Cementless Total Hip Arthroplasty
Owing to the problem of loosening of the cemented prosthesis at the
interface between the cement and the bone which may be caused by a
mechanical failure of the cement mantle and the technical difficulty
in achieving a perfect cementing technique an alternative method exists
which actually antedates the cemented method. The early pioneers were
Austin Moore (1940s) in the U.S.A. (whose hemi-arthroplasty prosthesis
is still used today for the immediate replacement of the fractured
femoral head) and Peter Ring (early 1960s) in the U.K. These pioneers
used stainless steel in direct contact with bone.
Nowadays the metal in contact with the bone that is used universally
is usually titanium with various special treatments to its surface
for the better ongrowth of bone onto the metal surface. This technology
has proved to be very successful and there are many designs on the
market. More and more total hip arthroplasties are being done without
cement. The operative technique is easier and quicker. The rare but
dangerous complication of cardiovascular collapse during cement insertion
is avoided. However difficulties have arisen with accelerated wear
of the polyethylene insert of the titanium shell-cup. Hence this combination
of the coupling of polyethylene cup insert with metal on even ceramic
heads should no longer be used. At this time a cementless primary
total hip arthroplasty must be done only with a metal on metal or
ceramic on ceramic coupling.
Other problems that have arisen are thigh pain and the question of
the quality of the patient’s host bone. A small number of patients
suffer from pain in the thigh after cementless total hip arthroplasty
which can be very aggravating. There is controversy as whether good
quality bone is a prerequisite for a cementless operation or whether
this can be done also in elderly osteoporotic bone.
At this time of writing a cementless arthroplasty done with a good
choice of implants using a ceramic or metal coupling is a good choice
for a young active individual needing hip joint replacement. The results
at ten years are as good as those for classical cemented hips and
the future looks very promising but is unknown.
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