Most people don't know that in humans (and other animals), healing of bone breaks is full-on regeneration. Michael Levin has been working on regeneration of whole limbs in animals that normally cannot, which probably will lead to it working in humans.
Immature humans can regenerate fingers severed back to the first joint if not stitched up, producing a complete fingernail and (different!) fingerprint.
But this incredible miracle might be already be before your eyes. Let me explain. To me the ability to regenerate our tissue after injury has become to look more and more like a miracle. I have, over the course of my life so far, had numerous injuries to my hands and fingers, including cuts, scrapes, gouges, slices, bumps, bruises, shocks and other insults and attacks be they physical, chemical, biological or what not with the consequence of discoloration, blood flow, pain, swelling, itching or what not. And yet now, I can look at my hands and they look almost perfect. Surely the act that can return these wounds back to near perfection is as incredible as the act of bringing life about in the first place. The two seem to be outcomes of the same code, at least from where I stand.
It's not a miracle, it's just biology. If you can generate a whole, adult organism from a single fertilized cell (which them becomes a zygote, and then an embryo), why can't you also regenerate missing pieces? Obviously, for organisms that can't (like humans), either something is broken, or we lost the ability because there was an evolutionary advantage in doing so (perhaps cancer protection?).
It should be entirely possible to change the way our bodies work to re-enable this regeneration, though it would probably come at some cost. However, since we're no longer primitive cave dwellers without modern medical care, who had to constantly worry about infection killing them, that cost can probably be easily mitigated.
He has some astonishing vids up on YouTube.