The Natural History of Symptomatic Fractures in Children and Adolescents with Osteogenesis Imperfecta Type 1: A Cohort Study from Western Australia

The fracture experience of children and adolescents with osteogenesis imperfecta (OI) type 1 is not well described in the literature. We present data on symptomatic long bones and axial skeleton fractures of all patients aged 0 to 18 years with OI type 1 seen at a specialized bone clinic in Western Australia in the period 2008 to 2020 using a retrospective chart review method. The cohort consisted of 44 patients (21 males, 23 females). Median (interquartile range [IQR]) age was 11.3 (6.2 to 17) years, giving a total of 520 patient‐years in the study during which 197 fractures were experienced. The mean fracture rate was 379 fractures per 1000 patient‐years (95% confidence interval [CI]: 310 to 440); however, the experience for fractures varied from ≤1 fracture in 23% (n = 10) to two to 20 in 77% (n = 34) of the cohort. Twenty‐one patients (48.5%) received bisphosphonates during the study period. In logistic regression, age, but not sex or family history of OI, was a significant predictor of fracture risk. The highest total fracture rate was observed in the age group 0 to <3 years at 469 fractures/1000 patient‐years, which declined to 140 fractures/1000 patient‐years in the age group 15 to 18 years. The lower limbs were the site of 49.7% of all fractures. The highest rate for lower limb fracture was in the age group 0 to <3 years at 331 fractures/1000 patient‐years, decreasing to 0 fractures/1000 patient‐years in the age group 15 to 18 years. Upper limb fracture rates increased from 100 fractures/1000 patient‐years in the 0 to <3 years age group to 307 fractures/1000 patient‐years in the 9 to <12 years age group and then declining to 70 fractures/1000 years in the 15 to 18 years age group. In pediatric patients with OI type 1, fracture risk is highest in early life, especially in the lower limbs. Multidisciplinary care of children with OI should have a particular focus on strategies to prevent these fractures. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.