Evidence behind the safety and benefit of cervical spine manipulation is explored.
By Ken Johnson, DO and George Pasquarello, DO, FAAO
Recently there has been an increasing concern about the safety of cervical spine manipulation Specifically, this concern has centered on devastating negative outcomes such as stroke.
Benefits
Spinal manipulation has been reviewed in meta-analysis published as early as 1991, showing a clear benefit for low back pain.1 There is less available information in the literature about manipulation in regards to neck pain and headache, but the evidence does show benefit.2, 3, 4, 5, 6 There have been at least 12 randomized controlled trials of manipulative treatment of neck pain.
Some of the benefits shown include relief of acute neck pain, improvement in pain as measured by validated instruments in sub-acute and chronic pain compared with muscle relaxants or usual medical care. There is also short-term relief from tension type headaches.7 Manipulation relieves cervicogenic headache and is comparable to commonly used first-line prophylactic prescription medications for tension-type headache and migraine.8 Meta-analysis of five randomized controlled trials showed that there was a statistically significant reduction in neck pain using a visual analogue scale.9
Risks
Since 1925, there have been approximately 275 cases of adverse events reported with cervical spine manipulation.10,11,12,13 It has been suggested by some that there is an under-reporting of adverse events.10 A conservative estimate of the number of cervical manipulations per year is approximately 33 million and may be as high as 193 million in the US and Canada. 14, 15 The estimated risk of adverse outcome following cervical spine manipulation ranges from one in 400,000 to one in 3.85 million manipulations.16, 17, 18, 19
The estimated risk of major impairment following cervical spine manipulation is 6.39 per 10 million manipulations.20 Most of the reported cases of adverse outcome have involved “Thrust” or “High Velocity/ Low Amplitude” types of manipulation.11 However, the risk of vertebrobasilar artery stroke from manipulation is less than the risk of a spontaneous vertebrobasilar artery stroke.7
A concern has been raised by a recent report that vertebrobasilar artery stroke following cervical spine manipulation is unpredictable.10 This report is biased because all of the cases were involved in litigation. The nature of litigation can lead to inaccurate reporting by patient or provider.
However, it did conclude that vertebrobasilar artery stroke following cervical spine manipulation is “idiosyncratic and rare.” Further review of this data showed that 25 percent of the cases presented with sudden onset of new and unusual headache and neck pain often associated with other neurologic symptoms that may have represented a dissection in progress.21
In direct contrast to this concern of unpredictability, another recent report states that cervical spine manipulation may worsen preexisting cervical disc herniation or even cause cervical disc herniation. This report describes complications such as radiculopathy, myelopathy, and vertebral artery compression by a lateral cervical disc herniation.12 The authors concluded that the incidence of these types of complications could be lessened by rigorous adherence to published exclusion criteria for cervical spine manipulation.12
Manipulative treatment for neck pain is much safer than the use of NSAIDs, which are the most commonly prescribed medications for neck pain. Research in the United Kingdom has shown NSAIDs will cause 12,000 emergency admissions and 2,500 deaths per year.22 The annual cost of GI tract complications in the US is estimated at $3.9 billion, with at least 2,600 deaths and up to 20,000 hospitalizations per year.23, 24
Provocative Tests
Provocative tests such as the DeKline test have been studied in animals and humans. This test and others like it were found to be unreliable for demonstrating reproducibility of ischemia or risk of injuring the vertebral artery.25, 26, 27, 28, 29, 30
Risk Factors
Vertebrobasilar artery stroke accounts for 1.3 in 1000 cases of stroke, making this a rare event. The most common risk factors for vertebrobasilar artery stroke are migraine, hypertension, oral contraceptive use and smoking.31
A study done in 1999 reviewing 367 cases of vertebrobasilar artery stroke reported from 1966-1993 showed 115 cases related to cervical spine manipulation; 167 were spontaneous, 58 from trivial trauma and 37 from major trauma.31
Complications from cervical spine manipulation most often occur in patients who have had prior manipulation uneventfully and without obvious risk factors for vertebrobasilar artery stroke.7 “Most vertebrobasilar artery dissections occur in the absence of cervical manipulation, either spontaneously or after trivial trauma or common daily movements of the neck, such as backing out of the driveway, painting the ceiling, playing tennis, sneezing, or engaging in yoga exercises.”10 In some cases manipulation may not be the primary insult causing the dissection, but an aggravating factor or coincidental event.21
It has been proposed that thrust techniques using a combination of hyperextension, rotation and traction of the upper cervical spine will place the patient at greatest risk of injuring the vertebral artery. In a retrospective review of 64 medical legal cases, information on the type of manipulation was available in 39 (61 percent) of the cases. 51 percent involved rotation, with the remaining 49 percent representing a variety of positions including lateral flexion, traction and isolated cases of non-force or neutral position thrusts. Only 15 percent had any form of extension.21
Conclusion
Manipulation of the cervical spine is a safe and effective treatment. As with all medical procedures, practitioners should be provided with sufficient information so they are advised of the potential risks and benefits.
Ken Johnson, DO is the Osteopathic DME, AOA FP Residency Director for the EMMC in Bangor, Maine. He is certified in Special Proficiency in Osteopathic Manipulative Medicine (CSPOMM) Family Practice and OMT.
George Pasquarello, DO, FAAO is an associate professor of osteopathic manipulative medicine at the UNECOM. He is certified by the AOBSPOMM and practices in Maine and Rhode Island.
This paper has been adopted by the AAO Board of Governors as an official position paper.
References:
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