Stability evaluation of anterior external fixation in patient with unstable pelvic ring fracture: a finite element analysis

The incidence of pelvic fractures among all fractures can be 4–5%, and the pelvic ring fractures (PRF) account for less than 1% in fractured patients (1). As a kind of PRF, vertical shear (VS.) pelvic fracture, defined as the complete disruption of both anterior and posterior ring, may be induced by falling from a height or a traffic accident and result an unstable situation on pelvic (2). Although the mortality cause by VS. pelvic fractures is lower than PRF, the high-energy impact transmitted axially by the pelvis will lead to instable and sever injures, making stabilization and definitive treatment a complex problem (3). Mechanical pelvic instability accompanied by possible haemodynamic status generally require urgent external fixation for future treatment or rehabilitation therapy. By this way, the vertical displacement of pelvic can be reduced to decrease the pelvic volume and control haemorrhage. It has been proved that the lack of early fracture reduction may lead to poor functional outcomes, chronic pelvic pain, deformity, and gait disturbance (4). Additionally, the external fixation can improve patients’ cardio-respiratory physiology, mobility, and nursing care through an early stabilization with an erect posture (5)