Dr. Su's experience with hip resurfacing shows 1.3%
complication rate
November 16, 2011
Original Link
http://www.orthosupersite.com/view.aspx?rid=89618
The retrospective study, which analyzed 925 hip resurfacings
performed by Edwin Su, MD, between 2004 and 2009 with a
minimum follow-up of 2 years, looked at three implants:
Wright Medical’s Conserve Plus Total Resurfacing Hip System,
Biomet Orthopedics’ ReCap Femoral Resurfacing System and
Smith & Nephew’s Birmingham Hip Resurfacing System. Conserve
Plus and the Biomet ReCap were used as part of clinical
trials, while the Birmingham hip was used after FDA approval
of the implant in 2006. Clinical scores and radiographs were
obtained at 1 month, 3 months, 1 year, and every subsequent
year. The hips in the study had a minimum of 2 year follow
up, both radiographically and clinically.
"[The Conserve Plus hip] was not FDA approved by our
government between 2004-2008, so we had to petition for each
patient to have the device, limiting the numbers of patients
receiving that implant," Su, from the Hospital for Special
Surgery in New York, said during his presentation at the
12th EFORT Congress 2011.
Su received training from some of the pioneers of hip
resurfacing, in both California and Europe, to gain the
experience necessary to perform the procedures. He used a
posterior approach during the procedures and was careful to
preserve the retinacular vessels and soft tissues to prevent
the need for reoperation. The implant specific guides were
used to ensure central positioning within the neck to
prevent notching, and cemented femoral fixation was used,
the study stated.
The study showed 12 revisions (1.3%) at a minimum follow-up
of 24 months. The K-M survival curve overall for the
procedure, using all 3 different implants, was 98.6% at 68
months. Su noted that these results compared favorably to
other published papers that describe short-term failure
rates of 8% and 13% for the procedure. The Conserve Plus
series had six revisions out of 157 cases (3.8%), which
involved two cup loosenings, three femoral loosenings and an
adverse metal reaction. The Birmingham series had six
revisions out of 748 cases (0.8%), and the ReCap had no
revisions.
Limitations for the study include the limited amount of data
collected for certain implants, such as the ReCap, which had
20 implants compared to the Conserve Plus (157 implants) and
the Birmingham series (748 implants). The Conserve Plus
series also had a longer follow-up compared with the
Birmingham series.
"For a surgeon contemplating adopting resurfacing, one must
be concerned about the learning curve," Su said. "The
exposure is more difficult, it is more time-consuming, and
it is more sensitive to technical errors." However, with
careful patient selection, proper surgical training, and a
good implant, the success rate can be excellent.
Reference:
•Su E. A single US surgeon experience with the adoption of
hip resurfacing using 3 different implants. Paper #1140.
Presented at the 12th EFORT Congress 2011. June 1-4.
Copenhagen.
•Berend KR, Lombardi AV, Adams JB and Sneller MA.
Unsatisfactory surgical learning curve with hip resurfacing.
J Bone Joint Surg Am. 2011; 93S:89-92.
•Mont MA, Seyler TM, Ulrich SD, et al. Effect of changing
indications and techniques on total hip resurfacing. Clin
Orthop, 2007;465:63-70
•Edwin Su, MD, can be reached at the Hospital for Special
Surgery, 535 East 70th Street, New York, NY, 10021;
202-606-1128; email: sue@hss.edu.
•Disclosure: Su provides consulting services for Smith and
Nephew Inc. on hip resurfacing products. Smith and Nephew
Inc. and Biomet Inc. have provided research support for
studies involving hip resurfacing.
Read Dr. Su's response to the NY Times article "Concerns
over 'Metal on Metal' Hip Implants" (March 4, 2010)
Dr. Su's response:
I have read and re-read this article with dismay. The writer
has chosen to focus upon rare occurrences of problems with
metal on metal joints. Most of these problems are avoidable
with good implant design and precise surgical technique.
Nonetheless, I do think it is important for yearly checkups
with me, x-rays of your hip, and blood metal level
monitoring. I've written a letter in response below, but I
fear they will not publish it, due to their preconceived
biases.
Letter to the Editor
I would like to comment on the article entitled
"Concerns over 'Metal on Metal' Hip Implants", dated March
4, 2010. As a hip surgeon who uses both metal on metal hip
resurfacing and total hip replacement implants, I feel it is
necessary to provide perspective on the issues raised in
this article.
First of all, metal on metal hip replacements have a rich
clinical history dating back to the 1970's. Cobalt and
chromium have been in use in hip surgery for over 30 years
because of their durability. In the last 5 years, the use of
metal on metal hip replacements has increased because of the
ability to create an artificial hip with a larger ball,
allowing for a greater stability to the joint and a high
activity level for patients.
While it is true that a metal on metal joint is less
forgiving, the key point is that the implants must be
properly positioned to ensure good function. Surgeons who
are experienced with the use of metal on metal hip implants
will have a low incidence of the problems described in the
article. At Hospital for Special Surgery, we have performed
over 2000 metal on metal hip resurfacings and replacements,
with less than a 1% incidence of problems requiring revision
surgery.
Secondly, all artificial joint materials are subject to the
creation of debris; all debris material can be bioreactive,
leading to tissue and bone damage. This is not unique to
metal on metal hip implants, but can occur more rapidly if
the implants are not positioned well. I have revised many
more metal on polyethylene hips with tissue and bone damage,
than metal on metal implants!
Finally, there are patients for whom a metal on metal hip
implant may be a better choice than other materials. At
present, all hip resurfacing devices consist of these
metals. For these patients for whom bone preservation is
paramount, the metal surfaces are the only option.
I believe that focusing upon the rare, negative aspects of
metal on metal hip implants without highlighting the
benefits, is a case of "throwing the baby out with the
bathwater".
Link to Frequently Asked HR Questions Answered by Dr. Su
Link to General Hip Resurfacing Questions Answered by Dr. Su
Link to Pre-Op Surgical Questions Answered by Dr. Su
Link to Surgical Questions Answered by Dr. Su
Link to Post-Op Questions Answered by Dr. Su
