Whenever you walk, sit, run, turn around or similar activities where you depend on the knee for support and mobility, it bears the full load of the body. It means, in a 70kg person the knee experience only 70 kg when he or she stands but it multiply even 210kg during running or sports. It is impossible for anybody to work properly without a pain-free, mobile knee .

For smooth function of the knee smooth gliding surface for the bony ends are mandatory. The surfaces of all three consisting bone come in contact during motion and covered with a thick smooth gliding surface (articular cartilage). Other components for good functioning knee are strong and healthy muscles around knee, ligaments and of course covering membrane (synovial membrane). Normally all these components work in harmony, but disease or injury can disrupt this harmony resulting pain, thigh wasting, repeated joint effasion and decrease or loss of functions of the knee.

The most common causes of the knee pain and disability is osteoarthritis. In Osteoarthritis the gliding surface of the bone become irregular and rough due to age related wear and tear. The painful stiff knee may also develop due to disease like rheumatoid arthritis or after injury or infection.

In the early stages of the usually the pain is relieved by painkillers only or in association with physiotherapy and sometime injection into the joint. But in advanced stage, when the pain is severe, conservative therapy fails and your daily activities become very restricted, you need an operation. Varieties of operations are there; the simplest is arthroscopic washout and the last option is total change of the knee joint and replaced by artificial joint. The artificial joint will give you pain free, mobile joint for quite long time which is more than 15 years.

What is total knee replacement surgery?
A total knee replacement is a surgical procedure where the diseased knee is replaced with an artificial knee joint (implant). During the total knee surgery the ends of the thighbone is removed and replaced wit the metal shell; the end of the leg bone is replaced with a plastic piece over a metal stem. Depending on the condition of the damage of the kneecap the undersurface is also resurfaced with plastic kneecap. Many design and different material are currently in use for the replacement with varieties of price.

When you need total knee replacement?

• If you are more than 60 years of age with severe knee pain that limits your daily activities including walking, going up and down stairs and getting in and out of the chair. You may find it very difficult to walk more than few steps without severe pain.
• If you are more than 60 years with moderate to severe pain while resting during day or night and deformity in the knee.
• If you are more than 60 years with moderate to severe pain, which is not relieved by drugs or you are taking the drugs for a long time, which is causing side effects.

Before 60 years of age total knee replacement operation is usually not done

Benefit of total knee joint replacement

• Relief of knee pain
• Increase movement of the joint
• Correction of deformity
• More leg strength (If you do exercise)
• Improve quality of life
• Ability to return to normal life

You can run, jump, play or whatever you would like to do after total knee replacement.

Dr M Ali, an arthroscopic surgeon and knee specialist is an Assistant Professor of National Institute of Traumatology and Orthopaedic Rehabilitation (NITOR), Dhaka.