title: The prevalence of dislocation in developmental dysplasia of the hip in Britain over the past thousand years.
abstract: BACKGROUND
  The aim of this study is to determine whether dislocation in developmental dysplasia of the hip (DDH) is changing in prevalence over time. This would allow us to see if modern improvements in diet, health, and obstetric care had any effect upon the likelihood of developing DDH.
  
  
  METHODS
  The material used was a large medieval skeletal collection excavated from Britain (6580 hips). The cemetery was in use from approximately AD 1100 to 1530.
  
  
  RESULTS
  The prevalence in the medieval series was found to be 2.7 per 1000.
  
  
  CONCLUSIONS
  This prevalence was comparable with published clinical series from 20th century Britain, with no statistical difference found on chi2 test.
  
  
  CONCLUSIONS
  It is concluded that hip dislocation secondary to DDH does not seem to be changing significantly in prevalence over the centuries, despite improvements in many other aspects of health over this time.
authors.affiliation: Department of Biosurgery and Surgical Technology, Imperial College London, UK. piers.mitchell@imperial.ac.uk
authors.forename: Piers D
authors.initials: PD
authors.lastname: Mitchell
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Redfern
mesh_terms: D006618:Hip Dislocation, Congenital / Q000453:epidemiology / Q000266:history*; D049668:History, 15th Century; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D049691:History, Medieval; D006801:Humans; D015995:Prevalence; D006113:United Kingdom / Q000453:epidemiology