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] .
There are two obturator muscles: obturator externus and obturator internus. The obturator muscles are attached to the obturator membrane which covers the obturator foramen of the pelvic bone. The obturator externus as the name suggests is located on the external surface of the obturator membrane and belongs to the medial compartment of thigh muscles. The obturator internus is located internally on the pelvis and belongs to the deep group of gluteal muscles.