股骨干骨折髓内钉固定的数字散斑法研究

Measuring the Deformation with Interlocking Intramedullary Nail of Internal Fixation for Femoral Fractures by Digital Speckle Correlation Method

目的以数字散斑法测试在不同拉力条件下的髓内钉锁钉的形变,为临床上分析锁钉断裂之原因提供依据。材料与方法取4根股骨,制作股骨中1/2交锁髓内钉内固定模型。交锁髓内钉置于股骨干骨髓腔。每具标本分A-D组测试顺序进行测试:A:安装交锁髓内钉模拟骨折愈合;B:在A组基础上股骨中段横形锯断2次,即中点锯断一次,中点下5 cm处行第2次锯断,模拟较复杂型骨折;C:在B组的基础上上端去除一枚锁钉;D:在C组基础上下端去除一枚锁钉。分别测量锁钉形变。在200、300N(牛顿)拉力下,电子万能试验机进行拉力测量,通过相关软件计算得出应变。结果在300N拉力下b组与c组有显著性差异(p<0.05)。结论骨折内固定远端锁钉易发生断裂,选择髓内钉大小要合适,过大易造成进钉困难。

Objective To measure deformation of nail under different tensile force before or after adult femoral interlocking intramedullary with nail internal fixation of femoral fractuer by the digital speckle correlation method. Analysis of the changes in the deformation of the nail before and after the fracture healing signs, aimed at providing a theoretical basis for clinical analysis of the nail fracture of reasons. Methods After taking 4 femoral specimen, a intramedullary nail fixation model in mid-sepament of the femur was made. Group A-D were measure by orders： A： the rally situation under femoral interlocking intramedullary nail internal fixation before femur break （simulation of bone healing state）;B： femur saw on the basis of A in order to simulating more complicated fracture （fractured twice on mid-sepament of the fumur） ;C ：removing a nail of the upper end on the basis of B;D：removing a nail of the lower end on the basis of C; Measuring the deformation of nail of 4 groups; respectively. Under the Rally of 200N and 300N（Newton）, with electronic universal testing machine to carry out, the computer automatically proceses the data, calculated the deformation by the ralated software. Results ,（1）B group and C group was significant difference （p〈0. 05）. Conclusion the remote nail for femoral interlocking intramedullary nail internal fixation is easily broken. Chooses in the marrow the nail size to be appropriate, oversized easy to cause the nail to be difficult.