| Dr. Bose
One of my patients from India
who has had a resurfacing, briefed me on the
current discussion in the surfachippy forum
regarding Dr. Klappers opinion of losing
acetabular bone in an attempt to preserve
femoral head bone in resurfacing. He wanted to
know my opinion and I thought it would be
appropriate for me to post my answer in this
forum. Dr. Klapper’s opinion is way off the
mark. The acetabular size is the most important
factor which determines the choice of femoral
head size in resurfacing and one never removes
more acetabular bone in hip resurfacings. In
other words if I would be performing a
conventional hip replacement on a given patient
instead of resurfacing, I would be using
precisely the same size acetabular component in
both the surgeries.
I would go as far as saying that if we are
taking out more acetabular bone in resurfacing
than in conventional hip replacement , then in
my opinion there is no role for resurfacing and
it must be discontinued immediately. Acetabular
conservation is as important if not more than
femoral bone conservation and all resurfacing
surgeons recognize and acknowledge this fact.
The ability to put large heads in resurfacing
stems from the fact that thin shelled acetabular
components are possible with the modern metal on
metal bearings. However when one uses
polyethylene it has to have a large thickness
,which in turn reduces the femoral head diameter
, (assuming the acetabular outer shell diameter
remains the same). The same argument holds true
for ceramic on ceramic bearing to a lesser
extent and therefore slightly large femoral head
sizes than metal on poly is possible. However an
anatomical size is currently possible only with
metal on metal bearings.
I strongly object to the terminology of “large
or jumbo head metal on metal hip replacement”
that some surgeons use to describe the current
versions of the total hip replacements which
employ the same metal on metal bearing used in
resurfacings. I point out in all my lectures
that this variety of total hip replacement is
the anatomical head replacement giving the same
natural size ( of the femoral head and the
acetabulum) that the patient has in other normal
hip and the conventional THR are indeed small
head hip replacements. One must never lose this
perspective. I hope this helps to clear the
sudden doubt that was cast on the hip
resurfacing principle recently.
Dr. Vijay C. Bose
Consultant orthopedic surgeon Chennai, India |
