強烈的撞擊和骨質疏鬆症是造成股骨骨折的主要原因，穩定度關係著手術的成敗，鎖定式骨板已經被廣泛應用於治療各種骨折，微創手術的發明減少臨床併發症的風險。骨板具有很多個螺絲孔允許醫師植入螺絲，螺絲的位置及數量關係著穩定度，所以兩者變得至關重要。然而，鎖定式骨板不同的螺絲位置及數量，治療股骨遠端骨折之生物力學結果，在過去尚未被宏觀地評估和討論。因此，本研究的目的是藉由腰椎後三節、骨盆、股骨的有限元素模型，分析不同骨折位置、螺絲位置及數量下固定系統的生物力學特性。
本研究的腰椎後三節、骨盆及股骨有限元素模型使用斷層掃描建立，包括有椎體(硬質骨、鬆質骨)、後方元件、椎間盤、關節軟組織、骨盆、股骨。鎖定式骨板及骨螺絲有限元素模型使用Solidworks建立。模型建立完成後，再匯進ANSYS 14.5有限元素分析軟體，針對兩種模型，其中包含腰椎-骨盆-股骨模型、單純考慮股骨模型；三種不同骨折位置；八種螺絲數量及六種螺絲位置，進行有限元素分析。評估螺絲數量及位置在不同股骨遠端骨折的生物力學特性，是以位移量及骨板表面應力的結果呈現。並且使用INSTRON-8872疲勞測試系統進行生物力學實驗，對六種不同螺絲數量進行壓力測試，並且擷取實驗過程的力-位移曲線，結果是以力-位移曲線的斜率(剛性)來呈現。最後，比較生物力學實驗跟限元素分析的結果。
在不同骨折位置、螺絲數量及位置，分析跟實驗結果顯示，螺絲數量的減少會增加位移量及減少剛性，而分析的結果如下，工作長度較短的螺絲打法能使位移量降低，提供較好的穩固效果；骨折發生在越靠近膝關節的骨折越不穩定，需要用更多的螺絲來做治療；位移量較大的螺絲打法也會使骨板有較高的應力。

High-energy impact and osteoporosis are the main causes of femoral fractures. Fixation stability can make a difference between success and failure in surgical operations. Locking-plate system has been widely used in the treatment of a big variety of bone fractures. The chance of occurring complications has been significantly reduced thanks to the invention of the Less Invasive Stabilization System (LISS).There are many screw holes on the plate allow surgeons to insert screws. The number and pattern of screws in use are critical because of the strong link to fixation stability. However, the biomechanical behaviors of plating system with different number and pattern of screw haven’t been investigated and studied in a comprehensive model. Therefore, the aim of this study is to obtain the biomechanical properties, using diverse numbers and patterns of screw and fracture sites in a relatively comprehensive numerical model.
The numerical model used in this study includes lower three segments of lumbar (cortical and cancellous bone), discs, pelvis, joints and femur. They are all created by applying the technique, Computer Tomography Scan(CTS). The plating system including locking plate, screws is developed with the software Solidworks. All numerical parts are imported into ANSYS 14.5 to do analyses. This study takes into account two models (lumbar-pelvis-femur model and only femur model), three fracture sites, eight different screw numbers and six screw configurations. Stresses on the top surface of bone plate and displacement of whole system are available in the numerical results. Biomechanical experiments are conducted with the equipment, INSTRON-8872. Six varying number of screws in use are chosen to carry out compression tests. Force-displacement curves are obtained during the biomechanical tests. Numerical and experimental outcomes are compared in the form of displacement and stiffness.
Biomechanical experiments and numerical analyses show that less number of screws in use can raise the displacement of whole system. The screw configurations with shorter working length are most likely to have low displacement as a result. Nearer to distal end fracture occurs, more unstable the system would be.

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