I Had A Complex Total Knee Replacement Over 4 Months

I had a complex total knee replacement over 4 months ago. ( I had osteonecrosis in the tibia and a fracture in the tibia.) I have had extensive physical theraphy. 3 times a week. the 1st 8 weeks the pt didn't work me hard enough so my ROM was only a little over 100/ got a new pt and he is good. now my ROM is over 120. The problem is that I have extreme tightness and lots of pain in and around my knee. Also as the day goes in to the evening I have a lot of pain in my whole leg below my knee and into my foot. The orthopedic doc doesn't know what is causing it.Just tells me to have patience and it takes time. he has indicated that i have RSD. Can you help me? Donna