Lateral supra-acetabular external fixation for unstable pelvic ring fracture: A biomechanical assessments

Unstable pelvic ring fractures are usually affiliated with high energy impact that inflicted upon the hip such as in vehicle, industrial and extreme sport accidents. These injuries are always associated with high rate of mortality due to excessive bleeding and involvement of surrounding organs. Early stabilization of the pelvic using an external fixation can be used to reduce the pelvic volume and consequently control the hemorrhage. However, not a single currently available external fixations are capable of stabilizing the unstable fracture sufficient enough to allow patient mobilization and early weight bearing. Hence, this study was conducted to introduce a new method of fixation known as lateral supra-acetabular and subsequently compare with anterosuperior and anteroinferior fixation methods. The comparison was made by means of physical experimentation and computer simulation. The physical experiment employed four sawbone models while the simulation was performed using virtual pelvic model reconstructed from an MDCT image with Type C1 fracture. Both experiment and simulation were performed for standing and sitting position to evaluate the strength of fixation before failure of the model occurs. Lateral supra-acetabular fixation method was found to be significantly performed better than anterosuperior and anteroinferior fixation for both physical experiment and computer simulation.