You're doing it.
You're in a different situation.
Apparently the game distinguishes between injured dwarfs and healing dwarfs. A healing dorf won't work (or not much), just heal. And healing is random - a % chance each season, apparently. So, a terrible injury (that can heal) might heal faster than a minor one that's just consistently unlucky.
The organs on the dorfs above are "healed" as much as they can get, but that's only up to a point. So they're healed as much as they're going to get, but now crippled at some level, and passing out from the pain. Getting more tough will stop the passing out, but any and all "healing" is done. You're still waiting for yours to heal, which is diff.
Once the leg injury does heal, that dorf should(?) be 100%. Red is pretty bad ("mangled"), but he's over the hump. But red wounds can take years to heal, so it's not surprising that it's taken this long so far. With luck, the yellow will go to... whatever that color is - olive green? - next season, and then to (light!) grey soon after that, and he'll be good to go in no time.
Meanwhile, see wiki articles on attributes, sparring and cross-training for suggestions on how best to increase stats - once your dwarfs get more Tough, this will happen less often, and they'll heal faster when it does.