[Osseous rupture of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb (author's transl)].

Osseous ruptues of the ulnar collateral ligament in the metacarpophalangeal joint of the thumb are to be found more frequently in experimental ruptures at an isolated preparation than they are described in clinical examinations. It must positively be achieved to re-affix also a small avulsion fragment to do not remove the entire compound attachment of the ligament. The own surgery technique is described.