Background

History!

 For over a century, surgeons have been attempting to treat arthritic hips with methods such as arthrodesis, osteotomy, joint debridements and nerve divisions. The theory behind these early methods was to smooth out surfaces of the hip joint by removing irregularities such as arthritic spurs, calcium deposits. The need to resurface of replace the damaged hip joints created a material search by the hip replacement industry.

 

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.

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