椎體成形術中骨水泥容量及位置之生物力學評估

Biomechanical Evaluation of the Volume and Location of PMMA bone cement in Vertebroplasty

陳政行(Zheng-Xing Chen)

指導教授 ： 陳文斌 ； 黃聰仁

中原大學/工學院/醫學工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300698

摘要

骨質疏鬆症所引起脊椎體壓迫性骨折是一個常見的疾病，發生在老年人（尤以婦女為甚）。這類型的病人一般是以保守療法如藥物治療，但有時效果不好，但使用內固定器有其危險及限制，而椎體成形術是用器械將骨水泥注入椎體，可以達到固定及矯正椎體變形之效。本研究目的有二，一是採用病人T10到L2的電腦斷層影像資料建立椎體的三維有限元素模型。根據文獻之椎體力學測試的力量－形變曲線推算出骨質疏鬆症及骨折後的材料參數。之後，再去分析骨質疏鬆症之椎體、骨折後之椎體以及”椎體成形術”中椎體植入骨水泥後之力學變化，去探討骨水泥的容量、位置(單邊、雙邊、中間)對於椎體勁度恢復及應力峰值的關係。二是發展出一套椎體成形術使用之器械，在接觸病患的部份為可拋式材料(注入針頭及注射器)，而後端之注入器為可重覆消毒的金屬材質，以達到控制成本的目的。結果指出，骨質疏鬆椎體壓迫性骨折，行椎體成形術後，確實可使椎體勁度、蒙馬氏應力恢復到未骨折之情形。並得知單側（左側、右側、中間）與雙側植入骨水泥在同一植入骨水泥體積下並無差異，因此，單側給予骨水泥是較安全之治療方式，而且，植入6ml骨水泥已可以恢復至未骨折的狀況。對於鄰近節而言，有無植入骨水泥影響不大，所以，只要讓骨折椎體恢復到原始高度即不會對鄰近節造成影響。最後，本研究設計之骨水泥注入器，操作容易，價格便宜，且可以有效的控制骨水泥的容量。

關鍵字

注入器 ； 骨水泥 ； 椎體成形術 ； 有限元素法

並列摘要

Osteoporotic vertebral compression fracture is one of the most common diseases that attack the elder population especially in postmenopausal women. Most of these patients received conservative treatment such as medication, bracing and rest, but sometimes in vain. Instrumentation and fusion surgery can be used in some cases, but most of these patients are older and with higher operative risk that are not eligible for these operations. Vertebroplasty involves inserting bone cement (PMMA) into the center of the collapsed spinal vertebra in order to stabilize and strengthen the crushed bone. The two objectives of this study are, (1) to develop a set of instruments used for vertebroplasty with disposable parts (trocar, needle, and syringe), and reusable part (introducer) and to reduce the expense for vertebroplasty, (2) to use a validated finite element model to evaluate the effects of bone cement with different volumes and locations in vertebroplasty and the stress distribution of the vertebral bodies after vertebroplasty. According to our analysis, there is no significant difference between 6-ml, one-sided and 10-ml, two-sided models. The effect of 6-ml, one-sided model was similar to 6-ml, two-sided and even better, but no significant difference. On the biomechanical viewpoint, vertebroplasty is an effective method in increasing biomechanical strength of vertebral bodies. The effects were related to the volumes of bone cement, but not totally proportional to them. There were similar results between the same volumes but different distributions (one-sided, two-sided). One-sided approach seems to be a safer method. We established another model with five motion segments to evaluate the effect of vertebroplasty on the adjacent vertebrae. The result showed that there was no significant effect on the adjacent vertebrae if the height of the injured vertebral body was recovered to the initial height. The introducer we designed is easy-to-use, less expensive and we can effectively control the amount of PMMA to be injected.

並列關鍵字

bone cement ； finite element method ； vertebroplasty ； introducer

參考文獻

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