Determinants of progression of hip osteoarthritis

Osteoarthritis (OA) is the most frequent disorder of the locomotor system and the prevalence of OA will increase with the aging of the Western society. Especially when the hip or knee is involved, OA causes considerable difficulty in walking, stair climbing and other lower extremity tasks. OA of the hip can be especially disabling because of the pain and functional impairment. The identification of patients at high risk for progression of hip OA is important for at least two reasons. Firstly, well-characterized ‘high risk’ groups may be useful in clinical trials and, secondly, assuming that disease-modifying OA drugs may become available in the future, to identify primary target groups in need of such therapy. Additionally, in a clinical situation the identified non-progressors can be reassured. Until now the prognostic factors of progression of hip OA have been investigated in small studies, with a short follow-up time, and only in a hospital setting. The overall aim of this thesis was to determine the prognostic factors of osteoarthritis of the hip in a large open population with a long-term follow-up. Nearly all studies presented in this thesis were based on data from the Rotterdam Study, a large prospective population-based cohort study in the Netherlands. Participants of this study were men and women aged 55 years and over living in Ommoord, a suburb of Rotterdam.