The BIRMINGHAM HIP
Resurfacing implant is not brand new. It has been in use
around the world since 1997 and has since been implanted
more than 60,000 times. It is new to the United States,
however, where it was approved for use by the Food and
Drug Administration in May 2006.
Although hip resurfacing is not a new concept, the
technology behind the ground-breaking BIRMINGHAM HIP was
developed by British orthopedic surgeons Mr. Derek McMinn
and Mr. Ronan Treacy. The two surgeons now train
orthopedists from around the globe on behalf of
London-based medical device manufacturer Smith & Nephew.
US surgeons given access to this implant may travel to
England for specialized training or may train at one of
the few US centers capable of hosting these focused
The benefits to patients of the BIRMINGHAM HIP Resurfacing
technique and implant are clear. The implantís head size,
its bearing surfaces, and its bone-sparing technique make
it a preferred choice for young, active patients. While
the implantís rate of survivorship is comparable to
standard total hip replacements after five years, these
three key advantages set the resurfacing technique and
implant apart from its total hip replacement counterparts.
The most noticeable aspect of this implant is its size.
While it closely matches the size of your natural femoral
head, it is substantially larger than the femoral head of
a total hip replacement. This increased size translates to
greater stability in your new joint, and it decreases the
chance of dislocation of your implant after surgery.
Dislocation is a leading cause of implant failure in total
hip replacement. While total hip implants dislocate at a
rate of one to three-percent over the lifetime of the
implant, a study of 2,385 BIRMINGHAM HIP Resurfacing
patients found that dislocation occurred in only
0.3-percent of cases five years after surgery.
BIRMINGHAM HIP Resurfacing takes advantage of one of the
orthopaedic medical industryís most technologically
advanced bearing surfaces. That means that the surfaces of
the ball and the socket are made from materials that
dramatically reduce joint wear when compared to
traditional hip implant materials.
In this case, both the ball and socket are made from
tough, smooth cobalt chrome metal. Traditionally, only the
ball is made from cobalt chrome, and the socket is lined
with a plastic cup. While this plastic cup has some design
advantages, it does wear out over the course of many years
since it rubs against the metal ball at a rate of nearly
two million footsteps per year in physically active
The plastic particles released into the area around the
joint as a result of this plastic wear can lead to a
condition called osteolysis, which causes the bone around
the implant to soften, become unstable, and ultimately a
corrective surgery and new implant are required.
However, when both surfaces of a hip implant are made from
cobalt chrome, wear particles are reduced by 97-percent1,
thus potentially extending the life of the implant.
There may be risks associated with metal-on-metal hip
implants, though. While no evidence has been established
on the subject, some are concerned that the increased
level of metal ions found in the blood of metal-on-metal
hip recipients may have negative effects on the human
body. For this reason, some surgeons may not implant such
a device in a patient with kidney disease (since healthy
kidneys filter ions from your body) or in women who are or
may become pregnant.
Perhaps the greatest benefit of the BIRMINGHAM HIP
Resurfacing implant is the fact that it conserves
substantially more bone than a total hip replacement. This
is important for two key reasons.
First, unlike a total hip replacement, the BIRMINGHAM HIP
Resurfacing preserves your natural femoral neck. It is
this neck length and angle that determines the natural
length of your leg, and since it is not removed and
replaced with an artificial device during a resurfacing
procedure, concerns regarding leg length discrepancy are
Second, if your surgeon should determine you need to have
your BIRMINGHAM HIP implant replaced at some point in the
future, you may undergo a regular total hip replacement
surgery. If you had originally undergone total hip
replacement instead of hip resurfacing, you would be
dealing with a more traumatic and complex procedure and
you would be receiving a more invasive implant.