There is a condition called deafferentation pain. Simply put, we can use the model of the person who loses a portion of their extremity. Phantom pain is a type of deafferentation pain. The nerves transmit painful messages to the brain. It is problematic and results in revision of stumps, etc. in order to change the stump's pressure points.
Paraplegics often have pain below the sternum.
Spinal cord stimulation could be used in this situation. It can be used above T-12. It can allow electrical impulses to bombard the spinal cord. I would suggest that you afford yourself of the opportunity to contact a pain center that specializes in these procedures. Because of this, he has to wear a back brace.