[Active otosclerosis of the stapes footplate: histological and clinical aspects of its influence on the perilymph (author's transl)].

Pathologic capillaries are usually seen in the center of an otospongious process. Next to obliteration, dilatation and increased permeability a loss of basement membrane structure is evident. Around the capillaries exists a wide network of mesenchymal cells which have a glycogen like mass within the cytoplasm; glycogen can be delivered into the extracellular fluidspace. Free erythrocytes are located around many vessels. Near the margin of the lacunae decalcificated areas are seen; in the center of these areas osteocytes undergo lysis; they show intracytoplasmatic deposits of apatite which we assume to be located within the mitochondria. The collagen structure in the neighbourhood of the osteocytes seems to be damaged. Once the resorptive process has reached the perilymphatic surface of the footplate there comes to an connection between the otospongiotic lacunae and the vestibule. Free erythrocytes, glycogen like drops and lysosomes are delivered into the perilymph. Comparing the histological results with the operative results in patients with floride otosclerosis we conclude that operation should be done as early as possible to prevent damage from the inner ear, caused by the continuous intoxication of the perilymph from the otosclerotic focus.