As far as I can discern, pelvis shots with handguns are pretty much not all that significant. Just exactly what is it you are going to break to cause the person to drop? The concept behind the pelvis shot is that the pelvis is the major skeletal support between the legs and torso and it is critical for locomotion (walking, running, etc.). About the only place you could hit with a pistol that would almost definitely produce such as result would be to hit the actual socket where the femoral head articulates or hit (and break) the femoral neck that is between the ball (which is in the socket) and the upright portion of the thigh bone. All in all, that gives you about a shot window of 1x3" for each side.
Do you think you can hit that?
If you shoot the iliac blade (the part you feel as your hip, you are not going to damage locomotion. That portion of the pelvis serves to support the organs above it and is not a locomotor support. You could hit the front and shoot the pubis bones and that might slow the person down, but what most guys don't realize is that the pubis bones actually separate from one another in women who give birth. Women can walk around after giving birth even though structurally they have a broken pelvis where the left and right pubic bones have separated. The other bone in the pelvis is the ischium and that is what you sit on and you are not likely to get really good penetration to his the ischium and even if you do, most of the energy of the round will have been spent.
What most folks don't know about pelves is how they actually function in the body in terms of biomechanics, so you get people saying that you should shoot the pelvis to break it. A handgun is a puny weapon with which to do that. Rifle rounds will create some horrendous damage and may even pass through the front and rear. Such damage may bring a person down. I have seen skeletal material (part of my job) where the pelvis showed wounds to iliac blade portion and the bullet passed through with enough velocity to create a nice puncture, but not structural failing. The lack of structural failing was due to the fact that the blade does not get a lot of locomotor stress that might cause such damage to result in a structural failing.
Something else most people do not realize is that most old folks who "fall and break their hip" don't fall and break their hip. Usually due to a condition such as osteoporosis (bone mineral loss), the hip breaks and the folks fall. What breaks will usually be the femoral neck which suffers a lot of biomechanical stress, but sometimes it is the socket that gives wayand the ball and neck blow through the socket and then you hear about hip socket replacement. Generally speaking though, the pelvis itself is not broken when somebody falls and breaks their hip or if it is broken, it is broken when the ball punches through. A lot of broken hips are actually broken legs, not hips, the femoral neck snapping.
In sum, if you are good enough to determine where to femoral neck and ball joint are to hit with your handgun on a moving target, then by golly go for it. But understand that each knee offers a much larger target area (and no, I don't suggest trying to hit a knee) and the head is a much larger target area.
People talk a lot about shooting the hip and I got that as well in a couple of handgun defense classes, but the people talking about shooting folks in the hip are not those associated with the medical community. If you do try to shoot somebody in the hip and they do go down, it probably is not because you have caused a failure of the hip anymore than a round to the gut often causes people to go down. The going down portion is often more of a reaction of the shootee then actual biomechanical failure.