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 superior pubic ramus is a part of the pubic bone which forms a portion of the obturator foramen. The obturator foramen, along with the ilium and other fused bones, forms part of either side of the pelvis. It extends from the body to the median plane where it articulates with its fellow of the opposite side. It is conveniently described in two portions, viz., a medial flattened part and a narrow lateral prismoid portion.