Most of the time, when someone calls a horse "club footed" it just means there is a front foot that's more upright than the other. It's usually nothing to worry about with proper hoof care, and is really more of a cosmetic issue than anything.
There are extreme cases, and true club foot is the result of contracted tendons and is most noted when the horse is a foal.
As an adult horse (or adolescent) if the upright foot persists, esp in spite of attempts by the farrier to "fix" it, then it's likely something the body has decided it needs to do to cope with an issue higher up, such as the shoulder. Leave it alone, as it's a coping mechanism and the horse will be fine.
Some so called club feet are created by years of crappy shoeing, and it's really more of a case of contracted heels.
But, in general, it shouldn' t affect his usablitlity. The horse will adjust accordingly and be quite sound in most cases. I find I start out with some "club footed" horses and pull the shoes, change the trim and over time they aren't clubby any more.