Hip replacements can be described in terms of how the components are fixed to the pelvis and thigh bone (Cemented or Uncemented) and by the materials that make up the part of the artificial joint that articulates (Bearing Surface). Hip resurfacing is a different type of hip replacement.
Parts of a Hip Replacement
Cemented Hip Replacement
These use bone cement to anchor the components to bone and do not rely on bone growing in to the components to fix them securely.
Uncemented Hip Replacement
The components are press-fitted into the bone very securely and the patients own bone then grows into the components to create a permanent bond. This bond is very solid and very rarely breaks down.
Bearing Surfaces
The ball can be made of a number of materials including metal (Cobalt Chromium), ceramic or Oxinium. The socket liner can be made up of plastic* (polyethylene) or ceramic.
Bearing surfaces (ball-liner) possible are as follows:
-metal – plastic
-ceramic – plastic
-ceramic – ceramic
-oxinium – plastic (Verilast)
*we use XLPE (highly cross-linked polyethylene)
Hip Resurfacing
This is a type of hip replacement that looks very different to a normal hip replacement and has the following features:
-large diameter ball that covers the existing head without a stem and therefore preserves bone
-metal-metal bearing
For further information on Total Hip Replacement please click here to read an article written by Mr Sood.