Good friend of my dad's had to wear a leg brace most of his life. (from a little "incident" during WWII in New Guina which involved some alcohol too apparently..)  He told his brace to Whites,,, and the Company actually fitted the brace right into the sole of the boot. The boot was actually cut and molded so the brace became part of the boot.  Looked kinda funny when he'd take his boots off and have a 2 foot brace that almost reached his knee sticking up from the boot. But worked great for him and all you could see was the steel brace coming up the sides of the boot.

You might give them a call and see what they could do ??