@Goldenseal It looks like that's how they will do it, but since it was for the purpose of stopping the poison from spreading it would normally cause even more damage to that limb once it is completely cut off. It's not like I really care if they don't follow the novel anyway, but I'm sure there was a reason for them to change it, otherwise they wouldn't do it.
Maybe they changed it because the manhwa is geared towards a younger crowd. Amputating is surprisingly less graphic than what happened in the novel.