So the "why would I ask such a dumbass question" answer is that I have a pretty significant retroversion in both hips, and square-headed femurs, and FAI. All this contributes to the fact that if I do full squats or ANY movement requiring even minor internal rotation on a regular basis and/or full hip flexion with any load (that is basically every bilateral squat type motion: front squat, back squat, leg press, gets worse with significant hip internal rotation and flexion, i.e., power-lifting squats are absolutely awful), I will end up needing hip replacements.
I've already had both hips scoped and any time I do a workout including squats, I can feel it in my right hip for days afterwards: a painful achy feeling that I've been told is inflammation related to arthritis and that will get worse with more work. Even if I push through the pain, just getting parallel is really hard.
Lately I've been doing 5/3/1 Boring But Big but subbing DB walking lunges for squats. The heavy work feels lacking on sets of 3 or less but the sets of 10 are really brutal and give a crazy pump, and even after all that volume my hips are fine.
Things that don't hurt: deadlifts, trap bar deadlifts, lunges, hip thrusts, GHR, exercise bike, non-sprinting sled work.
Things that do hurt: squats, front squats, leg press, sprinting, seated adductor.
So if you were in my shoes, what would you be doing for legs?