Prehospital Trauma Life Support (PHTLS) Practice Test

The anterior tibia, just below the tibial tuberosity, is the correct site for intraosseous infusion in an adult because it provides a reliable pathway for delivering medications and fluids directly into the bone marrow. This area is chosen due to the presence of a thick cortical bone and its accessibility, allowing for easy entry into the medullary cavity where vascularity ensures rapid absorption into the systemic circulation.

Utilizing this specific site minimizes the risk of injury to surrounding structures and maximizes the success rate of the procedure, which is vital in emergency settings. Other options listed, such as the anterior fibula and the posterior fibula, are either less accessible or have a greater likelihood of complications during the intraosseous infusion process. The anterior tibia above the tibial tuberosity may also have anatomical considerations that make it less ideal for this use compared to the specified area just below it. Therefore, selecting the anterior tibia just below the tibial tuberosity ensures effective and safe intraosseous access in adult patients.