[Otosclerosis like bone in osteogenesis imperfecta tarda].

Bone like in otosclerosis from a 34-years-old man, from 33 years and 22 years old women, suffering from osteogenesis imperfecta tarda, with hardness of hearing in both ears were removed with chisel from the lower border of the oval window. After that a stapedectomy was accomplished. The stapedial crura have been genetically interrupted or broken, the footplate attached to the oval window. The bone from the border of the oval window was prepared for the histological examination. The specimens were coloured with Hematoxylin-Eosin and corresponding to Gomöri. In the bone similar cartilage osteoclasia and osteogenesis are rare. There are in the chondroosseous bone rooms filled with connective tissue. The diseased osseous labyrinth in osteo genesis imperfecta tarda must be regarded as a special morphogenetic formation of osteopsathyrosis.