I'm having a three-level fusion on Wednesday (L3-S1). I saw the surgeon last week and they told me that instead of taking some bone from my hip, they will drill in and take some of my marrow instead. I will have dowels filled with cadaver bone placed, then the rest of the spaces will be filled in with BMP and the marrow. Apparently, this mixture not only causes better bone growth for fusion, but taking the marrow is less painful than a chip of bone. Has anyone else had this done?