Intensive Care For Turtles

We don't see box turtles too often anymore, but when we do we generally scoop them up, take their pictures, then let them go in the garden. This morning while I was out with the dog--who happens to spend a good deal of time indoors and never goes outside without a human attached to her leash--I found a turtle in the driveway. The turtle has a big hole in the top of its shell and seems to be partially paralyzed; it's unable to extend its hind legs and locomotes by using its front ones to drag itself across the ground. I won't be posting pictures of the injuries, which are rather.. erm.. gruesome. I feel awful about it, though, and don't really know what to do other than put it in the garden and hope it either heals on its own or doesn't linger in pain.
I saw an article about a man who found a turtle in a similar situation, and his solution was to epoxy wheels to her shell so she could still move unimpeded. I'm not sure that's really... I'm not sure what to think, honestly.
I hope the neighbor's dog doesn't make a habit of this.

Addendum: On closer inspection, the hole doesn't seem to be life threatening. The bone of the carapace is showing through, but the wound to the flesh underneath, while obviously painful, might not be as serious as I thought. The problem, now, though, is that the ants have found it and are interested in making turtle soup. I'm seriously bothered by this.
Okay. Brought the turtle in the house, got rid of the ants, put some Neosporin on the wound, and have put it in a box with some newspaper, greenery, and some carrot shreds. Next step is to find out what box turtles eat and provide suitable sustenance... assuming I can find some earth worms or whatever.