Potential risk factors and their roles in the aetiology of hip OA are poorly understood. We analysed several alleged risk factors predisposing to hip OA in a 22-yr prospective study.
A comprehensive health survey was carried out in 1978-80 in a nationally representative sample of adult Finns. In 2000-01, 1286 participants in that survey were invited for re-examination, and 909 agreed to participate. After excluding those with hip OA at the baseline and those who were no longer working, a total of 840 subjects constituted the present study population. Hip OA was diagnosed on the basis of a standardized clinical examination by physicians who applied uniform criteria both at the baseline and at the re-examination phase.
After 22 yrs of follow-up, hip OA was diagnosed in 41 subjects (4.9%). Heavy manual labour predicted the risk of developing hip OA [adjusted odds ratio (OR) 6.7; 95% CI 2.3, 19.5]. Permanent damage as a consequence of any musculoskeletal injury was also an independent predictor of hip OA (adjusted OR 5.0; 95% CI 1.9, 13.3). BMI, smoking, alcohol intake and leisure time physical activity were not factors which were predictive for hip OA.
Heavy physical stress at work and major musculoskeletal injuries are associated with an increased risk of developing clinically diagnosed hip OA.