Development, Animal Experimental And Biomechanical Study Of A Slide-Traction Plate Of Physeal In Child

Ohjective To develope a Slide-Traction Plate of epiphysis in Child,which can give the fracture a hard internal fixation,and will not restrain the growth of epiphysis.Methods A Slide-Traction Plate of Physeal for the configuration of the Child,s condylus of femur was developed.30 adolescent goats were used in the experiment.12 of them was used as normal control.The rest 18 adolescent goats were fixed with plates,whose right femurs were fixed with common plates,and the left femurs were fixed with Slide-Traction Plates.All the goats were given X-ray examination at 1 day,1 month,2 month,4 month,6 month after surgery,measured the both femur with the fPAX system;And half of the goats were sacrificed at 3 and 6 month,histological method and electron microscopy were performed to evaluate the development of epiphyseal plate.Seven fresh corpses were taken and made fracture at femurs,whose right femurs were fixed with common plates,and the left femurs were fixed with Slide-Traction Plates.Then vertical compression test,three-point bending test and torsion test were carried out.Another 18 adolescent goats were used in the experiment.Fractures were made above the subcondely of the femurs.The goats were fixed with plates,whose right femurs were fixed with common plates,and the left femurs were fixed with Slide-Traction Plates.All the goats were given X-ray examination at 1 month,2 month and 4 month.And 9 of the goats were sacrificed at 2 month and 4 month,then vertical compression test,three-point bending test and torsion test were carried out on the femurs.Results The both femurs of the goats in control group had no difference in evidence in length at all time we examined.The both femurs of the goats fixed with plates had no difference in evidence in length at 1 day after surgery.However,the both femurs of the goats fixed with plates had difference in evidence in length at 1 month,2 month,4 month,6 month after surgery.The length increased of the femurs at 1 month,2 month,4 month,6 month after surgery than the length at 1 day after surgery was also compared,there was difference in evidence between the right femurs of the normal control group and the femurs were fixed with common plates,but no difference in evidence between the left femurs of the normal control group and the femurs were fixed with Slide-Traction Plate.More thicker epiphyseal plate were found in the left femurs than the right femurs of the group fixed with plates at 3 and 6 month after operation.In the group fixed with plates,Safranine O staining showed cpiphyseal plates ot the left femurs had more fuscous staining than the right femurs at 3 and 6 month after operation.Electron microscopy also found that the cells of the epiphyscal plates of left femurs were more eugenic than the right femurs in the group fixed with plates at 3 and 6 month after operation.All the vertical displacement with 500 N load,bending displacement with 300 N load and angular displacement of rotation with 10 N·m have no difference in evidence between common plates and slide-traction Plates.The units of the femurs fixed with slide-traction Plates are more stronger than the femurs fixed with slide-traction Plates in 2 month and 4 month after operation.Callus grays have difference in evidence between the femurs fixed with different plates in 1 month 2 month and 4 month after operation,the callus grays of the femurs fixed with slide-traction Plates are higher than the femurs fixed with slide-traction Plates.Conclusion The Slide-Traction of Physeal can slide with the growth of epiphyses,and the new Plate has a adequate mechanical property for the fixation and unit of the fracture in this place.