Collar bone replacement

I have a problem with the length of my collar bones.  They seem to be short, which (I believe) has caused the shoulder blades to slip between the muscle layers in my back, causing a burning sensation and discomfort.  I was able to get things back in line by hanging from a bar with my hands.  Along with this, my shoulders appear small, giving a weak appearance.  I would be interested in the possibility of surgery to replace them with longer, straighter cadaver bones and the cost of such surgery.  I went to a doctor when I was in my 20's to see if there was something that could be done but he told me that the shape of my rib cage prevented any improvement.  I am 50 years old and a little curious about the healing time.  Any information you can offer would be appreciated.