title: Radiographic knee osteoarthritis in floorlayers and carpenters.
abstract: OBJECTIVE
  The aim of the present study was to examine the relationship between knee-straining work and radiological findings of knee osteoarthritis and to study the relation between radiological findings and self-reported knee complaints and clinical signs of knee osteoarthritis.
  
  
  METHODS
  The material consisted of 133 floorlayers, 506 carpenters, and 327 compositors, 26-72 years of age, who had completed a questionnaire and reported no previous knee trauma. A stratified sample of these questionnaire respondents, 50 floorlayers, 51 carpenters, and 49 compositors, were radiologically examined for knee osteoarthritis by 2 radiologists. The X-ray films were independently assessed by 2 radiologists and blinded with respect to knee complaints, trade, and age.
  
  
  RESULTS
  The radiological investigation showed estimated prevalences of knee-osteoarthritis (grades 2-4) for 14% of the floorlayers, 8% of the carpenters, and 6% of the compositors (not significantly different). For the subjects > or =50 years of age the estimated prevalences of the combination of radiological grades 2-4 for knee osteoarthritis and knee complaints during the last 12 months were 29% [95% confidence interval (95% CI) 17-44%], 9% (95% CI 1-26%), and 1% (95% CI 1-10%) for the floorlayers, carpenters, and compositors, respectively. Radiological grades 2-4 were mainly found for subjects above the age of 50 years, subjects with knee complaints, and floorlayers. Radiological knee osteoarthritis was positively associated with self-reported knee complaints and with clinical signs of intraarticular and retropatellar crepitation.
  
  
  CONCLUSIONS
  The data suggest that work in which a considerable amount of time is spent in knee-straining positions may be a risk factor for the development of knee osteoarthritis above the age of 50 years.
authors.affiliation: Clinic of Occupational Medicine, Glostrup Hospital, Denmark. SSAMALKJ@vibamt.dk
authors.forename: L K
authors.initials: LK
authors.lastname: Jensen
authors.forename: S
authors.initials: S
authors.lastname: Mikkelsen
authors.forename: I P
authors.initials: IP
authors.lastname: Loft
authors.forename: W
authors.initials: W
authors.lastname: Eenberg
authors.forename: I
authors.initials: I
authors.lastname: Bergmann
authors.forename: V
authors.initials: V
authors.lastname: Løgager
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D009790:Occupations; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000473:pathology; D015995:Prevalence; D011859:Radiography; D015203:Reproducibility of Results; D012307:Risk Factors