Red Flags in Spinal Conditions

Original Editor - Anna Butler, Fiona Stohrer and Katherine Moon as part of the Nottingham University Spinal Rehabilitation Project

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What are Red Flags?

Part of the UK guidelines for an assessment of lower back pain is to be able to rule out serious pathology and identify red flags. Red flags are features from a patients subjective and objective assessment which are thought to put them at a higher risk of serious pathology and warrant referral for further diagnostic testing. They often highlight non-mechanical conditions or pathologies of visceral origin and can be contraindications to many Physiotherapy treatments.

Although red flags have a valid role to play in assessment and diagnosis they should also be used with caution. Some guidelines contain no information on diagnostic accuracy for individual red flags, so it is the responsibility of individual practitioners to make themselves aware of these. Other guidelines even recommend immediate referral to imaging if any red flag is present, which could lead to many unnecessary referrals if clinicians did not clinically reason their referral.

History of Red Flags

The role of Physiotherapists in identifying red flags has changed as Physiotherapists increasingly become patients first point of contact with a healthcare professional. In McKenzies 1990 book he states that “the patient once screened by the medical practitioner, should have any unsuitable pathologies excluded.” Within today’s healthcare system patients may not have even been seen by a doctor before they present to a Physiotherapist as there is more scope for self referral and private clinics. The term ‘red flag’ was first used by the Clinical Standards Advisory Group in 1994. However, similar high risk markers date back to Mennell in 1952 and Cyriax in 1982   

Red Herrings

Red Herrings are “any misleading biomedical or psychosocial factors that will deflect the course of accurate clinical reasoning”.When assessing lower back pain red herrings can mislead a clinician into misdiagnosis resulting in a delay in appropriate treatment for the pathology causing the lower back pain.

Some of the common red herrings for serious spinal pathology are:

• Upper Motor Neurone Disease
• Multiple Sclerosis
• Diabetes
• Alcoholism
• Cervical Myopathy
• Peripheral Neuropathy
• Lower Limb Oedema leading to heaviness in legs as a result of cardiovascular disease
• Spinal Stenosis
• Nerve Root Compression

Spinal Masqueraders

Spinal masqueraders are conditions which present as lower back pain but are actually caused by non-mechanical referred pain from a visceral structure. 

Spinal masqueraders are examples of when red herrings can sometimes lead to misdiagnosis. Patients will present with lower back pain but the source is not a mechanical structure. Although the percentage of patients seen by Physiotherapists with these conditions is small it is important to be able to recognise the red flags that could point towards these conditions.

Some of the sources of visceral pain include:
• Inflammation - eg. Appendicitis
• Distention - eg. Bowel Obstruction
• Ischemia - eg. a tumour blocking blood supply
The blood supply to internal organs is in close proximity to the sympathetic nerve system so changes to the blood supply from ischemia, distention of inflammation can directly affect the nerve innervation.

This diagram depicts the most commong referral patterns for visceral pathologies.

Epidemiology of Red Flags

It is hard to get an exact picture of the epidemiology of red flags as it depends heavily on the level of documentation by clinicians. One study suggested that “the documentation of red flags was comprehensive in some areas (age over 50, bladder dysfunction, history of cancer, immune suppression, night pain, history of trauma, saddle anaesthesia and lower extremity neurological deficit) but lacking in others (weight loss, recent infection, and fever/chills)”.

 Table showing breakdown of the conditions lower back pain patients present with

Figures in brackets indicate estimated percentages of patients with these conditions among all adult patients with signs and symptoms of low back pain. Percentages may vary substantially according to demographic. Data obtained from 

Subjective History - Red Flags

The most important indicators for increasing the probability of underlying systemic disease are:

• age
• history of cancer
• unexplained weight loss
• duration of pain
• responsiveness to previous therapy

Age

In the UK, age above 55 years is considered a red flag (CSAG 1994), this is because above this age, particularly above 65, the chances of being diagnosed with many serious pathologies, such as cancers, increase.   

History of cancer

A patient history of cancer and also family history of cancer should be established, particularly in a first degree relative, such as a parent or sibling. The most common forms of metastatic cancer are: breast, lung and prostate.

The most common warning signs of cancer are:

• Change in bowel or bladder habits
• Sores that do not heal
• Unusual bleeding or discharge
• Thickening or lump in breast elsewhere
• Indigestion or difficulty swallowing
• Obvious change in wart or mole
• Nagging cough or hoarseness

Unexplained weight loss

This should depend on a patients previous weight and it is sometimes more useful to consider percentage weight loss. A weight loss of of 5% or more within a 4 week period is a rough indicator of when unexplained weight loss should cause alarm.

Pain

Constaint pain - this needs to be true constant pain that does not vary within a 24 hour period.

Thoracic pain - the thoracic region is the most common region for metatases.   

Severe night pain - this can be linked to be objective history if the patients symptoms are brought on when they are lying down or non weight bearing.

Abdominal pain and changed bowel habits but with no change of medication - a change is bowel habits can be a red flag for cauda equina.

Responsiveness to previous therapy

This can also be considered a yellow flag and should be taken with caution as many patients suffer episodic lower back pain. However, patients who initially respond to treatment and then relapse may be a cause for concern.

Other 

• Systemically unwell
• Bilateral pins and needles
• Trauma - fall from height, road traffic accident or combat
• Past medical history of tuberculosis or osteoporosis
• Smoking -has adverse affects on circulation, therefore decreasing the nutritional supply getting to the intervertebral disk and vertebrae. Over time this leads to degeneration of these structures and therefore instability which can cause lower back pain. It has also been suggested that regular coughing, which if often associated with smoking, can also lead to increased mechanical stress on the spine 
• Cauda Equina symptoms: urinary retention, faecal incontinence, unilateral or bilateral sciatica, reduced straight leg raise and saddle anaesthesia

Objective History 

The subjective assessment will provide the therapist with the majority of the information needed to clarify cause of symptoms

The objective assessment needs to be sufficiently thorough to ensure that if present, red flags are managed appropriately.
It is suggests that a total of 44 items in the objective examination can be considered as red flags

Physical Appearance

The therapist should determine if the patient is unwell objectively however this is a very subjective concept. The following signs may indicate that the patient has a systemic serious pathology.

• Pallor/flushing
• Sweating
• Altered complexion: sallow/jaundiced
• Tremor/shaking
• Tired
• Dishevelled/unkempt
• Halitosis
• Poorly fitting clothes

Observation

Deformity of the spine

Deformity of the spine with muscle spasm and severe limitation of movement are suggested to be key indicators of serious spinal pathology. A rapid onset of a scoliosis may be indicative of an osteoma or osteoblastoma however this may not be apparant in standing. Physiological movements are often required to detemine a rapid onset scoliosis 

Some spinal tumors can be large enough to be seen or felt. Swelling and tenderness may be the first sign of a tumour. It is also common for spinal tumours to limit physiological movements.

Muscle Spasm

This is suggested to be synonymous with low back pain and is therefore difficult to determine if it is associated with a red flag pathology. If a serious spinal pathology is present, the muscle spasm may be severe enough to be a cause of scoliosis in the spine. The correlation between muscle spasm, pain and other objective clinical measurements however, are poorly supported by strong evidence.

Neurological Assessment

Patients who report neurological signs in the subjective assessment require a neurological assessment. A neurological deficit is rarely the first presenting symptom in a patient with serious spinal pathology however 70% of patients will have a neurological deficit at the time of diagnosis

The dermatomes, myotomes and reflexes should be examined. The upper motor neurone should also be examined via extensor plantar reflex (Babinski), clonus and hoffmans. If brisk, it may indicate a upper motor neurone pathlogy.

Evidence Base

Evidence Base
A qualitiative investigation into the red flags experienced by a focus group of 7 senior palliative care clinicians was undertaken to improve the evidence base on objective red flags. The three items that had the strongest agreement were:
• Band like trunk pain
- often preceeded by vague symptoms
- commonly bilateral
- related to a bone or nerve root
• Vague non-specific lower limb symptoms
- apparent relatively late in the disease process
- often predates overt spinal cord compression
- heaviness preceeded by legs feeling odd or strange
- patients report that their legs ‘misbehave’
• Reduced mobility
- may have a mild foot drop
- may drag one leg
- patients do not often recognise these symptoms as important or significant

Diagnostic Tests

What is differential diagnosis?

A systematic process in which tools such as clinical tests are used to identify the proper diagnosis from a competing set of possible diagnoses. (Whiting et al, 2008)

For a clinical test to be the best test?
• Reliable
• Low Cost
• Validated findings
• High diagnostic Accuracy = SPECIFICITY AND SENSITIVITY

SPECIFICITY
Is the percentage of people who test negative for a specific disease among a group of people who do not have the disease
SENSITIVITY
Percentage of people who test positive for a specific disease among a group of people who have the disease

Likelihood ratio = The Likelihood Ratio (LR) is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that that same result would be expected in a patient without the target disorder.

http://www.cebm.net/?o=1158
http://www.physio-pedia.com/Test_Diagnostics

High sensitivity and LOW LR = RULE OUT people who don’t have the disease
High specificity and HIGH LR = RULE IN people who have the disease

1. Fracture

Table 2 : Table to show sensitivity, specificity, and likelihood ratios of subjective information in the diagnosis of fracture

Subjective Index	Sensitivity (%)	Specificity (%)	Positive likelihood Ratios (%)	Negative likelihood Ratios (%)
History of major trauma	0.65*7 0.36*13 1*12	0.95*7 0.90*13 0.51*12	12.8*7 3.42*13 1.93*12	0.37*7 0.72*13 0.12*12
Pain and tenderness	0.60*7	0.91*7	6.7*7	0.44*7
Tenderness	0.50*11 0.72*10	0.73*11 0.59*10	1.88*11 1.76*10	0.68*11 0.47*10
Age >50 years	0.79*7 0.79*13	0.64*7 0.64*13	2.2*7 2.16*13	0.34*7 0.34*13
Age >52	0.95*9	0.39*9	1.55*9	0.13*9
Female	0.47*7 0.72*8	0.80*7 0.43*8	2.3*7 1.26*8	0.67*7 0.65*8
Corticosteroid use	0.06*7 0*13	0.99*7 0.99*13	12.0*7 3.97*13	0.94*7 0.97*13

Roman Index tests 1. Leg or buttock pain 2. gender 3. Age 4. BMI<22 5. Gait abnormality 6. No regular exercise 7. Sitting pain 8. Osteoarthritis

Clustered Results	Sensitivity (%)	Specificity (%)	Positive likelihood Ratio (%)	Negative likelihood ratio (%)
1 of 5	0.97	0.06	1.04	0.43
2 of 5	0.95	0.34	1.43	0.16
3 of 5	0.76	0.69	2.45	0.34
4 of 5	0.37	0.96	9.62	0.66
5 of 5	0.03	1	7.63	0.98

Tests : Compression fractures
The examiner stands behind the patient. The patient stands facing a mirror so that the examiner can gauge their reaction. The entire length of the spine is examined using firm, closed-fist percussion.

Positive = when the patient complains of a sharp, sudden pain.

Table 3 : To show sensitivity, specificity and likelihood ratios for compression fracture.

Diagnostic Test	Sensitivity (%)	Specificity (%)	Positive Likelihood ratio (%)	Negative Likelihood Ratio (%)
Percussion Test	87.5	90.0	8.8	0.14

2. Cancer

Table 4 : To show sensitivity, specificity and likelihood ratios for signs and symptoma that could indicate cancer

Subjective Index	Sensitivity (%)	Specificity (%)	Positive likelihood ratio (%)	Negative likelihood ratio (%)
Age >50	0.77*15 0.75*13 0.50*17 1*16 0.55*19	0.71*15 0.70*13 0.74*17 0.41*16 0.35*19	2.5*23 1.92*13 1.66*17 0.86*16	0.36*23 0.68*13 0.06*17 1.27*16
Previous history of cancer	0.31*15 0.31*18 1*14	0.98*15 0.98*18 0.97*14	15.27*18 31.67*14	0.71*18 0.06*14
Failure to improve in one month of therapy	0.31*15 0.31*18	0.90*15 0.90*18	3.08*18	0.77*18
No relief from bed rest	>0.90*15	0.46*15
Duration more than one month	0.50*15 0.50*13	0.81*15 0.81*13	2.63*13	0.62*13
Unexplained weight loss	0.15*18	0.94*18	2.59*18	0.90*18

3. Sign of the Buttock

Tests : Indicates serious gluteal pathology.

When : The patient suffers from gluteal pain, which may or may not spread down the leg.

Positive : We perform the standard functional examination of the lumbar spine :
• in standing, we notice flexion is painful and limited
• straight leg raise is also painful and limited. We might suspect a lumbar disorder.
• However, passive hip flexion is even more limited than straight leg raise, i.e. a clear sign of the buttock ; the hip rotations also hurt in a non-capsular way.

Because of the positive hip signs, the complete hip examination should be included. Some resisted hip tests may prove positive
Positive test indicates potential:

• infection : osteomyelitis of the upper femur, septic sacroiliac arthritis,ischiorectal abscess, septic gluteal bursitis
• neoplasm at the ilium or at the upper femur
• fractured sacrum.

http://www.cyriax.eu/content/sign-buttock
http://www.physio-pedia.com/Sign_of_the_Buttock - This is a video that explains the ‘sign of the buttock in more detail including a video to demonstrate the test.

There is no research into specificity and sensitivity or likelihood ratios for the sign of the buttock. However there are case studies referenced below, where patients had positive sign of the buttock and were diagnosed with serious pathology
, 

4. Ankylosing Spondylitis

Table 5 : Table to show sensitivity and specificity of information from subjective assesment in reagrds to Ankylosing Spondylitis

Subjective Index	Sensitivity (%)	Specificity (%)
Age of onset <40	1.00	0.07
Pain not relieved by supine	0.80	0.49
Morning back stiffness	0.64	0.59
Pain duration >3 months	0.71	0.54
Chest expansion < or equal to 2.5cm	0.09	0.99
4 out of 5 of the above	0.23	0.82

http://www.physio-pedia.com/Ankylosing_Spondylitis - Link to Ankylosing spondylitis differential diagnosis

5. Cauda Equina

Table 6: To show sensitivity and specificity of the signs and symptoms associated with cauda equina .

Subjective Index	Sensitivity (%)	Specificity (%)
Rapid symtoms within 24 hours	0.89*23
History of back pain	0.94*23
Urinary Retention	90*23
Loss of sphincter tone	80*23
Sacrak sensation loss	85*23
Lower extremity weakness or gait loss	84*23
Abnormal anal tone	1*24	0.95*24
Altered pereneal sensation	1*24	0.67*24

There is no research into the specificity of the signs/symptoms above.

Clinical Reasoning

Clinical Reasoning is integral to physiotherapy practice. As a concept, clinical reasoning is quite a simple one however in practice, it is difficult and fraught with errors. The aim of clinical reasoning is to prevent misdirection  A robust clinical reasoning process is vital so the threshold of suspicion of serious pathology is at an appropriate level. The way a therapsit clinically reasons their finidings can strongly influence how the case is interpreted. This has implications as to how the clinician views the red flags and gives weight to any red herrings presented therein

The most common form of clinical reasoning within the physiotherapy profession is hypothetico-deductive reasoning Within hypothetico-deductive reasoning, the clinician gains initial clues in regards to the patients problem (from the subjective assessment) which forms initial hypotheses in the therapists mind. Further data is collected in the objective assessment which may confirm or negate the hypotheses. Continual hypothesis generation may occur during management and reassessment

Reflection after the initial assessment and also after the subsequent sessions will help the therapist to recognise mechanical and non-mecahnical patterns and their clinical reasoning process will improve

Process of Clinical Reasoning

Clinical reasoning should begin as soon as the therapist meets the patient as their behaviour can inform the therapists clinical reasoning There should be ongoing data collection which should not stop at the end of the assessment to aid this process. A hyptothetico-deductive model of clinical reasoning can be seen in Figure 1.

Figure 1: A Hypothetico-deductive model of Clinical Reasoning 

The therapist may be able to ascertain quickly that something is wrong with the patient due to the subjective and objective assessment along wither their subsequent clinical reasoning. The data gathered over sessions should be collated to best inform the therapist. This will contribute to the therapists evolving concept of the patients’ problem.

 Pattern Recognition

Pattern recognition is an important part of clinical reasoning however this will be limited in students and newly qualified physiotherapists

Knowledge is also an important consideration. The newly qualified therapist is expected to have many more potential hypotheses in comparison to a experienced therapist . There is suggested to be differences in novice and expert therapists in the process of clinical reasoning. Although largely similar, novice physiotherapists have to go through a longer process of clinical reasoning compared to expert therapists due to lack of knowledge in comparison; and less experience in pattern recognition. Figure 2 demonstrates the clinical reasoning process of expert therapists (with at least 3 years of experience) and novice therapists (with under three years’ experience or students).

Figure 2: Difference in clinical reasoning between expert and novice therapists .

Patient involvement in the clinical reasoning process

The patient should be an integral part of the clinical reasoning process as this can help the clinician to form hypotheses and lead towards the review of the outcome post physiotherapy intervention (See Figure 3).

Figure 3: Patient involvement in the clinical reasoning process

Errors in Clinical Reasoning

The use of red flags should not replace clinical reasoning but used as an adjunct to the process. A lone red flag would not necessarily provide a strong indication of serious pathology. It should be considered in the context of a persons history and the findings on examination.

Patients’ inappropriate misattribution of insidious symptoms to a traumatic event is common and can be misleading. Clinical reasoning is only as good as the information on which it is based indicating the importance of thorough questioning in the subjective assessment

The three types of errors that can occur in clinical reasoning include:
- Faulty perception or elicitation of cues
- Incomplete factual knowledge
- Misapplication of known facts to a specific problem

Red Herrings

Within the clinical reasoning process, the therapist should determine if there are logical inferences in regards to the information they are recieving from the patient . The therapist should not be reassured by previous investigations being reported on as normal . In the early stages, serious spinal pathology is difficult to detect and weight loss will not always be evident in these early stages

Red Herring for serious spinal pathology may include spinal stenosis, lower limb odema, nerve root compression, peripheral neuropathy, cervical myelopathy, alcoholism, diabeties, MS and UMND. Due the abundance of red herrings that can be present, it is important the the therapist interprets the red flags in the context of the patients current presenting condition and not singularly.

Management of red flags

If red flags are identified in the spine, the should first consider if onward referral is appropriate.

Students Responsibility

Whilst on a clinical placement, it is the students’ responsibility to inform the clinical educator if they find a red flag and document appropriately in the clinical notes. This will allow the educator to perform the assessment again if required.

Onward referral to Accident and Emergency

In some cases the red flags may be obvious. If serious enough, the therapist may refer onto Accident and Emergency. This may be the case in cauda equina syndrome for further surgical opinion

The patient however may not present with clear red flags and physiotherapy intervention may continue.

Referral Back to the GP

Failure to improve after one month is a red flag and the patient can be referred back to the GP for continued management and further diagnostic tests as required

The GP will be able to refer the patient on to have x-rays, CT/MRI, blood tests or nerve conduction studies. It has been suggested that to reduce the rate of false alarms, the patient should be referred back to the GP in the first instance to undertake further investigations as required before more advanced imaging is undertaken.

Further Specialist Medical Opinion

As well as a referral back to the GP, further specialist medical opinions can be gained. This may be referall onto a specialist spinal clinic.

Documentation

After onward referral red flags must be acknowledged in the notes as this will indicate contraindication to physiotherapy.

Student physiotherapists should be taught the medico-legal aspect of physiotherapy practice . All records should be full and clear

Physiotherapist documentation of red flags in the USA has demonstrated that 8 of 11 red flags were documented 98% of the time as seen below:
• Age over 50
• Bladder dysfunction
• History of cancer
• Immunosuppression
• Night pain
• History of trauma
• Saddle anaesthesia
• Lower extremity neurological deficit

Red flags that were not documented routinely included:
• Weight loss
• Recent infection
• Fever/chills

This study investigated 6 physical therapy clinics in Washington, USA. Of these clinics, 16 therapists treating a total of 160 patients were investigated.

In comparison to this data in the USA, Scotland undertook a review of the documentation of red flags on 2147 episodes of care. The investigation took place in two phases, between May and June 2008 and January and February 2009). The therapists were given an online tool to prompt them in respect to the most common red flags

Results reported that in the first phase, 33% of red flags were documented and of those 33%, 54% were cauda equina symptoms. In comparison, within phase two, the rate of documentation rose to 65% for red flags and within those, 84% recorded cauda equina . Despite documentation improving, this still left 1 in 5 therapists not documenting red flags.
Of all the red flag questions investigated, HIV/drug abuse was the least documented red flag

References

References will automatically be added here, see adding references tutorial.

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William R VanWye .Patient Screening by a Physical Therapist for Nonmusculoskeletal Hip Pain American Physical therapy Association, March 2009, 89, 3 248-256