Coronavirus (COVID-19) updates for UC San Diego Health patients and visitors. Learn More

Menu
Search

UCSD Medical/Bioengineering Researchers Show Titanium Debris Sabotage Artificial Joints

 

September 21, 2005  |  

Microscopic titanium particles weaken the bonding of hip, knee, and other joint replacements, according to research published online in Proceedings of the National Academy of Sciences by researchers at the University of California, San Diego (UCSD) School of Medicine and the Jacobs School of Engineering. The team demonstrated that titanium implants are safe in large blocks, but at the microscopic level, wear and tear can generate micrometer-sized particles.

“As replacement joints are becoming increasingly common in aging populations, our results explain how such devices fail and suggest that improvements should be made in artificial joint design,” said the study’s senior author K.L. Paul Sung, Ph.D., UCSD professor of orthopedic surgery and adjunct professor of cellular bioengineering.

The team measured how titanium particles affected the bonding strength of pins implanted in rat thighs. The pins were shown to come out more easily when the titanium particles were present, with the smallest and largest particles causing the greatest weakening. The researchers demonstrated how different-sized titanium particles affected bone-building cells called osteoblasts and bone-destroying cells called osteoclasts. Microscopic studies revealed osteoblasts did not form proper adhesions, with small- and medium-sized titanium particles concentrated inside cells. Increased production of the protein RANKL by osteoblasts recruited and activated osteoclasts at the insertion sites, further weakening the bone. Larger titanium particles also activated metalloproteinases, which chop up the extracellular matrix that holds cells together.

Currently, Sung is leading a team in using nano-technology to improve implant material which has three to five times higher wear resistance and fatigue properties to reduce particle generation from implants.

In addition to Sung, additional authors were first author Moon G. Choi, M.D., UCSD Department of Orthopedic Surgery; and Hae S. Koh, M.D., UCSD Department of Orthopedic Surgery; Daniel Kluess, M.S. and Daniel O'Connor, M.A., UCSD Department of Bioengineering; Anshu Mathur, Ph.D., George Truskey, Ph.D., Department of Biomedical Engineering, Duke University; Janet Rubin, M.D., Department of Medicine, Emory University School of Medicine and Veterans Administration Medical Center, Atlanta; and David X.F. Zhou, Ph.D., UCSD Department of Bioengineering.

The study was supported by a Bristol Meyers/Zimmer Award for Excellence in Orthopaedic Research and the National Institutes of Health.

##

News Media Contact:

Sue Pondrom, 619-543-6163, spondrom@ucsd.edu

UCSD Health Sciences Communications HealthBeat: /news/

 




Media Contact

Share This Article


Related News

8/5/2020
Researchers at UC San Diego School of Medicine report successfully implanting specialized grafts of neural stem cells directly into spinal cord injuries in mice, then documenting how the grafts grew a ...
8/5/2020
The National Institutes of Health will soon launch a Phase II clinical trial to evaluate the safety and efficacy of potential new therapeutics for COVID-19, including the use of investigational synthe ...
8/4/2020
Researchers at University of California San Diego School of Medicine report that sleep may help people to learn continuously through their lifetime by encoding new memories and protecting old ones.
8/3/2020
UC San Diego researchers discovered that people with an inactive RNA-editing enzyme respond better to cancer immunotherapy, and inhibitors of the enzyme help mice with difficult-to-treat cancers live ...



Follow Us