The use of the Flatt hinge prosthesis in the rheumatoid thumb.

Nine patients with marked destruction in both the metacarpophalangeal and interphalangeal joints of the thumb, were treated with fusion of the interphalangeal joint and insertion of the Flatt hinged metal prosthesis into the metacarpophalangeal joint. Of the nine thumbs treated in this manner, eight had good to excellent results. One prosthesis was removed after it became infected, leaving both joints fused.