Total Knee Replacement – Brief Introduction

Joint Replacement Surgery: Joint replacement surgery is one of the most successful advance in the history of medicine. This field combines the knowledge and skills of modern medicine, metallurgy,implant design and newer bearings.

Total knee replacement is one of the more commonly performed procedure. The term total knee replacement generally conveys a much radical procedure than it actually is. In fact it entails removing approximately only 9 mm from the ends of bone, which will be replaced with smooth artificial surfaces to allow for easier movement. It is more analogous to changing the hinge of a door than changing the door itself . The procedure can help relieve pain, restore lost mobility, and correct leg deformity. Knee replacement is done when there is knee arthritis which in other words mean loss of articular cartilage covering the bone ends at the joints.The most common reason for knee arthritis is osteoarthritis.Osteoarthritis in the knee occurs through natural wear and tear.The bare bone ends then have little or no protection to prevent them rubbing against each other when the knee moves, causing pain and lots of squeaks.

Other medical conditions that may make a knee replacement necessary include::

  • Rheumatoid arthritis
  • Haemophilia
  • Gout
  • Disorders that cause unusual bone growth (bone dysplasias) and bone death following problems with the knee’s blood supply (avascular necrosis).
  • Infections
  • Trauma especially injury to articular cartilage which when diagnosed early and treated early by keyhole techniques(arthroscopy) can prevent osteoarthritis

You may be a candidate for knee replacement surgery if:

  • You suffer daily knee pain that restricts work, recreation and regular daily activities such as walking, going up and down stairs, and getting in and out of chairs.
  • You have chronic stiffness and pain in your knee – even while resting.
  • Your knee lacks stability.
  • You experience chronic swelling and inflammation of the knee that does not respond to medications or rest.
  • Knee stiffness prevents you from bending or straightening your knee.
  • You have a deformity like extremely bowed legs or knock-knees.

Do you have knee arthritis?

When you have knee pain with swelling and stiffness particularly in the mornings with difficulty in climbing /descending with gradual bowing of legs,suspect knee arthritis. Non-surgical methods for knee relief include:

  • Losing weight
  • Physiotherapy to strengthen the muscles around the knee and reduce the strain on the joint
  • Using walking aids such as a cane or crutch
  • Painkillers, anti-inflammatory medicines and steroid injections to reduce inflammation and pain.Prollonged treatment with painkillers is harmful due to their side effects and to date no medicine is available to reverse Arthritis despite tall claims.

When pain persist inspite of these measures,think of knee replacement.

Who can have a knee replacement?

Knee replacement surgery may be considered for adults of any age. Most people who undergo a knee replacement tend to be aged between 60 and 80 in the western countries whereas in Indians the osteoarthritis sets in earlier and people require total knee replacement earlier.The most common reason for knee replacement is osteoarthritis, which tends to affect people over the age of 50.Knee replacements are also likely to last longer in older and typically less active people. So trying all the non-surgery alternatives is more likely to be recommended for younger patients.

What exactly is done during knee replacement?


The damaged ends of your thigh bone (femur) and shin bone (tibia) are very carefully cut away. The ends are precisely measured and shaped to fit the appropriate sized prosthetic replacement. A dummy joint is then positioned to test that the joint is working properly. The final adjustments are made, the bone ends are cleaned, and the final prosthesis is fitted. The end of your femur is replaced by a curved piece of metal, and the end of your tibia is replaced by a flat metal plate. These are fixed usually using special bone ‘cement’. A plastic spacer is placed between the pieces of metal. This acts like cartilage, reducing friction as your joint moves.

Complications.

Most people do not have any complications. Knee replacement surgery (arthroplasty) is now a routine and commonly performed operation . Your anaesthetist and surgeon will be able to answer any questions you may have about your personal risks from anaesthetics and the surgery itself. Normal wear and tear through everyday use means that your replacement knee will not last forever. However, a recent UK study (the Trent Regional Arthroplasty Study) has found that over 90% of artificial knees were still working 15 years after the surgery.This may be achieved, and perhaps increased, by making sure you look after your new knee properly and taking care to avoid straining it. There may be some activities, such as running or high impact aerobics, that you will be advised to avoid.

Anaesthesia

Anaesthetics are extremely safe, but they do carry a risk of minor side effects such as nausea (usually temporary), and also a slight risk of serious complications as in any other surgery.

What to expect after surgery?

The patient experience gratifying pain relief and can walk the very next day.You may be given some specific exercises to carry out, as well as advice on taking short walks and carrying out normal household activities, such as walking up and down stairs. These exercises will help restore your movement and strengthen your new knee. Most people find it possible to resume normal leisure activities 3-6 weeks after their surgery. However, it may take up to three months for your pain and swelling to settle down. As soon as you can bend your knee enough to allow you to get in and out of a car, and control the car properly, you can resume driving. This is also usually around four to six weeks after your surgery, but you should check that you are safe to drive with your physiotherapist or doctor.Most people are also able to return to work at around this time, but it will depend on how physically demanding your job is. Your knee will continue to improve over the next two years, as long as you keep up your recommended exercises, and follow your doctor’s and physiotherapist’s advice.this continued improvement is due to building up of the disused muscle with postoperative excercises.

Knee replacement surgery offers a number of benefits:

  • Improve your overall quality of life. With less pain and greater mobility, you’ll be able to perform daily tasks and low-impact activities more easily and lead a more comfortable, more independent life. (You’ll still need to avoid high-impact activities that might overload the new knee.)
  • Dramatically reduce knee pain. According to the American Academy of Orthopaedic Surgeons (AAOS), more than 90% of total knee replacement patients experience a dramatic reduction of knee pain.
  • Improve your range of motion. While your artificial knee won’t be as good as your real knee was in its prime, its range of motion should noticeably increase. Most importantly, it will no longer keep you from living a normal, active life.
  • Enjoy years of performance. This is especially so in the modern era as life expectancy is improving and people remain active even at old age.improved cardiac and respiratoy parameters has been noted after knee replacement as people walk after knee replacement

For people who wish to Add life to years rather than years to life ,who want a painfree independent life total knee replacement has opened up great opportunity .The success of the surgery depends to a large extent on the quality of the implants as well. so always opt for better implants and undergo the surgery at institutions where it is done routinely with all full fledged operating room facilities. For further information : www.aaos.org