Usually numbness in the hand can be related to inflammation of some sort. Not inflammation of the nerve but the surrounding anatomy.

For example, carpal tunnel syndrome is essentially inflammation of the tendon sheath that is directly above your median nerve which results in some swelling and compression of the nerve resulting in numbness. When people have surgery to help this, the surgeon essentially opens that part of the wrist and cuts that sheath in order to provide release.

In this case, If there were extra branches of nerve that shouldn’t be there it might have made the wrist Anatomy a little crowded resulting in some compression of all three nerves supplying sensation to your hand (median, radial, and ulnar). Not saying that is what happened but your wrist has a lot of structures in a small space so I could see that being plausible.