You'll usually be admitted to hospital on the day of your operation. The surgeon and anaesthetist will see you to discuss what will happen and answer any questions you have.

Most people would have seen their surgeon at a pre-assessment clinic and had the chance to talk about the operation.

A senior-level surgeon, consultant or registrar will do the operation. They may be helped by junior doctors. You should be told at your pre-operative assessment who will be doing the operation. Ask if you're not told.

How the operation is done

Hip replacement surgery is usually done either under general anaesthetic (you're asleep throughout the procedure) or under spinal anaesthetic (you're awake but have no feeling from the waist down).

Sometimes you may have an epidural, which is similar to a spinal anaesthetic.

Once you've been anaesthetised, the surgeon makes a cut (incision) of up to 30cm over the side of your hip.

The upper part of your thigh bone (femur) is removed and the natural socket for the head of your femur is hollowed out.

A socket is fitted into the hollow in your 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 your femur. The cup and the stem may be pressed into place or fixed with bone "cement".

The operation takes up to 2 hours.

Minimally invasive surgery

Some surgeons use minimally invasive techniques that help to avoid damage to the muscles and tendons around the hip joint.

1 or 2 small cuts (less than 10cm) are made and special instruments are used to remove and replace the hip joint.

Minimally invasive hip replacement appears to be as safe and effective as conventional surgery. It also causes less pain after the operation.

The National Institute for Health and Care Excellence (NICE) has more information on minimally invasive total hip replacement.

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

Metal-on-metal hip resurfacing is done in a similar way, however this is rarely done now because of possible complications and a higher "failure rate". This means that the hip joint must be replaced rather than resurfaced again.

The main difference with this procedure is that less of the bone is removed from the femur, as only the joint surfaces are replaced with metal inserts.

Choosing your implant

There are several types of implant made of plastic, metal or ceramic, or a combination of these.

The different parts of the implant can be cemented or uncemented:

• cemented parts are secured to healthy bone using bone "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

Metal-on-metal (MoM) hip implants are rarely used now as they can cause complications. Find advice about metal-on-metal implants.

NICE only recommends implants known to have a 95% chance of lasting at least 10 years.

Your surgeon should discuss any concerns you have about the choice of implant.

The National Joint Registry (NJR), which collects details on total hip replacement operations from hospitals in England, Wales, Northern Ireland and the Isle of Man, can help you to identify the best performing implants and the most effective type of surgery.

As with any operation, hip replacement surgery has risks as well as benefits. Most people who have a hip replacement do not have serious complications.

After having a hip replacement, contact your doctor if you get:

• hot, reddened, hard or painful areas in your leg in the first few weeks after your operation. Although this may just be bruising from the surgery, it could mean you have DVT (deep vein thrombosis) – a blood clot in the leg.
• chest pains or breathlessness. Although it's very rare, you could have a blood clot in your lung (pulmonary embolism) which needs urgent treatment.

To reduce your risk of blood clots, you'll be given blood-thinning medicine and compression stockings.

Moving your legs as soon as you can after the operation is one of the best ways to prevent blood clots. Check with a physiotherapist or nurse what you should be doing.

Loosening of the joint

This happens in up to 5 in 100 hip replacements. It can cause pain and a feeling that the joint is unstable.

Joint loosening can be caused by the shaft of the implant becoming loose in the hollow of the thigh bone (femur), or due to thinning of the bone around the implant.

It can happen at any time, but it usually happens 10 to 15 years after the original surgery was done.

Another operation (revision surgery) may be necessary, although this cannot be done in all patients.

Hip dislocation

In a small number of cases the hip joint can come out of its socket. This is most likely to happen in the first few months after surgery when the hip is still healing.

Further surgery is usually needed to put the joint back into place.

Altered leg length

The leg that was operated on may be shorter or longer than the other leg. People can adjust to this, but sometimes a raised shoe may be needed.

Infection

Hip replacement surgery is done in an ultra-clean operating theatre and antibiotics are given during the operation.

But in less than 1 in every 100 operations, an infection may still happen. You'll be given antibiotics.

Very rarely, the hip replacement may need to be "washed out" or a new replacement may be used.

It's normal for the wound to be slightly red and warm to touch while healing. However, if you feel unwell, the pain is getting worse or the wound starts to leak fluid, contact a GP straightaway or call 111.

How long will a replacement hip last?

Wear and tear through everyday use means your replacement hip might not last forever. Some people will need further surgery.

According to the National Joint Registry (NJR), only 7 in 100 hip replacements may need further surgery after 13 years. However, this depends on the type of implant and how it was fixed in place.

Most hip replacements last much longer than 13 years.

Find more information on how long hip implants last from the NJR website.

Recovery times can vary depending on the individual and type of surgery. 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.

Find out 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 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.

A physiotherapist will teach you exercises to help strengthen your hip and explain what should and should not 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 3 to 5 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 1 to 3 days.

Find out more about getting back to normal after an operation.

Recovering at home

Do not 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 a GP if you have any worries or queries.

After you're discharged from hospital, you may be eligible for up to 6 weeks of home help and there may be aids that can help you. You may also 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.

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 will not last for long.

You'll be offered pain relief medicines every few hours. It's a good idea to take these medicines regularly during the first 48 to 72 hours.

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

After hip replacement surgery, contact a 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 6 to 8 weeks after your hip replacement.

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

There are many things that can affect how quickly you get back to normal, such as:

• your age
• your general fitness
• the condition of your joints and muscles
• the job or activities you do

Everyone recovers differently, but it's often possible to return to light activities or office-based work within around 6 weeks. It may take a few more weeks if your job involves heavy lifting.

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 more about returning to normal activities.

When can I drive again?

You can usually drive a car after about 6 weeks, subject to advice from your surgeon. It can be tricky getting in and out of a 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 to12 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 6 to 8 weeks. Avoid vigorous sex and more extreme positions.

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 doctor's recommendations:

• avoid bending your hip more than 90° (a right angle) during any activity
• avoid twisting your hip
• do not swivel on the ball of your foot
• when you turn around, take small steps
• do not apply pressure to the wound in the early stages (try to avoid lying on your side)
• do not cross your legs over each other
• do not force your hip or do anything that makes it 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, which may mean you need more surgery.

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

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

Find out more about preventing falls in the home.

Patients with a common type of metal hip implant should have regular annual health checks.

Most people who have a metal-on-metal (MoM) implant have well-functioning hips and are thought to be at low risk of developing any serious problems.

But compared with other hip replacements, some metal-on-metal hip devices have been found to wear down more quickly in some patients.

This potentially causes damage and deterioration in the bone and tissue around the hip, which medical checks will monitor.

In 2017, the Medicines and Healthcare products Regulatory Agency (MHRA) published updated guidelines on monitoring patients with all types of metal-on-metal hip implants.

Check-ups are a precautionary measure to reduce the small risk of complications and monitor patients who have had the devices implanted for a long time.

What should I do if I have this type of hip implant?

Metal-on-metal (MoM) implants have only been used in a minority of all hip replacement surgeries. They are done on very few people now, so this may not affect you.

If you're not sure what type of implant you have or you have any concerns about your hip, you can consult your doctor for advice.

If you do have a metal-on-metal implant, make sure you attend any follow-up appointments you're invited to.

You should also be aware of the warning signs that could show there's a problem.

What are the warning signs?

You should contact your doctor if you have:

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

These symptoms do not necessarily mean your device is failing, but they do need to be investigated.

Any changes in your 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 are metal-on-metal implants?

As the name implies, metal-on-metal implants are a joint made of two metal surfaces:

• a metal "ball" that replaces the ball at the top of the thigh bone (femur)
• a metal "cup" that acts like the socket in the pelvis

What does monitoring involve?

Patients who have metal-on-metal implants should be monitored regularly for the life of the implant and have tests to measure levels of metal particles (ions) in their blood.

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

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

Wear and tear

All hip implants wear down over time as the ball and cup slide against each other during movements, including walking and running.

Although many people live the rest of their lives without needing a replacement implant, some people may eventually need surgery to remove or replace its components.

Evidence suggests that certain types of metal-on-metal implant wear down at a faster rate than other types.

As friction acts upon their surfaces, it can cause tiny metal particles to break off and enter the space around the implant.

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

If not caught early, this can cause damage and deterioration in the bone and tissue surrounding the implant and joint over time. This in turn may cause the implant to become loose and cause painful symptoms, meaning further surgery is required.

The Medicines and Healthcare products Regulatory Agency (MHRA) guidance is designed to detect and treat any complications like this.

Metal ions in the blood

Some news coverage has focused on the MHRA's recommendation to check for the presence of metal ions in the blood.

Ions are electrically charged molecules. Levels of ions in the blood, particularly of cobalt and chromium used in the surface of the implants, may therefore indicate how much wear there is to the artificial hip.

These ions in the blood are not blood poisoning and do not lead to sepsis, which is an entirely different type of illness. Talk of this in some news reports is very misleading and completely wrong.

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 blood have been associated with symptoms or illnesses elsewhere in the body, including effects on the heart, nervous system and thyroid gland.

How many people are affected?

Approximately 71,000 UK patients have had a metal-on-metal hip device implanted or had metal-on-metal resurfacing.

The majority of these patients have well-functioning hips and a low risk of complications.

Because of the problems with this type of implant, they are rarely used now.

How are medical devices regulated?

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

Once a product is on the market and in use, 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.

Further information

National Joint Registry: metal-on-metal hip implants