Histologic study of homograft cartilages implanted in the middle ear.

We examined conditions of the micro-sliced homograft cartilages implanted in the middle ear, implanted cartilages removed at revision surgery or implanted cartilages removed at the second stage of staged tympanoplasty, both macroscopically and histologically. Macroscopically, the appearance and shape of the cartilages remained unchanged, with no evidence of erosion. There was no evidence of any foreign body reaction or rejection phenomenon. In general, no marked histologic changes of the matrix tissues were found, although chondrocytes showed degenerative changes. There was partial absorption of cartilage and replacement by fibrous connective tissue when inflammatory changes occurred in the middle ear. It is concluded that implanted homograft cartilage maintains its stiffness for more than 6 months in a healthy, aerated middle ear and appears to be clinically useful for tympanoplasty.