I have a large indentation on my right buttock. Fat placement? (photos)

I am 40 years old and I have a large indentation on my right buttock. My mother told me that I received a shot when I was very young and it caused the indentation. However, a couple of years ago, I noticed that an indentation is also forming on the left buttock. I want to fix the issue, but the doctors I have seen give me different options about whether I have a nerve or muscular issue and whether the condition can be treated by placing fat in that area. I look forward to getting this fixed.