Duplicative Re-Association1 was a theoretical procedure conceived during the Cold-War Era. It involves the cloning, or duplication, of an existing body part in order to replace one that was found missing.

For example, a soldier loses an arm to an infected gunshot wound. Rather than this soldier being disabled for the rest of his life, the arm he didn’t lose is duplicated and reattached as a replacement.
It was the goal that countless scientists were attempting to reach. The proper results were only achieved by a select few laboratories including Dr. Havid Machenry, Dr. Tungstrum Gertales, and Dr. Glen Rerdum.2
Because of the difficulty and the expense of the procedure, in addition to the low success rate, it was never used as a practical method. The few subjects who survived the procedure also had a problem. The same arm was used on both sides, so they were both lefts, or both rights. Preventing, even the successful attempts, from ever fully renewing the subjects body.
2: All names listed are fabricated, any relation to real people is purely coincidental.