I have had a PA for about 18 years.
Never been a problem... but there are some things to consider.
The TYPE of ring is critical, depending on what you are gonna do with the dick its attached to.
Small gauge rings, curved barbells and the like are more dangerous than large gauges, up to a certain point. ( really huge can be a big problem)
The kind with threaded Ball closures always run the risk of coming unthreaded during active intercourse.
More often than not, perforations and such come from the exposure of the threaded end on the ball... or the sharply shaped end of the ring once the ball comes off.
The safest kind for active penetration are the kind with a fixed ball closure, that have to be bent open to put on and have to be SQUEEZED closed with a set of bullring pliers. These simply can not come undid during sex.
However, requiring hardware to remove, they are harder to clean...
And that is the other big issue.... you need to keep a PA scrupulously clean... Stuff gets into the hole in the ball, or the threads... and can breed bacteria...
Also- size is an issue... measure the distance from the PA hole to the urethral opening... you want a Ring with an Inside diameter just a little bit larger than this distance. THis will ensure that the ring can be pressed up against the underside of the head... with the ring arcing high thru the urethra... for a very smooth, tight fitting contour...