title: The evolutionary origins of osteoarthritis: a comparative skeletal study of hand disease in 2 primates.
abstract: OBJECTIVE
  To test the evolutionary hypothesis for joint failure by comparing the prevalence of osteoarthritis (OA) in 2 primate hands with different thumb usage.
  
  
  METHODS
  We studied the hand skeletons of 32 humans and 32 macaques for OA. We defined OA as the presence of joint eburnation.
  
  
  RESULTS
  The prevalence of OA in the distal interphalangeal joints was 26.7 and 50% for humans and monkeys, respectively. For the thumb base it was 37.5% in humans compared with 3.3% in macaques. The relative risk of thumb base OA in macaques may be due to the rudimentary design of the thumb. This finding supports the evolutionary hypothesis for joint failure and it may be applicable to many other joint sites.
authors.affiliation: Department of Medicine, University of Bristol, Bristol Royal Infirmary, UK.
authors.forename: K K
authors.initials: KK
authors.lastname: Lim
authors.forename: J
authors.initials: J
authors.lastname: Rogers
authors.forename: L
authors.initials: L
authors.lastname: Shepstone
authors.forename: P A
authors.initials: PA
authors.lastname: Dieppe
mesh_terms: D000818:Animals; D005075:Biological Evolution; D005260:Female; D005384:Finger Joint; D006801:Humans; D008253:Macaca mulatta; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors