摘要
目的通过生物力学试验比较平行和交叉构型螺钉固定PauwelsⅢ型股骨颈骨折的强度。方法对Synbone股骨近端模型骨进行80°截骨模拟PauwelsⅢ型股骨颈骨折。将18例标本随机分为3组,分别使用倒三角平行构型、上方加压交叉构型和下方加压交叉构型螺钉固定骨折,使用MTS 858 Mini BionixⅡ试验系统测试标本的生物力学性质。结果倒三角平行构型螺钉组及上方加压交叉构型螺钉组的刚度均大于下方加压交叉构型螺钉组(P<0.05);在疲劳试验中,上方加压交叉构型螺钉组位移大于另外两组(P<0.05)。平行螺钉在标本破坏后均发生不同程度退出,垂直于骨折线的加压螺钉均未发生退出。倒三角平行构型螺钉组和下方加压交叉构型螺钉组均有1例标本在破坏后可观察到骨折内翻。结论上方加压交叉构型螺钉能更好地对抗PauwelsⅢ型股骨颈骨折所承受的剪切应力、张力及内翻趋势,更适于此类骨折的固定。
Objective To compare the biomechanical stability of parallel and crossing screw configurations for the fixation of Pauwels type-3 femoral neck fractures.Methods Pauwels type-3 vertical femoral neck fracture was stimulated by using Synbone proximal femur model and 80 degree osteotomy.A total of 18 models were fixed by using 3 screw configurations： inverted triangle parallel configuration（group A）,crossing configuration with one superior compressive screw（group B）,crossing configuration with one inferior compressive screw（group C）.The biomechanical properties of each group were tested by using MTS 858 Mini Bionix Ⅱ system.Results The stiffness of group C and group B was significantly greater than that of group C（P〈0.05）.In the fatigue test,the axial displacement of group B was statistically greater than that of other two groups（P〈0.05）.In group A,all specimens failed as the 3 screws back out.In group B and group C,there were 1 or 2 parallel screws backed out when failed,while all the compressive screws in group C didn＇t back out.In group A and C,the separation of upper fracture end was observed in 1 specimen of each group,which representing the varus failure mode.Conclusion The crossing configuration with one superior compressive screw can provide better control of the shearing stress,tension and varus tendency,which indicate that it is more suitable for the fixation of Pauwels type-3 vertical femoral neck fracture.
出处
《山东医药》
CAS
北大核心
2010年第44期10-13,共4页
Shandong Medical Journal
关键词
股骨颈骨折
生物力学
骨折固定术
骨钉
femoral neck fractures
biomechanics
fracture fixation
bone nails
