Hip replacement

How do I know if I need a hip replacement?

The main reasons for having a hip replacement are pain and stiffness that cannot be helped by other treatments. The pain and stiffness can affect the ability to walk, to climb stairs, to get out of a chair and to undertake normal everyday household activities.

Symptoms will often vary from day to day - sometimes for no apparent reason. This is very common but, where symptoms are frequent, constant or very troublesome, despite painkillers, a hip replacement might be the best option.

Can I prevent needing a hip replacement?

Exercises to strengthen the muscles around the hip joint can help to reduce the need for a hip replacement.

General exercise, such as walking or cycling, also helps to reduce the pain. Swimming is particularly good as the water supports the weight of the body, reducing the strain on the joints.

Exercise helps with the symptoms of pain and stiffness, caused by arthritis, but also keeps the muscles strong and healthy so that, if a hip replacement does become necessary, recovery is faster and better.

When painkillers and exercises no longer help, hip replacement surgery may be necessary.

Hip replacement surgery

A hip replacement is done under anaesthetic. Usually this is a general anaesthetic but it is sometimes done under a spinal anaesthetic, which causes numbness from the waist down but does not send the person to sleep. The operation itself takes about two hours.

In a traditional hip replacement, the surgeon will make a cut (incision) about 20-25 cm long usually down the outside of the thigh. Increasingly a minimally invasive approach is used - this involves either one smaller incision on the outside of the thigh or two smaller incisions in the groin and behind the hip joint. The surgeon then cuts out the part of the hip joint that is being replaced. The hip joint is a 'ball and socket' joint; sometimes it's the 'ball' that needs to be replaced, sometimes the 'socket', but usually it's both.

Recovering from a hip replacement

Following a hip replacement, the most important aspect of recovery is mobilising as soon as possible. The involves walking on the affected leg, often later on the day of the operation. Within twenty four hours of the surgery, a physiotherapist will advise on the best exercises to do to strengthen the leg muscles.

While recovering, certain movements need to be avoided. These include bending the hip too far, twisting the hip and turning too quickly. A physiotherapist will explain how to adapt normal movements, including how to bend and sit, to avoid damaging the new hip.

Most people are able to go home after two or three days. To begin with, crutches are often used to walk with but it is usual to be able to stop using these (if exercises are being done regularly) within six weeks and independent walking (with no stick) is usual after 12 weeks.

Care after the operation

Some support with day-to-day activities for a week or two is likely to be needed.

This may mean needing to have a friend or relative to come to stay for a while.

What are the main reasons for needing a hip replacement?

There are two main conditions that can result in needing a hip replacement:

• Arthritis in the hip:

  • Arthritis means inflammation of a joint.

  • Osteoarthritis is the most common cause of arthritis in the hip and the most common reason for needing a hip replacement.

  • Rheumatoid arthritis is a less common cause. Fewer than one person in 25 who has a hip replacement has rheumatoid arthritis.

  • There are other causes of arthritis that may lead to needing a hip replacement.

• Breaking a hip (hip fracture):

  • A hip fracture is a fracture of the top part of the thighbone (femur). The fracture can be of the head, of the neck or below the neck.

  • Usually a hip fracture is treated by an operation to screw the broken ends back together again. However, if it is the head of the femur that has broken, this is often treated by replacing the broken head of the femur with an artificial head of the femur (prosthesis). This is particularly the case if the broken bits have moved away from each other or if there is already arthritis in that hip joint.

Will I need any tests before I have a hip replacement?

It is common to be asked to attend a 'pre-admission' or 'pre-assessment' clinic before having a hip replacement. The appointment for this clinic is usually six weeks or less before the operation. At this clinic, a nurse will assess the fitness for your hip replacement.

The following tests may be performed:

• Blood tests - to check that there is no anaemia and that the kidneys are working well enough to undergo the operation.

• Urine test - to make sure there is no urine infection and that there isn't any glucose in the urine.

• In people with diabetes, a test will be done to check that the diabetes is well enough controlled. The hip replacement is likely to be cancelled or postponed if the diabetes control is not good. This is because healing could be slower if the diabetes is not controlled; also an anaesthetic is more risky if the diabetes control is poor.

• Blood pressure.

• Infection screen - this includes looking for meticillin-resistant Staphylococcus aureus (MRSA). MRSA is a germ (bacterium) that is difficult to treat and can cause complications for a hip replacement.

• A heart tracing (electrocardiogram, or ECG).

There may be the chance to speak with an anaesthetist, physiotherapist or occupational therapist at this clinic but this isn't always possible.

Risks and benefits of hip replacement

The risks and benefits of the operation should be discussed in detail and in language that you can understand. If you have other conditions, such as heart disease, diabetes or a tendency to deep vein thrombosis or if you are obese, you should also have explained to you how these things may increase the risks of the operation for you.

You should be given advice on 'prehabilitation' - getting into the best possible physical shape before your surgery - when you are added to the waiting list for operation and on rehabilitation after the hip replacement before leaving the hospital after the operation.

What type of anaesthetic will I need?

Hip replacement can be carried out under a general or spinal anaesthetic. You can find out more detail in our separate leaflet called Anaesthetic for hip or knee replacement.

Are there different types of hip replacements?

Hip replacements can all be divided into two types:

• Total hip replacement (total hip arthroplasty):

  • This involves replacing both the 'ball' (femoral head) and the 'socket' (acetabulum) with artificial parts.

• Partial hip replacement (partial hip arthroplasty):

  • When either the 'ball' (femoral head) or the 'socket' (acetabulum) is replaced but not both.

The replacement part may be made of various materials, including metal, polyethylene and ceramic. They may be fixed in place using special cement (cemented) or they may not be fixed (uncemented) but designed so that the bone grows over them and fixes them in place that way. The 'socket' part is also sometimes called the 'cup' of the hip replacement.

Metal-on-metal hip resurfacing

• In this operation no part of the joint is removed completely but the surfaces of the ball and socket are removed.

• A specially designed metal cap is fitted over the head of the thighbone (femur) and another metal component is fitted into the socket (acetabulum).

• Re-do operations are more common and occur earlier than with hip replacements.

• MOMR is generally used for fewer patients but is still an acceptable option for younger people, especially men who are wanting to undertake vigorous sporting activity following their surgery (but see below).

Which type of hip replacement should I have?

This will depend on multiple factors including age, other medical conditions and the type of exercise or work that is required after the operation.

It will also depend on what types of hip replacements the surgeon is used to performing and which ones are used in their hospital. In the UK the National Institute for Health and Care Excellence (NICE) only recommends devices that are known to last at least 10 years in 95 out of every 100 people who have that type fitted.

All hip replacements can be divided into either cemented or uncemented.

Cemented hip replacement

In the UK about a third of people who have a hip replacement have a cemented one:

• They fix well.

• It is usually possible to get up and move early after the operation.

Uncemented hip replacement

These are now more common than cemented hip replacements in the UK.

• They are easier to re-do, making them possibly more suitable for younger people who are more likely to outlive their replacement.

• They can take longer to fix in place so full weight bearing and mobilising are not possible as early as with cemented prostheses.

Reverse hybrid hip replacements

These are becoming more common, particularly in Northern Europe. About 1 in 4 hip replacements in the UK use this method. The "cup" of the prosthesis is cemented but the "stem" of the prosthesis is uncemented.

• They seem to be as successful as the other methods of hip replacements.

• It is unclear whether they offer any benefit over cemented hip replacements.

Cemented hip replacements have been shown to last longer in people who are over 65 at the time of their hip replacement. They have also been shown to improve the quality of life in people over 60 earlier than uncemented hip replacements although by one year after a hip replacement both groups were the same. Uncemented hip replacements were more likely to fracture later on. Current guidance suggests that cemented hip replacements should be used in people over 60 or 65 but that uncemented may be better for those who are younger or more active.

How long will my new joint last?

Because of advances in medical appliances and surgical techniques, hip replacements are now lasting for longer than they used to. About 3 in 5 people who have a hip replacement today can expect it to last for at least 25 years. In over 92 in 100 people who have a hip replacement, their hip replacement will last over 10 years.

How long hip replacements last depends somewhat on how hard they have to work. Remaining a healthy weight and doing exercises to keep the muscles around the hip strong are really important for this.

Will I need to be seen again after my hip replacement operation?

Within about eight weeks of your operation, people should be followed up by the hospital where they had their surgery. Review is advised again after seven years and then every three years.

These review appointments may just involve having an X-ray organised by the surgical team and then a telephone conversation with someone from the team.

What are the possible immediate complications following hip replacement?

Bleeding

Blood transfusion may be needed. In 2022, NICE advised that all people having a hip replacement be given tranexamic acid during the surgery to reduce the risks of bleeding.

Pain

• This can be reduced by different anaesthetic techniques used at the time of the operation.

• It is important to make sure that pain relief is taken. It is vital to be able to move about start to walk as soon as possible after a hip replacement.

Venous thromboembolism

• A venous thromboembolism (VTE) is a blood clot inside a vein.

• All patients are given measures to prevent this happening, where it is safe to do so. This usually includes: medication, foot pumps and below-knee compression stockings. Although they significantly reduce the risks of getting a VTE they do not completely remove the risk.

• The most severe (but rare) form of thromboembolism is a pulmonary embolism (PE). The prevention measures reduce the risk of dying from a PE by 70%.

• Certain factors increase the risks of having a VTE. These include: having had a VTE before, being closely related to someone who has had a VTE, having cancer or chemotherapy or being obese.

Dislocation of the hip

• This can occur at any stage but is most likely in the early days and weeks after a hip replacement.

• It is important to follow the advice given by the physiotherapist about the strengthening exercises needed and how to do certain movements - for example, how to get in and out of a car - to reduce the chance of this happening.

Other complications

These include:

• A urinary tract infection often occurs when people have had a tube (catheter) put in their bladder during the operation.

• Constipation can be caused by certain painkillers and being immobile.

• Chest infections are more likely following a general anaesthetic and in people who already have a lung condition, such as chronic obstructive pulmonary disease (COPD).

• Wound infection and wound breakdown (also hip joint infection - see below).

• Breakage of a prosthesis.

• Fracture - of the thighbone (femur) or the acetabulum.

What are the possible later complications following hip replacement?

Long-term complications include the hip replacement 'failing' and infection of the hip joint.

Failure

Hip replacements can wear out and, when they do so, they become loose or break - this is often referred to as hip replacement failure. A further operation (a 'revision') may be needed to correct this. It is often a more complex operation. Needing to have the hip replacement revised is more likely when the first hip replacement was done at a younger age.

90% of people who have their hip replaced in their 70s never need any further surgery on that hip. In contrast, 90% of people who have their hip replaced under the age of 50 will need to have it re-done.

For people who have to have their hip replacement done again, most have run into problems by about seven years after the original operation. The hip may start to hurt again, but it doesn't always, which is why it is important that there is regular follow up arranged.

Infection

Infection of a hip replacement can be very serious. About 1 in 100 people get an infected prosthesis after a hip replacement.

An infected hip prosthesis may need to be removed and it may not be safe or possible to replace it.