More Controversy over MoM Devices

This month, a leading research group reversed its previous
position on the safety and efficacy of hip resurfacing devices as they compare
to total hip arthoplasty (THA).  The
California Technology Assessment Forum
released a new review of
these devices concluding that, based on current peer-reviewed literature, hip
resurfacing is not necessarily a better alternative than the current standard
of care (THA).

This is a step backward for supporters of the hip
resurfacing technique; just last year CTAF supported the position that hip
resurfacing could be a better alternative to THA for some patients.  However, as author Dr. Judith Walsh pointed
out, the group’s previous assessments acknowledged lack of clinical trials
directly comparing the two procedures.

Total Hip
Arthoplasty (THA) Vs. Hip Resurfacing

In case you are not familiar, total hip arthoplasty is the
same as a “total hip replacement”. This means that both the femoral head and
the acetabulum are replaced with artificial devices. In a hip resurfacing
procedure, the femoral head is left intact and an acetabular component is
inserted. Hip resurfacing has been promoted to younger patients, for whom THA
is not expected to last for the rest of their life. Reports of earlier return
to function and less restriction on function have made it more attractive for
younger patients, as well.

However, as CTAF’s 2011 report notes, there are downsides to
resurfacing. It can be a more complicated surgery, one that only specifically
trained surgeons should perform. It also can lead to avascular necrosis over
time, as the favored approach can devascularize the femoral head.

Hip Resurfacing Arthoplasty

 

CTAF October 2011
Review

Using a set of 5 criteria in a “technology assessment” (TA),
they evaluated three most common metal-on-metal (MoM) hip resurfacing systems. The
systems must meet the established criteria in order to confirm that resurfacing
provides notable benefits over THA. Three important criteria were not met. From
their analysis of peer-reviewed studies on the matter, they found that (1) the
technology (of hip resurfacing) did not improve health outcomes; (2) the
technology was not as beneficial as any established alternatives; and (3) the
improvement is not attainable outside of the investigative setting.

Limitations and
Further Study

According to the New York Times, a hip resurfacing
expert criticized the report for failing to take into account a number of
benefits for certain patients, including reduced potential for dislocating
joints and increased mobility. Dr. Edwin P. Su, an orthopedic surgeon at the
Hospital for Special Surgery in New York, argues that active men who are younger
than age 65 are good candidates for resurfacing and he sees significant
benefits for that group of patients.

CTAF acknowledges that many questions remain as far as long-term
results of resurfacing, THA, and revision surgeries. They also do not claim
their findings to be conclusive. However, the review did succeed in challenging
previous assumptions about resurfacing vs. THA. Dr. Walsh concludes that, based
upon CTAF’s review, “It is [now] incumbent upon the hip resurfacing community
to prove the efficacy and safety of MoM hip resurfacing in randomized clinical
trials, rather than subjecting young patients to significant potential harm
over their lifetimes.”

According to the New York Times, other prominent orthopedic
groups are planning to take a closer look at hip resurfacing and whether or not
it provides true advantages over THA.

DePuy Hip Recall- On Track to be Most Costly Since 2007

It has been roughly a year since DePuy Orthopedics, a
subsidiary of Johnson and Johnson, recalled their DePuy ASR and ASR XL hip
systems. According to a Bloomberg News publication
back in March 2011, a January 25 earnings statement showed that DePuy had taken
a $280 million charge in the fourth quarter to pay for the recall.

Image from Reuters

Michael Mahoney, Johnson & Johnson’s worldwide chairman
for medical devices, assured investors at a March 2011 conference “We are
setting the right high bar for the industry in how we’re managing the recall.
But it is something that we’re continuing to work through. We’ll see the impact
of the ASR diminish throughout, as we move forward in 2011.”

Perhaps he was being a bit optimistic. Later in March, the
British Orthopaedic Association and the British Hip Society came out with data
that showed the ASR system’s failure rate was nearly four times the rate cited
by DePuy when it recalled the device.

Mass Device is now saying that the device is on track to be the biggest and most expensive device
recall since Medtronic recalled its Sprint Fidelis lead in 2007. The overall
cost could be in the billions. Interestingly, since January of this year, the
FDA has received more complaints about metal-on-metal hip implants than in the
past four years combined.

As expressed in a recent Reuters
article, legal experts continue to scrutinize DePuy for outsourcing their
crisis control to Broadspire, pointing out that it is a way for DePuy to limit
payments while gaining control of material that could be used to their
advantage in court.