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 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 >>>