Neither of my two cats are declawed. They're indor cats and have been their entires lives (they'll be four this July) but I'm not a fan of declawing. I do, however, trim their claws every couple of weeks, mostly just so they don't accidently scratch me when playing with them.
My male, Apollo, is a polydactyl kitty - he's got extra "thumbs" on each of his front paws, which is partially why I trim their claws. Because he has a toe on each that is kind of tucked in, he can't keep those ones short them by himself when using the scratching posts. You'd think these would be the problem ones, but they're not, they're actually pretty easy for me to maintain for him. I've been doing their claws since they were kittens, so they don't really mind it.
Here's the problem though - on Apollo's right paw, one of his middle claws is, shall we say, "deformed." It grows in a lot thicker and it is NEVER sharp. While he doesn't mind me trimming the rest of his claws, he doesn't really like it when I try to trim that one. However, if I DON'T trim it, it will start growing into the pad of his toe because it is so thick. It's hard to describe, so here are a couple of pictures:
You can see in this one ^^ that his claw looks strange. Instead of one narrow, curving claw that should only be a millimetre or two thick, this one is a little less than a centimetre or so.
You can see here ^^ the difference in thickness from this claw compared to the others (I just trimmed them though, so they're short, but they are a "normal" size.)
As long as I regularly trim it, it doesn't seem to be a huge problem, but if I forget to do it for a few weeks, it will quickly start growing into the pad of his toe. A couple of months ago, it was long enough to break through a couple of layers of skin. With the help of my sister to hold him down, I cut it (very carefully so it wouldn't hurt too much) and it healed up right away, thankfully.
Have any of you ever seen anything like this before?? Like I said, I'm not a fan of declawing, but I wouldn't be opposed to having the one claw removed if it would prevent it from causing problems later, but it would seem kind of silly to bring him to the vet just to have one claw removed. The cost isn't an issue - if it will help him, I'm willing to pay for it, I just don't know if it's actually worth doing or if I should just simply keep monitoring it and trimming it myself.