No abstract

Children with limited or no ability to ambulate frequently sustain fragility fractures. Joint contractures, scoliosis, hip dysplasia, and metallic implants often prevent reliable measures of bone mineral density (BMD) in the proximal femur and lumbar spine, where BMD is commonly measured. Further, the relevance of lumbar spine BMD to fracture risk in this population is questionable. In an effort to obtain bone density measures that are both technically feasible and clinically relevant, a technique was developed involving dual-energy X-ray absorptiometry (DXA) measures of the distal femur projected in the lateral plane. The purpose of this study is to test the hypothesis that these new measures of BMD correlate with fractures in children with limited or no ability to ambulate. The relationship between distal femur BMD Z-scores and fracture history was assessed in a cross-sectional study of 619 children aged 6 to 18 years with muscular dystrophy or moderate to severe cerebral palsy compiled from eight centers. There was a strong correlation between fracture history and BMD Z-scores in the distal femur; 35% to 42% of those with BMD Z-scores less than −5 had fractured compared with 13% to 15% of those with BMD Z-scores greater than −1. Risk ratios were 1.06 to 1.15 (95% confidence interval 1.04–1.22), meaning a 6% to 15% increased risk of fracture with each 1.0 decrease in BMD Z-score. In clinical practice, DXA measure of BMD in the distal femur is the technique of choice for the assessment of children with impaired mobility. © 2010 American Society for Bone and Mineral Research

Until recently, radiography was the only available means of assessing acetabular development in infants with congenital hip dysplasia. Now that real-time ultrasonography (US) is successfully employed to determine hip position in infancy, it also offers an alternative method for evaluating acetabular development. In a review of 377 US studies of infant hips, the coronal-flexion images, which show a coronal section of the acetabulum with the hip in flexion, were measured to determine the percentage of the femoral head that was covered. Radiographs were measured to determine the acetabular index (angle). Acetabuli with indices exceeding the normal range for the subject's age showed head coverage of less than 33%. The 51 sonograms in this category were all associated with clinical abnormalities, whereas the 107 with coverage greater than 58% were associated with no clinical abnormalities and with consistently normal acetabular indices. The use of US in assessing acetabular development warrants continued investigation.

The multidetector CT finding of frothy airway fluid or high-attenuation airway sediment is highly suggestive of drowning; multidetector CT findings of pan sinus fluid, mastoid cell fluid, subglottic tracheal and bronchial fluid, and ground-glass opacity within the lung at multidetector CT are supportive of drowning in the appropriate scenario.