[The significance of bone spurs at the base of the 2d metacarpal bone in the pathogenesis of joint arthrosis of the base of the thumb].

A causal correlation is proved between an outgrowing osseous spur at the Os metacarpale II and the rhizarthrosis. The midhand bone of the thumb is connected by a ligament with the base of the Os metacarpale II. High tensile stresses elongate the ligament and lead to its partial ossification. The ligament looses its essential function and the thumb subluxates radially.