Skeletal fixation of implants by bone ingrowth into surface pores.

An alternative skeletal fixation by bone ingrowth into porous coatings has been studied. Stainless steel fiber coatings using different fiber diameters (50-100 micrometer) and different pore sizes have been tested. Plugs, intramedullary rods and various types of knee prostheses have been implanted in dogs in non functional and also in functional loading conditions. Histological and mechanical evaluation of the bone implant interface has been performed. Consistent bone ingrowth was observed for implants in non functional conditions if the pore size exceeded 70 micrometer. Ingrowth in functional loading conditions requires rigid initial stability of the implant and intimate contact of implantcoating and surrounding bone tissue.