Total knee replacement: Should you get a new knee?

Understanding what total knee replacement involves will help you decide whether you are a suitable candidate for the surgery

Old man with knee replacement

Seventy-year old Pramilaben had severe osteoarthritis. She had consulted a large number of doctors for her knee pain and had tried all kinds of treatments to no avail. Orthopaedic surgeons were unanimous in their advice to go for knee replacement. However, she was petrified and feared that, if operated, she would never be able to bend her knee or ever walk again. Like Pramilaben, there are plenty of individuals suffering from knee pain, limping, joint stiffness and deformity. Their lives have been severely affected by osteoarthritis. They want to go shopping or for a movie but their knees won’t allow them. They find it difficult to get in and out of cars or to climb and descend stairs.

The following FAQs will help them decide if replacement surgery is indeed the solution for their worn out knees.

What is osteoarthritis?

Osteoarthritis [OA] denotes wear and tear of a joint. It commonly affects the knees since they bear the weight of the body. Osteoarthritis affects the cartilage that covers the joint surfaces. The cartilage begins to degenerate and the fluid between the joint decreases. Gradually, the cartilage thins and cracks. Over time, it gets wears out, exposing bone surfaces. The exposed bones rub against each other, causing pain while moving. In the later years, it leads to disability—OA of the knees is among the top five causes of disability.

How is OA treated?

Not everyone with OA needs surgery. In the early stages, lifestyle changes, correct footwear and physiotherapy to stretch and strengthen the thigh muscles bring relief to the degenerating knees. Losing weight helps as it reduces the pressure on the joints. Lifestyle changes like following a good posture, avoiding taking the stairs and staying hydrated are beneficial too. Pain relief measures such as anti-inflammatory medications and local applications help, but the relief is temporary. Keyhole surgery like arthroscopy has shown its worth in early cases of knee wear. However, if the degeneration is not controlled by these measures, total knee replacement is suggested.

What is Total Knee Replacement?

In total knee replacement or TKR surgery, the degenerated parts are shaved off and substituted with smooth surfaces made of artificial material. Contrary to popular belief, the whole knee is not replaced, only the affected surfaces are. The newly-constructed knee almost behaves and moves like a normal joint. A metal cap covers the thigh bone, a plastic trough forms the upper end of the leg bone and a plastic disc is implanted on the lower surface of the kneecap.

Am I eligible for a TKR?

If you have arthritis of the knee and have run out of conservative options for treatment, and are otherwise medically fit, you could have a knee replacement. If you find walking or performing simple everyday activities such as getting up from a chair difficult, it may be time to consider knee replacement surgery.

Who cannot opt for a TKR?

A person with active infection in the arthritic joint, elsewhere in the body or in the skin near the troubled knee, should refrain from or defer TKR. Persons with compromised cardiac function, severe uncontrolled diabetes and hypertension should also be cautious.

How is TKR actually done?

The surgery is performed under anaesthesia. The anaesthesia is such that it provides up to 48 hours of post-operative pain relief, and allows for faster, more comfortable progress in physical therapy.

The skin over the knee is sterilised. Next, a tourniquet is applied at the thigh to temporarily stop blood supply to the knee. This helps preventing blood loss during the operation. A cut is made through the skin and the muscles to expose the knee joint. The joint is then cleaned by removing extra bone growths and damaged tissue. The tight soft tissues are released to adequately expose the surfaces of the bones. All this is done using specialised devices. Then, trial implants are positioned on the exposed bones. Placing of the trial implants ensures that the alignment of the knee is correct. The trial implants are taken through the range of full movement and other intricacies such as ligament balance.

Finally, the trial implants are removed and final implants are pressed onto the bone ends with a layer of cement between the implants and the bones. The components are held in place till the cement hardens. A drainage tube is placed and the cut is closed using stitches and staples. A dressing is given on the stitches.

How long does the surgery last?

No two TKR procedures are similar. Hence, the time taken to perform varies. However, a typical total knee replacement operation lasts between 60 and 80 minutes.

What tests are needed before surgery?

Patients undergoing TKR surgery usually will have to undergo a pre-operative surgical risk assessment. The routine tests include, full blood count, blood group, blood sugar, HIV, HCV [a hepatitis test] and Australia antigen status, ECG and chest X-ray. If required, further evaluation and tests are performed by an internal medicine physician who specialises in pre-operative evaluation. An anaesthesiologist also evaluates the patient before surgery.

How much does TKR cost?

The costs vary according to the grade of the hospital, the class of the room and the choice of implant. The break-up of the costs is as follows:

  • Surgeon’s fee
  • Anaesthetist’s fee
  • Medical consultant’s fee
  • Theatre charge
  • Implants and material
  • Bed charges
  • Drugs and transfusions
  • ICU charge if high risk.

The surgeon’s office will be able to give a correct estimate of charges at the hospital one is getting operated.

What are the complications?

Like any surgical procedure, TKR too is associated with certain risks. Although major complications are uncommon, there are possibilities of blood clots in the veins of the leg. There is a chance of excessive bleeding and anaesthesia-related cardiac complications or stroke. Studies have shown rare instances of death, with the risk being less than 1 in 400.

Risks specific to knee replacement include infection, which require further surgery. There is a remote possibility of nerve or blood vessel injury. Very rarely, the knee may become either too stiff or unstable. There is also a chance that pain might persist or new pain might arise. Sometimes, the joint replacement might not last the patient’s lifetime and might require revision surgery.

However, while the list of minor complications is long and intimidating, the frequency of major complications following a TKR is low. The overall risk of surgery is dependent on the surgeon’s skill, complexity of the knee problem and the patient’s medical profile.

How are the surgery-related risks managed?

The best way to manage potential complications is by preventing them. Early patient mobilisation and use of blood-thinning medications in some patients can prevent blood clots in the veins. Good surgical technique can help minimise post-operative infection and bleeding. With sound precautions and attention to detail, the overall likelihood of complications can be greatly reduced.

What can I do to avoid infections?

If you have an infection in your body, even a tooth infection, have it treated well before surgery. There is growing evidence that a calm mind can aid wound healing and keep away infection. Deep breathing techniques, relaxation music and meditation can be helpful in keeping surgical stress at bay.

How soon can I expect to become mobile?

If there are no complications, you can start moving within a couple of days after surgery. Initially, you’ll need a walker and gradually you will be encouraged to put full weight on the operated leg. At the time of discharge, many patients are able to walk with the help of a cane. Those who come for surgery with a lighter body and stronger muscles, start walking without support sooner.

Is there need for physiotherapy after TKR?

Physiotherapy is a must for early rehabilitation and longevity of your implants. Strong thigh muscles are necessary for optimum function after TKR. Your physiotherapist will teach you movements to keep the joint flexible and to maintain good posture after surgery. But you have to avoid sitting on furniture that is low in height.

How long will the new knee serve me well?

If performed by an experienced surgeon, the best implants can last about 15 years. You need to follow the advice regarding weight management and change of lifestyle for better and longer results.

What activities can I do after surgery?

The goal of TKR is to return patients to a good level of functioning without knee pain. To minimise long-term complications and extend the life of the artificial joint, certain broad guidelines help.

Recommended activities include:

  • Swimming
  • Water aerobics
  • Cycling on stationary bike
  • Level ground walking
  • Golf
  • Weight training exercises
  • Yoga without extreme knee bending
  • Table tennis
  • Ball room dance.

Activities that are not recommended include:

  • Jogging or running
  • Impact exercises
  • Full squats and sitting cross-legged
  • Sports that require knee twisting [aggressive tennis, basketball, badminton]
  • Contact sports
  • Heavy labour.

Can I avoid knee replacement?

Knee replacement can be avoided in many cases if one takes proper care in the initial stages of OA. I recommend the 3S goal of being Supple, Strong and Slim.

This article was first published in the February 2012 issue of Complete Wellbeing.

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