What is one method to prevent dislocation of pelvic fragments?

To effectively prevent dislocation of pelvic fragments, the use of a pelvic binder is recommended. This device provides stability by applying compression around the pelvis, which helps to reduce the space between the fractured bones, thereby minimizing movement and potential further injury. Pelvic binders stabilize the pelvis and promote hemostasis in cases of pelvic fractures, making them a critical tool in managing such injuries in tactical situations.

In contrast, methods like tying the casualty's hands or knees together do not address the specific biomechanical needs of a fractured pelvis and may not provide the necessary stabilization. Keeping the lower extremities apart could lead to further displacement of the pelvic fragments, which is counterproductive in injury management. Thus, the use of a pelvic binder is the most effective and clinically supported method for preventing dislocation of pelvic fragments during treatment.