Hip replacement surgery dates back almost one hundred years. The first attempts at replacing the joint were far from successful and were based on naïve mechanical principles and grossly inferior non-biological materials.
The real precursor to the modern hip replacement was first introduced by Professor Sir John Charnley in the late 1950s and early 1960s. He used a metallic stem in the upper end of the thigh bone made of stainless steel and a type of plastic liner in the acetabulum or pelvic socket. The first acetabular component was made of Teflon and, although it was of very low friction, unfortunately it did have a very high wear rate. The debris so liberated in the region of the hip joint gave rise to the formation of massive pseudotumours. This is where your own body mounts a response in an effort to gobble up these microscopic pieces of plastic and, in turn, forms a very large tumour in the groin. He had two or three hundred such patients and I remember his widow telling me that, during the early 1960s when they had to be removed, both he and she experienced the worse times of their lives. This was a very traumatic time for everybody.
The next major step forward was to replace the Teflon with polyethylene. Even today in 2016 we still use a type of polyethylene to line the hip socket.
Modern materials now include titanium, cobalt chrome, ceramic and highly cross-linked polyethylene.
There are more than 150 types of hip replacement available. They vary in size, shape and material construct. All of them aim to replace what is normally a painful arthritic joint between the ball and the socket with artificial materials.
The hip replacement surgery involves hospitalisation, an anaesthetic and an operative exposure of the joint. Varying lengths of stay are required following these operations but most patients are discharged within seven days.
The hip can be approached through the front, the side or the back. Much emphasis is placed by some people upon the operative approach that is used. In essence, they all yield much the same result. There is an old saying that, “No matter which airline you fly with, provided you just get there”. This probably also applies to the approach used for the hip replacement.
Complications can occur. Fortuitously, they are quite uncommon. They include problems with the anaesthetic and may even be as severe as death. Stokes can also occur. At a local level, we are concerned about infection, damage to arteries or nerves, fractures of the bones, clots travelling off to the heart and lungs and excessive bleeding.
Hip replacements are now vastly more successful than they were in Charnley’s day. Our registries show that 90% of well-performed total hip replacements will still be functioning in twenty years’ time. Obviously not all of them fall off the perch at twenty years and one day. Some may function for thirty or forty years or even longer. The survivorship of the joint will depend a great deal upon the biology of the patient, the way the hip replacement is used and the competence of the surgeon involved. These are just three variables of many. Whilst hip replacements are performed regularly all over the world every day, it is a serious and important operation. It should be treated so.