Hi ! I have gone through your question and I understand your concern . I would say that according to the symptom you prescribe numbness, tells me that a nerve damage has occurred ( a sensory nerve damage ) If it s permanent I would ask you a question first : The numbness is all the time or it comes and goes .If it s all the time it s a permanent damage . You can do a neuropsychology test to see the nerve function ( to confirm the diagnosis). You need the surgery to prevent possible further of the nerve .Meanwhile try to keep the wrist imobile . Wish you good health . If you have any other questions please feel free to ask me again.