I Had A Full Knee Replacement May 18 2015, When

I had a full knee replacement may 18 2015, when they took the decath out I felt a burning in the bottom or lower part of my penis, now almost a year later as soon as I start to pee, it burns or hurts at the base of the penis. my urologist sad sounds like ? I don't know what he said. I'm 73 years old male in good shape, with no other aliments. o when I ejaculate seems to burn more.