Because you’re so lean, your best chance for a reliable, predictable, and permanent result is with custom-made cosmetic hip implants. These implants can be designed to your dimensions and desires for more of a custom fit. Because an extremely few number of Board certified plastic surgeons perform cosmetic hip implants, make sure to seek consultation with one that is a reputable and experienced specialist. Unfortunately, you may have to travel a long distance from home in order to find this particular surgeon. Regarding “fillers” if you’re referring to injections of foreign substances like silicone liquid or PMMA or hydrogels, although they can be very cheap, they are extremely dangerous and therefore should never be done. If you’re referring to true “fillers” such as Sculptra or hyaluronic acids (eg Juvederm or Restylane) and which are all temporary, then if the doctor is truly using medical grade FDA approved materials then it will be extremely expensive to have 20+ cc injected (~ $ 800+ per cc). Keep in mind that when hip implants are used, the smallest implant is 120 ccs in each side (240 ccs total for two). So that means that only 20-40 ccs of fillers is like a drop in the ocean and provides insignificant augmentation to the hip dip unless you can afford $200,000+ for 200+ ccs. Finally all high volume injectables such as these carry a high risk of serious and deadly complications from skin/tissue necrosis to pulmonary embolism. Hence the FDA has issued multiple warnings to the public on this very same severe risk.