Knee Replacement or Knee Arthroplasty is a surgical procedure to resurface a knee damaged by arthritis. The most common condition that results in the need for knee replacing surgery is osteoarthritis. It can be performed as a partial or a total knee replacement surgery. It is for someone who has severe diseases such as arthritis or a severe knee injury.  Knee surgery consists of replacing the diseased or damaged joint surface with metal and plastic components used to keep the bones that form the knee joint, along with the kneecap.

Osteoarthritis is characterised by the breakdown of joint cartilage. Damage to the cartilage and bones limits movement and may cause pain. People with a severe degenerative joint disease may be unable to do normal activities that involve bending at the knee, such as walking or climbing stairs because they are painful. The knee may swell or “give-way” because the joint is not stable.

Types of Knee Replacement

The knee is a hinge joint which provides motion at the point where the thigh meets the lower leg. There are several different types of surgeries to treat the joint replacement depends on various factors. Such as the patient’s age, anatomy, general health, lifestyle, and personal preferences.

Partial Knee Replacement

There are three compartments of the knee – tibia, femur and the back side of the patella. If arthritis affects only one side of your knee – usually the inner side – it may be possible to have a partial joint replacing. Because it involves less interference with the knee than a total knee replacing, it usually means a quicker recovery and better function. It uses smaller incisions.

Total Knee Replacement

It is done to replace the end of the three joint’s compartments tibia, femur and the back side of the patella of the knee joint with the artificial and plastic replacement parts. The procedure is usually for older patients who suffer from pain and loss of function from arthritis and have no results from other conservative methods of therapy.

Revision Knee Replacement

This surgery is for removing and replacing a prosthetic knee joint that is worn out, or that has failed. Although implants last for many years, 15 to 20 years or more. Your prosthesis will break or wear out if you are overweight or you engage in high – impact activities such as running or court sports, the device may fail sooner. Revision knee replacing may also involve the use of bone grafts or an allograft.

Minimally Invasive Knee Replacement

It is similar to the knee replacement surgery. But it is performed through an approx 3 to 4-inch incision, half the length of a typical joint replacing incision. These small incisions are specific instruments which move around soft tissue, rather than cut through it.

Cost

The cost of surgery varies from $5,000 to $20,000 depending on other factors and one geographic area to another.

Causes

The most common cause of chronic knee pain and disability is arthritis. Although there are many types of arthritis, most knee pain is caused by just three types: Osteoarthritis, Rheumatoid arthritis, and Post-traumatic arthritis.

• Osteoarthritis. It is an age-related “wear and tear” type of arthritis. It usually occurs in people 50 years of age and older, but may occur in younger people, too. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against one another, causing knee pain and stiffness.
• Rheumatoid arthritis. It is a disease in which the synovial membrane that surrounds the joint becomes inflamed and thickened. This chronic inflammation can damage the cartilage and eventually cause cartilage loss, pain, and stiffness. Rheumatoid arthritis is the most common form of a group of disorders termed “inflammatory arthritis.”
• Post-traumatic arthritis. It can follow a serious knee injury. Fractures of the bones surrounding the knee or tears of the knee ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.

Procedure

• Firstly, the patient receives general anaesthesia or regional anaesthesia to block sensation from the waist down along with a relaxant.
• After you receive anaesthesia, your surgeon will make a cut over your knee to open it up. This cut is often 8 to 10 inches (20 to 25 centimetres) long. Then your surgeon will:
  • Move your kneecap (patella) out of the way, then cut the ends of your thigh bone and shin (lower leg) bone to fit the replacement part.
  • Cut the underside of your kneecap to prepare it for the new pieces there.
  • Fasten the 2 parts of the prosthesis to your bones. One part will be attached to the end of your thigh bone, and the other part will be attached to your shin bone. The pieces can be attached using bone cement or screws.
  • Attach the underside of your kneecap. A special bone cement attaches this part.
  • Repair your muscles and tendons around the new joint and close the surgical cut.
• The surgery takes about 3-4 hours.