Osteoarthrosis in the general population : a follow-up study of osteoarthrosis of the hip

Describing the prevalence and the radiological and clinial abnormalities as they occur in the Zoetermeer population survey and fixing the position of the EPOZ data regarding OA amidst other population surveys on rheumatic diseases was the first aim of this study. This will be, together with the study of determinants that play an initiating, promoting or protecting role, the major subject of this thesis. This very large random population survey containing data about several chronic diseases was held between 1975 and 1978 in Zoetermeer. The first part of this investigation is the result of an analysis of the existing data arid contains publications on radiological OA of hands, feet, spine, pelvis, knees and shoulders and the relationship with several anthropometric variables and life style habits. All radiographs were initially read by Prof.Dr. H.A. Valkenburg and were coded for osteoarthrosis, rheumatoid arthritis and chondrocalcinosis. Dr. H. Haanen who was the second reader of most of the radiographs presented a thorough description of the design and construction of the EPOZ study in his thesis on epidemiological aspects of low back pain [5]. Dr. L.K.J. van Romunde started an analysis of the pattern of OA by means of homogeneity analysis. The conclusions from this method were that a coherent pattern existed of degenerative joint disease. Disc degeneration of the cervical and lumbar spine from the age of 45 and OA of some small joints of hand and feet from the age of 55 can be considered 'normal aging' in this pattern. OA of the hips and to a lesser extent OA of the knees seemed to be exceptional within this pattern. Evidence of a divergent pattern of the hips was also mentioned by R.M. Acheson [3]. He considered the diviating relation between osteoarthrosis and body mass to be an argument for an the exceptional place of the hip in the pattern of OA. This special place that OA of the hip seems to occupy was reason for a special investigation, the result of which constitute the second part of this thesis.