Though uncommon broken bones do show up in combat, and a generally related to blast injuries. As always with TCCC your first duty is to put rounds down range, and make sure the combat zone is clear of immediate threats. Once that is done you may be able to extract the wounded or have to fall back to a dependable position till support arrives. This is the point in combat where you will splint your patient so you can move him to safety. This article details how to splint a leg fracture, and the video in the link below displays the splinting of a are fracture.

Added in Doc Knowlege