Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hip implant for long-term use

02.05.2012
Hip replacement is one of the most frequent operations carried out in Germany.

Each year, doctors implant some 200,000 artificial hip joints. Often the artificial hips need to be replaced just ten years later. In the future, a new implant currently being developed using high technology materials could help prevent premature revision surgeries.


The ceramic femoral head fits perfectly into the PEEK hip socket. © Fraunhofer IPA

Thanks to artificial hips, people with irreparable damage to the joint have been able to lead active, pain-free lives for the past 50 years. Still, some hip replacements do not function completely as intended, and metal-on-metal implants in particular, demand accurate positioning in surgery and implants positioned non optimally are often susceptible to premature failure notably in small female patients. Physicians are even calling for a prohibition on the use of artificial joints made of cobalt-chromium alloys in which the joint‘s metal ball rubs against its metal socket whenever the wearer walks.

Poorly designed or positioned metal on metal implants can lead to higher wear rates and this releases elevated cobalt-chromium ion levels that spread out through the blood and lymph, potentially damaging organs and triggering inflammation. Metal ions are also suspected carcinogens. Because these hip replacements are so robust, however, to date they have often been implanted in young, active patients.

... more about:
»IPA »bone tissue »hip »hip replacement »hip socket

A metal-free composite

Researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart, partnering in an international team on an EC-funded project entitled “ENDURE” (Enhanced Durability Resurfacing Endoprosthesis), have now developed a new kind of hip implant that, unlike the conventional counterpart implants on the market today, provide a metal-free solution and bone-like elasticity.

This is the result of a metal-free, high-tech composite: The hip socket is made of carbon fibre-reinforced PEEK – a high-strength, wear resistant, biocompatible polymer composite. For the femoral head, ceramic was used. In addition to this, a hydroxylapatite coating at the interface to the bone helps ensure that the bone tissue will fuse thoroughly with the surface structure of the implant. “The cobalt-chromium implants in use to date are very rigid, and the load transfer to the bone is non-optimal leading to potential adverse bone adaptation.

Thanks to the new combination of materials, the transmission of force through the PEEK hip socket to the pelvic bone is modeled on natural conditions. And there are no metal ions released,“ notes IPA engineer Jasmin Hipp. The researcher and her team were able to confirm the good wear resistance in initial tests of the new hip replacement using a robot that simulated various series of movements such as walking or climbing and descending stairs. The experiments used a prototype of the implant.

Tiny pins protect bone tissue

The ENDURE implants follow the bone-preserving principle of hip resurfacing: they are thin-walled shells which replace the bearing surface of the joint articulation alone, instead of employing large metal stems for support, which require a substantial volume of bone to be removed. Researchers have also redesigned the way the prosthesis is mechanically attached to the bone.

Without cement, and using a press-fit and an integral scaffold-type structure on the surfaces of the implant that contact the bone, the hemispherical ball and socket are tapped onto the prepared femoral head and into the acetabulum – the natural, concave surface of the pelvis – and anchored in place.

To ensure the best possible positioning of the artificial hip, the researchers at IPA have developed a size-scalable tool that attaches the implant to standard surgical instruments, enabling implantation, re-alignment and removal. The tool can be discarded after a single use – like a disposable surgical glove. The challenge is to attach instruments to the very thin-walled cup implant, with sufficient strength for implant repositioning. The instrument features a smart collet pin combination allowing strong, quick, single-position attachment and detachment by the surgeon. The scientists have already submitted a patent application for the tool.

A team of physicians at the University of Newcastle have demonstrated in operations performed on cadavers, the new hip can be set in place and, if necessary, removed without any difficulties. Meanwhile, the preclinical studies have been completed, and final development work is being planned to allow clinical studies to commence. Partners in the EU-funded project are Aurora Medical, Medicoat, Hunt Developments, Ala Ortho, CeramTec, Invibio, Biomatech and the Universities of Gothenburg and Southampton.

Jasmin Hipp | Fraunhofer Research News
Further information:
http://www.fraunhofer.de/en/press/research-news/2012/may/hip-implant-for-long-term-use.html

Further reports about: IPA bone tissue hip hip replacement hip socket

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>