Prosthetics
A prosthesis is a device designed to assist with the loss of a body part, commonly a limb. Ranging from simple devices like a wooden peg leg to complicated systems of harnesses and levers to replace the function of lost limbs more completely, the first prostheses date to a time before there were writers to record their existence. Artificial hands, fingers, toes, arms, and legs have been found in various forms in many historical sites, and modern metalworkers in large cities can create devices that can grasp like a real hand, even if the recipient of the prosthesis has lost their arm up to the elbow.
One of the earliest known prosthesis is the "gnoll's toes" found in Phyrian permafrost, a preserved sandal of wood and hide fitted for a gnoll's foot designed to replace two of the creature's toes. Perhaps lost to frostbite, the artificial toes would have allowed the ancient gnoll to maintain balance and at least walk if not run properly. Modern prostheses can be far more complicated, though simple devices are cheaper and still fulfill many of the basic functions of the lost limbs. Some have merely aesthetic value, to not make the missing body part conspicuous. Others incorporate weapons. Of recent, the blacksmiths of Fin-Allan have wondered at a strange commission one of their guild received, a dwarf prosthesis with a hook hand and an integrated switchblade.
Availability
The availability of prostheses depends on the complexity and materials of the product. A simple peg leg can be made out of easily available wood and cloth, without sophisticated tools or a specialist craftsman. A metal hand with articulated fingers capable of grasping is a more expensive proposition, requiring high quality steel and precision work, such an item would only be available to the rich. Many prostheses fall somewhere in the middle, providing some of the comfort and aesthetics of a high-end prosthesis but without all of the sophisticated mechanical functionality.
I really love the example of the earliest prosthesis in your world. That's really cool. :D