The Biomechanical Research Of The Novel Anatomic Locking Plate In Acetabular Fracture

1Research Background: Acetabular fracture is one of the most dramatic traumas,With the development of society, its incidence is increasing year by year. Because thefracture often involves the articular surface, posterior wall fracture often comes withposterior dislocation of femoral head, thus it requires early anatomical reduction ofarticular surface to provide sufficient fixation to get enough early exercise to avoid hipjoint instability and traumatic arthritis.It is usually used common re-construct plate tofixation acetabulum fracture in clinical, It has been postulated that increased jointcontact stresses from incongruity or altered load distributions within the hip jointeventually leads to degenerative posttraumatic arthritis through repetitive cartilagedamage. Professor Tang Peifu with his team has designed a new type of anatomiclocking plate of acetabular. It used three-dimensional reconstruction to obtain the dataof the posterior column with strict anatomy attach, it can not only avoid thepreoperative bending shaping to ensure the steel strength but also keep the direction ofthe screw away from the acetabulum. It can not only reduce surgical risk but also gaingreater control of bone, it helps to contribute a more stable and secure fixation withouttemporary shaping. This experiment will use bio-mechanical methods to validate thenew locking plate biomechanics and compare it with the common re-constructionplate.2Purpose: To research the strength and biomechanical properties between thenew locking plate and the common re-construction plate in the fixation of the posteriorwall fracture and try to find a method reducing post-traumatic arthritis to provide amore simple and effective fixation in clinical3Method: Using fresh cadaveric pelvic specimens to simulate the acetabularposterior wall fractures. After the new locking plate and the common re-constructionplate fix them respectively, biomechanical tests are conducted in a single leg stance to measure the displacement between the fracture surface and the stress distribution in theacetabular.4Results:①With the stress loaded to800N on the fresh frozen pelvis, there wasno clinical failure by the two fixation methods and no statistical differences;②Withthe stress loaded to1000N on the fresh frozen pelvis, the stability of the posterior wallfracture fixation using the new locking plates was superior to the commonre-construction plate(P<0.05)③With the limit loading on the fresh frozen pelvis, theloads are all up to2700N, there was a clinical failure in the common re-constructionplates with the displacement of the fracture fragment larger than2mm, and the screwnails tend to have retired, while the new locking plates fixed strongly with fracturefragment non-displacement and no screw nail retire.5Conclusion: With the stress loaded to800N, there was no differences betweenthe two fixation methods. But the new locking plate is better in the stabilization of theposterior wall fracture than the common re-construction plate when the stress loaded to1000N,(P<0.05).