A genetically determined affection For more than two centuries, successive studies have led one to consider arthrosis of the hands as a genetically determined affection, but the localization of the genes responsible is unknown. Other than this genetic factor, various etiological factors have been identified (age-related increase, predominance in women, influence of hormones and obesity, mechanical factors...). Its incidence is of 100 per 100 000 persons/year. Identification of patients The clinical criteria retained for arthrosis of the hands are those of the American College of Rheumatology (ACR). Radiological scores have been established to permit good identification. Selection and evaluation The selection requires the use of classical radiological criteria and the clinical criteria of the ACR or those proposed by Lequesne and Maheu for the study of symptomatic drugs. For drugs with structural effect, an X-ray alone is sufficient. The pain measured on a visual analog scale is the principle criterion of efficacy in clinical trials. It is also possible to measure pain using Maheu's weekly assessment, the daily consumption of analgesics and/or anti-inflammatories, or again Drieser's algofunctional index or the AUSCAN.