脊柱在人體的功能主要為支撐體軸並將軀幹的重量傳遞到下肢，除了保護內部的脊髓外，更提供了肋骨及頸部背部肌肉、韌帶的附著，以施行日常生理活動。由於醫療科技的進步發展，全球高齡人口的快速成長，伴隨而來的骨質疏鬆症不斷地增加造成脊椎創傷及相關病變患者劇增。美國國家骨質疏鬆基金會的研究報告指出：每年有超過50萬例的脊椎骨折，且65歲以上女性人口中超過四分之ㄧ罹患椎體骨折。根據2006年台灣衛生署統計資料指出，超過65歲以上老年人口中，因為骨質疏鬆而造成脊椎骨折的男性約有12.5%，女性有20%。以脊椎骨釘固定進行脊椎重建、固定、矯正及配合減壓，是目前外科手術治療脊椎創傷及相關病變的主流。受限於疏鬆的椎體骨質密度，往往使得傳統脊椎骨釘與疏鬆的海綿骨之間，因為界面強度不足而導致鬆動，進而造成骨釘及固定器鬆脫或位移的併發症。針對脊椎創傷及相關病變的骨質疏鬆患者，本研究的目的為設計研發適用於骨質疏鬆椎骨之新型骨水泥錨定型胸腰椎脊椎骨釘，以加強骨釘植入骨質疏鬆椎體後之界面握力強度與剪力強度，進而改善骨釘在椎體固定的穩定度，並減少術後骨釘鬆脫或位移的併發症。
本研究的特定目標主要分成三個階段：(1)以電腦輔助工程設計研發新型骨水泥錨定型胸腰椎脊椎骨釘，以提升並改善在骨質疏鬆椎體骨抓力的強度；(2)以新型骨水泥錨定型脊椎骨釘雛形植入sawbone假體之骨水泥擴散及生物力學測試分析（拉拔測試：有或無使用骨水泥加強）；(3)以有限元素法模擬分析新型骨水泥錨定型脊椎骨釘的拉拔測試（有或無使用骨水泥加強），來驗證第二階段的結果。

Abstract
Functionally, the spine mainly supports the body axis and transmits the weight of the trunk to the lower limbs. It surrounds and protects the spinal cord and provides attachment for the ribs, and ligaments and muscles of the neck and back to allow physiologic mobility and activities of daily living. In an individual with a normal spine, the spine performs these functions without injury to bones, soft tissues, or neurologic structures. Because of improvement and development of the medical technology, the dramatic increase of aged population and associated osteoporosis has lead to increased patients with spinal trauma and related spinal disorder. In 2002, the America National Osteoporosis Foundation reported that there are over 500,000 vertebral fractures annually, and more than one fourth of American women older than 65 years of age suffer from vertebral fractures. In 2006, the Taiwan Department of Health reported that 12.5% of aged male and 20% of aged female suffer from vertebral fracture due to osteoporosis.
Currently pedicle screw instrumentation is frequently used for spinal reconstruction, fixation, correction and coupling decompression in spinal trauma and related spinal disorder surgery. However, the conventional screw is unable to provide enough screw-bone interface strength for osteoporotic cancellous bone, and complications resulting from loosening or failure of the implant remain a significant clinical problem.
For patients with osteoporosis and sustaining spinal trauma and related spinal disorder, the purpose of study is to design and develop a new bone cement anchoraged thoracolumbar pedicle screw to enhance the interface strength and shear strength after screw inserting into vertebra body, and to improve the fixation stability and reduce the postoperative complications due to screw loosening and displacement.

The specific aims are divided into three stages: (1) design and develop a novel bone cement anchoraged thoracolumbar pedicle screw through applying computer-aided engineering to enhance the interfacial strength between screw and osteoporotic bone; (2) investigate bone cement distribution patterns and pullout strength for pedicle screws inserted into sawbones empirically; (3) employ finite element method to analytically simulate the pullout strength of bone cement anchoraged pedicle screws for validation.

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