Digital osteoarthritis (DO) which affects the interphalangeal joints and the Metacarpophalangeal (MCP) of the thumb is a common disease, the prevalence of which increases with age (36% of the population aged over 70). Certain forms of DO with clinical manifestations involving inflammatory features are particularly refractory to usual treatments (analgesics, NSAIDs, braces and local injections). The mechanism of osteoarthritis involves two major cytokines: interleukin-1 beta and tumor necrosis factor alpha. TNF alpha is particularly involved in the inflammation process.