In March, it will be two years since Dr. Knowlan replaced both of my knees. There are no words to express my appreciation. I was a 62 year old beat up P.E teacher with osteoarthritis and Dr. Knowlan came up with a plan for a bilateral knee replacement. Because of his surgical skills, I was on the driving range one month later and playing one week after that. Two years later and I have no need for ibuprofen, Tylenol, etc. I can walk daily for 5 miles and do the elliptical for 45 minutes with no pain and no discomfort. Great surgeon and wonderful physical therapists.