I have tailbone pain do to large amount of weight loss. Can fat be injected into the buttocks to help with this?

It is possible to have fat transferred from one area of your body to another, such as your buttocks. Consult with a board-certified plastic surgeon for a personal evaluation and a discussion of your best options.

One option for chronic tail bone pain (coccydynia), which presumably is do to a loss of soft tissue buffer between it and the skin, is to add fat. Fat injections are one method to do it but a more effective fat grafting option would be a dermal-fat graft. This is a more reliable method to have the fat survive. With your weight loss you have plenty of harvest site options.