After Googling Iovera, this is not an "injection" in the usual sense that some material/medication/solution is actually placed into the tissues or joint. It is a denervation of a peripheral nerve utilizing cold to "freeze" the nerve, thus killing it, at least for a while. The nerve may possibly recover/regenerate from this process over time, so it may be temporary. As I understand it, the needle(s) are put through the skin at the point where the nerve to be treated, then the needle(s) tip is turned freezing cold by using Liquid Nitrogen. As for the coding, you are using what appears to be the correct one. If there is an additional or potential charge for the instrument/device used, your physicians would have to contact the manufacturer or sales representative to see how it is done. It is FDA approved for knee arthritis.
Hope this helps some.
Respectfully submitted, Alan Pechacek, M.D.