4 research outputs found
Mechanical and tribological behavior of silicon nitride and silicon carbon nitride coatings for total joint replacements
Ceramic Materials in Total Joint Arthroplasty
Bearing surfaces made of ceramic materials are an alternative to metal-on-polyethylene (PE) articulations in total hip arthroplasty and total knee arthroplasty. The advantage of ceramic surfaces in total joints is the reduction in wear rates compared with metal-on-PE. Lower wear rates result in a decreased volume of wear particles produced by the articulating surfaces. In theory, this should reduce the risk of periprosthetic osteolysis and premature implant loosening, thereby contributing to the longevity of prosthetic joints. In addition to ceramics, other alternative bearings, such as highly cross-linked PE and metal-on-metal, also offer decreased wear rates when compared with metal-on-PE articulations in total joint arthroplasty. Alumina and zirconia ceramics are familiar to orthopedic surgeons because both materials have a long history of use in total joint bearings. Alumina-on-alumina ceramic total hip articulations are now available in the United States from several implant manufacturers. Composite materials made by combining alumina and zirconia, metal-on-ceramic articulations, and new ceramic materials will offer even more choices as the search for the ideal bearing combination in total joint arthroplasty continues. The purpose of this article is to review the material properties, clinical applications, evolution, and limitations of the ceramic materials used in total joint bearings
Recommended from our members
Community Report from the Biosignatures Standards of Evidence Workshop
The search for life beyond the Earth is the overarching goal of the NASA
Astrobiology Program, and it underpins the science of missions that explore the
environments of Solar System planets and exoplanets. However, the detection of
extraterrestrial life, in our Solar System and beyond, is sufficiently
challenging that it is likely that multiple measurements and approaches,
spanning disciplines and missions, will be needed to make a convincing claim.
Life detection will therefore not be an instantaneous process, and it is
unlikely to be unambiguous-yet it is a high-stakes scientific achievement that
will garner an enormous amount of public interest. Current and upcoming
research efforts and missions aimed at detecting past and extant life could be
supported by a consensus framework to plan for, assess and discuss life
detection claims (c.f. Green et al., 2021). Such a framework could help
increase the robustness of biosignature detection and interpretation, and
improve communication with the scientific community and the public. In response
to this need, and the call to the community to develop a confidence scale for
standards of evidence for biosignature detection (Green et al., 2021), a
community-organized workshop was held on July 19-22, 2021. The meeting was
designed in a fully virtual (flipped) format. Preparatory materials including
readings, instructional videos and activities were made available prior to the
workshop, allowing the workshop schedule to be fully dedicated to active
community discussion and prompted writing sessions. To maximize global
interaction, the discussion components of the workshop were held during
business hours in three different time zones, Asia/Pacific, European and US,
with daily information hand-off between group organizers