The damage to the knee joint from arthritis is is usually relentless and in most cases, irreversible. The arthritis wears away an increasing amount of the shiny white gristle (articular cartilage) lining the bones that make up the knee joint. It is this cartilage which normally makes the bone ends slippery and helps the joint to move smoothly without friction and also functions as a shock absorber. With time, an increasing proportion of the bone ends get exposed until finally a situation arises where bone is rubbing against bone.
While the patient starts feeling some pain soon after the onset of the arthritis, it is only in the later stages that it gets worse and may become quite restricting. The patient may find that his or her mobility is reduced and even day to day jobs such as walking to the local shops, going up and down stairs and getting up from a chair become painful. In the final stages the knee may become painful at rest and also cause pain at night in bed and keep the patient from sleeping.
The knee replacement operation is one of the most reliable operations in orthopaedic surgery and consistently reduces or eliminates the pain of the arthritis in most patients. The pain of the operation itself improves very much within the first ten days and is almost gone by 2 to 3 weeks. The artificial knee can also at times, but not always, improve the movements in a knee joint that has become stiff from arthritis and permit the patient to resume gentle activity and leisure pastimes. In this manner, it can improve the mobility, independence and the quality of life of most people with disabling knee arthritis. Patients can then get greater exercise and this can help in strengthening of the effected leg and lead to a feeling of well being. Often patients who have arthritis of both knees are so pleased with their first operation that they ask for the second one to be brought forward and done as soon as possible.