Re: Medial exam
Well first off what did you apply for? If your spouse is sponsoring you then they cannot refuse you because of medical issues.  If you applied another way I would take a letter from your surgeon stating the prognosis of your condition.  Usually a herniated disc surgery is pretty straight-forward and would not suggest you being a strain on Canada's healthcare system.  If I were you I would just take an operative report or a letter from your surgeon to your medical exam just to be safe.  Good luck.