NOT perform spinal manipulation. The study also found that even individuals who did not meet the clinical prediction rule for spinal manipulation did not have increased disability.   

Conclusion
The research suggests that severe adverse responses to spinal manipulation are extremely low. As physical therapists, we receive extensive training to assess for VBI and cauda equina syndrome. With a thorough subjective history and objective examination, you should be able to determine if the patient is appropriate for manipulation. If you find that the patient is demonstrating signs and symptoms of cauda equina or VBI, refer back to the appropriate medical provider. Stronger evidence on the benefits of spinal manipulation is emerging every year. If the patient is appropriate, we should be performing these techniques. 

If you do not feel prepared to perform these techniques, find a good manual therapy program to learn them!

Let me know if you have any questions,
Jim

References:
1. Rivett, D.A., Sharples, K.J., & Millburn, P.D. (1999). Effect of pre-manipulative tests on vertebral artery and internal carotid artery blood flow: A pilot study. Journal of Manipulative and Physiological Therapeutics, 22, 368-375​
2. Di Fabio, Richard P. "Manipulation of the Cervical Spine: Risks and Benefits."Physical Therapy 79.1 (1999): 50-65.
3. ​Coulter ID. Efficacy and risks of chiropractic manipulation: what does the evidence suggest? Integ Med1998;1: 61-6
4. J. D. Childs, T. W. Flynn, and J. M. Fritz, “A perspective for considering the risks and benefits of spinal manipulation in patients with low back pain,” Manual Therapy, vol. 11, no. 4, pp. 316–320, 2006.​