The NHS carries out around 85,000 hip replacement operations in England and Wales every year. Most people who undergo the procedure are aged 60-80 as many of the conditions treated with a hip replacement are age-related, such as osteoarthritis, rheumatoid arthritis or a fracture caused by a fall.
See also: More younger patients having hip replacement operations
See also: Double hip replacement op 'a risk' for TV's Eamonn Holmes
If you're considering a hip replacement, here's what you need to consider.
What to ask your surgeon
Hip replacement surgery has become a routine procedure, and the majority of patients who undergo the procedure report a significant reduction in pain and an improvement in range of movement.
That said, it's important that your operation is performed by an experienced surgeon – someone who has performed the operation many times before and has expertise in the area - so don't be afraid to ask how frequently they have carried out the procedure.
When you discuss the operation, it's important to talk about your expectations. Are you hoping to ride a bike or run a marathon, for example? That way, the surgeon can let you know what the procedure can realistically achieve.
As with any form of surgery, there will be risks, and these should be explained to you. While the chance of serious complications from a hip replacement is low – estimated to be less than one-in-a-100 – you need to be aware of the possibilities. For example: hip dislocation, infection at the site of the surgery, injuries to the blood vessels or nerves, a fracture, and a difference in leg length.
Your surgeon should also make you aware of what to expect during the rehabilitation process, which can be lengthy for this procedure. For the first month to six weeks after the operation you will need a walking aid, eg crutches, to get around. You may also need to attend an exercise programme to help you regain and then improve the use of your new hip joint. Most people find that they're able to resume normal activities within two to three months but it can take up to a year before you experience the full benefits.
There's more than one kind of hip replacement surgery – and your surgeon should discuss the options available to you. For example, whether you should have a total hip replacement (THR), or metal-on-metal resurfacing.
Full hip replacement or metal-on-metal hip resurfacing?
The most common procedure is the total hip replacement, according to Arthritis Research UK. The surgeon removes part of the thigh bone including the ball (head of femur) and then a new, smaller artificial ball is fixed into the rest of the thigh bone. The surface of the existing socket in the pelvis is roughened to accept a new socket component that will join up with the new ball component.
Many artificial joint components are fixed into the bone with acrylic cement. Sometimes, especially in younger, more active patients, one or both parts are inserted without cement. If cement isn't used, the surfaces of the implants are roughened or specially treated to encourage bone to grow onto them. Bone is a living substance and, as long as it's strong and healthy, it'll continue to renew itself over time and provide a long-lasting bond. Where only one part is fixed with cement, it's known as a hybrid hip replacement.
The replacement parts for your hip will be made of metal, plastic or ceramic. These are used in a variety of combinations, but a metal ball fitting into a plastic socket is the most common. Metal-on-metal or ceramic-on-ceramic is sometimes used for people who are younger and more active.
In the case of metal-on-metal hip resurfacing (or MOM), surgeons do not remove the top section of the thighbone. Instead they fit a hollow metal cap over the head of the thighbone and resurface the socket part of the joint with metal.
People who have this type of operation have a lower risk of dislocation and may be able to return to a higher level of physical activity compared with those having a conventional hip replacement. The procedure isn't appropriate for people who have low bone density, or whose bones are weakened because of osteoporosis.
However, metal-on-metal hip implants are controversial as they've been found to wear down more quickly in some patients, which may cause damage to the bone and inflammation in the tissues nearby.
In the case of large head metal-on-metal procedures, it's been known for traces of metal to leak into the joint and get into the bloodstream. As such, it's recommended that patients with this type of metal hip implant should have annual health checks for life. For these reasons, MOM procedures are being used less frequently in the UK.
What does hip replacement surgery involve?
A hip replacement can be carried out under a general anaesthetic (where you are asleep during the procedure) or a spinal or epidural anaesthesia – where an injection is given into your spine that numbs the lower half of your body. Usually you will be given sedation so you will be unaware of your surroundings and have no memory of the procedure taking place.
The type of anaesthetic your surgeon recommends will depend on the general state of your health. If you have an underlying health condition, for example, you may be advised to have an epidural as this has less chance of causing complications.
Depending on the type of procedure you're having, the surgeon makes an incision into the hip, removes the damaged hip joint and then replaces it with an artificial joint. The operation should take around 60-90 minutes to complete.
Today's artificial hip joints are designed to last for 15 years or more, but there is always the risk that the artificial hip joint can wear out before this time, meaning that further surgery is required to repair or replace the joint. Around one-in-10 people with an artificial hip will require revision surgery at a later date.