SATOSHI UMEDA

Pure titanium and titanium alloy are generally used as orthopaedic implants like total hip arthroplasty because of its high strength and high biocompatibility. Stability of bone-implant interfacial bonding is a critical factor for successful total hip arthroplasty. Because of the problems of loosening and dissolution of harmful ion with cemented techniques, alternative cement-less fixation of the total hip arthroplasty has been developed. Plasma spray coating of bone-like apatite is an example to add strong bonding capability with bone to metallic materials. However, this physical coating treatment shows weak base-coating bonding strength and difficult to apply on irregular surface. Chemical treatments do not have such drawbacks. The alkali-heat treatment method, developed by Kokubo et al, is a kind of chemical treatment to enhance the bone-bonding strength of pure titanium. This technique involves soaking the implant in an alkali solution and subsequent heating, resulting in a strong bone-bonding ability and a high bone affinity. This study transplants alkali heat treated titanium alloy on the rabbit femoral bone and examined in vivo interfacial bonding strength.