This Back in Focus resource was developed and funded by AbbVie Ltd. Date of preparation: June 2015; AXHUR150807o How to Investigate B ack P ain

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

Inflammatory vs mechanical causes of back pain 1. Deyo, RA and Weinstein, JN. N Eng J Med 2001;344:363– Date accessed May Papagelopoulos PJ. Eur Spine J (2005) 14: 683–688. Possible causes of mechanical back pain 1 Possible causes of inflammatory back pain 1 Other possible causes of back pain 1,2,3 Degenerative disc diseases Facet joint derangement Fracture Herniated disc Muscle imbalance Osteoarthritis Severe kyphosis Severe scoliosis Spinal stenosis Spondylolisthesis Transitional vertebrae Axial spondyloarthritis including patients with ankylosing spondylitis (AS) Psoriatic arthritis (PsA) Inflammatory bowel disease Psoriatic spondylitis Reiter’s syndrome Abdominal aortic aneurysm Disease of pelvic organs Fibromyalgia Gastrointestinal diseases Infections such as:  Epidural abscess  Osteomyelitis  Septic discitis  Paraspinous abscess  Shingles Paget’s disease of bone Renal diseases Scheuermann’s disease (osteochondrosis) Tuberculous sacroiliitis Tumours including metastases

Investigation and referral considerations 1–3 Mechanical back painInflammatory back painRed flags Symptoms/ suspicionsLower back pain <3 months Degenerative arthritis Osteoporosis with possible fracture Muscular sprain/strain Back pain >3 months Morning stiffness Good response to NSAIDs History of cancer Unexplained weight loss Significant trauma Fever/chills Bowel/bladder dysfunction with back pain Investigations to consider X-ray (for traumatic fracture only) ASAS criteria for IBP MRI/X-ray HLA-B27 blood test Ultrasound/MRI/X- ray/CT Blood tests: infection/ Tumour markers (only in a minority of cases) Urinalysis Referral possibilitiesPhysiotherapy (if X-ray shows no abnormality) Orthopaedics RheumatologyAccident and Emergency (A&E) Urology Orthopaedics Neurosurgery 1. Adapted from BMJ Best Practice. Assessment of back pain. Accessed June Bhangle SD et al. Cleveland Clinic Journal of Medicine. 2009;76:393– Sieper et al. Ann Rheum Dis. 2009;68:784–788.

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), ESR (erythrocyte sedimentation rate) 1 –HLA-B27 (human leukocyte antigen-B27) 2 Urine dipstick –Can be done in GP surgery Tumour markers: –E.g., Ca-125, AFP (alpha fetoprotein), PSA (prostate specific antigen) 3 Imaging X-ray Magnetic Resonance Imaging (MRI) Computerised tomography (CT) Ultrasound (US) 1. Castro C, Gourley M. J Allergy Clin Immunol. 2010; 125(2 Suppl 2):S238–S Sieper, J et al. Ann Rheum Dis 2009; 68:784– Perkins GL, et al. Am Fam Physician Sep 15;68:1075–1082.

9.5% of UK population are HLA-B27 positive 1 88–94% of AS patients are HLA-B27 positive 1,2 Useful in diagnosis –Study showed that 58% of patients with IBP and HLA-B27 positivity were diagnosed with SpA 2 –Study showed a sensitivity of 66.1% and specificity of 79.9% for HLA-B27 for diagnosing axial SpA 3 Useful for prognosis –Study showed that severity of baseline MRI sacroiliitis and HLA-B27 positivity predicted radiographic AS at 8 years 4 HLA-B27 1. Brown, MA et al. Ann Rheum Dis 1996;55:268– Brandt, HC et al. Ann Rheum Dis 2007;66:1479– Sieper, J et al. Ann Rheum Dis 2012;0:1–7. 4. Bennett, AN et al. Arthritis & Rheum 2008; 58:3413–18.

Not necessary in most cases of non-specific lower back pain 1 ‘Red flags’ should suggest serious pathology and prompt early referral (not necessarily imaging) –Generally detected on preliminary medical history and physical examination Radiological investigation of back pain 1. Teh, J. Investigation of back pain. The British Institute of Radiology Available at Accessed Aim: Rule out serious spinal pathology and significant neurological involvement 1

Lumbar X-ray accounts for 12% of all requests for diagnostic radiology from GPs 1 –21% of all X-ray requests 1 Limited value in absence of trauma or suspecting fracture –IBP suggestive of inflammatory disease may not always be associated with radiological features 2 –May miss early fractures in osteoporosis 3 High rate of false positives 4 Unnecessary radiation exposure 1 Lumbar X-ray 1. Kerry S, et al. Health Technology Assessment. 2000; 4(20). 2. Rudwaleit M, et al. Ann Rheum Dis 2009;68:777– Teh, J. Investigation of back pain. The British Institute of Radiology Available at Accessed January 2013; 4. Humphreys SG, et al. Am Fam Physician 2002;65:2299–306.

First choice if available but expensive No known radiation risk 1 Consider MRI if suspicious of: –Spinal malignancy –Infection –Fracture –Disc lesion –AS or other inflammatory disorders 2 Remember specific sequences need to be considered – consult radiologist Not suitable for all patients –E.g., ferromagnetic implants, cardiac pacemaker, intracranial clips 1 MRI 1. Humphreys SG, et al. Am Fam Physician 2002;65:2299– Savigny P, et al. Low Back Pain: early management of persistent non-specific low back pain. National Collaborating Centre for Primary Care and Royal College of General Practitioners Available at Accessed June 2015.

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

Computerised tomography (CT) Helpful in diagnosing fractures, partial/complete dislocation and certain tumours 1 –Not as useful in soft tissue conditions e.g., disc infection Limitations 1 –Radiation exposure –Less detailed images compared with MRI –Results are adversely affected by patient motion CT scan 1. Humphreys SG, et al. Am Fam Physician 2002;65:2299–306.

Occasional first-line diagnostic tool to evaluate the urinary tract in patients with symptoms of pyelonephritis 1 May visualise signs of renal enlargement, oedema or haemorrhage 1 Not all patients with suspected pyelonephritis are ultrasound- positive –As few as 20% of patients 1 Ultrasound 1. Craig WD et al. RadioGraphics. 2008; 28:255–276

A combination of laboratory and imaging tests can aid differentiation Do not offer X-ray of the lumbar spine for management of non- specific low back pain Consider MRI when spinal malignancy, infection, fracture, cauda equina syndrome or ankylosing spondylitis (or other inflammatory disorders) are suspected Only offer an MRI for non-specific low back pain within the context of referral for possible surgical intervention Summary: Recommendations for assessment and imaging 1 1. Savigny P et al. Low Back Pain: early management of persistent non-specific low back pain. London: National Collaborating Centre for Primary Care and Royal College of General Practitioners. NICE guideline CG88. May 2009.