Extension arthrodesis of the thumb carpometacarpal joint for the ‘Z’ thumb

Osteoarthritis of the thumb carpometacarpal joint (CMCJ) is a common and painful condition. With progressive disease there is longitudinal collapse of the thumb and adduction of the first metacarpal. The thumb metacarpophalangeal joint (MCPJ) compensates, hyperextending to maintain thumb span. Progression of this hyperextension increases the adduction contracture of the first web space and leads to pinch forces transmitted from the tip of the thumb to the metacarpal head (Eaton and Floyd, 1988). It is thus important to address the MCPJ hyperextension when treating the CMCJ arthriti