Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Aircraft technology helps diagnose artificial hip, knee problems

21.02.2003


To assess the wear and tear on jet engine parts, mechanics used an old technology called ferrography to run the aircraft’s lubricating fluid through a magnetic device to separate out metal shavings and other ferrous engine debris. A University of Rhode Island researcher uses a similar process to assess the wear and tear on artificial hip and knee joints so patients can reduce the number of follow-up surgeries they must undergo or reduce the time spent in revision surgery.



Donna Meyer, an assistant professor of mechanical engineering, anticipates using her research to create a "wear atlas" that can be used by orthopedic surgeons as a diagnostic tool. She said the atlas could be used to help identify the potential problems that patients are having with their implants prior to revision surgery.

Most artificial hips consist of a polyethylene socket and metal ball or metal-on-metal combinations that are connected to adjoining bones with screws or cement. Total knee replacements are made of similar materials. Over time as the ball, socket and bone rub against each other, tiny debris is produced and settles between the bone and the implant interface, discouraging the much needed growth of bone around the prosthesis. This contributes to the loosening and separation of the interface, which necessitates revision surgery to repair it.


"Polyethylene wear debris can be a significant problem for patients because a loosened joint can cause great discomfort," said Meyer, a Cranston resident. "If we can determine the number and size of wear debris contained in a patient’s synovial fluid, and also look at the ratio of polyethylene to other constituents like metal, bone, and cement particles, we can create a tool to assist in diagnosing the problem with the implant before surgery is necessary. Ultimately we would like to minimize the number of revision surgeries that patients face, or at least minimize the amount of time spent in surgery for additional operations."

Meyer takes a sample of a patient’s synovial fluid — " it’s a large component of the lubricating fluid around your knee or hip," she said — and uses a process called bio-ferrography to capture the tiny particles of polyethylene, metal, bone and cement using a very strong magnet. Since most of the wear debris isn’t magnetic and therefore wouldn’t be collected by the device, she adds to the fluid sample a magnetic compound that binds to the non-magnetic particles.

"We need to capture every tiny particle in each sample to make sure the atlas is accurate," said Meyer, whose research is funded by the National Science Foundation and the Rhode Island Biomedical Research Infrastructure Network.

Meyer’s interest in this research was sparked when she was a graduate student at Rensselaer Polytechnic Institute studying the lubrication of artificial hip joints. She talked to the chief of orthopedic surgery at the time at Albany Medical Center, who told her of his interest in bio-ferrography. She’s been researching the subject ever since.

Once she perfects the technique for collecting the wear debris, she will begin creating the atlas. Meyer said the atlas will be designed so doctors can easily compare a patient’s age, activity level, implant type and time since implantation with the size and composition of the wear debris to quickly determine which part of the implant is the likely cause of the problem. For example, small particles are more likely to lead to implant loosening. Large pieces of debris, on the other hand, contribute greatly to the wear volume, but it is not certain how much it contributes to implant loosening, if at all.

"The atlas can be used by doctors as a maintenance guide, in addition to a radiograph for example, and hopefully give more information about early wear detection, just like the guides used by aircraft mechanics," she said.

Todd McLeish | EurekAlert!
Further information:
http://www.uri.edu/

More articles from Process Engineering:

nachricht Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>