Massachusetts General Hospital (MGH) surgeons have performed the first total hip replacement using a joint socket lined with a novel material invented at the MGH. An advance over first-generation highly crosslinked polyethylene, which was also developed at MGH and significantly reduced a serious complication of early hip implants, the new material may be applied in replacements for a wider variety of joints in a more diverse group of patients.
“We think this material could be used for any joint in the body and in any implant design, even those demanding higher flexion and more mobility,” says Orhun Muratoglu, PhD, co-director of the Harris Orthopædics Biomechanics and Biomaterials Laboratory (OBBL) at MGH, who developed the new material in collaboration with scientists at the Cambridge Polymer Group.
Total replacements for hips and other joints were developed in the late 1960s, but it soon became apparent that hip implants could start loosening about 5 years after surgery and would eventually fail completely. A team led by William Harris, MD, DSc, now director emeritus of the MGH OBBL, investigated this complication and found that long-term friction of the implant’s head against the polyethylene-lined joint socket would break off small particles of polyethylene. The body’s immune system reacted against these foreign particles, eventually destroying adjacent bone tissue and causing the implant to loosen – a condition called periprosthetic osteolysis.
Harris and his colleagues, working with polymer chemists from MIT, found that high doses of radiation would “crosslink” the polyethylene, bonding molecules together to produce a much more durable material. The procedure also generates free radicals that could lead to oxidization and degradation of the implant, but the research team found that melting the material would eliminate free radicals. The first-generation highly crosslinked polyethylene was approved by the FDA for use in implants in 1999 and has been licensed to Zimmer, Inc.
However, the MGH researchers knew that the first-generation material had limitations in strength that made it unsuitable for some types of joint replacement implants. Subsequently, Muratoglu found that oxidation could be blocked by diffusing the antioxidant vitamin E throughout the polyethylene material. Both mechanical testing and animal studies have shown that the new material resists wear as well as the first generation and is much stronger. Vitamin-E-stabilized, highly crosslinked polyethylene has also received FDA approval for use in joint implants and has been licensed to both Zimmer and to Biomet, Inc., which made the implant used in the first surgical procedure on July 16.
“This material will allow us to offer our patients very long-term, high-performance joint replacements,” says Andrew A. Freiberg, MD, chief of the Arthoplasty Service in the MGH Department of Orthopædics, who performed the first implant with the new material. “It should be suitable for higher-stress applications in younger patients, those who are more active and those who are heavier.”
Sue McGreevey | EurekAlert!
Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University
Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Materials Sciences
20.07.2018 | Physics and Astronomy
20.07.2018 | Materials Sciences