EVALUATION OF CARCINOGENICITY AND CHRONIC TOXICITY ASSOCIATED WITH ORTHOPEDIC IMPLANTS IN MICE

The carcinogenicity and chronic toxicity of 316L stainless steel, nick el, Ti-6Al-4V, hydroxyapatite (HA)-coated Ti-6Al-4V, aluminum oxide co ntaining yttrium oxide, and zirconium oxide containing yttrium oxide w ere evaluated by implanting solid rods of each material in the thigh m uscle of C57BL/6N mice for 24 months. Nickel alloy showed high carcino genic and toxic potencies, whereas other materials showed no evidence of them. Tumors retaining nickel alloys were malignant fibrous histocy toma or fibrosarcoma. In some cases, lymphomata that seemed to develop spontaneously were found around the implants because lymphocytes were known to accumulate in chronic inflammatory lesions, and this phenome non also might be applied to lymphoma. (C) John Wiley & Sons, Inc.