Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Understanding Metal Ion Release from Hip Implants


Scientists of the Max-Planck-Institut für Eisenforschung publish their recent findings about material degradation of hip implants

1.8 million hip replacement surgeries were performed in developed countries in 2015. Due to lifestyle choices and a higher life expectancy, it is estimated that the number of total hip arthroplasties will increase to 2.8 million in 2050. At the end of the last millennium, artificial hip implants lasted only about 10 years.

Atom Probe Tomography helps in understanding the metal ion release of hip implants

S. Balachandran, Z. Zachariah, et al: Advanced Science 2020, 1903008

Since then physicians teamed up with material scientists to build longer lasting devices, with the goal to avoid any revision operations after implantation. One of the problems is the release of tiny small metal particles and ions into the surrounding tissue, a process accelerated by micromotion and corrosion between the modular parts of the artificial hip.

To identify the underlying atomic-scale mechanisms, Dr. Michael Herbig, leader of the group “Material Science of Mechanical Contacts” at the Max-Planck-Institut für Eisenforschung (MPIE), and his team analysed cobalt and titanium alloys used in hip implants.

The scientists modelled the loads and environment of the hip joint after surgery experimentally in the laboratory in collaboration with Prof. Alfons Fischer and Prof. Markus Wimmer, from the Rush University Medical Center in Chicago, USA. The results were recently published in the journal Advanced Science.

“Typical hip implants consist of a cobalt alloy femoral head fixed on a titanium alloy femoral stem. Fretting and corrosion at the junction of head and stem lead to so-called ‘tribocorrosion’ meaning that metal particles and ions are released into the body of the patient. The resulting adverse local tissue reactions could make it necessary to eventually revise the implant”, explains Dr. Shanoob Balachandran, first author of the publication together with his colleague Dr. Zita Zacharia, both postdoctoral researchers in the Mechanical Contacts Group.

Using the high-end techniques ‘atom probe tomography’ and ‘transmission electron microscopy’, it was revealed that a subsurface folding mechanism of the titanium alloy takes place, which leads to the formation of ‘shelves’ rising above surface.

“The shelves poke out of the titanium alloy surfaces and scratch the opposing cobalt alloy surface, hence promoting tribocorrosion of the cobalt head. And this in turn leads to the release of metal ions”, explains Herbig.

During the folding process, surface titanium and chromium oxides, in addition to chlorine from the surrounding serum are incorporated into the shelves leading to an intermixing with the matrix phases. The problem is that during the folding process a part of the oxides could be released and accumulate in the surrounding tissues instead of being incorporated into the implant.

“But how can this folding process be inhibited and how do the proteins present in synovial fluid affect the alloys’ dissolution? This would be the next step of our research in order to pave the way of developing tribocorrosion resistant alloys for medical applications.”, states Zacharia.

Wissenschaftliche Ansprechpartner:

Dr. Michael Herbig,


S. Balachandran, Z. Zachariah, A. Fischer, D. Mayweg, M. A. Wimmer, D. Raabe, M. Herbig: Atomic scale origin of metal ion release from hip implant taper junctions. In: Advanced Science 2020, 1903008

Weitere Informationen:

Yasmin Ahmed Salem M.A. | Max-Planck-Institut für Eisenforschung GmbH

More articles from Materials Sciences:

nachricht Capturing 3D microstructures in real time
03.04.2020 | DOE/Argonne National Laboratory

nachricht Graphene-based actuator swarm enables programmable deformation
02.04.2020 | Science China Press

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: When ions rattle their cage

Electrolytes play a key role in many areas: They are crucial for the storage of energy in our body as well as in batteries. In order to release energy, ions - charged atoms - must move in a liquid such as water. Until now the precise mechanism by which they move through the atoms and molecules of the electrolyte has, however, remained largely unknown. Scientists at the Max Planck Institute for Polymer Research have now shown that the electrical resistance of an electrolyte, which is determined by the motion of ions, can be traced back to microscopic vibrations of these dissolved ions.

In chemistry, common table salt is also known as sodium chloride. If this salt is dissolved in water, sodium and chloride atoms dissolve as positively or...

Im Focus: Harnessing the rain for hydrovoltaics

Drops of water falling on or sliding over surfaces may leave behind traces of electrical charge, causing the drops to charge themselves. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now begun a detailed investigation into this phenomenon that accompanies us in every-day life. They developed a method to quantify the charge generation and additionally created a theoretical model to aid understanding. According to the scientists, the observed effect could be a source of generated power and an important building block for understanding frictional electricity.

Water drops sliding over non-conducting surfaces can be found everywhere in our lives: From the dripping of a coffee machine, to a rinse in the shower, to an...

Im Focus: A sensational discovery: Traces of rainforests in West Antarctica

90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous

An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...

Im Focus: Blocking the Iron Transport Could Stop Tuberculosis

The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.

One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...

Im Focus: Physicist from Hannover Develops New Photon Source for Tap-proof Communication

An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.

A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

13th AKL – International Laser Technology Congress: May 4–6, 2022 in Aachen – Laser Technology Live already this year!

02.04.2020 | Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Latest News

TU Dresden chemists develop noble metal aerogels for electrochemical hydrogen production and other applications

06.04.2020 | Life Sciences

Lade-PV Project Begins: Vehicle-integrated PV for Electrical Commercial Vehicles

06.04.2020 | Power and Electrical Engineering

Lack of Knowledge and Uncertainty about Algorithms in Online Services

06.04.2020 | Social Sciences

Science & Research
Overview of more VideoLinks >>>