Showing papers by "T. M. Sridhar published in 2003"
TL;DR: In this article, a review of the issues in depth and examines emerging directions for improving the performance of orthopaedic devices is presented, including bulk alloying with titanium and nitrogen, surface alloying by ion implantation of stainless steels and titanium and its alloys, and surface modification of stainless steel with bioceramic coatings.
Abstract: Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in bone fractures and replacements. Corrosion is one of the major processes affecting the life and service of orthopaedic devices made of metals and alloys used as implants in the body. Among the metals and alloys known, stainless steels (SS), Co-Cr alloys and titanium and its alloys are the most widely used for the making of biodevices for extended life in human body. Incidences of failure of stainless steel implant devices reveal the occurrence of significant localised corroding viz., pitting and crevice corrosion. Titanium forms a stable TiO2 film which can release titanium particles under wear into the body environment. To reduce corrosion and achieve better biocompatibility, bulk alloying of stainless steels with titanium and nitrogen, surface alloying by ion implantation of stainless steels and titanium and its alloys, and surface modification of stainless steel with bioceramic coatings are considered potential methods for improving the performance of orthopaedic devices. This review discusses these issues in depth and examines emerging directions.
300 citations
TL;DR: In this article, an electrophoretic deposition at various deposition potentials from 30 to 90 V using the stoichiometric HAP (Ca/P ratio 1.67) powder in a suspension of isopropyl alcohol was developed on type 316L stainless steel.
156 citations
TL;DR: In this paper, the authors developed an electrorophoretically deposited hydroxyapatite (HAP) coating on type 316L SS at the optimum coating parameters of 60 V and 3 min.
114 citations
TL;DR: Findings support the need for the development of some innovative implant materials exhibiting resistance to localized corrosion attack and cooperative efforts by the materials and medical/surgical disciplines may result in even greater improvements in the future.
Abstract: Orthopaedic implants are exposed to the biochemical and dynamic environments of the human body; their design is dictated by anatomy and restricted by physiological conditions. In every failure of an orthopaedic implant, the concerned patient is made to experience the trauma of repeated surgeries, besides the severe pain experienced during the process of rejection of the device. The removal of the failed implant will cause great expense and hardship to the patient. Therefore, it is highly desirable to keep the number of failures to a minimum. The determination of the mechanism by which failure of an implant occurred is important, but it is also necessary to explore the event, or sequence of events, that had caused a particular mechanism or mechanisms to be operative. Furthermore, failure analyses can help improving the overall performance of implant devices through revision engineering. In the framework of this study, a survey of failure investigations of stainless steel implants was undertaken. The use of advanced stainless steels and the application of nitrogen ion implantation and bioceramic hydroxyapatite coatings as potential remedies are evaluated. Failure analyses reveal the occurrence of significant localized corrosion attack viz., pitting and crevice corrosion. These findings support the need for the development of some innovative implant materials exhibiting resistance to localized corrosion attack. Cooperative efforts by the materials and medical/surgical disciplines may result in even greater improvements in the future with respect to the durability and safety of these implant devices.
38 citations