Good in both cases. My dad was not young when he had the surgery and had other complications (a fused wrist due to arthritis), but the surgery stopped the pain and prevented further atrophy of the muscle in his hand.
My brother is only a few years older than me and had the surgery a few years ago. He had tingling and pain in his hand and the surgery fixed that and he returned to normal activity.
I'd be nervous too. Surgery of any kind is a little unnerving. Good luck and let me know how you make out with the test!