OA is not a single nosological form but a group of diseases with different origins. Nevertheless, the similarity of morphological and clinical manifestations of these diseases determines the common approach to their diagnosis and treatment. The ambiguous results obtained in a number of works devoted to the treatment of OA can be largely attributed to the heterogeneity of the observed groups of patients. The development of OA is a result of the combined effect of a number of factors and it is possible that some of these factors may become dominant in some patients, determining the formation of special variants of OA. Several such variants can be distinguished, including metabolic, inflammatory, traumatic and associated with changes in the subchondral bone. It is likely that treatment tailored to the pathogenetic variant of the disease could provide more favorable results than therapy given according to standard recommendations.