 I am Dr. Hemant Kalyan, consultant and head of the department of orthopedics and sports medicine working at Manipal Hospital, Bangalore. Osteoarthritis of the knee is very common as we mentioned in our country and the population of our country is aging. That is to say that the life expectancy is increasing. So a lot of people now live up to 80 even 90 plus and as they get older their expectation from life is that they would like to remain active and independent even if their children or family is there to look after them. Going back to the question in people who have stage 4 osteoarthritis that is where the cartilage is completely lost the space of the joint will become narrower and as a result of this the knee joint will become deformed. Commonly it becomes a bow leg shape and less commonly you will get a nock knee shape which is due to the osteoarthritis. Now in such situations other things like medications, exercises, physical therapy, massages, nutritional supplements etc. no longer can give relief to the person and the person experiences pain, limitation of movement and a complete breakdown of their independence and lifestyle. So this is a situation where the person needs a knee replacement. Knee replacement is a lifestyle choice. It's a choice a person in the family makes to make them the senior citizen in the family more mobile, more active and capable of looking after themselves. And I must say here that it's not an emergency surgery which you need to be forced to undergo tomorrow because osteoarthritis is a problem which happens over months or years and knee replacement should be done in a properly planned way.