摘要
[目的]检测股骨远端LISS倒置固定股骨转子下骨折的生物力学性能。[方法]选取成年股骨16根,在小转子下方1 cm处截骨成2 cm间隙,模拟粉碎性高位股骨转子下骨折。标本随机分成2组,第1组用倒置LISS固定,第2组用PFNA固定。先将标本置于液压伺服力学测试机,行非破坏性应力加载试验,观察载荷-应变关系、股骨头的载荷-位移关系、骨折固定后的强度和轴向刚度。再行非破坏性循环加载试验,循环周期2 000次。最后进行极限力学性能试验。对试验数据用Chauvent准则行精度分析,用t检验。[结果]轴向压缩试验中,LISS组在应变片1和应变片2处的应变均于PFNA组相应的应变值近似;载荷600 N时,LISS组与PFNA组股骨头纵向位移分别为(2.87±0.84)mm、(2.89±0.74)mm;载荷600 N时,两组的骨折固定后强度值近似;载荷600 N时,LISS组与PFNA组的轴向刚度分别为(209.06±18.63)N/mm、(207.61±18.73)N/mm。动态疲劳实验中,相同循环加载周期下,LISS组股骨头的最大下沉位移近似于PFNA组;LISS组与PFNA组在股骨头下沉位移0.5 mm时承受的力分别为(130.83±11.67)N、(128.76±8.35)N;股骨头下沉位移0.5 mm时,LISS组与PFNA组分别是循环加载周期的(1 231±30)次、(1 221±27)次。LISS组、PFNA组极限载荷分别为(3 728±128)N、(3 786±115)N。经统计学分析,以上差异均无统计学意义(P>0.05)。[结论]本试验结果证实了股骨远端LISS倒置固定股骨转子下骨折具有良好的力学稳定性,是一种固定股骨转子下骨折的有效方法。
[Objective]To explore the biomechanical stability of reverse femur LISS plating subtrochanteric femur fractures.[Method]Sixteen cadaveric femurs（30-50 years old） were selected,excluding any lesions.The sixteen femur specimens were randomly divided into two groups,one group was fixed by LISS,and the other group was fixed by PFNA.The specimens1 cm below lesser trochanter was saw off,and simulate comminuted fracture models with 2cm gap between both ends.One resistance strain gage at the medial of the specimens and at the point 1cm beside the fracture line was pasted.The specimens were fixed at Instron-8874 servo-hydraulic mechanical testing machine.Stress loading experiments was carried out.Observed were the load-strain relationship,load-displacement relationship of the femoral head,the strength of the fixed bone and the axial stiffness of the femoral head.Non-destructive cyclic loading experiment was then carried out.Peak valley value of load 0-150 N was set,loading frequency 1Hz,period of batching cycle 2000 times.At last,failure load was assessed.Accuracy analysis and error processing was made to all the biomechanics indexes gotten from the experiment by Chauvent Criterion,P〈0.05 showed statistically significant differences.[Result]In the experiment of axial compression,on load-strain relationship conclusions,the strain of LISS internal fixation group in strain gauge 1 and strain gauge 2 were similar to that of PFNA group; the results of load-displacement relationship was that femur vertical displacement of LISS group and PFNA group were（2.87 ± 0.84） mm and（2.89 ± 0.74） mm in 600 N respectively,when the load was 600 N,the strength of the fixed bone of LISS group were similar to that of PFNA group,and the axial stiffness of LISS group was（209.06 ± 18.63） N / mm,while the PFNA group was（207.61 ±18.73） N / mm.In the experiment of dynamic fatigue,under the same situation of cyclic loading cycle,the subsidence displace-ment of femoral head in LISS internal fixation group was similar to that of PFNA group.The force that LISS group bore was（130.83 ± 11.67） N when max subsidence displacement of the femoral head was 0.5 mm,while that of PFNA group was（128.76 ± 8.35） N.When the subsidence displacementwas 0.5 mm,LISS group had already been（1 231 ± 30） times of the cyclic loading cycle,while the PFNA group was the（1 221± 27） times.Failure load of LISS group was（3 728 ± 128） N and that of PFNA group was（3 786 ± 115） N.According to the statistical analysis,all the differences were no statistical significance（P〈0.05）.[Conclusion]Reverse LISS plating subtrochanteric femur fractures possess excellent biomechanical stability.
出处
《中国矫形外科杂志》
CAS
CSCD
北大核心
2015年第8期733-737,共5页
Orthopedic Journal of China
基金
天津市卫生局科技基金项目(编号:2011KY25)
关键词
股骨转子下骨折
骨折固定术
生物力学
微创固定系统
subtrochanteric femur fractures
fracture fixation
biomechanics
less invasive stabilization system（LISS）
