What Causes A Sensitive And Painful Spot On The Knee?

I had fallen about 6 months ago. I stepped over a child s gate that was on the 2nd step of the stairs. I fell forward landing on my knees and twisting my left foot enough to fracture (no displacement) of the cuboid bone. I have been in a walking boot, plaster cast, and a wheelchair. The healing took a long time, and I was finally given the OK to walk without support less than a month ago. My knees were heavily bruised when I fell and I couldn t touch the knee. The discoloration finally disappeared but there was always 1 spot on the knee that was extremely sensitive. That is the knee that now is causing a great deal of pain when I walk on it. Stairs are painful, but going down the steps is the most painful. If I try to turn my knee keeping my leg in place, there is a sharp pain. Thanks so much.