Hip Joint Replacement

There are two types of hip replacement; the traditional total hip replacement and the newer surface replacement.

• In traditional hip replacement, the diseased ball along with the top part of the thigh bone and the surface of the socket are removed and replaced with artificial components. These can be fixed either with a type of glue known as bone cement or without any similar material. The bone is allowed to absorb the specially made components.
• In surface replacement which is meant for younger patients, very minimal bone is removed from the thigh bone.

Resurfacing of Hip

Articular surface replacement of the hip is a recent addition to the various techniques of hip replacements. It was popularized in Birmingham and is suitable for younger patients involved in more active life.

Unlike in traditional hip replacement where the replaced ball is much smaller than the original head of femur, in surface replacement, the original head is preserved and only the surface is replaced with a metal component. Therefore the range movement is much more and the chances of dislocation are negligible. The patient will be able to take part in sporting activities and can even squat.

In this method, there is no polyethylene liner as in traditional hip replacement and therefore the wear of the components is also considerably reduced. In case the patient requires a revision surgery subsequently, it is much easier, as most of the bone is preserved. Earlier, younger patients were advised to postpone hip replacement as much as possible in order to reduce the chances of revision. Surface replacement has allowed patients to get back to a normal life in the most active and productive phase of their life.

Newer Materials in Hip Replacement

There has been a lot of research going on to find out an ideal material with which the artificial joint can be made, which will last forever. Researchers started using a material called ceramic in the mid, late 90's and this has become a boon to younger patients needing total hip replacement. Ceramic is very hard and scratch resistant. The wear property of this material compared to the traditionally used metal on poly ethylene is about 1400 times superior. Therefore a well performed hip replacement with this material should last any one's life time. In the traditional metal on plastic, the plastic wears slowly over time, and as the plastic wears out small particles of plastic debris develop. This triggers response by the body which can lead to loosening of the joint implant over time. This causes pain and leads on to revision surgery. In ceramic hips the amounts of wear is negligible. Another new material which has recently been introduced is oxinium, which also has superior wear properties compared to traditional metal alloys.