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EDUCATION PRACTICE
RATIONAL IMAGING
Low back pain in primary care
Richard A Deyo,1 2 3 4 5 Jeffrey G Jarvik,5 6 7 Roger Chou2 8
1
Department of Family Medicine,
Oregon Health and Science
University, Portland, OR, USA
2
Department of Internal Medicine,
Oregon Health and Science
University, Portland, OR, USA
3
Department of Public Health and
Preventive Medicine, Oregon Health
and Science University, Portland,
OR, USA
4
Oregon Institute for Occupational
Health Sciences, Oregon Health
and Science University, Portland,
OR, USA
5
Department of Health Services,
University of Washington, Seattle,
WA, USA
6
Department of Radiology,
University of Washington, Seattle,
WA, USA
7
Department of Neurological
Surgery, University of Washington,
Seattle, WA, USA
8
Department of Medical Informatics
and Clinical Epidemiology, Oregon
Health and Science University,
Portland, OR, USA
Correspondence to: R A Deyo,
Department of Family Medicine,
Mail code FM, Oregon Health and
Science University, Portland, OR,
USA 97239 [email protected]
Cite this as: BMJ 2014;349:g4266
doi: 10.1136/bmj.g4266
This series provides an update on
the best use of different imaging
methods for common or important
clinical presentations. To suggest a
topic, please email us at practice@
bmj.com
thebmj.com
Previous articles in this
series
ЖЖInvestigating stable
chest pain of suspected
cardiac origin
(BMJ 2013;347:f3940)
ЖЖInvestigating suspected
scaphoid fracture
(BMJ 2013;346:f1370)
ЖЖSuspected left sided
diverticulitis
(BMJ 2013;346:f928)
ЖЖInvestigating pleural
thickening
(BMJ 2013;346:e8376)
ЖЖInvestigating urinary
tract infections in children
(BMJ 2013;346:e8654)
A woman aged 71 with smoking related lung disease and
frequent use of corticosteroids presented to clinic with acute
severe low back pain. The pain began yesterday after she
moved furniture in her apartment, is centrally located in the
upper lumbar region without radiation to the legs, and is
worse with movement. On examination, she has tenderness
to palpation over the upper lumbar spine.
What is the next investigation?
Many observers argue that lumbar spine imaging is overused
in developed countries because of a low yield of clinically
useful findings, a high yield of misleading findings, radiation exposure (especially to the gonads), and costs. This is
a particular concern in the United States, where imaging
capacity is high, and spine specialists commonly have their
own imaging facilities. These concerns are valid, despite the
broad differential diagnosis of back pain, which includes
not only degenerative changes but deformity, fracture, and
underlying systemic diseases such as malignancy, infection, or ankylosing spondylitis. Though metastatic cancer
might be the most common of these systemic conditions,
its prevalence in primary care patients with back pain is less
than 1%.1
In the absence of neurological symptoms, the main
reason to consider early lumbar imaging is to identify serious underlying systemic disease or fractures. Fortunately,
these are rare, though their prevalence varies with age, sex,
and clinical presentation. In the case presented here, the
patient’s age, sex, smoking status, and use of corticosteroids
render her at high risk for an osteoporotic vertebral compression fracture.1 The acute onset, localized nature, and
aggravation with movement are consistent with a diagnosis
of fracture.
In the United Kingdom, the National Institute for Health
and Care Excellence (NICE) recommends “consideration
of MRI” when fracture is suspected.2 Guidelines from the
30 KEY POINTS
Imaging of the lumbar spine for low risk patients can be
overused given its low yield of useful findings, high yield of
misleading findings, and lack of proved benefit for outcome
Radiography (with or without erythrocyte sedimentation
rate) is often an appropriate initial test for suspected
cancer, fracture, or inflammatory spondylopathy
MRI is appropriate for patients with major neurologic
deficits. It is also appropriate for those with a clinical
picture of sciatica or stenosis who fail to improve with a
therapeutic trial and are potential candidates for surgery or
epidural steroids
Patient histories of cancer, injection drug use, major
trauma, or prolonged corticosteroid use are important “red
flags” to prompt imaging; other individual red flags have
weak likelihood ratios, and the full clinical picture should
guide the ordering of lumbar images
Fig 1 | Radiograph showing L1 compression fracture and
suggestion of osteopenia but no evidence of metastatic disease
American College of Physicians recommend plain radiography for patients with risk factors for vertebral compression
fracture but only after a therapeutic trial (table 1).3 In this
case, because of multiple risk factors for fracture, a compromise would be early radiography, which could confirm
the diagnosis, prompt appropriate treatment to reduce the
risk of future fractures, and raise the possibility of treatment
with calcitonin for acute pain.4 Radiography confirmed the
diagnosis of compression fracture (fig 1).
Imaging for neurological symptoms
The presence of severe neurological symptoms, such
as urinary retention, saddle anesthesia, or severe or
progressive motor deficits would raise the possibility
of massive disc herniation, tumor, or displaced fracture
fragment causing cauda equina syndrome or compression of the cord. Guidelines in both the UK and the US
suggest these rare findings are indications for advanced
19 July 2014 | the bmj
EDUCATION PRACTICE
Table 1 | Suggestions for imaging in patients with acute low back pain, from the American College
of Physicians and the British National Institute for Health and Care Excellence (NICE)2 3
Imaging
action
Suggestions for initial imaging
American College of Physicians guideline3
Immediate imaging:
Radiography* Major risk factors for cancer (history of cancer, multiple risk factors for cancer, strong clinical
plus ESR
suspicion for cancer)
MRI
Risk factors for spinal infection (fever and history of injection drug use or recent infection)
Symptoms or signs of cauda equina syndrome (new urinary retention, fecal incontinence, or saddle
anesthesia)
Severe neurologic deficits (progressive motor weakness or motor deficits at multiple neurologic levels)
Defer imaging after trial of treatment:
Radiography
Weaker risk factors for cancer (unexplained weight loss or age >50 years)
with or without Risk factors for or signs of ankylosing spondylitis (morning stiffness that improves with exercise,
ESR
alternating buttock pain, awakening because of back pain during second part of night, or younger
age (age 20-40))
Risk factors for vertebral compression fracture (history of osteoporosis, use of corticosteroids,
significant trauma, or older age (>65 for women or >75 for men))
MRI
Signs and symptoms of radiculopathy (back pain with leg pain in L4, L5, or S1 nerve root
distribution or positive result on straight leg raise or crossed straight let raise test) in patients who
are candidates for surgery or epidural steroid injection
Risk factors for or symptoms of spinal stenosis (radiating leg pain, older age, or pseudoclaudication)
in patients who are candidates for surgery
No imaging
No criteria for immediate imaging and back pain improved or resolved after 1 month trial of treatment
Previous spinal imaging with no change in clinical status
NICE guideline2
Keep diagnosis under review
Do not offer x ray of the lumbar spine for the management of non-specific low back pain†
Consider MRI when a diagnosis of spinal malignancy, infection, fracture, cauda equina syndrome or
ankylosing spondylitis or another inflammatory disorder is suspected
Only offer an MRI scan for non-specific low back pain within the context of a referral for an opinion
on spinal fusion
ESR=erythrocyte sedimentation rate; MRI=magnetic resonance imaging.
*Consider MRI if initial imaging is negative but clinical suspicion for cancer remains high.
†NICE definition of non-specific low back pain: tension, soreness, and/or stiffness in the lower back region for which it is not
possible to identify a specific cause of the pain. Several structures in the back, including the joints, discs, and connective
tissues, may contribute to symptoms.
cross sectional imaging: magnetic resonance imaging
(MRI) where available or computed tomography (CT)
where it is not.2 3 5
Minor neurologic findings are more common. A herniated disc causing radiculopathy might result in symptoms
of sciatica, limited straight leg raising, a missing deep tendon reflex, or mild foot weakness in dorsiflexion or plantar flexion. Spinal stenosis would be suspected in an older
adult with radiating leg pain or pseudoclaudication.
In these circumstances, guidelines from the American
College of Physicians (table 1) recommend a one month
trial of treatment before imaging because most patients
with acute back pain and radiculopathy improve substantially in that interval without invasive interventions6 and
imaging would not alter initial management.5 If patients
have not improved after a month, and interventions
such as surgery or epidural steroid injections are considered, advanced imaging is indicated (figs 2 and 3). The
NICE guidelines do not refer to imaging for these milder
n­eurologic findings.
Risks of unnecessary imaging
Clinicians and patients alike might imagine no harm in a
non-invasive imaging test. In the case of spine imaging,
however, there is a substantial risk of uncovering irrelevant and misleading findings. For example, in a study
of 98 MRIs from pain-free volunteers (mean age 42), only
36% had normal discs at all levels. Over half had a bulging
disc, and 27% had a protruded disc. Annular fissures were
found in 14% and facet arthropathy in 8%.7 A prospective
study of 200 individuals who initially had no back pain
showed that imaging abnormalities often preceded development of back pain. Among the 25% who developed back
pain over five years, most MRI findings were unchanged or
even improved.8 Plain radiography and computed tomography similarly show frequent “abnormalities” in pain-free
individuals. Both a randomized trial9 and observational
studies10 suggest that such findings can lead to more surgery and more aggressive treatment, without improvements in patient outcomes. In studies of geographic
variations in care, rates of spinal surgery are higher where
MRI rates are higher.11
Knowing about an imaging abnormality might have
adverse effects on patient self perceptions and behavior.
In a randomized trial, low risk patients who underwent
plain lumbar radiography reported worse pain and overall
health during follow-up than those who had no imaging.
They also sought more medical care.12 Similarly, in a trial
of lumbar MRI, patients were randomized to receive the
report or not. Although clinical outcomes were the same for
the two groups, those who did not receive results reported
greater improvements in general health.13 Thus, spinal
imaging in low risk patients might diminish self perceived
health and drive unnecessary visits and surgery.­
Radiation exposure is a concern for plain radiography
and computed tomography. Unlike chest radiography,
lumbar spine films result in substantial irradiation of the
gonads, slightly increasing both mutagenesis and carcinogenesis. Computed tomography results in higher radiation
exposure than radiography. In the US, an annual 2.2 million lumbar scans are projected to result in an additional
1200 future cases of cancer.14 Because of reproductive concerns and the time required for cancer to develop, radiation
risks are more important in younger than in older patients.
Impact of imaging on patient outcomes
The ultimate confirmation of the value of a diagnostic
test is that it improves patient outcomes, presumably by
guiding better treatment. Though randomized trials of
diagnostic tests are rare, we identified six randomized
trials of some form of lumbar spine imaging compared
with usual care without imaging for low risk patients. In
pooled analyses, the use of imaging was not associated
with any advantage in pain relief or functional recovery,
in either the short term (<3 months) or the longer term (6
months to a year).15
Strategies for selective ordering of lumbar images
Given the limitations of spinal imaging, several guidelines
have recommended highly selective use. The NICE guideline
recommends serial clinical review of the diagnosis; no radiography for non-specific low back pain; and consideration
of MRI when malignancy, infection, fracture, cauda equina
syndrome, or ankylosing spondylitis is suspected (table 1).2
The clinical challenge is to decide when suspicion of these
conditions is sufficiently high to warrant imaging.
Some studies and guidelines have proposed the use of
“red flags” to guide selective ordering of lumbar images or
the bmj | 19 July 2014 31
EDUCATION PRACTICE
Table 2 | Estimates of diagnostic performance for selected “red flag” clinical findings and
selected diagnostic tests in detecting spinal malignancy or fracture. Spinal malignancy is the
most common underlying systemic cause of back pain. Estimates are based on samples from
primary care1 5 16 18
Sensitivity
Specificity
Positive likelihood
ratio
Negative likelihood
ratio
History of cancer
0.31
0.98
15.3
0.70
Age >50
0.77
0.71
2.7
0.32
Unexplained weight loss
0.15
0.94
2.6
0.90
Not improved after 1 month
0.31
0.90
3.0
0.77
ESR ≥20 mm/h
0.78
0.67
2.4
0.33
ESR ≥50 mm/h
0.56
0.97
18.7
0.45
Plain radiography
0.6
0.95-0.995
12-120
0.40-0.42
MRI
0.83-0.93
0.90-0.97
8.3-31
0.07-0.19
Age >70
0.22-0.50
0.96
5.5-11.2
0.52-0.81
Use of corticosteroids
0.06-0.25
0.995
12-48
0.75-0.94
Significant trauma
0.25-0.30
0.85-0.98
2.0-10
0.77-0.82
Red flags for cancer
Test accuracy for cancer
Red flags for spinal fracture
ESR=erythrocyte sedimentation rate; MRI=magnetic resonance imaging.
Fig 2 | MRI from man in his 40s with persistent back and leg pain. Sagittal T2 weighted image
shows a disc extrusion at L5-S1 extending inferiorly from level of interspace (black arrow) (a).
Axial image shows that disc (long white arrow) is compressing right S1 nerve root (short gray
arrows) in lateral recess (b)
Fig 3 | MRI from middle aged man with metastatic lung cancer, with new hip pain radiating to
ankle. Sagittal T1-weighted image shows pathological fracture of L5 with hypointense tumor
diffusely infiltrating the normal hyperintense marrow (white arrows) (a). Axial T2 weighted
image shows extension of tumor posteriorly into lateral recess (white arrows) with presumptive
compression of right S1 nerve root (b)
32 to minimize the use of advanced imaging. Red flags are a
history or findings on physical examination that suggest
an increased probability of underlying systemic disease,
fracture, or neurologic injury—conditions that might
influence initial treatment. They typically include factors such as a history of cancer, a history of injecting drug
use, advanced age (variously defined), major trauma, use
of corticosteroids, and severe or progressive neurologic
deficit. Some lists include a wider range of findings, such
as limited straight leg raising, abnormal reflexes, spine
tenderness, unexplained weight loss, and others.1
The prevalence of serious spine disorders is low and
the sensitivity and specificity of most red flags modest (table 2).1 5 16 As a result, recent studies have highlighted the limited predictive value of most red flags and
suggested that performing imaging with the presence of
any red flag would result in unnecessarily high rates of
imaging.16 Observers have therefore suggested that use
of imaging should be guided by the full clinical picture
and observation over time, rather than by uncritical use of
individual red flags.17 Indeed, the predictive value of individual red flags varies substantially, and the presence of
multiple red flags generates higher predictive values.1 5 On
the other hand, clinicians sometimes fail to assess major
risk factors that should prompt early imaging, such as a
history of cancer or injecting drug use, so some guidance
seems appropriate.
One inexpensive strategy to augment the sensitivity and
specificity of clinical assessment is the use of an inflammatory marker such as the erythrocyte sedimentation
rate (ESR), which is often higher in patients with cancer,
infections, or inflammatory spondylopathies. This has
been incorporated into guidelines from the American
College of Physicians (table 1).2 Though the erythrocyte
sedimentation rate is non-specific, its use in this context,
combined with plain radiography, is mainly intended
to help “rule out” underlying systemic disease without
resorting to advanced imaging. A cost effectiveness analysis suggested that a reasonable strategy is to use advanced
imaging only for patients with a red flag plus either an
erythrocyte sedimentation rate ≥50 mm/h or a positive
result on radiography.18
Additional opportunities to reduce unnecessary spinal imaging include efforts to eliminate repeated testing,
potentially with reminders of recent imaging through the
use of electronic health records. Another strategy is to
alert primary care clinicians about the dubious clinical
importance of some degenerative findings on imaging by
pointing out their high prevalence in pain-free individuals. A small observational study suggested that adding
such a message to routine MRI reports could reduce the
use of subsequent imaging tests.19
Factors promoting unnecessary spinal imaging
Many patients are eager for an explanation of their symptoms and expect imaging when they have back pain. In
some studies, patients report higher satisfaction with care
for back pain if imaging is performed than if it is not or if
more advanced imaging is performed than radiography.9 12
Studies of insurance claims in the US suggest that clinicians
order earlier and more advanced imaging when they have
19 July 2014 | the bmj
EDUCATION PRACTICE
financial incentives based on patient satisfaction questionnaires. Patient education strategies might mitigate the
impact of delayed or no imaging on patient satisfaction.
Financial incentives are also important when there is
high imaging capacity and referral to self owned imaging
facilities. Both are concerns in the US, and the former might
become increasingly important in the UK if commercialization of the National Health Service increases access to
advanced imaging. Advanced imaging such as MRI offers
a relatively high profit margin in the US. Finally, physicians
are often concerned about legal liability if a serious diagnosis such as cancer or infection is delayed.
Outcome
The full clinical picture in this case prompted early radiography. The patient’s L1 compression fracture was readily
apparent on radiography, as was the suggestion of osteo­
penia. There was no indication of metastatic disease to
s­uggest a pathologic fracture related to malignancy. The
patient was treated with oral analgesics, and her symptoms
were s­ubstantially improved at six weeks’ follow-up. At that
point, she was started on treatment with bisphosphonates,
with the goal of reducing risk of further fracture.
Competing interests: We have read and understood BMJ policy on
declaration of interests and declare the following interests: RAD has received
honorariums as a member of the board of directors of the Informed Medical
Decisions Foundation, a non-profit organization. He receives royalties from
UpToDate for authoring topics on acute low back pain. His university has
received an endowment from Kaiser Permanente that supports part of his
salary. JGJ receives consulting fees from HealthHelp, a radiology benefits
management company. He has received reimbursement for co-editing a
book on neuroradiology from Springer Publishing. RC has received consulting
fees from Palladian Health, a healthcare management company. He was
reimbursed for authoring an article on low back imaging for the American
College of Physicians and also helped the American College of Physicians
and the American Pain Society develop guidelines for managing low back
pain. He has received honorariums from UpToDate for authoring topics on
low back pain. All three authors’ institutions have received multiple grants
from US federal agencies for research on low back pain.
Provenance and peer review: Commissioned; externally peer reviewed.
Patient consent: Patient consent not required (patient anonymised).
References are in the version on thebmj.com.
Accepted: 11 June 2014
CHANGE PAGE
Avoid surgery as first line treatment for non-specific low back pain
Wilco C Peul,1 2 Annelien L Bredenoord,3 Wilco C H Jacobs1
1
Department of Neurosurgery,
Leiden University Medical Centre,
PO Box 9600, 2300 RC Leiden,
Netherlands
2
Department of Neurosurgery,
Medical Centre Haaglanden, PO
Box 432, 2501 CK The Hague,
Netherlands
3
Department of Medical
Humanities, Julius Centre,
University Medical Centre Utrecht,
Netherlands
Correspondence to: W C Peul
[email protected]
Cite this as: BMJ 2014;349:g4214
doi: 10.1136/bmj.g4214
Change Page aims to alert
clinicians to the immediate need
for a change in practice to make it
consistent with current evidence.
We welcome any suggestions
for future articles (email us at
[email protected]).
Low back pain (LBP) ranks as the number one disorder in
terms of years lived with disability; estimated global one
year incidences range from 22% to 65%.1 Back pain as
a symptom, not attributable to spinal instability caused
by trauma, infection, progressive deformity, or tumour,
and not associated with radicular symptoms, is labelled
non-specific LBP (see box). Many of patients with nonspecific LBP may have degenerative intervertebral disc
and bony joint changes, including disc herniations and
spinal stenosis on imaging, but these findings are not
more common than in the general population, including people without LBP.2 Guidelines discourage surgery
for non-specific back pain3; some recommend surgery
only after two years of failed conservative treatments in
carefully selected patients.4 However, despite these recommendations, the rate of back surgery is rising, with
considerable geographical variation.5 The rates of spinal
fusion, including use of surgical implants, for all degener-
KEY POINTS
For non-specific low back pain (LBP), do not offer spinal
surgery as first line treatment, as insufficient evidence
exists for greater effectiveness of surgical interventions
than conservative treatment
Offer surgery only for severe persistent non-specific LBP if
multidisciplinary (combined physical and psychological)
conservative treatment is ineffective
Non-specific LBP should not be confused with sciatica or
neurogenic claudication, for which surgery may have a role
Magnetic resonance imaging should be performed only if
red flags exist or when considering surgery for persistent
and severe non-specific LBP for which conservative
treatment has been ineffective
SOURCES AND SELECTION CRITERIA
We searched the Cochrane Database of Systematic Reviews,
Cochrane Database of Abstracts of Reviews of Effectiveness,
Cochrane Central, and PubMed. We selected the most
recent, high quality systematic reviews comparing surgery
with conservative treatments for the treatment of patients
with chronic low back disorders
ative disorders of the lumbar spine show an unexplained
exponential increase,6 7 with a corresponding rise in serious perioperative complications, including stroke and
cardiopulmonary events.7 These rises are unexpected,
as the incidence of spinal diseases causing instability of
v­ertebral elements has not risen, and nor has the incidence of surgery for herniated discs and stenosis.5 We
propose that surgery should be avoided as first line treatment of non-specific LBP and that it is justified only in
selected well informed patients after multidisciplinary
conservative care has failed.
The evidence for change
For non-specific LBP, studies repeatedly show that
surgery does not offer clinically relevant benefits over
conservative interventions such as multidisciplinary
treatment. For instance, in non-specific LBP with documented degenerative disc disease, a systematic review
compared intradiscal electrothermal therapy with sham
surgery.8 This included two randomised controlled trials
(121 patients), which both showed no significant difference in outcomes, such as pain, disability, and quality of
life. In a meta-analysis that included four higher quality
randomised controlled trials (767 patients) comparing
spinal fusion surgery with conservative interventions,
the bmj | 19 July 2014 33
EDUCATION PRACTICE
thebmj.com
Conditions that may cause low back pain
Previous articles in this
series
Herniated intervertebral disc—This may cause nerve root
compression, which in turn may cause radicular leg pain,
low back pain (LBP), or both
ЖЖAdminister tranexamic
acid early to injured
patients at risk of
substantial bleeding
(BMJ 2012;345:e7133)
ЖЖDon’t use aspirin for
primary prevention of
cardiovascular disease
(BMJ 2010;340:c1805)
ЖЖAdvise use of rear
facing child car seats for
children under 4 years
old
(BMJ 2009;338:b1994)
ЖЖConsider β blockers for
patients with heart failure
(BMJ 2009;338:b1728)
ЖЖUse graduated
compression stockings
postoperatively to prevent
deep vein thrombosis
(BMJ 2008;336:943)
Isthmic spondylolisthesis—Anterior or posterior
displacement of a vertebra relative to the vertebra or sacrum
below it, due to a bone defect in the posterior elements of
that vertebra; this may cause compression of nerve roots,
which in turn may cause LBP, radiating pain, or both
Degenerative spondylolisthesis—Anterior or posterior
displacement of a vertebra in relation to the vertebra or
sacrum below, due to degenerative processes in the discs
and articular surfaces of the joints connecting vertebrae;
this may cause compression of the spinal cord or nerve
roots, which in turn may cause LBP, radiating pain, or both
Spinal stenosis—Abnormal narrowing (stenosis) of the
spinal canal causing compression of the spinal cord or
nerve roots with associated neurological deficit including
low back or radicular pain, numbness, paraesthesia, and
muscle weakness
Non-specific LBP—Pain with possible tension, soreness,
or stiffness in the lower back region, for which no specific
cause can be identified. Several structures in the back,
including the joints, discs, and connective tissues,
may contribute to symptoms.3 Imaging findings of disc
herniation and spinal stenosis may sometimes be incidental
and are not more common than in people without LBP2
surgery was not superior to intensive rehabilitation in
improving back pain, disability, and quality of life.9 A
Cochrane review of five randomised controlled trials with
1301 patients evaluated disc replacement for degenerative disc disease.10 It included one trial at low risk of bias
(173 patients) that showed a statistically significant (12.3
mm on a visual analogue scale for back pain) but clinical irrelevant (less than 20 mm) difference favouring disc
replacement over rehabilitation. Potential harms or surgical side effects were inconsistently reported in studies.
The guideline from the National Institute for Health and
Care Excellence (NICE) on non-specific low back pain
included only one cost effectiveness analysis, which
concluded that the chance that surgery as early treatment is cost effective compared with non-operative care
is only 20% if decision makers are willing to pay £30 000
(€37 600; $51 100) per quality adjusted life year.3
However, surgery may have more of a role for relief of
radicular pain and LBP with specific causes. For back pain
with predominant sciatica due to herniated lumbar discs,
a systematic review with five (two with a low risk of bias)
randomised controlled trials (1135 patients) concluded
that early surgery leads to short term benefits in function and leg pain (recovery after 4 v 12 weeks) but with
similar long term results.11 Surgery did not offer superior
relief of concomitant LBP in these studies, and patients
with predominant LBP were excluded. For back pain with
predominant neurogenic claudication due to lumbar
stenosis, systematic reviews show that, for patients with
neurogenic claudication with or without minimal back
pain, bony decompression (five randomised controlled
trials with 918 patients) and interspinous devices (two
randomised controlled trials with 142 patients) may be
better than conservative treatment from three months
34 up to at least four years in improving pain, disability,
and quality of life.12‑14 These studies excluded patients
with predominantly LBP as their major complaint. For
back pain due to isthmic spondylolisthesis (see box), in
a systematic review of eight randomised controlled trials
(385 patients),15 only one trial (111 patients) compared
surgery with conservative treatment, showing improved
overall outcome (74% v 43%) at two years after posterolateral fusion versus exercise, but this trial had a high risk
of bias. Unfortunately, for those patients with so called
“good” anatomical and physiological indications for
surgery (for example, spinal trauma, tumour, infection,
progressive deformity), back pain as an outcome was not
studied.
Barriers to change
Evidence suggests that surgery may have a role in patients
with sciatica from herniated lumbar discs or neurogenic
claudication due to spinal stenosis. However, patients
and physicians may wrongly extrapolate this to nonspecific LBP, especially when pain is poorly controlled.
The low threshold for performing magnetic resonance
imaging for back pain may also result in the diagnosis
of structural abnormalities of questionable clinical significance, triggering treatment algorithms and the quest
for surgery. Placebo effects of surgery should also not be
underestimated. In addition, the medical device industry expends great effort in promoting surgical procedures
with implants, and complications are often underreported in the literature, especially where financial ties
exist between authors and sponsors.16
Reluctance to generate systematically collected evidence to support the rise in surgery for non-specific LBP
might be explained by “surgical exceptionalism”—the
view that the ethical or regulatory status of surgery is
justified by its (questionably) unique nature.17 The view
that if interventions do no good they will at least do no
harm is a misunderstanding, especially given the potential discomfort for patients and possible risks of surgery.18
Evidence based surgical practice is necessary to protect
patients against unproved “treatments” and insufficiently
tested devices, as well as to make rational decisions in
times of scarcity.
Red flags prompting further diagnostic investigations in case of
first episode of low back pain
Possible
diagnosis
Clinical feature
History of cancer
Loss of bladder or bowel control
Severe motor weakness (MRC scale ≤3) or progressive
motor weakness
Loss of sensation in buttocks (saddle anaesthesia) or
progressive sensory deficit
Significant trauma
Chronic corticosteroid use, osteoporosis
Age >70 years
Lumbar surgery in previous year
Urinary tract infection or bacterial sepsis
Immunosuppression
Injecting drug use
Unexplained fever
Cancer
Cauda equina
syndrome
Fracture
Infection
19 July 2014 | the bmj
EDUCATION PRACTICE
How should we change our practice?
In view of the above, spinal surgery should be avoided
as first line treatment for non-specific LBP.19 It should
instead be considered only as the last line of treatment
for persistent and severe LBP if an adequate trial of multidisciplinary non-operative treatment, including a combined physical and psychological treatment programme,
has failed and following adequate informed consent. This
is in accordance with the NICE guidance, which found
insufficient evidence to advocate surgery as first line
treatment for non-specific LBP.3 Physicians should advise
patients that, for non-specific LBP, evidence is lacking to
show that surgery significantly improves pain, disability,
and quality of life or is any better than physiotherapy,
multidisciplinary non-operative care, or a careful “wait
and see” approach.
Where non-operative measures are not readily available, healthcare organisations should ensure that these
are a priority for implementation. Surgical societies and
the medical community generally need to promote cultural change towards evidence based spinal surgery and
create ample room for informed decision making by the
patient during the consultation.
Magnetic resonance imaging can lead to misleading
anatomical diagnoses and should not be performed
for back pain. It should be considered only when referral is i­nd­icated for consideration of surgery. If pain due
ANSWERS TO ENDGAMES, p 36
ANATOMY QUIZ
Contrast enhanced
axial computed
tomography slice
at the level of the
transpyloric plane of
Addison
A: Neck of the pancreas
B: Body of the gallbladder
C: Pylorus
D: Portal vein
E: Superior mesenteric artery
F: First lumbar vertebra
STATISTICAL
QUESTION
Understanding
P values
Statement a is true, whereas b
and c are false.
to sciatica or neurogenic claudication is significant or
is impairing function or quality of life, imaging and
subsequent surgical procedures should be considered.
The indications are more urgent if red flags, such as a
neurological deficit or a history of cancer, exist (table).4
Any surgery for non-specific LBP should be done only
under controlled study conditions. Surgical innovation
outside a randomised controlled trial is not in itself
unethical, but the patient should be fully informed about
the lack of evidence for added value in terms of reduction in back pain and objective evaluation of clinically
im­portant outcomes should be ensured.
Contributors: WCP developed the concept of the article. WCHJ did the
literature search and developed the first substantive draft. ALB discussed
the ethical rationale of evidence based surgery and its implications. All
three authors contributed to consecutive and final drafts and read and
approved the final version. WCP is the guarantor.
Competing interests: We have read and understood the BMJ policy on
declaration of interests and declare the following interests: WCHJ received
unrestricted research support for investigator initiated clinical studies from
ZonMw and AO Spine, is coordinator of the multidisciplinary Dutch network
for spinal disorders, and has an unpaid advisory role on an outcome
measurement committee for AO Spine, for the guideline on instrumented
spine surgery, and for the guideline on spinal metastases; WCHJ and WCP
are authors of some of the evidence used in the manuscript; WCP received
unrestricted research support for investigator initiated clinical studies from
ZonMw, CVZ, Medtronic, Braun Aesculaep, Paradigm Spine, The Hague
Hoelen Stichting, and the Leiden University Medical Center. ALB received
grants from ZonMw and BMM.
Provenance and peer review: Commissioned; externally peer reviewed.
References are in the version on thebmj.com.
For long answers go to the Education channel on thebmj.com
CASE REPORT
A woman with macrocytic anaemia and confusion
1 Red cell macrocytosis can be divided into two categories: megaloblastic and non-megaloblastic.
Megaloblastic macrocytosis is generally secondary to vitamin B12 or folate deficiency. Non-megaloblastic
macrocytosis is commonly caused by excess alcohol intake, hypothyroidism, myelodysplasia, or drugs.
2 Macrocytosis was secondary to severe vitamin B12 deficiency with subsequent haemolysis and
pancytopenia. The most likely cause is drug (metformin) induced vitamin B12 malabsorption because
she had negative tests for pernicious anaemia, an adequate dietary intake, no history of gastric or ileal
resections, and no evidence of an infectious cause. In addition, bone marrow examination confirmed a
megaloblastic process.
3 The most common cause of vitamin B12 deficiency worldwide is autoimmune gastritis (pernicious
anaemia). Other gastric abnormalities to consider include total or partial gastrectomy or ileal resections.
Drugs are being increasingly implicated, particularly proton pump inhibitors and metformin. Rarer
considerations include dietary deficiency (particularly in vegans), fish tapeworm (Diphyllobothrium latum),
and hereditary causes.
4 After a thorough history and clinical examination, blood should be taken for vitamin B12 and folate
measurements in addition to intrinsic factor and parietal cell antibodies. Blood film should be assessed for
hypersegmented neutrophils.
5 All patients with documented B12 deficiency can be treated parenterally or orally. The parenteral route is the
preferred one in patients with pernicious anaemia. If the cause cannot be reversed, lifelong treatment is
necessary, and a standard treatment regimen is cyanocobalamin 1 mg every day for one week, followed by
1 mg every week for four weeks, then 1 mg a month.
the bmj | 19 July 2014 35