- 學位論文
低切跡脛骨板狀外固定器之生物力學評估
Biomechanical evaluation of a low-profile external fixator of the tibia
摘要
摘要 脛骨骨折為常見的骨折之一，傳統的骨外固定器雖然能夠有效的固定骨折處以幫助骨骼的復原，但是由於體積大對於病人在復原期間的生活與穿著都相當不方便，低切跡骨板外固定器希望藉由有弧度的薄片設計，讓外固定器能更貼近小腿表面，縮小外固定器的體積以減少對病人所造成的不便。 此論文利用有限元素模擬來分析骨外固定器的生物力學特性，從斷層影像中建構了具有皮質骨與鬆質骨兩層結構的脛骨三維有限元素模型，並結合骨外固定器的模型來進行有限元素分析。比較兩種骨外固定器在承受施力下，所產生的應力、變形型態與位移量等變化情況。 低切跡骨板外固定器在體積上比較小，加上重量較輕，生物相容性好，病患在長時間康復期中，可以比較方便地行動。由於使用較多的骨釘，讓低切跡骨板上的受力可以更分散，可以減少固定器斷裂的機會。
並列摘要
Abstract Tibia fractures are very common fractures of the long bone. Although a conventional external fixator can effectively support skeleton for restoring bony continuity, the large size of bone fixator causes inconvenience to move and to wear the trousers during the long period of recovery. A low-profile external fixator similar to a bone plate is designed to keep the fixator close to skin surface. This will reduce the size of an external fixator and allow patient to move without much limitation. To assess the mechanical properties of the low-profile bone plate external fixator, finite element analysis was carried out in this study. The finite element model of tibia with two layers, spongy bone and solid compact bone, was built from the images of computer tomography. The three dimensional models of a conventional external fixator and the low profile plate external fixator were drawn and converted to finite element models. The tibia model and the external fixator models were bonded together to simulate the condition of tibia shaft fracture fixed by an external fixator. The tension of external fixator and movement of fractured tibia under compression were analyzed using the finite element simulation. The results show that the low-profile external fixator using eight titanium bone screws can spread the force to more screws and lower the tension in it. This lowers the changes of breaking the bone screw or bone plate under compression. The low profile external fixator is also small in size, light in weight, and allowed patients to move with less inconvenience.