Knee replacement surgery, also known as arthroplasty, involves replacing damaged or diseased cartilage and bone in the knee joint with an artificial joint made of metal and plastic. The prosthesis or the artificial joint will help the knee joint to move in the same way as a natural joint.

You may be suggested either a total or a partial knee replacement depending upon the extent of damage in your knee. Total knee replacements (TKR) which is more common involve both sides of your knee joint being replaced with a prosthesis. Partial knee replacements (PKR) involve less bone being removed and hence a smaller incision will be made.

Reasons for opting for knee replacement surgery:

Your physician may recommend the surgery for a number of reasons like:

• Severe pain and stiffness making it hard to walk, climb stairs, and standing after sitting for a long time.
• Persistent pain in the knee while resting that disturbs sleep.
• Swollen knee.
• Bowed knee or other defects.
• Alternative treatment methods like physiotherapy and medication have not helped.

The most common condition that leads to a knee replacement is osteoarthritis. Osteoarthritis causes the breakdown of joint cartilage resulting in limitation of movement and constant pain. Rheumatoid arthritis, hemophilia, gout, and any kind of injury to the knee are some other conditions that cause knee damage that may require knee surgery.

The procedure

The four basic steps to a knee replacement procedure are:

• Preparing the bone- The damaged cartilage surfaces removed along with a small amount of underlying bone.
• Positioning the implants- The removed cartilage and bone is replaced with a metal prosthesis. The most commonly used knee replacements are fixed into the bone with medical cement. Such cemented implants fit tightly into position and are immediately fixed well into the bone.
• Resurfacing the kneecap- The undersurface of the kneecap is cut and resurfaced with a plastic button. Some surgeons skip this step depending on the patient’s condition.
• Inserting a spacer- A medical-grade plastic spacer is placed between the metal components to create a smooth gliding surface.

Risks involved

Complications with knee replacement are rare but can include:

• Stiffness in the knee region
• Infection of the surgical wound
• Infection of the artificial joint needing further surgery
• Bleeding into the knee joint
• Nerve or ligament damage around the knee joint
• Blood clots
• Persistent pain in the surgery site
• Instability of the new joint which may need another surgery to correct it

After knee replacement surgery

Primary benefits of knee replacement surgery are reduced or no pain and being able to move around normally. Daily activities and exercises can be resumed shortly after the surgery.

Recovery post surgery will differ person to person. Your knee replacement doctor will suggest trying to stand within 12-24 hours after the operation and to attempt to walk with the help of crutches initially. Initial discomfort and swelling is common and will subside gradually.

Physiotherapy may be recommended over the first few weeks. A physiotherapist will suggest exercises to help strengthen your knee. You can usually return to work and activity 6 to 12 weeks after the operation.