Significance of chondrification in the development of otosclerotic stapedial footplate.

Thirty-four otosclerotic stapes of active type were investigated histologically with hematoxylin-eosin (H-E), periodic acid-Schiff-alcine blue (PAS-AB), and/or toluidine blue stain. The results show that chondrification plays an important role in the development of otosclerosis. To date, this specific histopathologic change has not been well recognized. Based on the findings of this study, it is suggested that the active type of otosclerosis be subdivided into two phases, the osteolytic phase and spongy chondroid phase.