How Can Prickling Sensation In The Knee Cap Be Treated?

About one month ago i bang my kneecap on the door frame, one week later the mussel at the back of my knee went numb and felt heavy , one week later I started with sharp pain down my left leg more so in the morning when getting out of bed so I took ibrufen to control it two weeks later the pain came to a head when suddenly I had pain that went off the scale followed by a very hot and very painful flow down the whole of my leg it was like somebody had poured red hot water down the inside of the leg, I then started to swet instantly and my temp went off the scale, One hour after that when all settled down the pain had gone. Now I am left with a prickly kneecap and the inside of the leg opposite the kneecap is feeling dull to the touch . My name is Steve I am 64, no history of medical issues, my weight is 13 stone and 5ft 8 height. Thanks Steve.