Due to limited time, this article was written without consulting anyone who has experienced losing a limb and having it replaced. Because of this, I have tried to focus on just the ways limbs CAN be replaced rather than the why, who, or when.
Regardless of the Realm grevious injuries are a commonplace. From work accident to war, Sophonts have lost limbs and had them replaced through mundane or magical means. These methods can vary from impaling metal bars to function as legs to regrowing entire arms through dedicated healing magic.
City of Marble is willing to replace the limbs with enchanted marble. But this is only available to those who have fought in the name of the White Flame Pantheon.
Seawatch has a variety of gadgets, some functional and others not so much, you can attach to your body. Each one costs at least a small fortune. The fortune being larger the more you actually want to be able to use the new limbs.
In Ravenpeak, besides magic to simply regrow the limbs, you have a variety of artificied limbs you can have. Or, if you are willing to pay an unknown price, a few hemomancers could regrow your entire arm, just better.
The Elves of Wyldkeep and Verdant are also capable of restoration magic but some druids prefer to grow new limbs out of the natural flora around them. Bark making a better replacement than flesh.
In Shardholm where they enjoy replacing limbs with other, not as useful objects. Such as pegs or hooks.
Shatterhold is where they might just attach an arm back to you and necromance it back to life. Maybe your arm. Maybe not.