The Fisher King was healed by Sir Percival and he was able to stand and move again, but the curse placed upon him by his former wife who gave him the wound still caused him to be unable to conceive an heir. The line of the Keepers of the Grail was broken. At the end of his life he was laid to rest in the Isle of Avalon so that his curse, which made the lands of his kingdom (and himself) barren would no longer affect the land in the human realm; the fairies have other means of working around his curse. There aren't many details about what that means in the books. If Gareth asks the Archivist, he'll say that it's just best not to venture much farther into the forest and not seem very comfortable talking about it.

Both the Grail and the Bleeding Lance's location (The Bleeding Lance, in this context, is the weapon used to create the Fisher King's unhealing wound) are not known, but it is said they were brought to Avalon long ago to remove them from human lands.