My husband is 58 years old and has been treated for the past 3-4 years for PD. He has developed a chronic case of arthritis of his left knee, bone on bone and total knee replacement has been recommended. The last thing we want is for him to be less mobile than he is now. Currently he is using a can for most of the day and has times when he can walk straight and other times when he has freezing bouts. I know each case is different but what does research show about rehabilitation and regaining mobility after knee replacement in patients with PD. Thanks for any advice you can give.