Feasibility of quantitative ultrasound measurement of the heel bone in people with intellectual disabilities
Low bone mineral density (BMD) and fractures are common in people with intellectual disabilities (ID). Reduced mobility in case of motor impairment and the use of anti-epileptic drugs contribute to the development of low BMD. Quantitative ultrasound (QUS) measurement of the heel bone is a non-invasive and radiation-free method for measuring bone status that can be used outside the hospital. QUS might be used for screening purposes to identify people with intellectual disability with poor bone status, who are in need of supplementary examination and treatment. To investigate feasibility of QUS in this group, QUS of the heel bone was performed on-site in 151 people with ID living in residential care. Measurements were successfully performed in at least one foot in 94.7%, were interpretable (resulting in a stiffness index) in 91.6%, and induced barely or no stress in 90.4% of the study population. Measurements generally took less than 10 min. In 93 persons bone status of both feet had been measured. The "mean percentage of the absolute difference" between outcomes of both feet was 15.5% (±15.3% SD, range 0-76.5%). Ultrasound measurement of the heel bone is a feasible and non-stressful method for measuring bone status in people with ID. Since the mean difference between outcomes of the left and right foot were large, measurement of both feet is recommended to prevent inaccurate interpretation.