A hip replacement is a common type of surgery where a damaged hip joint is replaced with an artificial one (known as a prosthesis).

Adults of any age can be considered for a hip replacement, although most are carried out on people between the ages of 60 and 80.

A modern artificial hip joint is designed to last for at least 15 years. Most people experience a significant reduction in pain and some improvement in their range of movement.

When a hip replacement is needed

Hip replacement surgery is usually necessary when the hip joint is worn or damaged to the extent that your mobility is reduced and you experience pain even while resting.

The most common reason for hip replacement surgery is osteoarthritis. Other conditions that can cause hip joint damage include:

Who is offered hip replacement surgery

A hip replacement is major surgery, so is normally only recommended if other treatments, such as physiotherapy or steroid injections, haven't helped reduce pain or improve mobility.

You may be offered hip replacement surgery if:

  • you have severe pain, swelling and stiffness in your hip joint and your mobility is reduced
  • your hip pain is so severe that it interferes with your quality of life and sleep
  • everyday tasks, such as shopping or getting out of the bath, are difficult or impossible
  • you're feeling depressed because of the pain and lack of mobility
  • you can't work or have a normal social life

You'll also need to be well enough to cope with both a major operation and the rehabilitation afterwards.

How hip replacement surgery is performed

A hip replacement can be carried out under a general anaesthetic(where you're asleep during the procedure) or an epidural (where the lower body is numbed).

The surgeon makes an incision into the hip, removes the damaged hip joint and replaces it with an artificial joint made of a metal alloy or, in some cases, ceramic.

The surgery usually takes around 60-90 minutes to complete.

Read about how a hip replacement is performed.

Alternative surgery

There is an alternative type of surgery to hip replacement, known as hip resurfacing. This involves removing the damaged surfaces of the bones inside the hip joint and replacing them with a metal surface.

An advantage to this approach is that it removes less bone. However, it may not be suitable for:

  • adults over the age of 65 years – bones tend to weaken as a person becomes older
  • women who have gone through the menopause – one of the side effects of the menopause is that the bones can become weakened and brittle (osteoporosis)

Resurfacing is much less popular now due to concerns about the metal surface causing damage to soft tissues around the hip.

Your surgeon should be able to tell you if you could be a suitable candidate for hip resurfacing.

Preparing for hip replacement surgery

Before you go into hospital, find out as much as you can about what's involved in your operation. Your hospital should provide written information or videos.

Stay as active as you can. Strengthening the muscles around your hip will aid your recovery. If you can, continue to take gentle exercise, such as walking and swimming, in the weeks and months before your operation.

You may be referred to a physiotherapist, who will give you helpful exercises.

Read about preparing for surgery, including information on travel arrangements, what to bring with you and attending a pre-operative assessment.

Recovering from hip replacement surgery

The rehabilitation process after surgery can be a demanding time and requires commitment.

For the first four to six weeks after the operation you'll need a walking aid, such as crutches, to help support you.

You may also be enrolled on an exercise programme that's designed to help you regain and then improve the use of your new hip joint.

Most people are able to resume normal activities within two to three months but it can take up to a year before you experience the full benefits of your new hip.

Read about recovering from hip replacement surgery.

Risks of hip replacement surgery

Complications of a hip replacement can include:

  • hip dislocation
  • infection at the site of the surgery
  • injuries to the blood vessels or nerves
  • a fracture
  • differences in leg length

However, the risk of serious complications is low – estimated to be less than 1 in a 100.

There's also the risk that an artificial hip joint can wear out earlier than expected or go wrong in some way. Some people may require revision surgery to repair or replace the joint.

Read about the risks of a hip replacement.

Metal-on-metal implants

There have been cases of some metal-on-metal (MoM) hip replacements wearing sooner than would be expected, causing deterioration in the bone and tissue around the hip. There are also concerns that they could leak traces of metal into the bloodstream.

The Medicines and Healthcare products Regulatory Agency (MHRA) has issued new guidelines that certain types of MoM devices should be checked every year while the implant is in place. This is so any potential complications can be picked up early.

If you're concerned about your hip replacement, contact your GP or orthopaedic surgeon. They can give you a record of the type of hip replacement you have and tell you if any follow-up is required.

You should also see your doctor if you have:

  • pain in the groin, hip or leg
  • swelling at or near the hip joint
  • a limp, or problems walking
  • grinding or clunking from the hip

These symptoms don't necessarily mean your device is failing, but they do need investigating.

Any changes in your general health should also be reported, including:

  • chest pain or shortness of breath
  • numbness, weakness, change in vision or hearing
  • fatigue, feeling cold, weight gain
  • change in urination habits

Read our metal-on-metal implant advice Q&A.

The National Joint Registry

The National Joint Registry (NJR) collects details of knee replacements carried out in England and Wales. Although it's voluntary, it's worth registering. This enables the NJR to monitor knee replacements, so you can be identified if any problems emerge in the future.

The registry also gives you the chance to participate in a patient feedback survey.

It's confidential and you have a right under the Freedom of Information Act to see what details are kept about you.

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How is it performed?

Before you have hip replacement surgery, you may be able to choose the type of anaesthetic you're given.

There are two options:

  • general anaesthetic – where you're asleep during the operation
  • a spinal or 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 won't be aware of your surroundings and have no memory of the surgery

Your surgeon may sometimes recommend an epidural as this has less chance of causing complications in people with an underlying health condition.

How the operation is carried out

Once you've 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 (the stem) 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 stem may be pressed into place or fixed with acrylic cement.

Metal-on-metal hip resurfacing is carried out in a similar way. The main difference is that less of the bone is removed from the femur as only the joint surfaces are replaced with metal inserts.


The prosthetic parts can be cemented or uncemented:

  • cemented parts are secured to healthy bone using acrylic cement
  • uncemented parts are made from material that has a rough surface; this allows the bone to grow on to 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 don't 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.

The hip replacement operation has become a routine procedure. However, as with all surgery, it carries a degree of risk. Read about the risks of hip replacement surgery.

Choosing your prosthesis

There are more than 60 different types of implant or prosthesis. 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.

The National Institute for Health and Care Excellence (NICE) only recommends prostheses known to have a 95% chance of lasting at least 10 years. Your surgeon will also be able to discuss any concerns you have regarding metal-on-metal 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.

Minimally invasive hip replacement

In conventional hip replacement, a relatively large cut of 20-30cm (8-12 inches) is made in the skin above the hip, for the surgeon to gain access to the hip joint.

A new technique, called minimally invasive hip replacement, uses a smaller cut of around 10cm (4 inches). Specially designed instruments are then passed through the incision to perform the surgery.

Minimally invasive hip replacement appears to be as safe and effective as conventional surgery, with the added benefit of causing less post-operative pain.

However, access to this type of specialised treatment is limited and will probably involve waiting much longer for treatment.

NICE has more information on minimally invasive total hip replacement.

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The most common problem that can arise as a result of a hip replacement is loosening of the joint, which causes pain and feeling that the joint is unstable. This happens in around 10% of cases.

This can be caused by the shaft of the prosthesis becoming loose in the hollow of the thigh bone, or due to thinning of the bone around the implant.

Loosening of the joint can occur at any time, but it normally occurs 10-15 years after the original surgery was performed.

Another operation (revision surgery) may be necessary, although this can't be performed in all patients.

Hip dislocation

In around 3% of cases the hip joint can come out of its socket. This is most likely to occur in the first few months after surgery when the hip is still healing.

Further surgery will be required to put the joint back into place.

Wear and tear

Another common complication of hip replacement surgery is wear and tear of the artificial sockets. Particles that have worn off the artificial joint surfaces can be absorbed by surrounding tissue, causing loosening of the joint.

If wear or loosening is noticed on X-ray, your surgeon may request regular X-rays. Depending on the severity of the problem, you may be advised to have further surgery.

There have been reports about metal-on-metal implants wearing sooner than expected and causing complications. The Medicines and Healthcare products Regulatory Agency (MHRA) advises that certain metal-on-metal implants should be checked annually.

You can consult your doctor for further advice if you have any concerns about your hip replacement or don't know which type you have.

Read our metal-on-metal implant advice Q&A.

Joint stiffening

The soft tissues can harden around the implant, causing reduced mobility.

This isn't usually painful and can be prevented using medication or radiation therapy (a quick and painless procedure during which controlled doses of radiation are directed at your hip joint).

Serious complications

Serious complications of a hip replacement are uncommon, occurring in fewer than one in a 100 cases.

Blood clots

There's a small risk of developing a blood clot in the first few weeks after surgery – either deep vein thrombosis (DVT) in the leg or pulmonary embolism in the lung.

Symptoms of DVT include:

  • pain, swelling and tenderness in one of your legs (usually your calf)
  • a heavy ache in the affected area
  • warm skin in the area of the clot

Symptoms of pulmonary embolism include:

  • breathlessness, which may come on suddenly or gradually
  • chest pain, which may be worse when you breathe in
  • coughing

If you suspect either of these types of blood clots you should seek immediate medical advice from your GP or the doctor in charge of your care. If this isn't possible then call NHS Direct Wales on 0845 46 47 or your local out-of-hours service.

To reduce your risk of blood clots you may be given blood thinning medication such as warfarin, or asked to wear compression stockings.


There's always a small risk that some bacteria could work its way into the tissue around the artificial hip joint, triggering an infection.

Symptoms of an infection include:

  • a high temperature (fever) of 38C (100.4F) or above
  • shaking and chills
  • redness and swelling at the site of the surgery
  • a discharge of liquid from the site of the surgery
  • hip pain that can persist even when resting

Seek immediate medical advice, as detailed above, if you think you may have an infection.

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Recovery times can vary depending on the individual and type of surgery carried out. It's important to follow the advice the hospital gives you on looking after your hip.

After surgery

After the operation, you'll be lying flat on your back and may have a pillow between your legs to keep your hip in the correct position. The nursing staff will monitor your condition and you'll have a large dressing on your leg to protect the wound.

You may be allowed to have a drink about an hour after you return to the ward and, depending on your condition, you may be allowed to have something to eat.

Read more about what happens after an operation.

How soon will I be up and about?

The staff will help you to get up and walk about as quickly as possible after surgery. If you've had minimally invasive surgery or are on an enhanced recovery programme, you may be able to walk on the same day as your operation.

Initially, you'll feel discomfort while walking and exercising, and your legs and feet may be swollen. You may be given an injection into your abdomen to help prevent blood clots forming in your legs, and possibly a short course of antibiotics to help prevent infection.

physiotherapist may teach you exercises to help strengthen the hip and explain what should and shouldn't be done after the operation. They'll teach you how to bend and sit to avoid damaging your new hip.

Going home

You'll usually be in hospital for around three to five days, depending on the progress you make and what type of surgery you have.

If you're generally fit and well, the surgeon may suggest an enhanced recovery programme, where you start walking on the day of the operation and are discharged within one to three days.

Recovering at home

Don't be surprised if you feel very tired at first. You've had a major operation and muscles and tissues surrounding your new hip will take time to heal. Follow the advice of the surgical team and call your GP if you have any particular worries or queries.

You may be eligible for home help and there may be aids that can help you. You may want to arrange to have someone to help you for a week or so.

The exercises your physiotherapist gives you are an important part of your recovery. It's essential you continue with them once you're at home. Your rehabilitation will be monitored by a physiotherapist.

How soon will the pain go away?

The pain you may have experienced before the operation should go immediately. You can expect to feel some pain as a result of the operation itself, but this won't last for long.

Is there anything I should look out for or worry about?

After hip replacement surgery, contact your GP if you notice redness, fluid or an increase in pain in the new joint.

Will I have to go back to hospital?

You'll be given an outpatient appointment to check on your progress, usually six to 12 weeks after your hip replacement.

How long will it be before I feel back to normal?

Generally, you should be able to stop using your crutches within four to six weeks and feel more or less normal after three months, by which time you should be able to perform all your normal activities.

It's best to avoid extreme movements or sports where there's a risk of falling, such as skiing or riding. Your doctor or a physiotherapist can advise you about this.

When can I drive again?

You can usually drive a car after about six weeks, subject to advice from your surgeon. It can be tricky getting in and out of your car at first. It's best to ease yourself in backwards and swing both legs round together.

When can I go back to work?

This depends on your job, but you can usually return to work 6-12 weeks after your operation.

How will it affect my sex life?

If you were finding sex difficult before because of pain, you may find that having the operation gives your sex life a boost. Your surgeon can advise when it's OK to have sex again.

As long as you're careful, you should be able to have sex after six to eight weeks. Avoid vigorous sex and more extreme positions.

Will I need another new hip?

Nowadays, most hip implants last for 15 years or more. If you're older, your new hip may last your lifetime. If you're younger, you may need another new hip at some point.

Revision surgery is more complicated and time-consuming for the surgeon to perform than a first hip replacement and complication rates are usually higher.

It can't be performed in every patient, but most people who can have it report success for 10 years or more.

Looking after your new hip

With care, your new hip should last well. The following advice may be given by the hospital to help you care for your new hip. However, the advice may vary based on your doctors recommendations:

  • avoid bending your hip more than 90° (a right angle) during any activity
  • avoid twisting your hip
  • don't swivel on the ball of your foot
  • when you turn around, take small steps
  • don't apply pressure to the wound in the early stages (so try to avoid lying on your side)
  • don't cross your legs over each other
  • don't force the hip or do anything that makes your hip feel uncomfortable
  • avoid low chairs and toilet seats (raised toilet seats are available)

Avoiding falls

You'll need to be extra careful to avoid falls in the first few weeks after surgery as this could damage your hip, meaning you may require more surgery.

Use any walking aid, such as crutches, a cane or a walker as directed.

Take extra care on the stairs and in the kitchen and bathroom as these are all common places where people can have accidental falls.

Read about preventing falls in the home.

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Metal implant advice

Patients with a common type of metal hip implant should have annual health checks for life, according to the UK body for regulating medical devices.

The all-metal devices have been found to wear down at an accelerated rate in some patients, potentially causing damage and deterioration in the bone and tissue around the hip. There are also concerns that they could leak traces of metal into the bloodstream, which the annual medical checks will monitor.

In 2012, the Medicines and Healthcare products Regulatory Agency (MHRA) issued guidelines on larger head forms of "metal-on-metal" hip implants. Advice on smaller head devices or those featuring ceramic heads has not changed.

Check-ups are a precautionary measure to reduce the small risk of complications and the need for further surgery.

The new guidelines were reported in the media.

What should I do if I have a hip implant?

The guidance only applies to large head metal-on-metal implants, which have been used in only a minority of hip replacement surgeries. However, you can consult your doctor for further advice if you have any concerns about your hip replacement or don't know which type you have.

Patients with hip implants should also be aware of the warning signs that could signal a problem.

What are the warning signs?

Patients with metal-on-metal implants should ensure they attend any follow-up appointments as usual.

You should see your doctor if you have:

  • pain in the groin, hip or leg
  • swelling at or near the hip joint
  • a limp or problems walking
  • grinding or clunking from the joint

These symptoms don't necessarily mean your device is failing, but they do need investigating.

Any changes in general health should also be reported, including:

  • chest pain or shortness of breath
  • numbness or weakness
  • changes in vision or hearing
  • fatigue
  • feeling cold
  • weight gain

What types of implants are involved?

There are numerous designs and materials used to make hip implants. In 2012 the MHRA issued major updates to its advice on a type of metal-on-metal hip replacement. As the name implies, metal-on-metal implants feature a joint made of two metal surfaces – a metal "ball" that replaces the ball found at the top of the thigh bone (femur) and a metal "cup" that acts like the socket found in the pelvis.

The MHRA's updated advice concerned the type of metal-on-metal implant in which the head of the femur is 36mm or greater. This is often referred to as a "large head" implant. The agency now says patients fitted with this type of implant should be monitored annually for the life of the implant, and should also have tests to measure levels of metal particles (ions) in their blood.

Patients with these implants who have symptoms should also have MRI or ultrasound scans, and patients without symptoms should have a scan if the level of metal ions in their blood is rising.

The previous guidance on this type of hip implant, issued in April 2010, advised that patients should be monitored annually for no fewer than five years.

Advice on following up patients with other types of metal-on-metal implants remains the same, and guidance has not changed on:

  • Metal-on-metal hip resurfacing implants – where the socket and ball of the hip bone has a metal surface applied to it rather than being totally replaced.
  • Total metal-on-metal implants where the replacement ball is less than 36mm wide.
  • A particular range of hip replacements called DePuy ASR – these hip replacements were recalled by their manufacturer, DePuy, in 2010 because of high failure rates. The company made three types of ASR implant.
  • Implants featuring ceramic heads.

How many people are affected?

It is estimated that 49,000 people in the UK have been given metal-on-metal implants with a width of 36mm or above. This represents a minority of the patients given hip replacements, who mostly have devices featuring ceramic or smaller metal heads.

In 2010 there were 76,759 hip replacements, and approximately 5% of these surgeries used an metal-on-metal implant sized 36mm or above.

What exactly is the problem with metal-on-metal implants?

All hip implants wear down over time as the ball and cup slide against each other during walking and running. Although many people live the rest of their lives without needing a replacement implant, any implant may eventually need surgery to remove or replace its components.

However, data now suggests that large head metal-on-metal hip implants (those with a width of 36mm or greater) wear down at a faster rate than other types of implants. As friction acts upon their surfaces, it can cause tiny metal particles (medically referred to as "debris") to break off and enter the space around the implant.

Individuals are thought to react differently to the presence of these metal particles, but in some people they can trigger inflammation and discomfort in the area around the implant.

Over time this can cause damage and deterioration in the bone and tissue surrounding the implant and joint. This, in turn, may cause the implant to become loose and cause painful symptoms, meaning that further surgery is required.

News coverage (such as this BBC story) focused on the MHRA's recommendation to check for the presence of metal ions in the bloodstream, potentially released either from debris or the implant itself. Ions are electrically charged molecules. Levels of ions in the bloodstream, particularly of the cobalt and chromium used in the surface of the implants, may therefore indicate how much wear there is to the artificial hip.

There has been no definitive link between ions from metal-on-metal implants and illness, although there has been a small number of cases in which high levels of metal ions in the bloodstream have been associated with symptoms or illnesses elsewhere in the body, including effects on the heart, nervous system and thyroid gland.

The MHRA points out that most patients with metal-on-metal implants have well functioning hips and are thought to be at low risk of developing serious problems. However, a small number of patients with these hip implants develop soft tissue reactions to the 'wear debris' associated with some metal-on-metal implants.

How are medical devices regulated?

In the UK, the MHRA is the government agency responsible for ensuring that medical devices work and are safe. The MHRA audits the performance of private sector organisations (called notified bodies) that assess and approve medical devices.

Once a product is on the market and in use, the MHRA has a system for receiving reports of problems with these products, and will issue warnings if these problems are confirmed through its investigations. It also inspects companies that manufacture products to ensure they comply with regulations.

This system differs greatly from that for testing and approving drugs. Drugs require several years of research testing and trials before they can be approved for clinical use.

What action have regulators taken?

The MHRA has convened an expert advisory group to look at the problems associated with metal-on-metal implants, meeting regularly to assess new scientific evidence and reports from doctors and medical staff treating patients. The agency says it's continuing to closely monitor all the latest evidence about these devices and may issue further advice in the future.

In the US, the Food and Drug Administration (FDA) says it's gathering additional information about adverse events in patients with metal-on-metal implants. In the meantime, it advises patients with metal-on-metal hip implants who have no symptoms to attend follow-up appointments as normal with their surgeon. Patients who develop symptoms should see their surgeon promptly for further evaluation.

What actions have critics called for?

In light of the PIP breast implant controversy and the information on hip implants, there is currently intense scrutiny on the way medical devices are regulated in the UK and Europe, with patient groups and the media arguing that medical devices should be regulated in a similar way to medicines.

Clearing a medicine for use in the UK is a lengthy process involving several stages of laboratory and animal testing, and then carefully controlled and monitored tests in humans. Only once there's enough evidence to suggest that a medicine is reasonably safe can it enter clinical use, and even then patients will be monitored to look at the longer-term effects of the drug.

However, medical devices aren't required to go through human trials before entering use, and can currently be approved on the basis of mechanical tests and animal research.

While certain devices, such as hip implants, have been monitored through systems such as the National Joint Registry, in light of health concerns over PIP breast implants, patient groups are calling for more testing before devices are allowed into clinical use, and closer, mandatory monitoring schemes to ensure their safety once they enter the market.

Further reading

D Cohen How safe are metal-on-metal hip implants? – BMJ 2012

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The information on this page has been adapted by NHS Wales from original content supplied by NHS Choices.
Last Updated: 22/11/2016 11:29:08