A 45-year-old woman presents with dull back pain which started suddenly three days ago and has since worsened. The pain is exacerbated by movement. There is no history of trauma or of lifting heavy weights. She was diagnosed with moderate persistent asthma 10 years ago and started on inhaled salmeterol and fluticasone. However, compliance has been poor; and she has experienced frequent exacerbations, often treated with oral prednisolone. She is physically active. She does not smoke and only drinks socially. Her menstrual cycles are regular. Her family history is unremarkable.

Spinal x-rays reveal a compression fracture of the second lumbar vertebra. The entire spine is mildly osteopenic. A full blood count, liver profile, renal profile, thyroid profile, HbA1c, ESR, and CRP are all normal.