Osteosarcoma in association with total hip replacement.

The occurrence of an osteosarcoma at the site of a cobalt-chrome total hip replacement is described, and the possibility of the tumour arising as a result of the liberation of cobalt particles is discussed. The experimental and clinical evidence relating tumour formation to the presence of particulate metals, and to the presence of solid and particulate polyethylene, is presented. It is considered that the risk of tumour formation at the site of any total hip replacement is very small.