There is a severe lack of physicians who specialize in pediatric trauma care. 

In order to be a Level 1 Pediatric Trauma Center a hospital must have pediatric-trained surgeons, neurosurgeons, orthopedic surgeons, emergency medicine physicians, anesthesiologists, critical care physicians and nursing staff - all available at a moment's notice 24/7. 

There is also very little opportunity for training new physicians and medical personnel specifically in pediatric trauma care.  The lack of highly specialized, highly skilled caregivers is a key reason for the high mortality rate from injuries in children.