Actually, we do.. It can be used for a multitude of injuries, and was specifically made for the elbow, shoulder or knee. Wooden, has a support bar and a wing nut to adjust. Yes, it's old. Older than old, prolly even older than Dust.
Also, there is a new splint that can be use for such injuries. Seen it in October 07 JEMS. Traction splint, dislocated knee splint, lots of uses. Expensive though.
I'd prolly have boarded them and used a 54" splint, and crossed over two 36" splints. Lots of cravats, maybe a SAM, some padding. I'd need to see it to get a better idea.