How useful is tricalcium phosphate ceramic in middle ear surgery?

In our experiments on the hypotympanum of the pig, resorbable porous tricalcium phosphate ceramic has proved to be serviceable for reducing radical mastoidectomy cavities and as a substitute for osseous walls. For our initial clinical trials with porous tricalcium phosphate ceramic in middle ear surgery, we had implants made especially for the purposes of replacing osseous walls and reducing radical mastoidectomy cavities. When implants have been used to replace osseous walls, insufficient ventilation of the tympanic cavity has frequently coincided with complications in the covering between implant and auditory canal. Follow-up operations have afforded opportunities for histologic examination of fifteen implants, which served as wall replacements for nine to thirty months. There were only the slightest traces of resorption and replacement by bone. In contrast with our findings on the replacement of walls with ceramic implants, postoperative observation for periods of up to four years has shown that granules of porous tricalcium phosphate ceramic are well suited to reducing radical mastoidectomy cavities.