What Causes Knee Pain And Weight Gain After Having Liposuction On Thighs/belly?

i am 53, woman and i had 2 liposuctions on my belly and one inside my thighs. that was 3 years ago. i have gained weight since then around 15 pounds. i can tell some of the fat has settle in my knee area. i am starting to have problem with my knees. when i sit for a while 10 to an hour, and i stand up, my knees hurt. i notice ican't bend my right knee all the way. when i excerse i find my self scared of hurting my knee.