Clinical practice algorithm for Eaton's injury of the thumb.

Trapeziometacarpal joint instability is a well-recognised but under-diagnosed cause of basal thumb pain. A systematic approach with sound understanding of anatomy and clinico-pathological correlation is required to make a diagnosis. We discuss an overview of the principles of diagnosis and management of basal thumb joint instability. An evaluation algorithm for Eaton's injury of the thumb is proposed for clinical application with evidence in literature.