Research Review By Dr. Ceara Higgins©

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Date Posted:

November 2019

Study Title:

Current evidence for spinal X-ray use in the chiropractic profession: a narrative review

Authors:

Jenkins HJ, Downie AS, Moore CS & French SD

Author's Affiliations:

Macquarie University, Sydney, Australia; University of Technology, Sydney, Australia; Queen’s University, Kingston, ON, Canada.

Publication Information:

Chiropractic & Manual Therapies 2018; 26: 48–59.

Background Information:

X-ray technology has been used for chiropractic clinical examinations since 1910 to “visualise the alignment of spinal vertebrae and direct appropriate treatment” (1). However, more recently, evidence about the diagnosis and management of spinal pain has prompted a transition from a static mechanical model, which supports the use of x-rays, to a patient-centered model within a biopsychosocial context (2). When you combine this with the low diagnostic yield of most radiographic findings (3) and an increased awareness of the risks associated with x-ray exposure, the routine use of imaging must be questioned and considered within the context of existing evidence. To illustrate, current evidence-based practice guidelines recommend limiting imaging to cases of suspected underlying serious pathology or trauma (4).

This review summarized the current evidence for the use of spinal x-rays within chiropractic practice, with consideration given to the related risks and benefits.

Summary:

Current Use of Spinal X-Rays in Chiropractic

The percentage of patients who receive X-rays as part of a chiropractic consultation ranges dramatically – from 8-84% (7)! This wide variation may be partly due to the variety of treatment techniques which exist, as some advocate for the use of routine spinal x-rays, while most do not. As well, different chiropractic educational institutions teach differently regarding potential reasons and requirements for obtaining x-rays (9). General reasons given by practicing chiropractors for the use of x-rays include diagnosis of pathology or trauma, determination of treatment options, detection of contraindications to care, spinal biomechanical analysis, patient reassurance, and medicolegal reasons (8). Many of these reasons are not supported by evidence of benefit, as discussed below.

Evidence for Potential Reasons for Obtaining Spinal X-Rays within Chiropractic

Diagnosis of pathology or trauma:
Current imaging guidelines recommend the use of x-rays to assist in the confirmation of suspected pathology or traumatic injury (7). However, incidence of serious pathology presenting as low back pain in primary care settings is estimated to be between 0.2 and 3.1%, and incidence of fracture is estimated to be between 0.2 and 6.6% (3). Therefore, the routine utilization of x-rays for these purposes cannot be recommended, due to the rarity of their presentation in clinical practice. As well, evidence more strongly supports the use of MRI and bloods tests when serious pathology such as cancer or infection is suspected (10).

X-ray findings are also commonly used to diagnose more benign findings such as degenerative arthritis, spondylolisthesis and transitional vertebral segments. However, research has shown either no or only weak association between these findings and symptomatology (12), calling into question their clinical relevance and impact on patient outcomes and/or safety.

Determining treatment options:
In patients with certain conditions, such as radiculopathy or spinal stenosis, imaging may be used to help determine the course of treatment (ex. whether conservative or surgical care is more appropriate). However, in most of these cases, it is useful for patients to undergo an initial trial of conservative care first (10). As a result, current guidelines recommend that imaging be undertaken only after a trial of care, and only in cases with progressive or widespread neurological compromise (4). As well, MRI is a much more useful imaging modality for these types of cases (5).

Despite claims by some chiropractic technique systems, no studies were found that assessed the impact of routine X-rays for technique modality selection on patient outcomes. As well, spinal X-rays have not been found to be useful in determining the proper site for spinal manipulation (14). Thus, clinicians should select treatment modalities based on clinical presentation rather than x-ray findings.

Screening patients for contraindications prior to care:
Chiropractors commonly suggest the use of x-rays to screen for anomalies or serious pathology which may be a contraindication to treatment. Serious pathology which has not started manifesting symptoms is unlikely to show up on x-ray, making presenting symptoms a more useful tool to indicate a possible serious pathology. In cases where patients do show symptoms of possible pathology, MRI is generally recommended due to its higher sensitivity. As well, pathological causes of back and neck pain are rare (3) and even fewer cases would be asymptomatic. There is, therefore, no evidence to support the use of routine imaging for ruling out or evaluating for unsuspected serious pathology.

It can be difficult to diagnose anatomical abnormalities in the upper cervical spine (ex. agenesis of the dens or fusion of the occiput), and these have been theorized to be related to increased upper cervical instability or neural compromise, which may contraindicate cervical manipulation (11). However, the contraindication to cervical manipulation is still only theoretical and the rates of these anatomical anomalies are so low (between 2.1 and 3.7%) that the evidence does not currently support the use of routine X-rays to screen for them.

Spinal biomechanical analysis:
Traditionally, X-rays have been analyzed to measure intersegmental rotation, tilt, or displacement, and to measure spinal curvatures, but the clinical significance of these variations is very controversial. It has not been sufficiently demonstrated that these findings are useful for directing treatment selection. As well, alterations in spinal alignment seen on x-ray may actually be caused by other factors, such as variations in patient positioning during imaging, pain, or short-term muscle spasms (16), so it may not be appropriate to use them to guide patient management. Currently, there is insufficient evidence to support the use of routine x-rays for biomechanical analysis.

In cases of structural spinal deformities, x-rays are recommended to direct appropriate treatment in children or adolescents due to concerns about curve progression, or in adults with progressive or acutely painful scoliosis or thoracic kyphosis (4). In these cases, x-ray findings may lead clinicians to undertake alternative management, or indicate the need for bracing or spinal surgery to prevent further deformity, or show potential pathological causes of progressive or acutely painful spinal curves (17). There is no evidence to support the use of routine x-rays for adults with benign scoliotic curves or in children or adolescents with functional scoliotic curves (note: most curves in this patient group are structural and do require initial and perhaps follow-up x-ray evaluation).

Patient reassurance:
Some clinicians support the use of routine X-rays to reassure patients that they have no underlying serious pathology. However, routine imaging has been correlated to a lesser sense of wellbeing (18) and lower health status overall (15). It is suggested that other strategies, such as education and explanation of the evidence on the use of routine imaging, be used as a first approach (5).

Medicolegal reasons:
As previously discussed, there is no evidence that X-ray imaging is a reliable tool for early detection of serious underlying pathology, or in screening for unsuspected anomalies. No evidence was found that suggests that routine imaging can decrease the risk of malpractice claims being made against chiropractors.

Evidence of Possible Risks or Limitations Associated with the Use of Spinal X-Rays

Radiation exposure:
A single set of spinal x-rays involves low levels of exposure, comparable to less than 1 year of exposure to natural background radiation (19). However, as some chiropractors advocate repeat spinal x-rays to monitor spinal changes, cumulative exposure must also be considered (6). It can be difficult to calculate the risks of harm from low levels of radiation exposure, leaving some uncertainty as to these risks. As well, there is no definitive data on levels of radiation exposure which would be considered safe, and no way to accurately calculate radiation exposure from natural or other sources in order to account for cumulative radiation exposure. We must assume that there is some level of risk associated with the use of x-rays and use them only when clinically indicated as recommended in evidence-based guidelines (4).

Overdiagnosis:
Routine spinal x-rays may lead to findings with uncertain clinical significance such as osteophytes, reduced disc height, spondylolisthesis, transitional segments, and other anatomical anomalies. These findings are common, have poor correlation to clinical symptoms (12) and may lead clinicians to recommend more complex investigations, leading to potential unnecessary worry for the patient. In patients without clinical indicators of serious pathology, the additional information provided by x-rays provides little additional benefit to patient health, but may increase patient concern or lead to an erroneous belief in a pathoanatomical cause for their pain (20). This may additionally increase the risk of the patient developing chronic pain (13) or fear-avoidance behaviours. Early imaging of the low back has been associated with increased levels of disability (21), a decreased sense of well-being (18), and lower overall health status (15).

Missed diagnosis:
Early spinal x-rays are often unable to detect early pathological changes, leading to false negatives and a false sense that no pathology exists.

Waste:
Unnecessary diagnostic procedures and subsequent treatment lead to increased waiting time for people who need more appropriate imaging, poor utilization of resources (21), and increased financial costs to the health care system, patient, and the population. Early imaging has also been associated with greater use of medical care and associated costs (13).

Guidelines for the Appropriate use of Imaging

As most cases of acute spinal pain will improve within the first 4 weeks (22), imaging is discouraged within this time period, but should be considered if the patient fails to respond to care over a 4 to 6-week time period. It is recommended that diagnostic imaging still only be used when there is clinical suspicion of serious pathology or when imaging is likely to lead to a beneficial change in management, improved patient outcomes, or decreased patient harm. However, as serious pathology is a rare cause of LBP (estimated at < 5% of cases) and the diagnosis of serious pathology is the main indicator for x-ray imaging, utilization rates for x-ray should be low. Current guidelines for x-rays are summarized below.

Alternate x-ray guidelines have been proposed for the chiropractic profession (23). However, they assume that spinal x-rays are required for chiropractors to provide optimal management to the patient, are not supported by high quality evidence, have not been published in a peer-reviewed journal, and do not adequately consider the potential risks of routine spinal x-rays. Therefore, they have not been included in this review.

Evidence-Based Recommendations for Diagnostic Imaging of the Spine for Chiropractors:

Spinal Fracture (cervical):
  • Alerting Clinical Features: Canadian C-Spine Rule – history of cervical trauma and any one of the following – performed in this order: 1) at least one high risk factor (age 65+, dangerous mechanism of injury, extremity paresthesias); 2) absence of all low risk factors (simple rear-end MVA, sitting position upon presentation, ambulatory at any time post trauma, delayed onset of neck pain, absence of midline tenderness); 3) inability to actively rotate neck 45 degrees right and left.
  • Imaging, Referral or Clinical Action: cervical x-rays (AP, open-mouth, lateral); perhaps CT or MRI.
Spinal Fracture (other region):
  • Alerting Clinical Features: spinal pain after significant trauma with multiple risk factors – older age (65+ for women, 75+ for men), history of osteoporosis, prolonged use of corticosteroids, severe trauma, contusion or abrasion.
  • Imaging, Referral or Clinical Action: x-ray (if negative with strong clinical suspicion – obtain MRI or CT).
Cancer:
  • Alerting Clinical Features: new onset spinal pain with history of cancer, prior cancer, unexplained weight loss, pain at rest or at night, failure to improve with one month of conservative care, age > 60 (especially with first time spinal pain – most will have had back pain by this point!).
  • Imaging, Referral or Clinical Action: MRI preferable, x-ray if only/immediate option, blood tests.
Infection:
  • Alerting Clinical Features: new onset spinal pain with risk factors – fever or chills, history of infection, history of IV drug use, recent surgical procedure, pain with rest or at night.
  • Imaging, Referral or Clinical Action: MRI and blood tests, specialist referral.
Spondyloarthropathy:
  • Alerting Clinical Features: chronic pain (> 3 months) with risk factors – age < 40, insidious onset, improves with exercise, alternating buttock pain, pain at night, positive family history, extremity articular symptoms, improvement with NSAIDs, extra-articular symptoms (psoriasis, inflammatory bowel disease, uveitis).
  • Imaging, Referral or Clinical Action: x-ray and blood tests (if negative and strong clinical suspicion seek MRI), specialist referral pending imaging/lab results.
Radiculopathy:
  • Alerting Clinical Features: back or neck pain with leg or arm pain, sensory loss, weakness or decreased reflexes.
  • Imaging, Referral or Clinical Action: single level radiculopathy = conservative care first; multi-level or progressive radiculopathy = imaging and specialist referral.
Lumbar Spinal Stenosis:
  • Alerting Clinical Features: older age, buttock/thigh/leg pain, worse with walking/standing, relieved with sitting or flexed postures.
  • Imaging, Referral or Clinical Action: non-surgical candidates = trial of appropriate care before further workup; surgical candidates = MRI and specialist referral.
Spinal Cord Compression:
  • Alerting Clinical Features: Risk factors for cervical myelopathy – neck pain with multi-level, progressive upper limb neurological deficits (especially motor/reflex), older age, increased lower limb reflexes. Risk factors for Cauda Equina Syndrome (CES) – multi-level, progressive lower limb neurological deficits (especially motor/reflex), new bowel or bladder dysfunction, saddle anesthesia.
  • Imaging, Referral or Clinical Action: acute/severe symptoms = emergency referral; chronic/less severe symptoms = ultrasound or MRI with specialist consultation/referral.
Arterial Dissection, Stenosis or Aneurysm:
  • Alerting Clinical Features: Cervical spine risk factors – severe, persistent or unusual headache, cranial or upper limb neurological symptoms. Thoracic spine risk factors – severe chest or back pain, hypotension, absent distal pulses. Lumbar spine risk factors – severe abdominal, back or groin pain, hypotension, absent distal pulses.
  • Imaging, Referral or Clinical Action: acute/severe symptoms = emergency referral; chronic/less severe symptoms = ultrasound or MRI with specialist consultation/referral.
Osteoporosis:
  • Alerting Clinical Features: major risk factors – history of fracture with minimal trauma, prolonged corticosteroid use, older age (65+ in women, 75+ in men), premature menopause, hypogonadism (males), predisposing condition (RA, hyperthyroidism, hyperparathyroidism, chronic kidney or liver disease, celiac disease); minor risk factors – parental history, low physical activity, low body weight, poor nutrition, poor balance, frequent falls.
  • Imaging, Referral or Clinical Action: DXA scan of spine and proximal femur
Progressive Spinal Structural Deformity:
  • Alerting Clinical Features: child or adolescent – rigid coronal or sagittal curve, positive Adam’s forward bending test, rib humping; adult – rigid coronal or sagittal curve with either acute presentation or recent progression of curve.
  • Imaging, Referral or Clinical Action: x-ray and specialist referral if underlying pathology or large Cobb angle (> 25 degrees).

Clinical Application & Conclusions:

The use of routine spinal x-rays in chiropractic care remains controversial, with limited or non-existent evidence of the postulated benefits and strong evidence demonstrating potential harms, including increased exposure to ionising radiation, over diagnosis, subsequent low-value investigation and treatment, and increased unnecessary costs. In the vast majority of cases presenting to chiropractors, the potential benefits of spinal x-rays do not outweigh the potential harms. Therefore, spinal x-rays should not be performed as a routine part of chiropractic practice. The use of diagnostic imaging should be informed by evidence-based clinical practice guidelines and clinician judgement.

Study Methods:

Broad search terms were applied to PubMed and The Index of Chiropractic Literature, and the reference lists of relevant articles were also searched. Wherever possible, guidelines and systematic reviews were selected and incorporated into this paper. No further details pertaining to article evaluation or selection were provided, as this was a narrative literature review.

Study Strengths / Weaknesses:

Strengths:
  • This author group provided an appropriate, contemporary summary of the evidence in this area.
Weaknesses:
  • As this was a narrative literature review, few details were provided regarding the selection of articles for this review. It is therefore unclear if they did in fact identify all, or most, relevant articles.

Additional References:

  1. Bolton, SP. X-ray dispossessed-expedience versus standards? Chiropractic Journal of Australia 2004; 34(1): 23-29.
  2. Pincus T, Kent P, Bronfort G, et al. Twenty-five years with the biopsychosocial model of low back pain – is it time to celebrate? A report from the twelfth international forum for primary care research on low back pain. Spine 2013; 38(24): 2119-2123.
  3. Henschke N, Maher CG, Refshauge KN, et al. Prevalence of and screening for serious spinal pathology in patients presenting to primary care settings with acute low back pain. Arthritis & Rheumatism 2009; 60(10): 3072-3080.
  4. Bussiéres A, Taylor J, Peterson C. Diagnostic imaging practice guidelines for musculoskeletal complaints in adults – an evidence-based approach – part 3: spinal disorders. J Manip Physiol Ther 2008; 31: 33-88.
  5. Chou R, Qaseem A, Owens D, et al. Diagnostic imaging for low back pain: advice for high-value health care from the American College of Physicians. Ann Intern Med 2011; 154: 181-189.
  6. Oakley PA, Cuttler JM, Harrison DE. X-ray imaging is essential for contemporary chiropractic and manual therapy spinal rehabilitation: radiography increases benefits and reduces risks. Dose-Response 2018; 16(2): 1559325818781437.
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  17. Home JP, Flannery R, Usman S. Adolescent idiopathic scoliosis: diagnosis and management. Am Fam Physician 2014; 89(3): 193-198.
  18. Ash L, Modic M, Obuchowski N, et al. Effects of diagnostic information, per se, on patient outcomes in acute radiculopathy and low back pain. Am J Neuroradiol 2008; 29: 1098-1103.
  19. Webb D, Solomon S, Thomson J. Background radiation levels and medical exposure levels in Australia. Radiation Protection in Australia 1999; 16(2): 25-32.
  20. Flynn TW, Smith B, Chou R. Appropriate use of diagnostic imaging in low back pain: a reminder the unnecessary imaging may do as much harm as good. J Orthop Sports Phys Ther 2011; 41(11): 838-846.
  21. Webster B, Bauer AS, Choi Y, et al. Iatrogenic consequences of early MRI in acute work-related disabling low back pain. Spine 2013; 38(22): 1939-1946.
  22. Vassijen O, Woodhouse A, Bjorngaard JH, et al. Natural course of acute neck and low back pain in the general population: the HUNT study. Pain 2013; 154(8): 1237-1244.
  23. Harrison D, Harrison D, Kent C, et al. Practicing chiropractors’ committee on radiology protocols for biomechanical assessment of spinal subluxation in chiropractic clinical practice. International Chiropractors Association 2009; http://www.chiropractic.org/wp-content/uploads/2018/01/PCCRP-Radiology-Guidelines.pdf