young–burgess classification young–burgess classification the young–burgess classification is a system of categorizing pelvic fractures based on fracture pattern, allowing judgment on the stability of the pelvic ring. classification type anterior posterior compression lateral compression vertical shear i apc i - symphysis widening < 2.5 cm lc i - compression fractures of the pubic rami (superior pubic ramus and inferior pubic ramus) and ipsilateral anterior sacral ala vs - posterior and superior directed force ii apc ii - symphysis widening > 2.5 cm. anterior si joint diastasis. disruption of sacrospinous and sacrotuberous ligaments lc ii - rami fracture and ipsilateral posterior ilium fracture dislocation iii apc iii - si dislocation with associated vascular injury lc iii - ipsilateral lateral compression and contralateral apc