Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hip implant patients with unexplained pain likely to have tissue damage

20.03.2013
The cause of unexplained pain among metal-on-metal hip implant patients is more likely to be tissue damage than wear of the implant, Hospital for Special Surgery researchers have found. The study, performed by Dr. Danyal Nawabi, orthopedic surgery fellow, and research collaborators at HSS, will be reported at the upcoming annual meeting of the American Academy of Orthopaedic Surgeons, March 19-23, in Chicago.

Researchers set out to determine causes of unexplained pain among patients with metal-on-metal hip implants (in which the ball and socket are both made of metal) who came to the hospital for revision surgery. Metal-on-metal implants have potential advantages, said Timothy Wright, Ph.D., Kirby Chair of Orthopedic Biomechanics at Hospital for Special Surgery (HSS):

"If they remain well lubricated, as happens with the oil in your car, it minimizes wear." In addition, surgeons can implant a bigger head, or ball, making the hip joint more stable. But nationwide, failure of metal-on-metal hip devices due to unexplained pain is rising.

The research group, which did not have any ties to hip implant manufacturers, was led by Dr. Douglas Padgett, chief of the Adult Reconstruction and Joint Replacement Division and chief of the Hip Service at HSS, and Dr. Hollis Potter, chief of the Division of Magnetic Resonance imaging (MRI). They compared 50 patients (33 with total hip arthroplasties and 17 with hip resurfacing arthroplasties) who came to HSS for revision surgery because of unexplained pain, to a control group of 48 patients (23 with total hip arthroplasties and 25 with hip resurfacing arthroplasties) who came to HSS for revision surgery because of loosening, malalignment, infection or fracture. The investigators combined results from clinical examinations of the patients, magnetic resonance imaging, wear analysis studies on the removed implants, and pathology studies of tissues removed at surgery, including the degree of aseptic lymphocytic vasculitis-associated lesions (ALVAL), a sign of adverse tissue reactions to metal debris.

Thirty patients with unexplained pain (60% of the group) had an ALVAL score of at least 5 on a 10-point scale, indicating moderate to high adverse tissue reactions. Twelve percent of patients had some buildup of metal deposits in their soft tissue. The average synovial thickness was three times higher in the unexplained pain group compared to the control group, and the average synovial fluid volume was five times higher in the unexplained pain group compared to the control group. Ten times as many patients in the unexplained pain group had high-grade tissue damage scores compared to the control group.

Researchers found no differences between the unexplained pain group and the control group in terms of age, sex, body mass index, length of implantation, or size or positioning of the implants. Implants in both groups showed similar signs of wear.

"We found that some patients had a significant amount of tissue damage but not a lot of wear," Dr. Wright said, "suggesting that factors other than wear are contributing to the problem regardless of whether the patients have pain. We have used the information from our study to develop guidelines for patients and surgeons."

"Hip implant patients with unexplained pain should be followed closely by their surgeon," added Dr. Padgett. "Early identification of patients with unexplained pain is vital to avoid significant tissue damage. The work by Dr. Potter using novel MRI protocols has proven to be invaluable in diagnosing and monitoring these patients."

HSS doctors perform more than 9,000 joint replacement surgeries per year, of which about 10 percent are revision surgeries. Many patients who have had their joint replacement surgeries elsewhere come to HSS for revision surgery.

Other Hospital for Special Surgery investigators involved in the study include Nader A. Nassif, M.D.; Stephanie L. Gold; Kirsten Stoner, M.S.; Marcella Elpers; and Edwin P. Su, M.D.

Unexplained Pain in Failed Metal-on-Metal Hip Arthroplasty: A Retrieval, Histological and Imaging Analysis (Paper 70)

Wednesday, March 20, 9:12 a.m. CDT, McCormick Place, Room N427

About Hospital for Special Surgery

Founded in 1863, Hospital for Special Surgery (HSS) is a world leader in orthopedics, rheumatology and rehabilitation. HSS is nationally ranked No. 1 in orthopedics, No. 3 in rheumatology, No. 10 in neurology and No. 5 in geriatrics by U.S. News & World Report (2012-13), and is the first hospital in New York State to receive Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center three consecutive times. HSS has one of the lowest infection rates in the country. From 2007 to 2011, HSS has been a recipient of the HealthGrades Joint Replacement Excellence Award. HSS is a member of the NewYork-Presbyterian Healthcare System and an affiliate of Weill Cornell Medical College and as such all Hospital for Special Surgery medical staff are faculty of Weill Cornell. The hospital's research division is internationally recognized as a leader in the investigation of musculoskeletal and autoimmune diseases. Hospital for Special Surgery is located in New York City and online at http://www.hss.edu.
For more information contact:
Phyllis Fisher
212-606-1197
FisherP@hss.edu
phyllis.fisher@gmail.com
Tracy Hickenbottom
212-606-1197
HickenbottomT@hss.edu

Phyllis Fisher | EurekAlert!
Further information:
http://www.hss.edu

More articles from Health and Medicine:

nachricht Potential seen for tailoring treatment for acute myeloid leukemia
10.12.2018 | University of Washington Health Sciences/UW Medicine

nachricht UC San Diego researchers develop sensors to detect and measure cancer's ability to spread
06.12.2018 | University of California - San Diego

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: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Small but ver­sat­ile; key play­ers in the mar­ine ni­tro­gen cycle can util­ize cy­anate and urea

10.12.2018 | Life Sciences

New method gives microscope a boost in resolution

10.12.2018 | Physics and Astronomy

Carnegie Mellon researchers probe hydrogen bonds using new technique

10.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>