Knee problem

Patient: Doctor 1 am 42 6 yrs back i had ligament tear in my both knee doctors told me to get it opreated but didnt go for in fact as on today i am well i can run walk but some times only after climbing and comming down form amy hill my knee starts painingwhat should i do i stand in my shop for atleast 5 to 6 hours a day without any problem suggest what to do