Hip Augmentation with HA filler over iliac crest - what complications could arise from this? (photos)

As you can see there is not much feminine flare of my iliac crest and very harsh transition from my obliques (My muscles are strong even though I do not exercise due to extreme post exertional malaise). Is it dangerous to use HA filler in this area? I know it can safely be used for "hip dips" but can it be used over the iliac crest and possibly under that oblique for a nice smooth and feminine shape. Safety is my number one concern so please elucidate what complications could arise from this