New FDA Study to Look at Causes of Failure in MOM Hip Implants


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FDA Solicitation

…FDA said it is still concerned about hip implants in general, and most
especially with respect to how they are worn down. In the case of metal-on-metal
hips, the chromium coatings of the device wore each other down, in some cases
dislodging metal chromium shavings that caused tissue damage and raised fears
about metal ions entering the bloodstream and causing cancer…

…FDA noted that "there is renewed concern of wear and corrosion of conical
head/stem taper junctions in modern modular total hip replacements"…

…FDA said it’s embarking on a new project to … Read the rest

Metal Ions & Pregnancy

You have your MoM’s ions

Public release date: 9-Mar-2010

Study finds elevated levels of cobalt
and chromium in offspring of patients with metal-on-metal
hip implants

Hip replacement patients with metal-on-metal (MoM)
implants (both the socket and hip ball are metal) pass metal
ions to their infants during pregnancy, according to a new
study presented today at the 2010 Annual Meeting of the
American Academy of Orthopaedic Surgeons (AAOS). Data showed
there is a correlation between cobalt and chromium levels in
the mother and those in her infant at the time of delivery.

"Although the affects of metal ions in maternal … Read the rest

Researchers set safe upper limit metal ion levels for metal-on-metal hip resurfacings

Orthopedics Today, July 2012


Read original study by clicking here

An award-winning study by researchers from Belgium identified safe upper
limits of 4.6 ug/L for chromium and 4.0 ug/L for cobalt in unilateral
metal-on-metal hip resurfacing arthroplasties and 7.4 ug/L for chromium and 5.0
ug/L for cobalt in bilateral procedures.

"Levels higher than [these] established limits were significantly correlated
with clinical symptoms, smaller component size, a smaller coverage arc, smaller
contact patch to rim distance and a higher cup inclination," Catherine Van Der
Straeten, MD, said. "Females and small head sizes are more at risk of having
problematic hips."

"These … Read the rest

Metal Ion Testing by Dr. Su 2013

Dr. Su’s Protocol for Metal Ion Testing

Metal Ion Testing The testing of metal ion levels after hip resurfacing is controversial,
to say the least. Because we are still learning about the metals used in
resurfacing, how they are released (and in what quantity), and how the body
reacts to these metals, there are no definitive guidelines for metal ion levels
in every patient.

There has been research done regarding the amount of metal ions that
we
expect to be produced and remain in the body after hip resurfacing.
However,
what we don’t know is: "At what level do these … Read the rest

Researchers set safe upper limit metal ion levels for metal-on-metal hip

Researchers set safe upper limit metal ion levels for metal-on-metal hip
resurfacings
Orthopedics Today, July 2012


http://www.healio.com/orthopedics/hip/news/print/orthopedics-today/%7B3FF58413-C747-4495-BA51-BBF8ECAA7FBA%7D/Researchers-set-safe-upper-limit-metal-ion-levels-for-metal-on-metal-hip-resurfacings

An award-winning study by researchers from Belgium identified safe upper
limits of 4.6 µg/L for chromium and 4.0 µg/L for cobalt in unilateral
metal-on-metal hip resurfacing arthroplasties and 7.4 µg/L for chromium and 5.0
µg/L for cobalt in bilateral procedures.

"Levels higher than [these] established limits were significantly correlated
with clinical symptoms, smaller component size, a smaller coverage arc, smaller
contact patch to rim distance and a higher cup inclination," Catherine Van Der
Straeten, MD, said. "Females and small head sizes are more … Read the rest

Revision parameters for metal-on-metal hip implants outlined by Dr. Schmalzried

Thomas P. Schmalzried, MD, presented his experience at the International
Congress for Joint Reconstruction San Diego 2012 meeting…

Although there has been no standard of review established in the United States,
Schmalzried noted routine follow-up should be considered good practice…

…Schmalzried mentioned the special risks inherent in metal-on-metal hip
replacements, including higher monoblock loosening rates and adverse local
tissue reactions (ALTRs)…

"Head size seems to matter when we talk about total hip replacement in
metal-on-metal bearings," Schmalzried said. "Loosening is the issue you get when
you start looking at large diameter bearings. The majority are greater than 36
mm."

…The … Read the rest

AAOS Responds to Metal on Metal Hips

AAOS Responds to FDA’s Public Health Communication on Metal-on-Metal Hips
Orthopaedic surgeons raise awareness and provide information on hip replacement
components to patients, colleagues and medical community at-large

02/10/2011
Rosemont, IL

The U.S. Food and Drug Administration (FDA) today posted a public health
communication about metal-on-metal hip components used in total hip arthroplasty
(THA). The American Academy of Orthopaedic Surgeons (AAOS) appreciates this
thorough and well-considered look at the concerns surrounding the use of these
implants. The FDA’s communication also keeps each of the key stakeholders in
mind: patients, potential patients, orthopaedic surgeons and other medical
practitioners.

With the patient’s … Read the rest

Understanding Pseudotumors in Metal on Metal Hip Resurfacing

Metal-on-Metal Hip Replacements 02/17/2011

The 2011 Kappa Delta Young Investigator Award was presented to Young-Min Kwon, MD, PhD, FRCS, FRACS, an orthopaedic surgeon at Massachusetts General Hospital, Harvard Medical School for his research titled, "Evidence-Based Approach in Understanding ‘Pseudotumors’ in Metal-on-Metal Hip Replacements."

His paper found that the five-year survival rate for young and active patients who undergo a metal-on metal hip resurfacing arthroplasty (MoMHRA) procedure is at 95 percent or above. However, a great deal of attention has been given to the failure of such devices, specifically with instances of soft tissue pseudotumors. Such complications are relatively rare, yet … Read the rest

Larger Cups and Optimal Positioning Produce Lowest Ion Levels Medical Study

Larger cups and optimal positioning produced lowest ion levels and wear

In a review of 585 blood serum evaluations following hip resurfacing, only
femoral size and cup inclination were found to have an effect on ion levels,
according a study by orthopedic investigators.

The findings were presented at the 2010 Annual Meeting of the American
Academy of Orthopaedic Surgeons.

David J. Langton, MRCS, and his colleagues also found that the size of the
coverage angle of the acetabular component contributed significantly to its
tolerance of suboptimal positioning.

"Larger joints, it must be emphasized, tolerated suboptimal cup position," he
said. "This … Read the rest

ASR Recall by DePuy 2010

DePuy has announced that it is voluntarily recalling the
ASR™ XL Acetabular Head System and DePuy ASR™ Hip
Resurfacing System. DePuy is providing the information
below to help visitors with questions and concerns.
Visitors are also invited to visit the DePuy website at

www.depuy.com.

 

  • DePuy makes patient safety and health a top priority
    and is continually evaluating data about its
    products. Most ASR hip replacement surgeries have
    been successful. However, data recently received by
    the company shows that more people than expected who
    received the ASR hip experienced pain and other
    symptoms that lead to a second hip replacement
Read the rest