How many children remain fracture-free during growth? A longitudinal study of children and adolescents participating in the Dunedin Multidisciplinary Health and Development Study

While much is known regarding the incidence and pattern of fractures during growth, information is sparse as to how many children fracture repeatedly and how many remain fracture-free during growth. The Dunedin Multidisciplinary Health and Development Study, a birth cohort, whose members were questioned regularly throughout growth (at ages 5, 7, 9, 11, 13, 15 and 18 years) concerning injuries including fractures, has provided a unique opportunity to answer these questions. Life-table analysis showed that approximately half the children remained fracture-free throughout growth [girls 60.1%, (95% CI 54.7-65.0) and boys 49.3% (95% CI 44.0-54.4)]. Data on fracture history, for participants seen at every phase, was available for 601 members through to the age of 18 years (61.1% of the cohort seen at age 5 years). Two hundred and ninety-one of these 601 participants reported 498 fractures, with 172 sustaining a single fracture, and 119 more than one fracture (15.8% girls and 23.4% boys). The most common site of fracture was the wrist/forearm (24.1% of all fractures). We conclude that although bone fractures are a common adverse event in childhood, half of all children remain fracture-free throughout growth.