At this time, medical scientists and bio-engineers are working on the solutions you bring to mind. As long ago as the 1940s, French scientists were able to induce a rat with a severed foot to regrow at least one toe! Today, we are looking at wildlife that can regrow some of their extremities and hope to be able to use the knowledge gained to help humans regrow new fingers and toes, even hands and feet.
For now, hand and foot transplants are working increasingly well, and the science of prosthetic devices is more practical each month. Artificial skin with actual electronic nerve endings will soon allow artificial limbs and even robot skin to feel sensations. We live in awesome times!