janines, yes you can have additional cortisone shots https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2819336
Local injections don't have the same effect because they don't usually enter the bloodstream. If you have a choice of osteoporosis medications ask about Forteo. It speeds the healing of the fracture and can reduce the pain involved. Your interventional radiologist might advise vertebroplasty. That procedure can also alleviate pain. Calcitonin can be prescribed in addition for pain from the fracture. I hope you get some relief soon.