指導教授：王兆麟臺灣大學：醫學工程學研究所李典翰Li, Tien-HanTien-HanLi2014-11-302018-06-292014-11-302018-06-292014http://ntur.lib.ntu.edu.tw//handle/246246/264433簡介：早發性小兒脊椎側彎的定義為十歲以下的幼童脊椎出現異常不對稱的生長，雖然此疾病發生機率不高，但是幼兒階段為脊椎成長與心肺功能發育的關鍵時期，若無早期治療將會嚴重影響將來的生活品質。保守治療如背架或物理治療若無法有效控制側彎惡化情形，就須採取手術治療。目前臨床上常使用生長桿系統植入以維持術後脊椎的生長與心肺功能的發育，依不同設計概念其主要常見的系統包含外力控制生長桿;第二種則是生長導引系統。兩種系統皆能有效地提供矯正脊椎效果，但是外力生長桿系統需要定期進行侵入式的延長手術，才能確保脊椎能達到預期的生長，易造成傷口感染的問題，還會影響孩童的日常生活以及產生許多心理上的問題。而生長導引系統的優點則在於不需要手術進行延長手術，但由於不限制生長桿間的活動，主要缺點為脊椎的生長量不如預期以及矯正效果較差的問題。 目的：綜觀目前生長桿系統的問題，本研究的目的有兩個：第一是設計一款不須經過重複延長手術並可以提供良好矯正效果與生長能力的新型自我調適生長桿；第二是驗證此新設計系統能與傳統臨床器械有類似的脊椎生物力學特性，本研究將測試此新型自我調適生長桿在延長前後安裝於脊椎側彎模型相較於傳統器械上的穩定度。 材料與方法：本研究設計新型自我調適生長桿之核心機構為一允許單向軸向延長之套筒連接器，套筒內包含圓柱棘齒條及三角斜面棘爪，利用彈簧使棘爪與與棘齒條配合，當棘齒條沿脊椎生長方向運動，將把棘爪推回而不限制活動，但於反向運動時則可利用斜面配合抵抗軸向壓力，另外套筒上下端可連接目前臨床現有植入物，不影響現有手術流程。於植入物對脊椎生物力學特性的影響實驗中，本研究使用八副T1-T9豬隻胸椎試樣，將T4-T6三節椎骨切開並植入楔形塊，創造出共30度之側彎角度之體外脊椎側彎模型。脊椎側彎模型建立後，分別將長節與短節的新型自我調適生長桿與模擬傳統外力控制生長桿的金屬棒安裝於其上，藉由量測整體及植入節的活動度及中性區來評估兩者的生物力學特性，在測試同時也使用應變規量測桿件上的應變。此外，也將對本研究之自我調適生長桿進行拉伸測試，量測其每單位延長所需之力量大小。 結果：經過多次的機構設計修改，本研究成功設計出一套自我調適生長桿系統，並加工製作其原型版本以供生物力學測試之用。經由拉伸測試，得到自我調適生長桿每單位延長所需力量大小為2.78牛頓。由生物力學測試，在植入自我調適生長桿或是金屬棒後，不論是長節或是短節之安裝，其總活動度和中性區與脊椎側彎模型組相比皆有顯著性下降，而自我調適生長桿組與金屬棒組相比較無顯著差異。於植入節的活動度比較上，自我調適生長桿組於側彎活動時顯著大於金屬棒組，其餘無顯著差異。從應變規訊號分析指出，在側彎動作時，自我調適生長桿組之應變均大於金屬棒組，尤其在凸側桿件之應變均達顯著性差異；在前彎後仰動昨時，整體而言，自我調適生長桿組之凸側桿件的應變大於金屬棒組，其中只有在短節安裝在作後仰動作時未達顯著性差異。 結論：本實驗成功設計出一套自我調適生長桿系統，並藉由活動度及中性區資料驗證其生物力學特性與傳統外力控制生長桿相似。此系統於將來可能用來治療早發性小兒脊椎側彎，維持良好的矯正效果並減少重複手術開刀的需求。此外於桿件應變分析中，雖然發現自我調適生長桿組應變較金屬棒組來的大，但仍低於其破壞條件，於將來改良設計時似乎不需過度顧慮。Introduction. Early Onset Scoliosis (EOS) is commonly defined as the development of an observable spinal curve that is diagnosed in children before age 10. Despite the relatively low incidence of EOS, the associated disabilities are often severe and with significant impact on the quality of life for the affected individuals. Children that failed to respond to conservative intervention such as brace and physical therapy treatment will often undergo corrective spinal surgeries. Clinically, instrumentations commonly employed to correct scoliosis can be divided into two systems: the forced growing rods system and the growth guidance system. Both systems have been found to demonstrate spinal alignment correction; however, both systems have its own shortcomings. The forced growing rods system required revision surgery to be carried out periodically in order to realign and lengthen the rods instrumentation as the children grow. The need for repeated open surgery increases the risk of complications such as wound infection and hardware failure as well as the detrimental effect on one’s quality of life and the subsequent psychological stresses. The growth guidance system was originally designed with the intention to avoid the need for revision surgery; however, due to the less restrictive nature of the implantation, some concerns regarding its efficacy in ensuring appropriate growth and to achieve the necessary spinal alignment correction have been raised. Aim. Given the shortcomings and the disadvantages of the currently available implementation systems to treat EOS, the aim of the current study has two-folds: one is to design a novel self-adaptive growing rods system that would allow adequate spinal correction without the need for revision surgery and secondly, to validate and compare the biomechanical properties of the self-adaptive growing rods system to the traditional rigid-rods system in an in-vitro study. Materials and methods. The design of the self-adaptive growing rods system, using the SolidWorks software, was centered on the development of a mechanism housed within a connector, which would allow a unidirectional extension of the connecting rods. The connector housing included a combination of a spring and a cylindrical inner sleeve and triangular slope ratcheted pawls. The inclusion of a reverse slope on the ratchet provided resistance against axial pressure and thus preventing the undesirable shortening of the system. The design focused on the maximal use of currently available systems with the addition of the described connector in order to prevent unnecessary deviation from current surgical procedures. For the biomechanical comparison of the self-adaptive growing rods system against the traditional rigid rods system, the biomechanical testing included comparison of the total Range of Motion (ROM) and Neutral Zone (NZ) of the instrumented as well as the adjacent levels between the two rods system, both in pre-extended and extended positions. The strains on the rods when performing the movements were also monitored and included. Moreover, the minimally required force for the extension of the self-adaptive growing rods will also be determined. Eight freshly harvested T1-T9 porcine spines were used in the study to create a scoliosis model. Wedge with 10 degrees of slope were inserted into T4, T5 and T6 respectively to create an overall scoliosis angle of 30 degrees. The biomechanical testing was then carried out using the simulated scoliosis model with and without the self-adaptive and rigid rods systems. Results. A number of revisions were conducted and remodeled prior to the production of a prototype, which was then utilized in the next stage of biomechanical testing. It was also determined that a pull force of 2.78 Newton is required for the self-adaptive growing rod to be lengthened by a single scaled unit. In the pre-extended and extended positions, both systems demonstrated a significant decrease in total ROM and NZ when compared to the scoliosis model without the instrumentations but no significant differences were found between the two systems. In terms of the instrumented levels, the self-adaptive growing rods demonstrated a significant increase in ROM when compared to the rigid rods. The rods strain analysis revealed that for lateral bending, the self-adaptive growing rods generally demonstrated greater tensile and compressive strains when compared to the rigid rods system, especially for the growing rods placed on the convex side of the spine. For flexion and extension, a similar trend was also observed with the self-adaptive rods generally demonstrating a greater tensile and compressive strain than those measured from rigid rods. Conclusion. The current study successfully designed and validated the development of a self-adaptive growing rods system, which possess a comparable biomechanical property to those of the traditional rigid rods system in terms of ROM and NZ. It is anticipated that such system will be useful in controlling the development of spinal curvature in EOS and more importantly, avoid the need for revision surgery for the young patients. The greater strain observed in the self-adaptive growing rods system is well within hardware failure tolerance and should not be of concern in the design of the next version of the prototype.目錄 致謝 I 中文摘要 II Abstract IV 圖目錄 IX 表目錄 XI 第一章 緒論 1 1.1 早發性小兒脊椎側彎(Early Onset Scoliosis, EOS) 1 1.2 生長桿系統(Growing Rod, GR) 2 1.2.1 外力控制生長桿(Forced Growing Rod System) 2 1.2.2 生長導引生長桿(Growth Guidance System) 5 1.2.3 各種生長桿之優缺點比較 7 1.3 實驗目的與假說 8 第二章 材料與方法 9 2.1 研究方法簡介 9 2.2 新型早發性小兒脊椎側彎自我調適生長桿之設計 10 2.2.1 設計概念與規格 12 2.2.2 其他設計 17 2.3 拉伸測試 18 2.4 穩定度測試 20 2.4.1 健康組試樣處理 22 2.4.2 健康組穩定度測試 23 2.4.3 小兒脊椎側彎體外模型與其穩定度測試 23 2.4.4 長節自我調適生長桿組與金屬棒組穩定度測試 25 2.4.5 短節自我調適生長桿組與金屬棒組穩定度測試 27 2.5 資料分析 28 2.5.1 量測參數 28 2.5.2 統計方法 31 第三章 結果 32 3.1 拉伸試驗 32 3.1.1 自我調適生長桿每單位延長所需之拉伸力量 32 3.2 穩定度測試 33 3.2.1 總活動度 34 3.2.2 植入節活動度 37 3.2.3 上鄰近節活動度 39 3.2.4 下鄰近節活動度 43 3.2.5 中性區 45 3.2.6 應變 47 第四章 討論 57 4.1 拉伸測試 57 4.2 穩定度測試 57 4.2.1 穩定度 57 4.2.2 應變 60 第五章 結論 62 參考文獻 63 附錄 673500088 bytesapplication/pdf論文公開時間：2017/08/08論文使用權限：同意無償授權早發性小兒脊椎側彎生長桿生物力學測試thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/264433/1/ntu-103-R01548021-1.pdf