Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Standard helps control quality of joint replacements

10.12.2003


Ionizing radiation isn’t generally thought of as good for you, but it’s good for artificial hips. A new reference material from the National Institute of Standards and Technology (NIST) will help researchers determine what methods of irradiating the plastic parts in joint replacements during manufacturing will best increase their wear resistance.



Reference Material 8457 is intended to help address concerns about the long-term durability of orthopedic hip implants amid growing use of these devices in younger, more active patients. It is well known that radiation can create new chemical bonds between adjacent molecular chains in a special form of polyethylene used to make the socket for the metal ball and shaft in an artificial hip. This "crosslinking" creates a structure that resists sliding forces and wear. Manufacturers and researchers need to control radiation conditions to achieve the intended wear resistance; too much radiation causes brittleness, and too little can result in poor wear resistance.

The NIST material consists of 10 small, identical cubes of polyethylene. The cubes are intended for use as control samples in a new ASTM International standard test method. The method involves immersing cubes in an organic liquid and measuring how much the material swells. Samples that expand the most have the least amount of crosslinking. Each reference material comes with a certificate that provides precise cube dimensions and information about swelling from a series of round-robin tests involving six laboratories.


The reference material will help researchers and implant manufacturers control or optimize a variety of processing parameters, such as the type (gamma radiation or electron beams), timing, and doses of radiation used for crosslinking

Laura Ost | EurekAlert!
Further information:
http://www.nist.gov/

More articles from Materials Sciences:

nachricht Breaking bad metals with neutrons
16.01.2018 | DOE/Argonne National Laboratory

nachricht White graphene makes ceramics multifunctional
16.01.2018 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

White graphene makes ceramics multifunctional

16.01.2018 | Materials Sciences

Breaking bad metals with neutrons

16.01.2018 | Materials Sciences

ISFH-CalTeC is “designated test centre” for the confirmation of solar cell world records

16.01.2018 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>