Histology of synthetic ossicular prostheses.

Thirty-three synthetic middle ear prostheses removed after two to 99 months of implantation were examined histologically. All prostheses were infiltrated by fibroblasts, capillaries, collagen fibrils, and multinucleate foreign body giant cells. Although some of the giant cells contained tiny particles of the prosthetic material, there was no evidence of erosion or engulfment of larger particles of the prosthesis or structural dissolution of the prosthesis. New histologic findings were aseptic necrosis and focal calcification in the interior of some of the prostheses.