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