Miller M E, Hangartner T N
Department of Pediatrics, Wright State University Scool of Medicine, Dayton, Ohio, USA.
Osteoporos Int. 1999;9(5):427-32. doi: 10.1007/s001980050167.
The objectives of this study were (1) to determine whether there are differences in bone density in children versus adults with osteogenesis imperfecta type I (OI-type I) using computed tomography (CT) bone density measurements, (2) to determine whether there are differences in bone density between normal infants and infants with OI-type I using CT bone density measurements and (3) to determine whether CT bone density measurements could be helpful in investigating the infant with unexplained fractures. CT bone density measurements determine both the cortical bone density (CBD) and the trabecular bone density (TBD). CT bone density was determined using the OsteoQuant in 14 individuals with OI-type I who ranged in ages from 8 months to 45 years. The control groups consisted of over 1000 normal individuals, mostly adults, and included 7 normal infants who ranged in age from 10 months to 27 months. One of the individuals with OI-type I was a 4-month-old infant with multiple, unexplained fractures who had no other features of OI-type I and whose parents were accused of child abuse. Infants and children with OI-type I had low CBD and low TBD compared with normal controls, whereas adults with OI-type I had low TBD and high CBD when compared with controls. The one infant with multiple unexplained fractures and no other features of OI-type I had a bone density profile suggesting OI-type I with a low TBD and low CBD. Subsequent collagen analysis showed biochemical evidence of OI-type I. Individuals with OI-type I have abnormal CT bone density profiles that evolve over time from a low CBD and low TBD during infancy and childhood to a high CBD and low TBD during adulthood. This may explain the decreased frequency of fractures in individuals with OI-type I in adulthood compared with childhood. Individuals with OI-type I can present with only multiple unexplained fractures and have no other clinical features to strongly suggest the diagnosis. CT bone density measurements can be helpful in these atypical cases of OI-type I and should be considered in the investigation of the infant with unexplained fractures to help distinguish intrinsic bone disease from child abuse.
（1）使用计算机断层扫描（CT）骨密度测量来确定I型成骨不全症（OI-I型）儿童与成人的骨密度是否存在差异；（2）使用CT骨密度测量来确定正常婴儿与OI-I型婴儿的骨密度是否存在差异；（3）确定CT骨密度测量是否有助于调查不明原因骨折的婴儿。CT骨密度测量可同时测定皮质骨密度（CBD）和小梁骨密度（TBD）。使用OsteoQuant对14名年龄在8个月至45岁之间的OI-I型个体进行CT骨密度测定。对照组由1000多名正常个体组成，大多为成年人，还包括7名年龄在10个月至27个月之间的正常婴儿。其中一名OI-I型个体是一名4个月大的婴儿，有多处不明原因骨折，无OI-I型的其他特征，其父母被指控虐待儿童。与正常对照组相比，OI-I型婴儿和儿童的CBD和TBD较低，而OI-I型成人与对照组相比TBD较低但CBD较高。那名有多处不明原因骨折且无OI-I型其他特征的婴儿，其骨密度特征提示为OI-I型，TBD和CBD较低。随后的胶原蛋白分析显示了OI-I型的生化证据。OI-I型个体具有异常的CT骨密度特征，随时间从婴儿期和儿童期的低CBD和低TBD演变为成年期的高CBD和低TBD。这可能解释了OI-I型个体成年期骨折频率低于儿童期的原因。OI-I型个体可能仅表现为多处不明原因骨折，且无其他强烈提示诊断的临床特征。CT骨密度测量有助于诊断这些不典型的OI-I型病例，在调查不明原因骨折的婴儿时应考虑使用，以帮助区分先天性骨病和虐待儿童。
