FOREIGN-BODY GRANULOMATOUS RESPONSE TO PARTICULATE BONY DEBRIS

Archival material was retrieved in order to histologically assess the body's response to micron-sized, necrotic bony particles. Specimens we re obtained from (1) human bone grafts in a subcutaneous or muscular p ouch of athymic nude mice, (2) a massive bone allograft replacing a pa tient's humerus, (3) rabbits' healing tibial cortical bone defects lit tered with finely dispersed bony particles, (4) periprosthetic tissues of patient's aseptically loosened artificial joints and (5) interfaci al membranes of intramedullary nails used for fixation of patients' fr actured long bones. Necrotic bony debris was found to induce a giant c elled granulomatous reaction. In sections of undecalcified samples sta ined by the von Kossa method, small calcific particles were observed t o be present within polykaryonic macrophages (foreign body giant cells ) and surrounded by mononuclear macrophages. It is concluded that a fo reign body-type giant celled granulation tissue participates in the de gradation of micron-sized, necrotic bony detritus, whether the disinte grating bone is of the xeno-, allo- or autogenic provenance.