I always put splint boots on my horse prone to them. We used a treatment of DMSO mixed into FuraZone cream, it's good for breaking down the splint to reduce the permanent misshapenness. We just applied the Fura/DMSO combo and wrapped until things solidified and diminished, with the horse showing no sensitivity or lameness.

Splints develop in a strained or weaker part of the leg. Their purpose is to reinforce the cannon. Once they develop they stay there forever. The only thing you can do is stable bandages while they are developing and they sometimes prevent them from getting much larger. With horses that are prone to splints, you could also bandage them more often after work, and this may help in prevention.