There are 4 types of pelvic ring fracture that can occur depending on the MOI and surrounding factors/situation:
Lateral Compression (LC) Fractures – LC fractures can be caused by internal rotation of the pelvic ring because of direct force applied to the iliac crest, or indirect force via the femoral head. Force from this internal rotation can cause the pelvis to fracture at a single or multiple points along one side of the pelvis depending on the MOI involved. Typical causes of injury can include side impact RTC’s and falls from height.
Vertical Shear (VS) Fractures – A VS fracture is where one side of the pelvis structure ‘shears’ from the main structure and is displaced vertically. This injury can occur through significant trauma, such as a fall from height and the patient landing on one leg first. This form of fracture will likely cause massive disruption to the pelvic cavity damaging blood vessels and soft tissues, causing significant internal blood loss.
Anterior-Posterior Compression (APC) Fractures – A APC fracture commonly occurs through crushing type injuries or high energy transfer, for example a pedestrian that has been impacted by a car. This type of injury can cause fractures to form at multiple points in the pelvic ring structure. Where enough force has fractured and sheared both sides of the pelvis, the pelvis bones can move apart and rotate. This gives the ‘open book’ pelvic fracture name where the pelvis has sprung open due to the fractures.
Combined Mechanical (CM) Fractures – CM fractures consist of a combination of multiple types of fracture as discussed above. This would mean that multiple forces have been exerted on the pelvis causing it to fracture and rotate/shift in a variation of ways. These injuries could occur in a rollover RTC for example.
Further defining these fractures for the hospital environment is the Young and Burgess Classifications. These classifications take each of the different types of fracture and put them into a type from 1 to 3 and identify if they are stable or unstable depending on the fracture features.
Further injury and complications can occur through tissue and organ injury. Urethral and vaginal injuries can occur from bony fragments or through indirect forces from the pelvic structure. Further female reproductive organs can be damaged through either direct or indirect forces. Bladder rupture occurs in up to 10% of pelvic fractures.