| Background:Acetabular fracture is one of the common complex fractures usually caused by high-energy injury. With the aging population, the incidence of acetabular fractures caused by low-energy injury gradually increased. Traditional conservative therapy has been replaced by open reduction and internal fixation. The most commonly used methods of fixation within clinically include reconstruction plate, locking plate and minimally invasive percutaneous lag screw fixation, however, there are some issues, such as pre-contouring the plate, screws penetration and a higher incidence of complications. Preliminary study, we have designed a novel anatomy orientation locking plate which can place screws, anterior column lag screw and magic screw safely. However the biomechanical experiment about this novel anatomy locking plate is inadequate.Objective:Compare the biomechanics stability of nine different types of internal fixations for t-shapede acetabular fracture by finite element analysis and verify the effective fixation method by novel anatomy locking plate, providing a strong theoretical basis for clinical popularization.Methods:Establish acetabular three-dimensional model by using the CT data of the fourth-generation synthetic sawbones. Build the finite element model of t-shaped acetabular fracture and nine different fixation models, including novel anatomy locking plate, reconstruction plate, locking plate and so on, by mimics and abaqus software. Compare the anterior, posterior and inferior displacements of nine finite element models after applying the same load.Results:The anterior displacement, posterior displacement and inferior displacement fixed by novel anatomy locking plate were 0.2805mm,0.3177mm and 0.6842mm, respectively. The smallest and largest anterior displacements of all models were fixed by anterior 7.3mm lag screws plus with posterior locking plate and anterior 5.5mm lag screws plus with posterior reconstruction plate, respectively. The smallest and largest posterior displacements of all models were fixed by novel anatomy locking plate and anterior 5.5mm lag screws plus with posterior reconstruction plate, respectively. The smallest and largest inferior displacements of all models were fixed by novel anatomy locking plate and anterior 5.5mm lag screws plus with posterior reconstruction plate, respectively. Fixations by the same reconstruction or locking plate, the displacement decreases as the diameter of the screw increase. With the same diameter screws, the whole displacements of models fixed by locking plate are smaller than fixed by reconstruction plate.Conclusion:(1) Novel anatomy locking plate provides sufficient stabilization for t-shaped acetabular fracture and would well restore the inverted Y-shaped construction of acetabulum. (2) The fixation strength increases with the diameter of the screw increase when fixing the anterior column by percutaneous screw. (3) The locking plate is stronger than reconstruction plate when fixing the acetabular fracture. |
