History!
In
1925, Dr. Smith-Petersen created smooth surface replacement by molding
glass into
a hollow hemispheric shape, but the glass was unable to withstand
normal
stresses. The glass modling initiated a new era of hip replacement
methods
called mold athroplasty. A
decade later,
cobalt-chromium alloy was manufactured, and this material was tested in
orthopaedics.
The alloy provided strong resistance to corrosion, and strength, but
the
resurfacing technique was inadequate. The less than adequate
resurfacing
resulted in less than hoped pain relief.
In
the 1950’s a new type of hip replacements were seen, called
hemiathroplasty.
Invented separately by Frederick R. Thompson and Austin T. Moore, they
both developed
replacements for the entire ball of the hip. The prosthesis consisted
of a
metal stem that would be implanted in the marrow cavity of the femur.
The other
end of the stem would be connected to a metal ball which fitted into
the hip
socket. Despite the popularity of the device, many patients developed
pain
caused by loosening of the implant.
Loosening
was also experienced by Dr. Jean Judet and Dr. Robert Judet who
attempted to
use an acrylic material as a replacement for the arthritic hip
surfaces. The
material provided a smooth surface, but still experienced loosening. An
improvement was developed by, Dr. Edward J. Haboush. He used "fast
setting
dental acrylic" to glue the prosthesis to the bone, which sparked a new
era in fixation techniques..
In
1958, Dr. John Charnley attempted to replace both the femoral head and
acetabullum of the hip. He addressed the issue of the eroding socket by
replacing
it with polyethylene. In attempts to fix the polyethyele socket and
femoral
implant to the bone, Charnley utilized polymethylmethacrylat, bone
cement, and
sparked the birth of total hip replacements.
In the last decade, there have been strong efforts to improve the fixation process because it was seen that cement fixtures wear out over time. The goal of newer fixations was to utilize living bone bond as the fixture. These ideas have initiated a movement to creating cementless implants. Where the implants are created with textured surfaces that allow bone to grow into them have been developed. In addition the materials used in hip replacements have also undergone considerable research. One type of material used is ceramics, and this leads to the topic of the site.
© 2007 Dhondup Pemba