Joint replacement surgery is a procedure in which an orthopedic surgeon removes part or all of a diseased or damaged joint – most commonly the knee or hip – and inserts a prosthetic as replacement. The goals of this procedure are to reduce chronic pain and improve mobility in patients, goals that these procedures achieve in the majority of cases. So why do people need these procedures? While there are many conditions that can damage joints and create a need for joint replacement, there are some that are more common than others. Among those are these 3 conditions that often lead to joint replacement: