【作者】 陈鹏涛；

【导师】 张树桧；

【作者基本信息】 郑州大学 ， 骨外科， 2003， 硕士

【摘要】 接骨板内固定是治疗长骨骨折的主要方法之一，以加压钢板为代表的传统钢板是目前临床上最常用的接骨板固定系统，通过加压钢板实现的坚强内固定能够为骨折愈合和功能恢复提供稳定的力学环境。然而，在临床应用中，加压钢板源性骨质疏松是钢板取出后发生再骨折的主要原因，针对这一问题，学者们提出了应力遮挡和接骨板下皮质骨缺血坏死诱导骨质疏松的观点。以保护局部血供和减少应力遮挡为基础，对传统加压进行改良是接骨板研究和应用的热点。依据生物力学固定和生物学固定，在齿接触半环抱槽式加压钢板的基础上，设计出一种新型内固定系统—齿接触板-带式槽形加压钢板，对其固定股骨骨折的生物力学效果进行研究，以期提高钢板内固定的生物力学性能，为临床应用提供实验依据。 材料与方法： 采用8具16根成年新鲜、湿润尸体股骨为实验标本(由上海第二医科大学解剖学教研室提供)，其中女性3具，男性5具。年龄39～50岁，体重平均56公斤(范围47～65公斤)。剔除股骨标本上所有软组织，股骨两端用骨水泥包埋固定，置于-20℃冰箱中保存待用，实验前将标本浸入20℃的林格氏液中3～4小时解冻，所有标本实验前均摄X线片，以排除病理骨。 16根股骨标本随机分成两组，实验组为8根(左右各4根)，对照组为8根(左右各4根)。在股骨干中段横断截骨，所有标本的制作均保持一致。实验组用齿接触板-带式槽形加压钢板固定，对照组用普通加压钢板固定，钢板所用材料均为316L医用不锈钢。模拟人体单足站立状态，确定载荷类型和载荷范围，最大载荷500N为平均体重的90％，轴向压缩载荷范围为0～500N；弯曲载荷范围为0～500N；扭转载荷范围为0～20Nm；加载速度为1.4mm／min，实验采用分级加载。依次进行轴向压缩实郑州大学2003届硕士研究生学位论文齿接触板一带式槽形加压钢板固定股骨骨折的生物力学实验研究验、三点弯曲实验、扭转实验。每次实验前预载(1/10负荷)10次，以消除股骨的蠕变等因素的影响，以提高检测精度。在轴向压缩实验中，先给予完整股骨4OON、SOON的载荷，记录相应的股骨应变值，随后将骨折固定标本按预定的载荷方式加载。在三点弯曲实验中，载荷作用点位于股骨标本的中间。整个实验过程所有标本均保持湿润状态。实验中获得数据以均数士标准差表示，用t检验，取a=0.05为检验水准。结果: 1.轴向压缩实验:在各级载荷点，实验组的应变、位移均大于对照组，两者间差异有显著性(P<0.05)。在SOON时，实验组的轴向刚度为1 17.90士4.45N加即，对照组的轴向刚度为133.09士4.79N/r田卫，两者相差n.4%(尸<0.05);其轴向强度实验组为23.11士2.llMpa，对照组为19.58:I= l.83Mpa，两者相差18%(P<0.05)。 2.三点弯曲实验:在各级载荷点，实验组应变、挠度均小于对照组，两者间差异有显著性(P<0.05)。在SOON时，实验组的弯曲刚度为532.30士20.19Ncn口degree，对照组的弯曲刚度为377.70士16.93Ncn口degree，两者相差40.9%(p<0 .05)。 3.扭转实验:在各级扭矩点，实验组的扭角均小于对照组，两者间差异有显著性(P<0.05)。在12Nm时，实验组的扭转刚度为60.81士7.62Nc而degree，对照组的扭转刚度为39.55士4.2州cn“de笋e，两者相差53%(P<o.os)。在扭角为ldegree/cm时，实验组股骨承受的扭矩为16.92士1.92 Nm，对照组则为12.83士1.45 Nm，两者相差32%(P<0 .05)。 4.轴向应力遮挡率的比较:在4OON时，实验组的轴向应力遮挡率为29.1士2.4%，对照组的轴向应力遮率为39.7土1.8%，两者相差28%(P<0.05)。在SOON时，实验组的轴向应力遮率为40.3士1.4%，对照组则为50.2士2.4%，两者相差19%(P<0 .05)。结论: 齿接触板一带式槽形加压钢板抵抗弯曲变形、扭转变形的能力均明显优于普通加压钢板，而轴向应力遮挡率比普通加压钢板低。这些表明，齿接触板一带式槽形加压钢板固定股骨骨折的生物力学效果优于普通加压钢板，齿接触板一带式槽形加压钢板的设计符合生物力学要求，固定可靠稳定。更多还原

【Abstract】 The internal fixation with bone plate is one of the important methods in treating long bone fractures. As the representative of conventional plate, compression plate is currently the most popular fixed system of bone plate. The rigid internal fixation by compression plate can provide stable mechanical environment for bone healing and functional recovery. However, in clinical practice, osteoporosis due to compression plate is the main cause of re-fracture after removing the plates. According to this problem, researchers think that bone may occur in response to either altered cortical perfusion or stress shielding. Considering maintaining regional circulation and reducing stress shielding, modifying the conventional compression plate has been a highlight in the study and application of bone plate. Based on biomechanical fixation and biological fixation, and the structure of the compression plate of gear contact half cycle and channel type (GCC), the author developed a new kind of internal fixed system of compression plate of gear contact plate-band and channel type (GCPC), then applied it to femur fractures and studied its biomechanical effect of fixing femur fractures, expecting to improve biomechanical property of conventional plate and provide experimental basis for clinical work. Materials and methods:Eight pairs of fresh and moist human cadaveric femurs harvested from eight specimens of adults (provided by Anatomical Department of Shanghai Second Medical University), there were three females and five males. The specimens were aged betweenthirty-nine and fifty years old at the time of death, weighing 56kg on average (range: 47-65). After removing the soft tissue, the proximal and distal ends of femurs were cemented with polymethyl methacrylate (PMMA), and stored in a refrigerator at-20 until the day of the study. Before testing, each femur was thawed in Ringer" s solution at room temperature of 20 for three ~ four hours. All have no known skeletal pathology by plain radiographs.The femurs were assigned randomly to the experimental group (n=eight femurs) and the control group (n=eight femurs). All specimens of the experimental and control group were sawed transversely to the model of fracture of femoral shaft by the control osteotomy, these fracture models should be as consistent as possible. The femurs in the experimental group were fixed with GCPC and the femurs in the control group were fixed with general compression plate (GCP), Plate fixation was accomplished by standard AO technique, all plates were made of stainless plate 316L. On the basis of the simulation of the standing phase with load on single leg, the load type and load scope were decided as follows: the axial compression load and the bending load were done from ON to 500N, and torsional load of ONm to 20Nm, with a load speed of 1 .4 mm/min, Classified loading way was adopted, the maximum load was chosen to approximate ninety percent of the average body weight of all specimens.The procedure of the test consisted of axial compression test, three-point bending test and torsion test. In each testing, the femur was firstly loaded with a tenth of pre-load for ten times at the velocity of 1.4mm/min, in order to eliminate the effect of the viscoelasticity of femur. In axial compression test, the intact femur was firstly exerted with two main loads of 400N and 500N, with a load speed of 1.4 mm/min, two corresponding strain values were recorded. Subsequently the fixed femur was carried out by the loads from ON to 500N. In three-point bending test, the loading point was situated in the midpoint of the middle two holes of the plate. The specimens were kept moist throughout the procedure. All the experimental data were expressed as mean ?standard deviation, using the SPSS10.0 software. Student’s t test was employed to verify the significance of the data. And a P value<0.05 was considered as significant difference.Results:1 . Axial compression test. At every classified load, strain and displacement of the experimental group were greater than them of the control group (更多还原