【作者】 李颖；

【导师】 范清宇；

【作者基本信息】 第四军医大学 ， 外科学， 2004， 硕士

【摘要】 最近二十余年来，带锁髓内钉技术已被公认为是一种治疗长管骨骨折有效的方法。其优良的生物力学特性，使它在骨折固定技术中具有重要的地位，但是，其操作中对手术技巧和手术设备的要求较高，这严重制约了它的推广和普及。目前关于带锁髓内钉的研究在材料力学、生物力学、结构设计、工具的研制等方向上均有深入的研究，随着人们对髓内形态和生物力学的认识逐步深入，髓内钉的发展日渐成熟，特别是自锁技术的进一步发展为髓内钉的进步带来了新的契机。本实验在全面复习国人髓内形态的基础上，根据髓内自锁的基本思路(通过髓内把持力控制骨折断端移动，从而取得稳定的固定)设计并验证了一种新型自锁髓内钉——斜面型自锁髓内钉。初步的力学实验证明了它具备有较为满意的力学性能。希望它能够为临床提供一种简便、实用的骨折固定方法。 由于国人髓腔形态学研究中关于股骨和胫骨的研究较为彻底和深入，肱骨的髓腔形态学上缺乏令人信服的数据，所以本实验首先从肱骨的髓腔形态入手，彻底了解国人髓腔内形态，为自锁钉(SLN)的研制打下坚实的基础。 1、肱骨髓腔形态的观察与测量： 目的：为髓内钉的研制提供解剖学依据。方法：分别以防腐湿肱骨，新鲜肱骨和干肱骨为材料，用牙托树脂灌铸成型后测量其内径；用螺旋CT测量活体肱骨髓腔内径，所有数据进行统计处理，观察各组数据的相关性关系。结果：肱骨髓腔在中上2/3接近不规则圆柱体，自中下1/3开始在矢状面上有一向前为(8.82±0.27)的弧度。在桡神经沟部位的单侧骨密质最厚(6.0±1.5)mm。髓腔最狭窄的部位在肱骨中下1/3左右， 第四军医大学硕士学位论文其冠状径、矢状径在7一Slnln左右。分组统计结果证明，防腐湿肪骨的形态与新鲜脆骨无差别，干胧骨的形态与其他组差别显著，CT实测结果在大部分平面上与防腐湿胧骨及新鲜胧骨的结果无显著差别，与干胧骨组差别显著。结论:胧骨髓内形状大体上接近于不规则圆柱体。 2、斜面型自锁髓内钉的设计 目的:设计一种新型的髓内钉，它能够操作简便，使骨折端获得良好的对位、对线和稳定的固定，减少手术时间，无需大型放射设备，减少医生和患者的放射暴露时间。方法:本型髓内钉为斜面推动型自锁髓内钉，包括外钉和插装在外钉中的内钉，本结构的设计特点为:通过斜面结构的原理将轴向的推动力转化为横向的推动力，从而实现了通过髓内钉尾部的运动控制横钉的收缩运动的意图，进一步通过横钉的髓内把持作用实现带锁髓内钉的功能。在制成原型钉后，用10根干骨为标本制造股骨中上端骨折模型，验证该结构运动的可行性和可靠性，通过X线片检查髓内固位情况，模拟受力检验实际的抗剪切力。结果:该结构能够顺利完成设计动作，运动过程稳定、可靠，髓内固位情况满意;横钉与主钉接触面间可以提供相当的剪切力切断可能的包绕物(如骨痴、骨屑及其他可能的增生组织)。结论:该结构简单，运动可靠，在主要的受力面上无明显的应力集中点;操作简便，无需大型放射设备。 3、斜面型自锁髓内钉的生物力学实验 目的:检验本型自锁髓内钉的生物力学特征。方法:取12根新鲜尸骨的标本，随机分成四组，分别用来测量拉、压、弯、扭的力学指标。冲洗处理，逐次扩髓后，制造股骨中上1/3骨折的模型(带有10flun的缺损)，用原型钉击入后固定，用PE塑料做双头夹具，模拟单腿负重的受力的力线，在instron一1342型MTs机测试力学指标。结果:在拉、压、弯、扭四项指标上，本型自锁钉的性能与G一K钉接近，比分叉钉略优，比梅花针和ender氏钉明显优越。结论:本型髓内钉结构新颖，受力合理，生物力学性能满意，基本能够达到设计要求，可以满足术后在免除外固定的情况下进行有控制的功能训练的要求。更多还原

【Abstract】 Interlocking intramedullary nailing has been accepted as an established technique for several decades. Depending on the excellent biomechanical properties, the technique is an important method in the fixation of fracture. However, the difficult of operating process and the demand for radio-equipment restrict the ’ development of intramedullary nailing. At present, the study about material, biomechanics, frame-Contrivance, and instruments has been performed deeply. With the deeper cognized about biomechanics and intramedullary morphology, the interlocking intramedullary nailing has matured on rise, and the development of self-locking nailing brought an important chance for it. After the review about the intramedullary morphology completely, a new type SLN, Bevel-SLN, has been designed as the philosophy of self-locking in the intramedullary. It was shown that the prototype Contrivances represents satisfying mechanical properties, and this new development may be of particular interest for clinics as a convenient and applied method of fracture fixation.The intramedullary morphologic study of Chinese femur and tibia has been performed completely and deeply, but, the data of Chinese humerus intramedullary morphologic study was defected until my study. So it is the first step in my experience to measure the humerus morphology for the completing the intramedullarymorphology and for the contriving about SLN. 1. Measurement of Intramedullary Cavity:Object: Through the measure about intramedullary cavities castings of humerus, we acquire the data of native for developing the inter-locking nail. Method: There are four groups in the experiment. In the first to third group which is divided by the material: wet bone, fresh bone and dry bone, we measure the intramedullary cavities castings which were cast by activated dental resin; in the fourth group, we measure the intramedullary cavity about humerus of the volunteers by helix CT. All of the data has been put into the SPSS for observing the relation among the four groups. Result: It is nearly an irregular cylinder at the upper 2/3 of humeral medullar, but there is a forth angle with 8. 82 + 0. 27 degree at the under 1/3 of the humeral medullar in sagittal plane. The thickest compact bone lies in the groove for radial nerve, near6 mm in average. The most narrow part of the intramedullary cavity is located in the under 1/3 of humerus, and its diameter is from7 mm to 8 mm in the sagittal and corona plane. It has been proved by statistic data that there is no difference between the wet bone and fresh bone group, but there is a remarkable difference between the dry bone and others’ group. The data of CT group is near to the wet bone and fresh bone group at most plane, and more different than the dry bone. Conclusion: the morphologic shape of humerus is similar to an irregular cylinder. The wet bone is an ideal material in the intramedullary morphologic study.2. Contrivance of Self-locking nail with BevelsObject: A new interlocking system has been developed which is easy to use, carries out an aligning on the distal fracture fragment and stabile fixation, reduces the exposure to radiation for the surgeon and the patient, and allows for a decrease in operating time. Method: the new interlocking system is a Self-locking nail with Bevels; including in-nail, out-nail and across-nail, the designproperties of frame: basing on the bevel-principle, the axial force is turned into across-force, which is completed the intention of controlling the across-nail’ s movement by the trail’ s movement . there are ten dry-bone simples which has been made as the fracture model of the middle-femur to test the handling of prototype nail and the shearing force, and showing the retention in intramedullary cavity by the radiogram. Result: frame of prototype nail has performed the movement as design; the process is stable and reliable; it is satisfied on the retention of intramedullary cavity; the shearing force between the across-nail and main-interface is enough to cut anythi更多还原