Quantitative Microchemical Analysis of otosclerotic stapes

Etiological factors considered responsible for the development of otosclerosis are reported in many studies without any concrete conclusions. Most of the papers deal with histopathological patterns and enzymatic mechanism of the otospongiotic disease. Only few data wich deal with the inorganic component of the otosclerotic bone are reported in the literature. One of the reason for this lack may be the restricted size and quantity of material from individuals with otosclerosis, which make the use of the classic analytic procedures impossible. The hardness and physical strenght of normal bone, differentiating it from other connective tissues, stem from the extracellular deposition of calcium phosphate (OCP) Ca8H2(PO4)6•5H2O, which participates in the formation of bones as the initial precipitate, wich then hydrolyzes to HA. As for otosclerosis, some authors observed a decreas in Ca/P ratio in the spongiotic lesion and hypothesized the precence of OCP as an immature phase of otospongiotic lesion. We have attempted to quantitatively evaluate the mineral composition of otosclerotic lesions from surgically removed footplates to document the status of mineralization in the different types of lesion.