1.Mises stress analysis of 42A2 type tibial mid segment oblique fracture fixed with external locking plate at different angles
Yunqi YANG ; Xiaoye WANG ; Lei MI ; Guanjun ZHANG ; Ling ZHANG ; Shitao FANG ; Yun WANG
Journal of Chinese Physician 2023;25(5):700-703,708
Objective:To establish a three-dimensional model of locking plate fixation for 42A2 type oblique tibial fractures with different fracture line directions and different angles between the fracture line and the long axis of the tibia. Finite element analysis was used to calculate and analyze the biomechanics of locking plate, screw, and tibia, providing theoretical basis for clinical application.Methods:A healthy adult volunteer, 25 years old, male, with a height of 173 cm and a weight of 69.5 kg, was selected to perform computed tomography (CT) scans on the left tibia. Relevant data were obtained to establish a locking steel plate fixation model for 42A2 type tibia with different oblique fracture line directions and different angles between the fracture line and the long axis of the tibia. Eight hole pure titanium plates were used for fixation, respectively. We compared the Mises stress changes of locking plates, screws, and tibia in different angle fracture models.Results:In the case of a 42A2 type fracture in the left oblique direction with a fracture line from outside to inside, the maximum Mises stress in the tibia was 114 MPa, the maximum Mises stress in the screw was 279.8 MPa, and the maximum Mises stress in the locking steel plate was 302.4 MPa; In the case of a 42A2 type fracture in the right oblique fracture with a fracture line from the bottom to the top, the maximum Mises stress of the tibia was 93.41MPa, the maximum Mises stress of the screw was 353.4 MPa, and the maximum Mises stress of the locking steel plate was 411.8 MPa.Conclusions:Regardless of the oblique fractures in both left and right directions, the maximum stress values are: locking plate>screw>tibia; When the position of the locking steel plate is fixed, the maximum stress values of the locking steel plate and screw are both right oblique fracture>left oblique fracture; And the maximum stress values all increase with the increase of angle.
2.Effects on different frequencies of whole body vibration on gross motor function and walking function in children with dyskinetic cerebral palsy
Qiu ZHANG ; Jihua YU ; Weiping LI ; Yunqi LING ; Jianxiong WANG ; Fangyuan XU
The Journal of Practical Medicine 2024;40(3):353-359
Objective To provide reference for the subsequent clinical application of WBV,based on the impacts of whole body vibration(WBV)with different frequencies on gross motor function and walking function in children with dyskinetic cerebral palsy.Methods 60 children aged 6~12 with dyskinetic cerebral palsy,who had been treated at the department of rehabilitation medicine in the Affiliated Southwest Medical University from October 2021 to November 2022,were selected.They were randomly divided into a control group(n = 20),(25±5)Hz group(n = 20),and(35±5)Hz group(n = 20).All the three groups received conventional rehabilitation,while the(25±5)Hz group received additional WBV with(25±5)Hz and the(35±5)Hz group received WBV with(35±5)Hz.They were treated for eight weeks.The scores on D and E domains of GMFM-88,TUGT,the score on Berg Balance Scale,and footprint analysis were used for assessment of the efficacy after treatment.Results As compared with the baselines,the scores were improved in the three groups after treatment(P<0.001).BBS(F = 12.502),TUGT(F = 8.211),scores on D and E domains of GMFM-88(F = 12.802 and 8.505),stride length(F = 12.279),1MWT distance(F = 12.619),and step width(F = 13.582)were better in the(35±5)Hz group than in the(25±5)Hz group and the control group(P<0.05 and P<0.01);and the efficacy was better in the(25±5)Hz group than in the control group,the difference was statistically significant(P<0.05 and P<0.01).Conclusion WBV can improve trunk control,lower limb gross motor function,and walking function in children with involuntary motor type cerebral palsy.(35±5)Hz is better than(25±5)Hz for the efficacy of WBV.