It's kind of hard to say which model is most reliable. Taken care of properly, they'll all hold true. But there are some models more prone to certain things (subframe, etc) than others, but again, the main thing is how well it was looked after by the person before you.
obÂ·tuÂ·raÂ·tor forÂ·aÂ·men. A large, oval or irregularly triangular aperture in the hip bone, the margins of which are formed by the pubis and the ischium; it is closed by the obturator membrane, except for a small opening for the passage of the obturator vessels and nerve. Synonym(s): foramen obturatum [TA] .
The obturator foramen (Latin foramen obturatum) is the large opening created by the ischium and pubis bones of the pelvis through which nerves and blood vessels pass.1  1 Structure.t is bounded by a thin, uneven margin, to which a strong membrane is attached, and presents, superiorly, a deep groove, the obturator groove, which runs from the pelvis obliquely medialward and downward.