I Have Begun To Have Pain Below My Left Knee

I have begun to have pain below my left knee near the shin bone. It feels like a burning sensation when my leg rubs against a firm surface (like when climbing into bed) but there is nothing on the surface of the skin. Three years ago I had a laminectomy at L4/L5 but the pain was always on the right side. Any ideas as to the cause of the burning sensation.