The scoliosis most likely doesn’t have much to do with your hand numbness. The previous history of “shoulder separation” also rarely causes nerve problems like you describe. Hand numbness without neck pain or no pain/numbness that radiates from the shoulder rarely is caused by the neck.
Most likely, you have an entrapment neuropathy. That means that the nerve or nerves are getting trapped in a “tunnel” in your shoulder, elbow or wrist. The most common ones are thoracic outlet syndrome, cubital tunnel syndrome, carpel tunnel syndrome and tunnel of Guyon syndrome.
Dr. Corenman