Broken arms don't seem to do anything

Playing with experimental. Disabled limbs do not prevent me from wielding anything; one disabled limb appears to reduce my dexterity but the second does nothing and actually restores my dexterity to max.

Broken arms aren’t fully implemented.
At the moment the only effects are lowered move speed for broken legs and inability to wield 2h items with broken arms.

Well, what you can wield with one hand is determined by weight, and is perhaps determined by your current strength (at the time of wielding).

If you have a zweilhander equipped before you bust your hand up you can continue to do so just fine after. albeit slowly.

If you try to wield a shotgun after your hand busts it will deny you.

And if you ever break both hands but live Id suggest never unequipping your current weapon until it fixes.