A member of my Hip Talk Discussion Group
http://www.surfacehippy.info/hiptalk/ asked why it took surgeons so long to
learn how important the angle of the acetabular cup angle is during hip
resurfacing surgery. Incorrect placement of the acetabular cup has caused many
failures of hip resurfacing resulting in revisions to total hip replacements.
My answer to that questions of why it takes so long to learn if a hip device
and/or surgical technique is successful is if anyone has worked in the
engineering or design field, they will realize that usually the original design
of a product or machine is never what the final design turns out to be. We are
not machines that can determine perfect designs for anything. There are always
unknowns. If you think about many things in our lives, they are always under
constant change and updates. Car models are often changing, TVs are changing,
cell phones, computers, etc. are constantly in change. Software for computers
are always updating and changing. Athletes are always changing techniques to
improve their skills. Musicians are always practicing to improve their skills.
Medicine and joint replacement is not any different. Engineers are trying to
design a device to replace a human joint while doctors are trying to place that
foreign object in our bodies to act as the original equipment. This is not an
easy task. There have been thousands of designs of hip devices over the years.
The metals or plastics continue to change, the metallurgy changes, and the
designs of the components change. There is nothing static about designs, they
are constantly changing.
I learned from the many hip resurfacing conferences I attended, that it takes
time for doctors to learn how the devices are actually working in patients.
Typically it takes about 3 to 4 years for them to start to see trends about how
the device has acted and how the bone growth has attached to the components. It
takes time for the results to become statistics. So with any device, the wait
period takes time and often by then, there has been a change in the device. So
there are few devices of the same design left after a few years to compare
results.
It simply is very difficult tracking the new devices and their results right
after their implant. Many of the top experienced surgeons were placing the
actabular cups at a good angle early on. They knew instinctively that the
acetabular cup should be in a certain position to work well. I have always said
and heard surgeons say the same thing, that surgical skill is more than a skill
or learned process, it is also an art. It is like the great athletes that
instinctively know what to do. They do learn and practice, but have a God given
skill that places them way above many other athletes. The same is true with the
really top surgeons. If you think about sports or activities you are personally
really good at, you are not looking at the educational videos or books to learn
how to throw a ball, play an instrument or type on a computer. Those with really
good skills are able to do it almost without thinking. That's is the way it is
with the top surgeons. They had an instinct about how things should work and
were very successful. McMinn of the UK is doing that all the time as he develops
devices. Many of the other top surgeons have helped develop hip devices and many
of the surgical instruments to help place hip devices. A recent example of one
is with Dr. Kusuma in Columbus.
http://www.surfacehippy.info/observinglivesurgery.php He wanted a
better way to insure his placement of a BHR was correct. He developed a template
system which no other surgeon had done before. Smith & Nephew are thinking of
having him teach it to new surgeons.
There is a great deal of constant change with any hip device or any man made
mechanical device. Designs keep changing and hopefully for the better. Skills
and instruments to place joint devices keep changing and hopefully for the
better. It is very complex and just takes time to develop excellent devices and
how to place them exactly. The orthopedic surgeons keep track of their series of
hip resurfacings and the National Directories
http://www.surfacehippy.info/nationalregistries.php keep track of hip
resurfacing patients. It takes time for all the statistics and results to
accumulate and become tools to help learn about a hip device and a specific
surgical technique.
Pat
