Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine
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In the history of medicine, the understanding of the nervous system, both from an anatomical and a functional point of view, has always required new and more sophisticated tools. It has been widely demonstrated that engineering has helped towards this end. ⋯ Neurosurgery probably presents the most major challenges and always benefits from the introduction of sophisticated tools, from cranial trephination to the most modern robotics. This review examines the role of engineering to assist in neurosurgery.
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Coronary artery stents have become the medical device of choice for the treatment of coronary artery disease. Since their introduction in 1987, significant advances in stent technology have taken place. A major objective of these developments was the reduction of in-stent restenosis, the formation of neointimal tissue inside the stent triggered by vessel injury and the inflammatory response, which results in renarrowing of the coronary artery. ⋯ However, concerns have been raised with respect to their long-term safety, particularly in relation to the occurrence of late thrombosis. The post-procedural monitoring of stent-related complications is also of interest, including the relative suitability of invasive techniques such as angiography and intravascular ultrasound, and non-invasive techniques such as computed tomography and magnetic resonance imaging scanning. This paper reviews the current issues in stent technology.
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Proc Inst Mech Eng H · Jan 2007
ReviewDevelopment and clinical application of meniscal unicompartmental arthroplasty.
About one-third of osteoarthritic patients requiring knee replacement have focal lesions limited mainly to the medial compartment and can achieve excellent postoperative function after medial unicompartmental replacement. However, late failures of many unicompartmental prostheses require revision at a rate about twice that of total knee replacement. The use of a fully conforming mobile-bearing meniscal unicompartmental prosthesis in the hands of experienced surgeons can reduce revision rates to levels equivalent to the best results achieved with total knee replacement. The paper argues the case for such a prosthesis and demonstrates that the usual modes of failure of unicompartmental arthroplasty, most of them biomechanical, can thereby be avoided.
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Proc Inst Mech Eng H · Jan 2000
ReviewBiological reactions to wear debris in total joint replacement.
The vast majority of total hip prostheses currently implanted consist of a hard metal or ceramic femoral head articulating against an ultra-high molecular weight polyethylene (UHMWPE) acetabular cup. Over the last 10 years, evidence has accumulated to show that these prostheses are prone to failure due to late aseptic loosening and few survive beyond 25 years. With an increasing need to implant hip prostheses in the younger, more active patient the need to understand the mechanisms of failure and to develop artificial hip joints using alternative materials have become major issues in the orthopaedic community. ⋯ For metal-on-metal prostheses, the prospects for increasing the osteolysis free life of the implant are good but additional biological problems associated with the nanometre size and reactivity of the wear particles in vivo may emerge. For the ceramic-on-ceramic prostheses, although initial prospects are encouraging, more data are needed on the characteristics of the wear particles generated in vivo before predictions can be made. It is concluded that the pre-clinical testing of any new materials for joint replacement must include an analysis of the wear particle characteristics and their biological reactivity in addition to the usual assessment of wear.
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Proc Inst Mech Eng H · Jan 1996
ReviewThe medical device directives and their impact on the development and manufacturing of medical implants.
The introduction of a legal framework for the supply of medical implants is discussed with reference to the Active Implantable Medical Device Directive and the Medical Device Directive. The definitions of medical device and manufacturer are discussed. The application of the Directives to device/drug combinations is considered. ⋯ The role of standards and the new approach to writing them in Europe is presented. After placing a product on the market, the manufacturer must set up a system of post-market surveillance, including a vigilance procedure, in order to monitor product performance. Individual Member States can exercise the safeguard clause when a product appears to have had the CE marking incorrectly applied.