Osteoporotic fractures of the vertebrae are often silent and if left untreated will lead to progressive loss of vertebral body height and significant kyphoscoliosis, with its associated morbidity. However if vertebral fractures (VF) are detected early, treatment with bisphosphonates accelerates healing of prevalent fractures and reduces incident fractures.
A survey of members of the British Paediatric and Adolescent Bone Group showed that treatment is started when two or more VF are diagnosed, therefore children with long-term conditions predisposing them to VF undergo routine regular surveillance. It follows that a simple, reliable, objective, low radiation, and cost-effective method of VF assessment (VFA) is required. No current method fulfils all these criteria for VFA in children.
Traditionally, diagnosis of VF is from lateral spine radiographs, however we have shown (funded by the National Institute for Health Research under its Research for Patient Benefit Programme (grant reference number PB-PG-0110-21240)) that dual energy X-ray absorptiometry (iDXA) is able to replace radiographs for diagnosis of VF at an average 28% of the radiation exposure. We demonstrated the poor ability of both iDXA and radiographs to differentiate mild VF from normal physiological variation; the absence of an objective external gold standard was a further confounder, complicating our cost-effectiveness analysis, and raising the question, does iDXA really miss fractures or does spine radiography overcall them?
Existing scoring systems for adult VFA have been tried or modified and novel systems developed for use in children, however there is no standardisation and although prevalence of mild fractures is relatively low in published papers, observer reliability is variable.
Semi-automated VFA is used in adults, with a number of software tools available, including SpineAnalyzer (Optasia Medical Ltd). Our on-going trial (funded by the University of Sheffield Faculty Innovation Fund) in children using SpineAnalyzer suggests that it reduces interobserver variability, but leads to incorrect interpretation. The latter is not surprising since outcome is based on standards developed for adult vertebrae; significant physiological changes in vertebral morphometry occur throughout childhood, which would need to be captured before similar VFA software can be used reliably in children.
Funding: Funded by the National Institute for Health Research under its Research for Patient Benefit Programme (Grant Reference Number PB-PG-0110-21240).
Funded by the University of Sheffield Faculty Innovation Fund.
Disclosure: Receipt of grants/research support and participation in company-sponsored speakers bureau: Biomarin.
27 - 30 Jun 2015