The present invention provides methods for modifying surfaces made from metal alloy and/or UHMWPE, preferably surfaces
which are frictionally engaged, e.g., in an orthopaedic implant. The methods of the present invention reduce the coefficient of
friction of the metal alloy component, reduce the shearing of fibrils from the UHMWPE component, and reduce sub-surface
fatigue in the UHMWPE component. The method involves solvent immersion of the UHMWPE component to remove short
chains of polyethylene at or near the surface of the component, and to swell and toughen the subsurface of the component. The
method also involves firmly coating the surface of the metal alloy component with an adherent layer of diamond-like carbon
("DLC") by creating a metal-silicide interface at the surface of the metal alloy to permit firmer adhesion of DLC. Although the
methods of the present invention are particularly useful in orthopaedic applications, the methods also can be used to treat similar
components used in other applications.
Geoffrey Dearnaley; James Lankford, Jr.