Degenerative and post-traumatic arthritis affecting the carpometacarpal joints of the fingers.

Symptomatic post-traumatic arthritis affecting the finger CMC joints is less common than might otherwise be expected based on the frequency of injury, especially to the fifth CMC joint. For the fifth CMC joint, the shallow concavoconvex articulation combined with the typical fracture location may provide a protective effect. Non-operative measures are typically successful, except in cases of missed fracture/dislocations and symptomatic joint instability. In these instances, re-construction emphasizes stability first, with an eye toward mobility for the ulnar column. It is common to detect a bony prominence in the region of the dorsal second and third CMC joints during examination of the hand. In most instances, the projection is asymptomatic and likely represents an os styloideum [18]. When painful and unresponsive to nonoperative treatments, this carpometacarpal boss can be excised surgically.