You may be able to choose the type of anaesthetic you are given during surgery.
There are two options:
- general anaesthetic – where you are asleep during the operation
- an epidural anaesthesia – where an injection is given into your spine that numbs the lower half of your body; this is often combined with sedation so you will be unaware of your surroundings and have no memory of the surgery taking place
Depending on the general state of your health your surgeon may recommend you have an epidural as this has less chance of causing complications in people with an underlying health condition.
The procedure
Once you have been anaesthetised, the surgeon removes the existing hip joint completely. The upper part of the thigh bone (femur) is removed and the natural socket for the head of the femur is hollowed out.
A socket is fitted into the hollow in the pelvis. A short, angled metal shaft with a smooth ball on its upper end (to fit into the socket) is placed into the hollow of the thigh bone. The cup and the artificial bone head may be pressed into place or fixed with acrylic cement.
Metal-on-metal (MoM) hip resurfacing is carried out in a similar way. The main difference is that much less of the bone is removed as only the joint surfaces are replaced with metal inserts.
Materials used
The prosthetic parts can be cemented or uncemented:
- Cemented parts are secured to healthy bone using a special glue.
- Uncemented parts are made from permeable material that has many tiny holes. This allows the bone to grow into it, holding it in place.
Most prosthetic parts are produced using high-density polythene for the socket, titanium alloys for the shaft and sometimes a separate ball made of an alloy of cobalt, chromium and molybdenum.
Some surgeons use a metal ball and socket and in some cases ceramic parts are used, which do not wear as quickly as plastic.
There have been recent reports about metal-on-metal hip replacements causing complications. Read our metal-on-metal implant advice Q&A for more information.
The hip replacement operation has become a routine and simple procedure. However, as with all surgery, it carries a degree of risk.
Choosing your prosthesis
There are more than 60 different types of implant or prosthesis. In practice, however, the options are usually limited to around four or five. Your surgeon can advise you on the type they think would suit you best.
NICE only recommends prostheses known to have a 90% chance of lasting at least 10 years. Ask your doctor if you will be getting one of these, and if not, why not. Your surgeon will also be able to discuss any concerns you have regarding metal-on-metal (MoM) replacements.
The National Joint Registry (NJR), which collects details on total hip replacement operations from hospitals in England and Wales, can help you to identify the best performing implants and the most effective type of surgery.
Your specialist
Choose a specialist who regularly performs hip replacements and can discuss their results with you. This is even more important if you are having a second or subsequent hip replacement, known as revision hip transplant, which is trickier to perform.
Look for a specialist who will work with you to find the best treatment for you.
