I just Googled images of the "femoral bone" and this is nothing more than the FEMUR. the Femur is the bone that inserts into the pelvic socket. It is the upper part of the leg and in NO WAY, SHAPE OR FORM does it come in contact with any pressure that a toy could create. A toy *could* stretch your pelvic opening by a VERY VERY small margin as it is mostly bone with the only stretchable parts being the three ligaments called:
-Sacrospinous
- Sacrotuberous
- Superior Pubic
Ligaments
can stretch but not by much so if your pelvic opening only allows you to take a maximum of 3.75 inches in width, you
may be able to stretch to 4 inches wide but I would nt bet that you can go further than that.
See here
http://www.tipna.org/info/anatomical_images/index.htm