Method for manufacturing surgical implants at least partially coated with a layer of a metal compound, and implants manufactured according to said method

A method of manufacturing surgical implants comprising a substrate at least partially coated with a deposition formed of a metal compound, comprising the following steps:

• i. a step of forming an implant blank from an electrically conductive substrate, said blank comprising at least one contact bearing surface having dimensional tolerances substantially equal to those of the finished implant;
• ii. a step of initial polishing of this contact bearing surface;
• iii. a step of cleaning of the contact bearing surface, once polished, by physico-chemical means;
• iv. a step of decontaminating by an ionic cleaning on the atomic scale of any trace of oxidisation of this contact bearing surface, said decontaminating step being carried out by bombarding this surface with heavy ions such as titanium ions and hafnium ions coming from an evaporation source, in a reactor having a structure similar to that of an oven for thermo-chemical treatment by ionic bombardment in a non oxidizing atmosphere comprising a neutral gas such as argon or nitrogen, at a pressure of 10.sup.-6 T to a few millitors, the implant blank being brought to a cathode potential greater than 800 volts so as to obtain an ionic bombardment of the contact bearing surface in which high kinetic energy ions strike the contact bearing surface while being repulverized and a fraction of the kinetic energy of the ions is transformed into heat energy causing heating of the blank;
• v. a step of heating of the blank to a predetermined temperature at which said deposition is to be carried out, such heating being at least partially obtained in the decontaminating step by the transformation of the kinetic energy of the ions;
• vi. once said predetermined temperature has been reached, the formation of said deposition by creating metal vapor inside the reactor, by introducing into the reactor a reactive gas and by reducing the cathode potential of the blank to a value between 100 and 400 volts;
• vii. a step of final polishing of the contact bearing surface comprising said deposition.