what would cause sudden onset of severe soreness (like being kicked in the shin, but have not), accompanied by aching pain, mild redness, slight swelling, and mildly warm to touch. Had Xrays 2 weeks ago. showed nothing. Hurts to walk also. In an area of my leg that was broken when I was 11. I am 61, and have NEVER had any problem whatsoever with this until now?