Hi there! I'm a radiology tech and totally understand your concern. Ovaries, testes and your thyroid are the most radiation sensitive parts of your body. The dose effect of radiation is cumulative, so all the radiation you've had in your life adds up in its total effect.
Although you can't get away from having x-rays for a total hip replacement, obviously, you can ask your orthopedic Dr. to order them a little differently. If it is just your hips he is interested in for most of the follow up films, he can order just your hips xrayed rather than your entire pelvis with hips. This way, the technologist can shield your ovaries with a small lead shield. It won't block all of the scatter radiation, but it will help. Make sure he communicates this to the radiology tech, or else they won't want to shield you because the shield will obstruct the entire pelvic area.
Overall, I wouldn't worry about the radiation too much, unless you're pregnant of course. From what I remember in my radiation physics courses, the dose required to have a measurable effect on the ovaries is pretty high- like radioactive fallout high!
But still, it's great you're aware. Don't lose any sleep over it. Just make absolutely sure you're not pregnant , as the most damage from radiation occurs very early in development- before you know you're pregnant usually.
Good luck! Becky