Hip replacement

What is a hip replacement?

The hip is a “ball and socket” joint. The head of the thigh bone is round and sits like a ball in a hollow in the pelvic bone. Cartilage covers both surfaces so they turn smoothly. If the cartilage wears away (osteoarthritis), or the bone is damaged by a fracture or another disease, the hip becomes painful and hard to move.

In a hip replacement the surgeon removes the damaged part of the head of the thigh bone and the hip socket and puts in artificial parts. The aim is to reduce pain and improve movement.

Who is it for?

A doctor may raise a joint replacement in these situations:

• Hip pain that makes walking, bending or climbing stairs hard
• Pain at rest or at night that disturbs sleep
• Stiffness in the hip
• Other treatments that have not worked or have worked little, such as anti-inflammatory medicines, physiotherapy, and a stick or walker

There is no set age or weight for the operation. The decision is based on pain and how much it limits you. In sources most patients are between 50 and 80 years old, but each person is assessed on their own. Examination, history and an X-ray are the basis of the decision, and sometimes an MRI is needed too.

Before the operation you may be asked for blood and urine tests, an ECG and a chest X-ray. Major dental work is best finished before the operation. If there is a skin infection on the leg to be operated on, the operation may be postponed.

How is the operation done?

You talk with the anaesthetic team about the type of anaesthetic: general, or a spinal block. Then:

1. The surgeon removes the damaged bone and cartilage from the head of the thigh bone and the hip socket.
2. The new parts are fitted: a stem inside the thigh bone, a ball (head) on top of it, a cup in the pelvis, and usually a smooth lining between the ball and the cup.
3. The stem may be fixed with a special cement or fitted so that the bone gradually grows onto it.

Medical sources usually give the operating time as one to two hours. After the operation you stay in the recovery area for a few hours until the anaesthetic wears off. The surgeon chooses the type of implant and the method based on your situation, and you should ask him directly before the operation.

After the operation

• Hospital. Some patients go home the same day and some stay at least one night. The surgeon will tell you the plan before the operation.
• Walking. It starts soon after the operation with a walker, crutches or a stick. Gradually you build up the walking programme and the hip exercises.
• Preventing clots. Moving the ankle, walking early, compression stockings and sometimes a blood-thinning medicine are used. The doctor decides the details.
• Stitches. They are usually taken out after about two weeks. Keep the wound dry until it is fully closed.
• Care with body position. Usually in the first few weeks (in sources, about six weeks and sometimes up to eight weeks) you need to take care when sitting, bending and lying. For example, do not cross your legs, do not raise the knee above the hip, and do not bend further than you have been told. The exact list of precautions depends on the surgical approach, and the surgeon or physiotherapist will give it to you.
• Daily life. In sources, a return to most light activities is given as three to six weeks. For a few weeks you may need help with cooking, shopping, bathing and washing clothes.
• Swelling and exercise. Mild to moderate swelling may last three to six months. Continue the physiotherapy exercises for at least two months.

Recovery speed differs from person to person. Full recovery can take months.

Risks

Most patients recover well, but every operation carries risks:

• Blood clot. This is one of the most common complications. If it reaches the lung it is dangerous. Prevention and knowing the signs are important.
• Infection. One American source reports serious infections in under 2 percent. A superficial infection gets better with treatment. A deep infection may need another operation.
• Dislocation (the ball coming out of the socket). It happens mostly in the first few months and is not common. Sometimes it is fixed by putting the joint back without surgery. If it keeps happening, surgery may be needed.
• Difference in leg length. A small difference may remain.
• Less common problems. Nerve or blood vessel damage, bleeding, a fracture of the bone, stiffness, loosening or wear of the implant, and lasting pain.

Your personal risk depends on your age, other conditions and the state of your bone. You should ask your doctor about this.

When to call

Contact your doctor or treatment centre soon if:

• You have a temperature of about 38 degrees or higher, or chills
• The area around the wound is red, hot, painful or swollen, or has discharge or pus
• Hip pain gets worse even at rest
• You have pain or tenderness in the calf that has nothing to do with the wound, or new or worsening swelling in the thigh, calf, ankle or foot
• Your leg suddenly looks a different shape or length, or you cannot put weight on it (the joint may have come out of place)

If leg pain or swelling comes with sudden shortness of breath or chest pain, call 115 (the emergency number in Iran) at once or go to the emergency department, and do not drive yourself.

Every patient’s treatment plan is different; ask your doctor about your own situation.