【作者】 郭碧云；

【导师】 李晓阳；

【作者基本信息】 北京工业大学 ， 工程力学， 2007， 硕士

【摘要】 自体肋软骨是再造耳廓支架的首选材料,耳廓支架是一个多层面的三维立体结构,需具有一定的力学强度以维持其稳固性。因此,肋软骨作为支架材料用于耳廓再造,其力学性能对维持再造耳外形、取得满意的术后效果至关重要。然而随年龄的增长肋软骨的组织结构会发生变化,从而影响其力学性能,故选择在合适的年龄进行耳廓再造手术,与取得良好的术后效果密切相关。目前,对耳廓再造手术时机的选择,大多数学者是从心里、耳廓大小及肋软骨量是否充足来考虑,并未从肋软骨的力学性能及组织学特性来考虑,尽管有不少研究软骨力学性能的,但多以关节软骨或病态肋软骨为主,对不同年龄健康肋软骨的力学性能和组织学特性的研究尚未见报道。本文通过研究不同年龄健康肋软骨的力学性能及其组织结构,探讨年龄对肋软骨力学性能的影响,旨在为肋软骨作为支架材料应用于耳廓再造术时选取最佳手术时机提供理论依据。本研究包括对不同年龄肋软骨的力学性能实验和组织学特性实验。实验材料来自25位女性和45位男性捐献者,均是进行耳重建手术后剩余的部分。实验按照年龄、性别不同将肋软骨共分为六组:儿童组(5～10岁)、青年组(11～17岁)和成人组(18～25岁)。力学实验包括拉伸强度、应力-应变关系、应力松弛、蠕变试验,目的是探讨年龄对肋软骨力学性能的影响。组织学实验包括普通病理染色、免疫组织化学染色和Ⅱ型胶原蛋白免疫组化定量分析,是为了探讨肋软骨组织结构随年龄发生的变化。此外,本研究还对力学实验和组织学实验结果进行了对比分析。本研究结果表明健康肋软骨的组织结构及力学性能是与年龄及性别有关的。儿童肋软骨的拉伸强度最高,而青少年的强度最低;女性肋软骨较男性肋软骨钙化的早,两性肋软骨应力松弛和蠕变性能也存在显著差异;Ⅱ型胶原染色强度随年龄增长呈现逐渐减弱的趋势。本文研究的结果能够部分地解释临床现象,即在青少年时期利用肋软骨进行耳重建手术,会引起较大的变形;而在成年期进行手术,则软骨太硬,不易雕刻成形,且支架容易外露。另一方面,本研究对肋软骨力学性能的研究可以作为支架设计和雕刻的参考;这些数据也可用于评价组织工程样本的力学性能;而关于不同年龄组肋软骨力学性能的函数关系可以作为相应年龄段肋软骨力学性能本构方程的参考。本文的研究鉴于不同年龄健康肋软骨的组织结构及力学性能的不同,综合各方面因素,建议在利用肋软骨进行耳廓再造术时,优先考虑在儿童期进行。更多还原

【Abstract】 Autogenous costal cartilage is the first selection as the frameworks material in ear reconstruction operation. The auricular frameworks are three-dimensional and require some certain force to maintain its stability. So, the biomechanical property of the rib cartilage is crucial in maintaining good appearance and good postoperative result of the reconstructed ear. With increasing age of the rib cartilage, the histology characters changes accompanying the alternation of the mechanical properties. Therefore, successful ear reconstruction is closely related to suitable time for operation. At present, surgeons pay more attention to the psychology, the volume of rib cartilage or the size of the reconstructed ears in the option of time for ear reconstructed, they give less consideration to the histological and biomechanical properties of the rib cartilage. Several studies have investigated the biomechanical properties of cartilage, however, they were mainly confined to joint cartilage or pathological rib cartilage and little is known on the age-related mechanical and histological behavior of the health human coastal cartilage yet. The aim of this study was to analyze the influence of donor age on biomechanical and histological characteristics of human rib cartilage and to provide theoretical reference in option of operative time when the rib cartilage is used as framework material in ear reconstruction surgery.This study includes age-related biomechanical and histological experiments. Human costal cartilages were harvested from 25 female and 45 male donors of 5-25 years old after auricular reconstructive surgery. The specimens were divided into six groups: children (5~10years), adolescent (11~17years) and adult (18~25years), respectively in males and females. Tensile strength, stress-strain relationship, stress relaxation and creep were tested by using a material testing machine and aimed at investigating the influence of age on biomechanical of human rib cartilage. The general pathological staining, immunizing histochemical staining and typeⅡcollagen protein quantitative analysis were done to find age dependency exists in histological structure of human rib cartilage. In addition, the comparison and analysis between the biomechanical and histological properties were discussed.The current study confirms that the biomechanical properties and histological structure of costal cartilage are donor age and gender related. The children group has the highest tensile strengths ( p <0.05) in both male and male+female groups. The ossification of the male group, which relaxed and creep more than that of the female group in all three age groups ( p <0.05), occurred later than the female group. The intensity of typeⅡcollagen weaken with the growing of the donor age.The results indicated in this study can partly explain the clinical phenomenal that using the adolescent costal cartilage caused a bigger distortion and adult costal cartilage were sculptured difficultly during the auricular reconstruction operation. Moreover, the mechanical properties of the human costal cartilage indicated in the present study can be used as a reference in the design and fabrication of rib cartilage-based implants. Furthermore these data can be used for evaluating the mechanical properties of the tissue engineered samples, which should have the similar mechanical properties to those of the native tissues. The functions of mechanical properties of costal cartilage can be used as referenced constitutive equations of mechanical properties of corresponding age costal cartilage.According to current study, consideration in all comprehensive factors, it is suggested to operate in childhood when using autogenous rib cartilage as framework material in ear reconstruction.更多还原