Indeed the risk of fat embolism when transferring fat to the hip area is lower than fat transfer to the buttock, notably when the fat is injected into the buttock muscle. In general, cosmetic hip implants are the most reliable, predictable, and permanent option for filling in the hip dips and creating more of that feminine hourglass figure, whether slim or not. Typically hip implants are best custom designed and created for each individual patient’s anatomy. Because an extremely few number of board-certified plastic surgeons perform this procedure, make sure you seek consultation with a reputable and experienced cosmetic hip implant specialist. You may have to travel a long distance from home to find this particular surgeon. On the other hand, fat transfer to the hip area tends to survive quite poorly in most patients and thus produces only short term results (often less than 10-12 months). Glad to help.