Perthes' disease: deprivation and decline

Introduction Perthes' disease is a childhood hip disorder which frequently precipitates premature osteoarthritis necessitating joint replacement in young adults. The highest incidence reported worldwide is in Merseyside, UK, where a unique disease register is maintained. Objective To describe the temporal trends in disease incidence in a geographically defined area of Merseyside, and to examine the relationship to area deprivation. Design Descriptive observational study utilising a regional disease register in Merseyside, UK, 1976–2009. Patients 1082 children with Perthes' disease (682 from a geographically defined area). Outcome Disease incidence by region, year and deprivation quintile (measured by the Index of Multiple Deprivation 2007, and the Child Well-Being Index 2009). Results There was a dramatic decline in incidence over the study period in Liverpool, with rates falling from 14.2 to 7.7 cases/10 000 0–14-year-olds (p