A new stainless steel alloy for surgical implants compared to 316 S12.

The physical, mechanical and corrosion resistant properties of cold worked Ortron 90(TM) have been determined. In comparison with an annealed austenitic 316 S12 stainless steel the results indicate that Ortron 90 is superior in yield stress, UTS, torsion, fatigue, corrosion fatigue, pitting and crevice corrosion. Comparison is made with published results for fully worked 316L stainless steel. Ortron 90 is a significant advance on 316 S12 as a material for load bearing implants.

A physical examination of orthopaedic implants and asjacent tissue.

This paper reports a metallurgical study of five metal-on-metal total hip replacements removed from patients because of varying degrees of loss of bone substance and/or proven sensitivity to Ni and Cr. Evidence of corrosion of the Co-Cr-Mo-C alloy used to fabricate the prostheses was found. It is suggested that the products of this corrosion may alter the balance of bone formation/resorption to produce a loss of bone substance. An unusual tissue response which included rod-like particles (1-2 micron long x 0.2 micron in cross section), of possible immunological origin, was seen on examination of the articulating surface of one of the prostheses by scanning electron microscopy.