Its a curvature deformity and probably why her tailbone hurts! It was seen in the Hottentot Venus freak show lady hundreds of years ago. It’s worth a google.I've always assumed it's because she spends 95% of her life sitting down.
It seems more pointy these days though, and we know she's not moving around more.
Upper arm and elbow. it's from 17:00 in this video and rotated left:What is it then?