This character I have lost his leg from the knee down, and so he got a wooden peg leg. Note, this is medieval times. Now, from this point on I've explained in the book that he walks with a limp. Would that be correct? I think it is...I just need to make sure. Another question, he walks with a cane. Would a man that lost his leg from the knee down use a cane as well? (He is 74 years old though, so that could be a reasoning as well) The thing is I've made that cane into a very character specific item, and removing it would not be favorable to me right now.
Personally, I see no problem with the cane issue, and given that it is simply a wooden peg leg, not anything to today's prosthetic legs, I can understand that the character would walk with a "limp", like you said. I'd just say go for it Good luck with your work.
Mediaeval times, he'd have had a crutch (think Long John Silver). Yes, walking with a limp would be what he'd do. Has he lost his leg below the knee, or above the knee? Absence of the knee joint would make a major difference to his agility - see Oscar Pistorius (before that unpleasantness in the bathroom) for an example of how well you can get by if you've still got your knees.
I have a character in a similar position. Mine hasn't lost his leg; he's had a major injury to his knee that never healed, and he cannot walk without a crutch. By that, I mean a crutch he has to lean his armpit on - without it, he falls over. I don't say he walks with a limp, I say he hobbles on a crutch or something equivalent. I think a crutch is more appropriate than a cane for your character. I think of canes as being for mild injuries, and your guy obviously has a major one.