Biomechanical Analysis Of The Distal Tibia Posterior Locked Plate

Objective: Posterior Pilon column fracture is a kind of intra-articular fractures caused by the vertical force,if not effective reduction and fixation,there will be a poor prognosis and a high risk of degenerative changes.At present,for the treatment of such fractures is open reduction and internal fixation,but the choice of implant no uniform understanding of the more commonly used implant for the lag screws,buttress plate.Most plate are 1/3 of the tubular steel support plate and there are many disadvantages: intranperation needs shaping and influences periosteal blood supply,and can not be multi-directional fracture fixation block.We based on posterior distal tibial anatomical characteristics of independent research and device distal tibial posterior Pilon Locking Plate for the treatment of posterior column Pilon fracture.The purpose of this study is to explore two different fixation methods on biomechanical properties after Pilon fracture column,select the appropriate implant to provide a reference for clinicalMethods:We collected the First Affiliated Hospital of Dalian Medical University orthopedic trauma patients from 2010.10 to 2015.10 admitted Pilon posterior column fracture patients,according to a retrospective analysis of preoperative lateral ankle X-ray,CT scan and reconstruction identify column fracture block features to find its characteristics.20 people made the right of the tibia were randomly divided into groups A and group B.We based on its characteristics and clinical classification to produce Pilon posterior column fracture model,group A with 5 holes distal tibial posterior locking plate fixation,group B uses two 3.5mm cortical screws from back to front bicortical fixation,after samples produced were placed Instron Electro Puls E3000 universal electronic static and dynamic materials testing systems,preload to 0.05 mm / s vertical speed loaded into internal fixation failure(fracture fragment appears 2mm step),recording appears 0.5mm,1.0mm,1.5mm,2.0mm axial load step when loading.Results: After loading the two groups did not occur specimens screws bent or broken,distal tibial bone compression fixation is the cause of the failure.Appears 0.5mm,1.0mm,1.5mm,2.0mm steps when,distal tibial posterior locking plate group axial load is greater than screw group,with the increase in the posterior column fracture fragment displacement,axial direction between the two groups the difference between the loading force is also growing,and the comparison was statistically significant(P <0.05)between groups.Conclusion: The biomechanical test showed that after treatment Pilon column fractures,distal tibial posterior locking plate fixation is better than screw group.