The equivalent is removing the outer parts of your fingers. Imagine if you were confined to 4 legs and your fingers/toes were removed. That's what it does. It's utter animal abuse. 'Just give it pain killers' isn't enough. Their feet and legs will start to atrophy because it can't walk or use it's muscles properly, the pain can potentially be so overwhelming that pain killers won't take it all, it can cause further damage and infenction that can lead to death, etc.
Treat your cat properly and teach it not to claw instead of mutilating it for life.