What Causes Pain Below The Knee Joint?

The area of my pain is on the inside and below my right knee, and radiates to the area just below the knee. It definitely does not appear to be related to the knee joint itself. In 1988, I had rods through both legs to support 6 weeks of skeletal traction due to broken femurs sustained in a motor vehicle accident, during which time the pin site located where my pain is now located became infected. That infection cleared up back in 1988, and since that time only very sporadically has that location ached, and that happened most commonly during change of weather, and never lasted too long. The best I can describe the pain is to say it feels like what chewing tin foil does...Approximately two months ago, that sensation began again with much more frequency. It is also now warm to the touch as well as tender. I d been controlling it with ibuprofen, but for the last 3 or 4 days, the pain is always present in some way, and at this point is also interfering with sleep. Walking has not been problematic; however the pain does increase dramatically for a brief period when I try to raise my knee, or curl my leg behind me, or lifting my leg doing actions such as turning in bed. And the absolute weirdest thing to me is that it increases dramatically in a wave that lasts a couple of seconds upon coughing, sneezing, yawning, or deep breaths. There is a small lag time between when I sneeze or cough and the wave of pain that follows in my leg - similar to when you stub your toe. The pain can be mitigated a bit if a feel the sneeze or cough coming on and I apply pressure to the area.