There are some exciting emerging technologies in prosthetic limb technology these days. You'd be amazed just how close scientists are to restoring nearly complete functioning in every way to those who have lost a limb.
Tactile Sensation Restoration in Artificial Limbs
It's easy to forget your limbs aren't only functional in a mechanical sense. It's true that being able to move and pick things up is a critical part of what you want from a limb, but your body also gives you the sensation of touch as well. Some people may miss being able to feel their environment even when they have a largely mechanically functioning prosthetic.
However, new technology is now making it possible to get some feeling sensation back with new artificial limbs, like those from Cotton Orthotic and Prosthetic. The technology takes physical interactions and translates these into electronic impulses. The user then receives these impulses on the nerve endings at the end of their body in order to feel them just like they could before.
This does require surgery to pull nerve endings on remaining limb tissue to the surface so they can be connected to the limb, but many people who go through the process describe it as a "rebirth." This technology is still expensive to the tune of $11,000 or more, but there's every indication that it will come down in price in the near future.
This technology is at an even earlier stage than the tactile legs which have human prototypes already, but the promise of lab-grown limbs are possibly even more exciting. Researchers have grown rat limbs in test tubes just by using progenitor cells.
Essentially, this is done by creating a matrix in the shape of the desired limb. The matrix is also referred to as a "scaffolding," and it's created by taking the limb from a dead donor and stripping it of cells. Then, various cells such as progenitor muscle cells are injected into the limb to allow them to grow.
In the case of the lab-grown rat limb, it took only two weeks to graft grown skin onto the limb. The first one didn't have bones or cartilage, but it did function when it was electrically stimulated with as much as 80% of its normal power. The researchers were even able to graft it on to rats under anesthesia.
It may be some years before this is adapted for human use, but there can be no doubt that the technology is now on its way. The goal with the tech is to eventually allow those ho have lost limbs to grow new ones that are 100% their own in labs which can then be attached to restore their functioning.