[Finite element analysis of the development of subchondral bone cysts].

In principle three different types of subchondral bone cysts have been described in literature: subchondral bone cysts in osteoarthritis, subchondral bone cysts in rheumatoid arthritis and in intraosseous ganglia. However, an exact differentiation of these lesion types has not yet been defined, as there is no consensus on etiology. The aim of this study is the investigation of the etiology of cysts using finite element analysis. We assume that local cartilage lesions, i.e. the typical arthritic joint disease, can cause cysts. The results of these investigations are confirmed by clinical observations. Cartilage lesions generating stress induced microfractures may be able to explain the process of subchondral cyst formation. We assume that bone resorption is caused primarily by local overload. Moreover, local stress concentration along the border of cysts may account for their tendency to enlarge.