Total Knee Replacement

Knee replacement surgery is usually necessary when the knee joint is worn or damaged so that your mobility is reduced and you are in pain even while resting. A healthy joint is one that bends easily. It absorbs stress and allows pain- free movement and activities. When the joint is damaged, it may lose the ability to cushion stresses placed upon it, and movement may become painful. Sometimes a damaged knee joint will swell and hurt even when you are at rest.

It is the articular cartilage that covers the ends of the bones that becomes damaged. It starts to crack and wear away. The cartilage is not able to heal itself, and the damage may keep increasing. At first, the knee may be just a little stiff, but as the bones begin to rub together you are more likely to feel pain.

A joint replacement gives the knee new surfaces, which move smoothly and less painfully. It is not the same as a healthy joint, but works well. The goal of joint replacement is to give pain relief, which may help you return to many of your activities.

Osteoarthritis (OA)
This is a degenerative disease. Years of normal use can cause articular cartilage to crack and wear away. As the ends of the bones rub against each other they become rough and pitted, and eventually the cartilage may wear away altogether. This results in stiffness, pain and loss of function.

Being overweight, or having alignment problems, (e.g. bow legs or knocked knees) puts extra stress on the joint, which may speed up the damage process.

According to the World Health Organisation osteoarthritis affects half the world’s population over the age of 65. The causes are not well understood. Ageing is the factor most strongly associated with OA. Genetic factors are among the major causes.

Onset of OA can also occur as a secondary effect of injury. For example, a bad fall, blow to the knee, previous fracture, or ligamentous injury can injure the articular cartilage leading to OA.

Rheumatoid Arthritis (RA)
This is an inflammatory joint disease. It can cause swelling and heat in the joint lining. It usually affects multiple joints throughout the body. As the disease progresses, the articular cartilage is destroyed and, eventually, the bone itself is also affected. Joints are usually painful, hot, swollen and stiff.

Once your new joint has healed properly, you should look forward to some or all of the following benefits:

• Greatly reduced joint pain.
• Improved quality of life by allowing you to do daily tasks and low-impact activities in greater comfort.
• Increased leg strength. Without knee pain you will be able to exercise more and this will help to build up the muscles around the knee.
• Correction of angular leg deformity i.e. knock-knee or bow-legs.

Not everyone wishes to have, or requires, knee joint replacement when they have damage to their articular cartilage. Some people will have different pain tolerances, and others may not wish to undertake the risks this surgery carries.

• Alternatives to surgery include:
  Regular pain relieving medicines
• Use of walking aids to relieve any stress on the joint.
• Weight loss to reduce stress on the joint.
• Special shoe inserts that help to cushion the joint.
• Exercises to maintain joint movement, muscle strength and help with pain relief.
• Activity modification.

Only when these measures fail to give acceptable pain relief, is a total knee replacement offered.

The decision to proceed with surgery should be made jointly by you, the patient, and your surgeon. This decision should only be made after you feel that you understand both the benefits and the risks involved with this surgery and have had chance to ask questions. Operation is the last resort when other treatment like medications / injections / altering life style have failed.

If you decide to proceed, you will have a pre operative check usually by a pre operative nurse few days / weeks prior to surgery. Routine blood test / ECG test is done to check your fitness for surgery. There will also be another opportunity to ask questions.

Once you are listed for surgery, make sure that you have any tooth or gum problems treated before your operation. If you don’t, there is a risk that germs in your mouth could enter the blood stream and infect your new joint. If for any reason you change your mind about surgery, it is not a problem, but it is better to let us know in advance of your surgery date, so that we can allocate another patient in your place.

What do I have to do before my surgery?

• You will receive a letter with the details of your admission. You will be admitted on the day of your surgery.
• Follow the advice given by the pre-operative assessment nurse about your medicines, including herbal remedies / blood thinning medications. Pre operative nurse may ask you to stop some medications few days prior to surgery.
• If you live alone, it is advisable to stock up your freezer with easy to cook meals for when you return home. See if you can make arrangements for someone to help with buying fresh food and help with cleaning and laundry.
• Get a neighbour, friend or relative to look after your house.
• If you develop a cough, cold, chest or skin infection, or an infected in-growing toenail, please let us know, as it may be necessary to postpone surgery until you have recovered.

What will happen on admission to hospital?

• The anaesthetist will see you. They will discuss the anaesthetic with you and your pain management after the operation. You can also discuss any worries you may have.
• If you did not see a doctor at your pre-operative visit, the doctor will see you, explain the operation again and you will sign the consent form and go for an x-ray if necessary.
• The doctor will also mark your appropriate leg with a felt tip.

What will happen on the day of my operation?

• You will not be able to eat or drink (including water, sweets) for a minimum of 6 hours before your surgery.
• You will be taken to theatre, on a bed or in a wheelchair, by a nurse.
• In the anaesthetic room the anaesthetist will give you your anaesthetic.

The artificial knee

Prosthesis used by your surgeon is one with a very good proven long term track record.

Each prosthesis is made up of three main parts:

1. The tibial component (bottom portion) replaces the top surface of the lower bone the tibia, and is made of titanium.
2. The femoral component (top portion) replaces the bottom surface of the upper bone (the femur) and the groove where the patella fits, and is made of cobalt chrome. A high-density polyethylene spacer sits between them.
3. A plastic patellar component (kneecap portion) is sometimes used to replace the surface of the patella where it glides in the groove on the femur.

The cemented prosthesis is held in place by acrylic cement that attaches the metal to the bone.

Once you are stable in recovery, you will be taken back to the ward. That evening you will rest and the nurses will check you regularly. You can have visitors but you are likely to be tired and drowsy, so try and keep them to a minimum.

What will happen on the days following my surgery?

Day one

• You will be assisted with a full bed bath.
• You will have a blood test and Xrays
• The drip will be taken down if you are drinking well, not feeling sick and do not need a blood transfusion.
• The dressings will be reduced.
• You will be able to start some exercise, under the supervision of the physiotherapist. The exercises are shown later in the booklet.Moving both your feet and ankles up and down and in circles quite vigorously also helps circulation.
• If you feel well enough, you will be able to sit out of bed, with assistance.
• When lying in bed, or sat in the chair, keep moving feet and ankles up and down to help with your circulation.
• The physiotherapist or assistant will see you 1or 2 times a day.
• Use the advice and exercises in this booklet to help you treat yourself regularly.

Day two

• The bandages will be removed.
• You will start to walk, usually with a Zimmer frame at first, and gradually progress to crutches.
• The physiotherapist will instruct you on exercises to get your knee bending. The knee will feel tight and sore to bend but will get easier with time. You will be taught by physiotherapist to use stairs if you are comfortable.
• The knee will still be sore, so keep taking pain relief medication as needed.
• If the knee is swollen, ice will be offered.
• Elevating the leg on a stool or bed will also help reduce swelling.
• Once the physiotherapist is happy with your progress, will be discharged on Day 2, occasionally on Day 3 if required.

You will be allowed to go home when your knee is bending well, and your consultant is happy with your progress. You will also need to be safe on your crutches, be able to negotiate stairs, manage to get off a chair, toilet and bed, and generally be able to look after yourself at home if necessary.

Most people leave hospital 2-3 days following their surgery. If there are any postoperative complications, then you may need to stay longer. You can travel home in a car. An ambulance is only arranged in special circumstances.

Continue with all your exercises and keep progressing your walking. How long and frequently you will attend physiotherapist after surgery depends on your progress, but appointments are usually once a week. The district nurse / hospital nurse will remove clips from your knee, 12-14 days after your operation.

You will attend the outpatient clinic to see the doctor 6-8 weeks after your surgery.

Do not drive until you can safely do so (please check with your insurance company). Usually at the 6-week stage, once you comfortable and confident you should be able to start driving. It can be earlier if you having your left knee replaced and driving automatic car.

This is an operation that requires hard work and determination. Your knee will be sore at times and to get the knee bending and the muscles working again will be hard work, which only you will be able to do. Unless you are determined to do regular exercises before and after operation, you will not get successful outcome of knee replacement surgery.

Remember, every patient and every joint is different. Even in same patient each knee is different. Results can be different than your other knee if its replaced. Don’t worry if some days your knee is more stiff, swollen or painful than others, it will get better.

Can I return to playing sports after my total knee replacement?
You can return to playing low-impact sports. This means sports that don’t put high stresses on your knee. These include golf, bowling, cycling or swimming.

When will I experience the full benefit from surgery?
Although you will experience relief of your pre-operative pain quite soon after the operation, the return of full function can take much longer. After three months, you will probably have regained some of the strength in the muscles around the knee, and range of movement will be improving. However, it may take up to 6-12 months to feel the full benefits.

When will I be able to drive?
You are able to drive 6 weeks after the operation, providing there have been no problems in your rehabilitation. If you have an automatic car, and have had a left knee replacement, you could return to driving once the wound is healed, which is usually around 2 weeks post op.

How long will my joint replacement last?
Research shows at 10 years 95% of knees are functioning satisfactorily this reduces to 90% at 15 years and 70% at 20 years.

When will I be able to fly?
You are able to fly no sooner than three months after your operation. Your risk of having a DVT (clot in the calf) is still high within this time period.

Will I set off the alarm at the airport?
The prosthesis is made of titanium and cobalt chrome and, in theory, shouldn’t set off the alarms. If the alarm does go off, then the scar on your knee will help confirm that you have had knee surgery. If you are worried then you could ask your consultant for a letter to confirm you have had a joint replacement.

Is it normal for my knee to make a noise when I move it?
Yes. This is the metal and plastic components moving over each other.

Can I kneel after my knee replacement?
A third of patients find this is difficult and painful to do following this type of surgery. Kneeling on hard surfaces is not recommended but special kneeling mats can sometimes help.

Will any further surgery be required?
On a few occasions, some patients may find their knee is very stiff even though they have tried hard to get it to bend. Your surgeon may then recommend a manipulation. This involves going back to theatre and being put to sleep again. This is usually required within 3 months if you haven’t achieved good movement despite physiotherapy.

Will I be pain free?
The majority of patients may well be pain free and no longer need painkillers. About a third of patients will have some pain, but it should be much less than the pain they had before the operation.