1. How to Investigate Back Pain
Facilitator notes:
These notes aim to provide guidance to facilitators and accompany the presentations.
This Back in Focus resource was developed for UK healthcare professionals only, organised and funded by AbbVie.
Available to download at:
Date of preparation: August 2017; AXHUR150807w(1)

2. Back pain: the challenge of differentiation
Definitive diagnosis difficult – not made in up to 85%1
The majority of cases are mechanical;
~7% of back pain reported is inflammatory2,3
When does a patient need further investigation/referral to secondary care?
Definitive diagnosis difficult – not made in 85%1
Therefore, it is important to identify those patients who require further investigation and to be aware of the appropriate referral pathway
Reference:
1. Wong, L L-S. Hong Kong Bulletin on Rheumatic Diseases 2005;5:8–13
1. Wong, L L-S. Hong Kong Bulletin on Rheumatic Diseases 2005;5:8– Dillon CF and Hirsch R. Am J Med Sci Apr;341(4):281-3.
3. Hamilton et al. Rheumatology 2014;53;161-4

3. Inflammatory vs mechanical causes of back pain
Possible causes of mechanical back pain
Possible causes of inflammatory back pain2
Other possible causes of back pain
Lumbar muscular strain/sprain1
Degenerative disc disease1,2
Facet arthropathy1
Fracture1,2
Herniated disc1,2
Osteoarthritis3
Congenital disease:2
Severe kyphosis
Severe scoliosis
Transitional vertebrae
Spinal stenosis1
Spondylolysis and/or spondylolisthesis1,2
Axial spondyloarthritis including patients with ankylosing spondylitis (AS)
Psoriatic arthritis (PsA) 
Inflammatory bowel disease
Psoriatic spondylitis
Reiter’s syndrome
Abdominal aortic aneurysm1,2
Disease of pelvic organs2
Fibromyalgia4
Gastrointestinal diseases2
Infections such as:2
Epidural abscess
Osteomyelitis
Septic discitis
Paraspinous abscess
Shingles
Paget’s disease of bone2
Renal diseases1,2
Scheuermann’s disease (osteochondrosis)2
Tuberculous sacroiliitis5
Neoplasia2
Malignancy1
In addition to mechanical and inflammatory back pain, it is important to be aware that back pain may in some cases be caused by other conditions including:
Tumours
Gastrointestinal or renal diseases
Infections
Inflammatory back pain may be the result of PsA or IBD
1. BMJ. Assessment of Back Pain – Differential Diagnosis (Last updated: June 2017). Available at: (Accessed August 2017); 2. Deyo RA and Weinstein JN. N Eng J Med. 2001;344:363–70; 3. Goode AP, et al. Curr Rheumatol Rep. 2013;15(2):305 doi: /s z; 4. NHS Choices. Fibromyalgia – Symptoms (Last updated: March 2016). Available at: (Accessed August 2017); 5. Prakash J. J Clin Orthop Trauma. 2014;5(3):

4. Investigation and referral considerations
Mechanical back pain
Inflammatory back pain
Red flags
Symptoms/suspicions
Lower back pain <3 months1
Degenerative disc disease/facet arthropathy2
Compression fracture2
Muscular sprain/strain2
Back pain >3 months1
Morning stiffness1
Good response to NSAIDs1
History of cancer2
Unexplained weight loss2
Significant trauma2
Fever/chills2
Bowel/bladder dysfunction with back pain2
Investigations to consider
X-ray (for traumatic fracture only)3
ASAS criteria for IBP4
MRI/X-ray4
HLA-B27 blood test4
Ultrasound/MRI/X-ray/CT2,3
Blood tests: infection/tumour markers (only in a minority of cases)2,3
Urinalysis3
Referral possibilities
Physiotherapy (if X-ray shows no abnormality)
Orthopaedics
Rheumatology
Accident and Emergency (A&E)
Urology
Neurosurgery
Different investigations are required for each of mechanical back pain, inflammatory back pain, and red flags
The presence of any red flag symptom is an indication for urgent referral to Oncology/Gastroenterology/Urology/A&E as appropriate
Red flag symptoms may be the result of any of the following:
Abdominal aortic aneurysm
Tumours
Renal disease
Gastrointestinal disease
Infection
1. Sieper J, et al. Ann Rheum Dis. 2009;68:784–8; 2. BMJ. Assessment of Back Pain – Differential Diagnosis (Last updated: June 2017). Available at: (Accessed August 2017); 3. BMJ. Assessment of Back Pain – Diagnosis Approach (Last updated: June 2017). Available at: (Accessed August 2017); 4. NICE. SpA in over 16s: diagnosis and management. NG65 (Last updated: June 2017). Available at: Accessed: August 2017.

5. What investigations may assist differentiation?
Laboratory analysis
Blood tests:
FBC (full blood count)1, U&Es (urea & electrolytes), LFTs (liver function tests)
CRP (C-reactive protein),2 ESR (erythrocyte sedimentation rate)1
HLA-B27 (human leukocyte antigen-B27)2
Urinalysis:3
Can be done in GP surgery
Tumour markers:4
E.g., Ca-125, AFP (alpha fetoprotein), PSA (prostate specific antigen)
Imaging3
X-ray
Magnetic Resonance Imaging (MRI)
Computerised tomography (CT)
Ultrasound (US)
Laboratory and imaging investigations may be used to aid diagnosis
Laboratory investigations (HLA-B27 and CRP) and imaging investigations (MRI) are part of the ASAS criteria for axial SpA1
Reference
1. Rudwaleit M, et al. Ann Rheum Dis 2009; 68:
1. Castro C and Gourley M. J Allergy Clin Immunol. 2010;125(2 Suppl 2):S238–S Sieper, J et al. Ann Rheum Dis. 2009; 68:784–8. 3. BMJ. Assessment of Back Pain – Differential Diagnosis (Last updated: June 2017). Available at: (Accessed August 2017); 4. Perkins GL, et al. Am Fam Physician. 2003 Sep 15;68:1075–1082.

6. HLA-B27 8-9% of UK population are HLA-B27 positive1
90-95% of UK patients with AS are HLA-B27 positive2
Useful in diagnosis
Study showed that 58% of patients with IBP and HLA-B27 positivity were diagnosed with SpA3
Study showed a sensitivity of 66.1% and specificity of 79.9% for HLA-B27 for diagnosing axial SpA4
Useful for prognosis
Study showed that severity of baseline MRI sacroiliitis and HLA-B27 positivity predicted radiographic AS at 8 years5
Study showed that HLA-B27 positivity at baseline had a larger effect of MRI inflammation on radiographic damage at 5 years when compared to HLA-B27 negativity6
HLA-B27 is one of the most predictive criteria for SpA;1 however, do not rule out a diagnosis of SpA solely on the basis of a negative HLA-B27 resullt.2
References:
Sieper J, et al. Ann Rheum Dis. 2012;0:1–7
NICE. SpA in over 16s: diagnosis and management. NG65 (Last updated: June 2017). Available at: Accessed: August 2017
1. Orchard TR, et al. Aliment Pharmacol Ther. 2008;29:193-7; 2. Sheehan NJ. J R Soc Med. 2004;97:10-4; 3. Brandt, HC, et al. Ann Rheum Dis. 2007;66:1479– Sieper J, et al. Ann Rheum Dis. 2012;0:1–7. 5. Bennett, AN et al. Arthritis & Rheum 2008; 58:3413–18; 6. Dougados M, et al. Ann Rheum Dis. 2017;0:1-6.

7. Radiological investigation of back pain
Aim: Rule out serious spinal pathology and significant neurological involvement1
Not necessary in most cases of non-specific lower back pain2
‘Red flags’ should suggest serious pathology and prompt early referral (not necessarily imaging)
Generally detected on preliminary medical history and physical examination
Imaging is not necessary in most cases of non-specific lower back pain and rapid improvements in pain and disability are seen within a few weeks to a few months1
However there are certain features or ‘red flags’ which may be the symptom of serious pathology and prompt early referral and additional tests where necessary
Reference:
1. NICE. Low back pain and sciatica in over 16s: assessment and management. NG59 (Last updated: November 2016). Available at: Accessed: August 2017.
1. BMJ. Assessment of Back Pain – Diagnosis Approach (Last updated: June 2017). Available at: (Accessed August 2017); 2. NICE. Low back pain and sciatica in over 16s: assessment and management. NG59 (Last updated: November 2016). Available at: Accessed: August 2017.

8. Lumbar X-ray
Lumbar X-ray accounts for 12% of all requests for diagnostic radiology from GPs1
21% of all X-ray requests
Limited value to osteoporotic fracture follow-up and post- treatment measurement of alignment and stability in trauma and deformity2
IBP suggestive of inflammatory disease may not always be associated with radiological features3
High rate of false positives4
Unnecessary radiation exposure1
Plain radiography (X-ray) is of limited value as degenerative changes are very common and pathology may easily be missed
X-ray will only detect damage resulting from inflammation, but not the inflammation itself
Unjustifiable use may lead to unnecessary exposure to potentially harmful radiation
1. Kerry S, et al. Health Technology Assessment. 2000; 4(20);1-119; 2. NICE. Low back pain and sciatica in over 16s: assessment and management. Assessment and non-invasive treatments. NG59: Methods, evidence and recommendations (Last updated: November 2016). Available at: Accessed: August 2017; 3. Rudwaleit M, et al. Ann Rheum Dis 2009;68:777–783; 4. Humphreys SG, et al. Am Fam Physician 2002;65:2299–306.

9. MRI First choice if available but expensive No known radiation risk1
Extremely good at showing soft tissue and pathology of the cord, disc and ligaments1
Remember specific sequences need to be considered – consult radiologist
Not suitable for all patients2
E.g., ferromagnetic implants, cardiac pacemaker, intracranial clips
MRI is good for showing soft tissue and pathology of the cord, disc and ligaments.
NICE. Low back pain and sciatica in over 16s: assessment and management. Assessment and non-invasive treatments. NG59: Methods, evidence and recommendations (Last updated: November 2016). Available at: Accessed: August 2017.
1. NICE. Low back pain and sciatica in over 16s: assessment and management. Assessment and non-invasive treatments. NG59: Methods, evidence and recommendations (Last updated: November 2016). Available at: Accessed: August 2017; 2. Humphreys SG, et al. Am Fam Physician. 2002;65:2299–306.

10. Reassurance from a normal X-ray
31-year-old patient with IBP:
Images courtesy of Dr Raj Sengupta

11. CT scan Computerised tomography (CT)
Useful in diagnosing bony pathology, assessing trauma, deformity and planning surgery1
Not as useful in soft tissue conditions e.g., disc infection2
Limitations
Radiation exposure1
Less detailed images compared with MRI2
Results are adversely affected by patient motion2
CT images are less detailed than MRI1
Useful in diagnosing bony pathology, assessing trauma, deformity and planning surgery2
CT may be used to complement information from other diagnostic imaging studies
Reference:
1. Humphreys SG, et al. Am Fam Physician 2002;65:2299–306.
2. NICE. Low back pain and sciatica in over 16s: assessment and management. Assessment and non-invasive treatments. NG59: Methods, evidence and recommendations (Last updated: November 2016). Available at: Accessed: August 2017
1. NICE. Low back pain and sciatica in over 16s: assessment and management. Assessment and non-invasive treatments. NG59: Methods, evidence and recommendations (Last updated: November 2016). Available at: Accessed: August 2017; 2. Humphreys SG, et al. Am Fam Physician. 2002;65:2299–306.

12. Ultrasound
Occasional first-line diagnostic tool to evaluate the urinary tract in patients with symptoms of pyelonephritis1,2
May visualise signs of renal enlargement, oedema or haemorrhage1
Not all patients with suspected pyelonephritis are ultrasound- positive1
As few as 20% of patients
Ultrasound may be used to evaluate the urinary tract in patients with symptoms of pyelonephritis1
Ultrasound may also be used to visualise signs of renal enlargement, oedema or haemorrhage1
Reference:
1. Craig WD et al. RadioGraphics. 2008; 28:255–276.
1. Craig WD et al. RadioGraphics. 2008; 28:255–76; 2. BMJ. Assessment of Back Pain – Differential Diagnosis (Last updated: June 2017). Available at: (Accessed August 2017).

13. Summary: Recommendations for assessment and imaging of low back pain
Think about alternative diagnoses when examining or reviewing people with non-specific low back pain, particularly if they develop new or changed symptoms. Exclude specific causes of low back pain, for example, cancer, infection, trauma or inflammatory disease such as SpA1
Please refer to NICE guideline NG65 for recommendations on the assessment and imaging of patients with suspected SpA. Available at:
Do not routinely offer imaging in a non-specialist setting for people with non-specific low back pain with or without sciatica1
Consider imaging in specialist settings of care (for example, a musculoskeletal interface clinic or hospital) for people with non-specific low back pain with or without sciatica only if the result is likely to change management1
Think about alternative diagnoses when examining or reviewing people with non-specific low back pain, particularly if they develop new or changed symptoms
Consider imaging in specialist settings of care (for example, a musculoskeletal interface clinic or hospital) for people with non-specific low back pain with or without sciatica only if the result is likely to change management
NICE. Low back pain and sciatica in over 16s: assessment and management. NG59 (Last updated: November 2016). Available at: Accessed: August 2017.