Co-Based Surgical Implant Alloys

Co-based surgical implant alloys (see Table 3.1-88 for compositions) are used to fabricate a variety of implant parts and devices. These are predominantly implants for hip and knee joint replacements, implants that fix bone fractures such as bone screws, staples, plates, support structures for heart valves, and dental implants. The mechanical properties (shown in Table 3.1-89) depend sensitively on the thermal and thermomechanical treatments of the materials. 

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Table 3.1-89 Mechanical properties of Co-based surgical implant alloys...

Metallic materials such as stainless steels, Ti and Co-Cr based alloys are currently used as permanent implant materials. These alloys are also used for temporary implant applications in the form of plates, screws and pins, for the repair of bone fracture. However, these metal implants have to be removed by a second surgical proceditre after the tissues have healed sufficiently, since they pose a risk of releasing toxic metalhc ions and/or particles through corrosion or wear processes. The second surgical procedure adds to the cost and bmden to the patients. Identification of implants to support tissue regeneration and healing in specific applications by material corrosion and simultaneous implant replacement by the surroimding tissues is an important area of research. 

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