Spirit Bodies

As the glorious in heaven differ one from the other so will the flesh from the resurrected beings living within these glories. Such as the difference between our mortal flesh and the flesh of the fowls of the air and the beasts of the field, insects and fish differ, one from another. Resurrected beings with immortal flesh will be intrinsically tied to our spiritual flesh. The matter that our spirits are made of is actual physical material. Our resurrected and immortal bodies will be permanently affixed to our spirit body. D&C 131 7-8

I imagine that when injury or loss of limb occurs that it will heal and regrow a new in it's perfect form based on the physical traits of the spirit body after which it is modeled. Perhaps even re-growing from that actual spirit matter.

As we know from the plan of salvation, there are three possible glories to which we can attain. We are guaranteed at least, the least of these because Christ made it written in the law of the universe when he retook his mortal frame making it an eternal and unchanging law, like gravity.