Treatment Choice - Treatment Choice | Compare Prices | Find Hospital | Knee replacement surgery (arthroplasty) involves replacing a damaged, worn or diseased knee with an artificial joint.<br/>It's a routine operation for knee pain most commonly caused by arthritis.<br/>More than 70,000 knee replacements are carried out in England and Wales each year, and the number is rising. Most people who have a total knee replacement are over 65 years old.<br/>For most people, a replacement knee will last for at least 15 to 20 years, especially if the new knee is cared for properly and not put under too much strain.