Orthopaedic Surgery - You and your Knee Replacement

Introduction

Those with arthritis know how unbearable pain can be. Joint replacement offers relief from this pain and an improved quality of life. It involves a major operation and there are some risks as with all types of surgery.

The medical and nursing staff, physiotherapist and occupational therapist, all have an important role to play in helping you to return to a better quality of life.

What is arthritis?

Arthritis is the wearing away of a joint surface. At first this may cause pain and swelling, but can later lead to the bones actually rubbing together. In severe cases the bone-ends become roughened and movement becomes difficult.

Can it be cured?

It is not actually possible to prevent arthritis progressing once the surface of the joint is damaged. If the pain or disability cannot be controlled by a change of lifestyle, or painkillers, then surgery can replace the worn joints with artificial ones.

What is a total knee replacement?

A total knee replacement, or unicompartmental knee replacement, involves replacing damaged bone surfaces with a metal and plastic joint (shown in the diagrams below). The new joint aims to relieve pain and improve movement in the knee. The knee cap is sometimes resurfaced.

How will the operation benefit me?

There are two objectives of surgery - to reduce pain and improve the function of the joint, thereby giving sufficient freedom of movement to allow most normal activities. It can also correct any obvious deformity.

Will the operation be painful?

You may have some pain immediately after the operation. However, instead of the constant dull aching pain, the sensation becomes a pain that you know will eventually ease. Your consultant will prescribe strong pain relief to help ease this operation pain.

What are the risks of having a joint replacement?

It must be emphasised that complications following knee replacement are rare. Rest assured that most patients are delighted with their new joint. Any operation involves an element of risk. It would be wrong to over-emphasise these risks, but you should be aware of them.

Infection

Sometimes the wound is slow to heal and the stitches may need to be left in longer than usual. Loosening of the joint is rarely a problem, but, as with all replacement joints, infection is the most worrying complication.

All infections must be cleared up prior to the operation, particularly tooth abscesses, urine infections and skin infections, otherwise bacteria circulating through the body can lodge on the bone surface of the new joint and cause infection in the bone.
You will be given a preventative antibiotic 24 hours after surgery.

You are screened for MRSA prior to surgery. Following surgery, about one per cent of patients develop an infection in the joint. If an infection does not respond to treatment, it may be necessary to undergo further surgery. There is a small risk of developing a chest infection after surgery. This risk increases if you already have chest problems.

Thrombosis

One in ten patients are at risk of developing a blood clot in the veins in the leg (DVT). This may occur with any operation and steps will be taken to prevent this. The main method of prevention is to get you mobile as soon as possible. Blood clots cause swelling in the leg, usually in the calf muscles and may be accompanied by pain or a burning sensation. In about two per cent of cases, these clots travel to the lungs and cause a blockage, preventing normal breathing. This can occasionally be fatal.

Death

Death is a risk, due to the physical stress of a major operation and the risks associated with anaesthetic.

Bleeding

Total knee replacement is a major operation and there is a certain amount of blood loss anticipated. In some cases a blood transfusion may be needed.

Knee stiffness

The knee exercises are an essential part of your recovery. If you do not get the knee bending and the muscles working in the early stages following your surgery, you may not get a good result from the operation.

Occasionally patients are unable to achieve enough bend in the knee and may have to return for a manipulation under anaesthesia (MUA). This involves another visit to theatre, where the surgeon bends your knee for you whilst you are asleep. After this you will need to work VERY hard to maintain the extra movement gained.

Preparing for surgery and the pre-operative assessment clinic

Preparation for a total knee replacement usually begins two weeks before the proposed date for surgery. You will be asked to attend the pre-operative assessment clinic where your level of fitness for surgery and anaesthesia will be assessed.

You will be screened for infection prior to surgery. You will also be introduced to some, if not all of the members of the multidisciplinary team who will be responsible for your care in hospital.

On the ward

The doctor will explain the operation to you and obtain your consent. He will identify the leg to be operated on by marking it with a black marker pen.

Your operation may be performed under either a general or a spinal anaesthetic. The anaesthetist will visit you prior to your operation to determine which is the most suitable option for you and to answer any questions you may have.

The physiotherapist will discuss the operation with you and tell you what is expected of you after surgery (this may have already been done at pre-operative assessment clinic).

You will be advised when to stop eating and drinking.

The operation usually takes between one and a half to two hours to complete. When the operation is finished, you will be taken to the anaesthetic recovery room where your condition will be monitored. Once the recovery nurse is satisfied that your condition is stable, you will return to the ward.

After the operation

Points to note:

• You will have a large dressing over your wound. Occasionally you may also have your leg resting in a canvas splint
• You may be given oxygen via a mask for up to 24 hours. This may be longer if you have existing respiratory problems
• Fluids may be given intravenously via a vein in the back of your hand
• Occasionally a blood transfusion may be required
• You will have an x-ray of your knee
• You should start the circulatory and deep breathing exercises taught to you by the physiotherapist as soon as possible
• Due to fluid loss during surgery, reduced mobility and certain painkillers, you will be more prone to constipation which can then affect urine output. It is vital to drink plenty, eat foods containing fibre and inform nursing staff if you are constipated so that treatment can be provided. If you are normally prone to constipation, follow the above advice prior to admission or consult your GP
• Stitches or clips will be removed day 10-14 after the operation
• Discharge usually occurs between 1-3 days depending on progress

Physiotherapy

When muscles are not used, they become weak and do not perform well in moving and supporting the body. Your leg muscles are likely to be weak because you have been unable to use them effectively due to your condition. Surgery can correct this problem but the muscles remain weak and can only be strengthened by regular exercise.

You will be assisted and advised how to progress through the exercises but the overall responsibility of carrying them out is yours.

• Knee exercises start on the day of your operation under the supervision of a physiotherapist
• Depending on your consultants’ regime you will begin to mobilise on the same day as your operation or the following day
• 2 physiotherapists will help you get out of bed and take a short walk using a walking aid
• The physiotherapist will help you to progress your exercises. The aim is to achieve a 90 degree knee bend and a straight leg raise

Straightening exercises (extension)

1.    Tensing up the thigh muscles

Sit or lie with your leg out in front of you. Tighten the muscles at the front of the thigh, pushing the knee down. Hold the contraction for 3 seconds then relax.

2.    Heel lifts

Sit or lie with a rolled-up towel or blanket under the knee. Keep the knee down on the roll and raise the heel. Straighten the knee as far as possible and hold for 3 seconds. Slowly lower.

3.    Straight leg raise

Sit or lie with the leg out straight. Tighten the thigh muscles, straighten the knee and lift the whole leg 6 inches (15cms) up off the bed or floor. Hold for 3 seconds and slowly lower.

4.    Passive knee stretches

Sit or lie with your leg out in front of you. Put your heel on a rolled up towel so that the back of the knee is not in contact with the bed or floor. Let the knee stretch in this way for 5 minutes (less if painful).

Bending exercise (flexion)

5.    Knee bends

You can use a board or a tray for this exercise. Keep the heel down on the board and slide the foot towards you, bending the knee. Hold it at full bend for 2-3 seconds and release.

6.    Knee bends in the chair

Sit in a chair with your foot on the ground. Slide your foot firmly towards you and then away.
Hold for 3 seconds in the fully bent position. You may be given a roller to place under your foot.

Walking

The sequence is always:

1. Move the crutches/frame forward
2. Step into the crutches/frame with your operated leg
3. Lean on the crutches/frame and step the un-operated leg through, placing it slightly in front of your operated leg

• Turning should be performed using small steps, keeping the operated leg on the outside of the turn. DO NOT swivel on your ‘new’ knee
• As you become more mobile and confident the physio will progress you eventually onto walking sticks
• Once the physio is happy that you are safe and walking correctly you will be able to get up and walk on your own with the appropriate aid

Stairs

The physiotherapist will teach you how to ascend and descend stairs safely. Even if you do not have stairs at home it may still be taught to you, as you may have to go up and down steps outside, or visit relatives whose bathroom is upstairs.

Going upstairs

• Hold on to the handrail with one hand and the walking aid in the other
• Step up onto the first step with your un-operated leg, keeping the walking aid with the operated leg
• Step up onto the same step with the operated leg and then bring up the walking aid

Going downstairs

• Hold on to the handrail with one hand and the walking aid in the other
• Place the walking aid down onto the first step and carefully lower your operated leg next to it
• Then bring the un-operated leg to the same step

Daily activities

The occupational therapist (OT) will assess your ability to perform the activities of daily living. Advice will be given and equipment may be provided for your use in hospital and at home.

Dressing

If you have been dressing independently before the operation you should be able to do so afterwards. The OT will assess your ability to carry out this task during your hospital stay.

When can I go home?

The multidisciplinary team will discuss with you when you are ready to go home. However, your overall progress, the amount of pain you are experiencing, the condition of your wound and the availability of home services will determine your discharge date. A letter will be sent to your GP to inform them of your surgery.

If you require support at home following surgery, the hospital social worker will assess your needs and discuss the services available to you. Social Services may provide all or part of the assistance required, but your family, friends or neighbours may also provide support. You will also be informed of any financial entitlements. There are certain requirements you must meet to be eligible for the above entitlements and you may have to pay something towards the cost of the services received. This will be discussed with you in detail and any agreed services will be written into your care plan.

Your discharge

You will normally make your own arrangements to go home. If transport home is a problem, please tell the nursing staff on admission or as soon as possible afterwards.

When you are ready to leave the ward, you may be given a supply of medication. A letter will be given to you for your GP.

You will also be sent an appointment to see your consultant at the outpatient clinic.

Things to remember

• DO NOT twist your new joint
• DO NOT kneel. Avoid kneeling where possible for the first four months after your operation
• DO NOT cross your legs when sitting
• Continue to use ice, as instructed on the ward
• 3 or 4 short walks are better than 1 long walk
• Avoid prolonged standing and long walks which may tire you
• Continue with the exercises you were taught on the ward
• Your physiotherapist will arrange some follow up according to your needs
• DO NOT stop using your walking aids until instructed by your physiotherapist
• Due to pain and stiffness after the operation, you will have to work hard to regain muscle power, mobility and knee bend
• It may take 3 months for all the pain from surgery to subside and you will have to keep it working during this time

Driving/Travelling

It is at your consultant’s discretion when you can begin driving. Remember to contact your insurance company and inform them of your operation. Failure to do so may make your policy invalid.

You may travel in the front seat of a car if flexion of the knee allows.

Flying is not recommended, because of the limited legroom and knee flexion space.

A letter from your GP/consultant informing the airport of your knee replacement may prevent embarrassment with metal detectors in security systems.

Work

If you are planning to go back to work after your operation check with your consultant at your first follow-up appointment.

Sport

Check with your consultant before returning to sport. Walking and swimming are excellent, but sports which include jogging such as football and squash are not recommended.

Sexual intercourse

Usually sexual intercourse may be resumed whenever you feel well enough.

Contact number

Orthopaedic Department - Telephone: 0161 206 4898