I have broken my wrists repeatedly during childhood and teenage years from various accidents such as falling off of buildings and bad skateboard accidents.. my doctors told me that the broken bones usually grow back stronger than they were to begin with before you broke them. In that case, your wrists may be better suited for parkour now that you have broken and healed them, so stop looking for excuses and go train. ;p
I'm not a doctor but I do know that it's usually which part you break. Breaking a long major and individual bone will grow back stronger and in most cases be stronger, like breaking an ulna or a tibia/fibula.
However when you get into places such as the wrist which has so many bones that make up one acting joint, location of the break is a very big deal. My sister recently broke her wrist and because of the location and specific bone.cartilage that was broken she will never again regain the same strength in her wrist.
Just proceed with caution and if you EVER feel your wrists (or any other body part for that matter) start signaling pain, stop and let it heal.