Expansion
Features suggesting malignancy, infection, fracture or cauda equina
Expansion
Red flags
- Age under 20 or over 50 at first presentation
- Trauma, or minor trauma in osteoporosis
- Thoracic pain
- Night pain, or pain unrelieved by rest or position
- Weight loss, fever, night sweats
- History of malignancy
- Immunosuppression, intravenous drug use, recent infection
- Progressive neurological deficit
- Structural deformity
- Prolonged corticosteroid use
Cauda equina syndrome is the emergency, and requires immediate MRI and referral:
- Bilateral sciatica
- Saddle anaesthesia
- Urinary retention with overflow incontinence, or loss of bladder sensation
- Faecal incontinence or loss of anal tone
- Progressive lower limb weakness
Urinary retention is the most reliable feature, and by the time it is established the prognosis is already worse, which is why the earlier symptom of altered bladder sensation must be asked about specifically.
Metastatic spinal cord compression presents with back pain plus upper motor neurone signs and a sensory level. It requires dexamethasone and urgent whole spine MRI.
The great majority of back pain is mechanical, self-limiting and needs no imaging, which is precisely why the red flags must be screened for deliberately.