[Kirner deformity].

A 14 years old boy with Kirner's deformity is demonstrated. He has the typical radial and volar deviation of the terminal phalanges of the 5th finger. Nature and inheritance of the disease are discussed. We assume inborn ossification disturbances. Most authors recommend to avoid any therapy. But we feel that nowadays it is possible to use plaster splints in young children or to do a corrective operation in older ones with good success.