A 66 year old man presented to his general practitioner with lower back pain, worsening over a three month period, which radiated into his abdomen. His history included hypertension and hypercholesterolaemia, and he was a long term smoker. He was afebrile with a blood pressure of 132/84, heart rate 84, and oxygen saturations 96%. His GP requested a lumbar spine radiograph (figure⇓) and blood tests—haemoglobin was 12.8g/dL, white cell count 6.4, Na+ 138, K+ 3.9, Cr 121, and Ur 6.6 mmol/L (the GP performed the radiograph as a firstline investigation for back pain. It is worth noting, however, that guidelines from the National Institute for Health and Clinical Excellence recommend against ordering a radiograph of the lumbar spine in lower back pain). (1) The radiograph shows evidence of spondylotic changes at multiple levels of the lumbar spine, but no vertebral collapses or evidence of sacroiliitis. There is opacification centrally, however, with a …