Speaking from personal experience, God can and does heal people. Alfweich, limbs being restored from amputation was common at the Azusua St. revival. I know a girl who much like myself had a condition which needed the use of glasses to correct. I was there when the healing took place.
Really? Were these people ever documented? Were they seen by a doctor? Because the growing of bone, cartilage, muscle, veins and skin from a 'stump' into a brand new leg would be world news. Seriously; it would make the first face transplant seem like childs play.
I'd imagine God made sure to include some convenient reason that this couldn't be documented. 
If there weren't documentation, then how did I find out? I've been to the historical site of that revival. There are plenty of books on the miracles that occurred there.
