A Finite Element Analysis And Learning Curve For The Treatment Of Various Types Of Calcaneal Fractures In Sanders Ⅱ And Ⅲ By Using A New Type Of Calcaneal Minimally Invasive Anatomical Locking Plate

Part Ⅰ A finite element analysis for the treatment of various types of calcaneal fractures in Sanders Ⅱ and Ⅲ by using a new type of calcaneal minimally invasive anatomical locking plateObjective:To establish a finite element model for the treatment of various types of calcaneal fractures in Sanders Ⅱ and Ⅲ by using a new type of calcaneal minimally invasive anatomical locking plate.Through the finite element analysis technology to explore the effectiveness of the application of new bone plate in the treatment of various types of calcaneal fractures.Methods:The image data were obtained by CT scanning of the foot and ankle of a healthy adult male.Then 3D slicer and Geomagic studio 12 software were used to reconstruct the normal calcaneus 3D model,and UG12.0 software was used to draw the new calcaneal anatomical plate and various types of calcaneus fracture model.Third,the data were imported into Hypermesh,which is the finite element preprocessing software,to establish a new finite element model of each subtype of calcaneus fracture treated by the new plate.And next,through Abaqus2016,which is the finite metadata analysis software,load and boundary constraints were applied to each model,and calculation was performed at the same time.At last,the stress and displacement of each type of calcaneus fracture finite element model were compared and analyzed in the Hyperview,which is the post-processing software.Results:The new type of plate was used to treat calcaneal fracture with high simulation degree,and the maximum stress of the whole structure of each model was concentrated on internal fixation.For the types of calcaneal fractures involving the distal process,such as Sanders Ⅱ C,Sanders Ⅲ AC and Ⅲ BC,the maximum stress was more concentrated on the screws fixing the distal process,and the displacement of the fracture end was larger.Conclusion:Under the condition of high-strength load,the displacement of fracture end of each finite element model was less than 1mm,and there was no failure of new steel plate and screw.From the results of the finite element analysis,the application of the new type of plate in the treatment of various types of calcaneal fractures is effective,which provides a basis for its clinical application.Part Ⅱ The learning curve of the treatment of calcaneal fracture through tarsal sinus approach combined with a new type of minimally invasive anatomical locking plate of calcaneusObjective:To evaluate the learning curve of the treatment of calcaneal fracture through tarsal sinus approach combined with a new type of minimally invasive anatomical locking plate of calcaneus.Methods:A retrospective analysis of 113 Sanders type Ⅱ and Ⅲ calcaneal fractures(120 feet)admitted from August 2017 to August 2018 in our hospital.These cases were divided into A,B,C,D groups according to the time sequence,and each group had 30 cases.All of them were treated with the tarsal sinus approach combined with the new calcaneus minimally invasive anatomical locking plate.The anatomic parameters such as Bohler angle,Gissane angle,calcaneus length and calcaneus height were compared before and after operation in each group.The operation time,VAS score and AOFAS score were compared between groups.Results:There was significant difference in operation time between the four groups(P<0.01).Compared with group A,the operation time of group B,C and D was shortened,the difference was statistically significant(P<0.01).And compared with group B,the operation time of group C and D was shorter,the difference was statistically significant(P<0.01).There was no significant difference between the four groups in VAS score and AOFAS score(P>0.05).There were statistically significant differences in the anatomical data of Bohler angle,Gissane angle,calcaneus length and calcaneus height before and after operation in each group(P<0.01).Conclusions:The treatment of calcaneal fracture with new type calcaneus minimally invasive anatomical locking plate via tarsal sinus is an effective and advantageous operation method for Sanders Ⅱ and Ⅲ fractures of calcaneus.The operation effect of this method is good,and the learning curve of this surgical treatment is about 60 cases.What’s more,in the early learning curve,by continuously summing up experience and skills,it can effectively shorten the operation time,reduce the complications of hand operation,and accelerate the early rehabilitation after operation.