Suggest Treatment For A Dislocated Knee Cap

hi just need some info i had a dislocated knee kap about 2 year ago and some time it hurts below the knee (about 2 inc below) but i have don a lot of work the past week and tonight while at work (standing in one place) i have had pains town the inside of my ley starting from the knee hight and working down. is this normal and it there anything my doctor can give me as i don't like taking ibprophen all the time and i have been told it can damage my kidneys?

IM a 24 yo male

Thanks in advance