Pain In Interior Knee Area, Done Major Back Surgery A Week Ago. Cause Of Concern?

About a month ago I had major surgery on my back. Currently I have two rods and 6 screws plus 4 other inserts from S1-L4. My concern today is my interior right knee area is very painful. It has been this way for most of the day. It not red or more painful when pressed upon. I have not been wearing the white compression hose. Heat or cold does not resolve the issue. Of course with this major surgery I am in pain, but this is new and different. I am aware it is a challenge to make a prediction. Based on what I read I should not be concerned. Comments?