弹性髓内钉治疗学龄前儿童股骨干长螺旋形骨折：有限元、生物力学及临床研究

发布时间：2018-05-31 05:15

  本文选题：股骨干骨折 + 弹性髓内钉　； 参考：《第四军医大学》2017年博士论文

【摘要】：股骨干长螺旋形骨折,即骨折斜面长度大于骨折部位股骨直径2倍以上的股骨干螺旋形骨折,是一种以长度不稳定为主要特点的特殊骨折类型,多由高能暴力引起。随着社会经济水平提升,儿童出行和各种活动增加,交通事故等高能旋转暴力因素所导致的儿童股骨干长螺旋形骨折发病率逐年增加,如何治疗成为小儿骨科研究和争论的热点。得益于手术方式、固定技术的突破,使得儿童股骨干骨折的治疗不再局限于牵引和石膏固定,从而获得更加快速可靠的治愈。特别是法国医生Metaizeau、Prévot发明的弹性髓内钉技术(elastic stable intramedullary nailing,ESIN),经过近40年来的全球广泛实践证明,被公认为治疗儿童长骨干骨折的首选治疗方式。然而大部分研究认为ESIN方法仅适用于7-14岁儿童的股骨干横形或短斜形骨折,并不推荐用于长螺旋形这样的长度不稳定型骨折。主要理由有以下两方面:1.学龄前儿童骨骼重塑能力强,ESIN技术相较非手术治疗优势不明显;2.长螺旋形骨折稳定性差、易旋转,可能造成更高并发症几率。本课题组认为学龄前儿童(2-7岁)同样有着快速康复的需求,前期本课题组已经开展了ESIN治疗学龄前儿童股骨干长螺旋形骨折的临床探讨性试用,初步随访结果证实能获得良好的临床效果。但目前国内外对该方法治疗股骨干长螺旋形骨折置钉方法及稳定机制研究较少。研究目的:采用“有限元模拟”、“离体生物力学实验”等方法,比较不同弯钉置钉方式对于治疗后股骨整体力学性能的影响,分析ESIN对骨折的固定机制并优化置钉方法;通过回顾性病例比较研究,比较ESIN治疗两种类型骨折(长螺旋形骨折vs横形/短斜形骨折)的临床疗效及并发症情况,分析ESIN治疗学龄前儿童股骨干长螺旋形骨折的临床效果,为该技术的临床提供实验依据。研究方法:一、两种不同ESIN弯钉置钉方式治疗股骨干长螺旋形骨折的有限元模拟研究。(1)建立股骨长螺旋形骨折数字模型,与弹性髓内钉模型组合后进行网格划分;(2)采用Abaqus软件,比较“骨折顶点置钉”和“对称置钉”在静力条件和模拟单足站立时的应力分布及其特点;(3)采用模拟四点弯曲、旋转、负重等载荷,比较两种弯钉置钉方法修复后股骨的抗弯曲、抗旋转及抗压缩刚度。二、两种不同ESIN弯钉置钉方式及尾帽治疗股骨干长螺旋形骨折的生物力学研究。(1)标准化股骨干长螺旋形骨折人工股骨24根,随机分为4个实验组(n=6),横形骨折人工股骨3根,设为对照组;(2)实验组分别采用“骨折顶点置钉(Vertex Nailing,VN)”、“骨折顶点置钉+尾帽(Vertex Nailing with End Cap,VN+EC)”、“对称置钉(Symmetrically Nailing,SN)”、“对称置钉+尾帽(Symmetrically Nailing with End Cap,SN+EC)”固定方式,横形骨折对照组(Control,Con)进行传统对称置钉固定,不加尾帽;(3)采取重复测量方法,分别进行四点弯曲、扭转、0°及9°压缩实验;(4)观察比较各组间股骨整体的各向抗弯曲刚度、旋转刚度及压缩刚度。三、ESIN治疗学龄前儿童股骨干两种类型骨折(长螺旋形骨折vs横形/短斜行骨折)的临床比较研究。随访本课题组2009年1月至2015年3月采用ESIN治疗学龄前儿童(2-7岁)股骨干长螺旋形骨折21例,并将其与同期收治、采用ESIN治疗的59例横形/短斜行骨折患儿比较,分析两组病例一般资料、手术时间、术中出血、住院费用、骨折愈合时间、负重时间及并发症情况。研究结果:一、通过收敛性检验和模型验证表明所建模型有效。应力云图显示在负重位时,骨折顶点置钉组较对称置钉组在皮质与弹性髓内钉接触部位提供支撑力更大(7.54MPa vs 5.33 MPa),同时骨折线周围应力分布为均匀,但弹性髓内钉钉尾残存应力亦更大(177.29MPa vs 156.22MPa)。有限元模拟加载结果显示骨折顶点置钉较对称置钉能有效提高股骨抗旋转能力,其中内旋刚度提高175%(0.22 Nm/°vs 0.08 Nm/°),内旋刚度提高92%(0.27 Nm/°vs 0.14 Nm/°),此外骨折顶点置钉抗压缩性能也具有优势。二、通过体外生物力学实验发现,VN+EC组抗反屈、抗内翻刚度分别为1.79±0.19 Nm/mm,1.12±0.22 Nm/mm,较其他各组更具优势。骨折顶点置钉在抗旋转方面较对称置钉组及对照组更强(P0.05),并且加装尾帽后这一作用进一步增强。9°模拟生理位置和0°轴向压缩时,EN+EC组治疗股骨干长螺旋形骨折能提供与横形骨折对照组相似的抗压缩刚度(514.70±32.86vs 504.55±25.22,294.99±23.91 vs298.18±17.33,Nm/mm),并显著优于其他各组。三、本研究纳入ESIN治疗学龄前儿童股骨干骨折80例(81肢),其中长螺旋形骨折21例(22肢),平均年龄4.0±1.37岁,平均随访17个月(12~30个月)。平均骨折临床愈合时间7.6±1.4周,平均完全负重时间为12.1±1.6周。全部病例于术后6~10月骨折愈合后拔除弹性髓内钉。随访检查时绝大多数患儿双下肢等长,步态正常,膝关节活动正常、无疼痛;8例(长螺旋形骨折3例)出现有针尾皮肤过敏“激惹”现象,拔除髓内钉后很快自愈;3例(长螺旋形骨折1例)出现患肢超过1cm过度生长。所有病例均未发现断钉退钉、骨髓炎、骨骺损伤、术后再移位及拔钉后再骨折、骨不连现象。结论:采用ESIN治疗学龄前儿童股骨长螺旋形骨折,“骨折顶点置钉+尾帽”的固定方式较“对称置钉”具有更高的抗反屈、抗内翻、抗旋转及抗压缩性能,骨折断端间的受力更为均匀;临床研究证实该方法治疗患儿的临床愈合时间、完全负重时间与“横形/短斜行骨折”患者无显著差异,是治疗学龄前儿童股骨长螺旋形骨折的安全有效的方法。但由于ESIN并非坚强固定,因此建议术后早期辅助石膏或支具外固定。
[Abstract]:The long spiral fracture of the femoral shaft, that is, the length of the fracture surface is more than 2 times the femoral diameter of the fracture site, is a special type of fracture, which is mainly characterized by the instability of the length. It is caused by high energy violence. With the social and economic level, the children go out and all kinds of activities increase, traffic accidents and other high energy rotations. The incidence of long spiral fractures of the femur caused by violence has increased year by year. How to treat it has become a hot spot in the research and debate in the pediatric department of orthopedics. The treatment of the fracture of the femoral shaft of children is no longer limited to traction and plaster fixation. It's an elastic intramedullary nail technique (elastic stable intramedullary nailing, ESIN) invented by the French doctor Metaizeau, Pr e VOT. After nearly 40 years of worldwide practice, it has been proved to be the preferred treatment for the treatment of long bone fractures in children. However, most of the studies believe that ESIN is only suitable for the transverse or short femoral shaft of 7-14 year old children. Oblique fractures are not recommended for long spiral fractures such as long helix. The main reasons are the following two aspects: 1. preschool children have strong bone remodeling ability and ESIN technique is not obvious compared with non operative treatment; 2. long spiral fractures are poor in stability, easy to rotate, and may cause higher risk of complications. Children (2-7 years old) also have a rapid recovery demand. In the earlier period, the group has carried out a clinical trial of ESIN for the treatment of long spiral fractures of the femur in preschool children. Preliminary follow-up results confirmed that good clinical results can be obtained. However, the method and stability of the treatment of long spiral fracture of femoral shaft with this method at home and abroad is at home and abroad. The purpose of this study is to compare the effects of different bending nailing methods on the overall mechanical properties of the femur after treatment by using "finite element simulation" and "experiment in vitro biomechanics", to analyze the fixation mechanism of ESIN on the fracture and to optimize the method of nail placement, and to compare the two types of ESIN treatment by comparing the case study. The clinical effect and complication of fracture (vs transverse / short oblique fracture) of long spiral fracture, analysis the clinical effect of ESIN treatment for the long spiral fracture of femur in preschool children and provide experimental basis for this technique. Research method: a finite element model of two different ESIN bending nailing methods for the treatment of long spiral fracture of femur (1) to establish the digital model of long spiral fracture of the femur, and to divide the mesh with the elastic intramedullary nail model. (2) the stress distribution and characteristics of the "fracture apex nail" and "symmetrical nail" are compared with the static condition and the simulation of the single foot. (3) using the simulated four points bending, rotation, load, and other loads, (3) To compare the flexural, anti rotation and compressive stiffness of the femur after two kinds of bending nailing methods, two, two different ESIN bending nailing and tail cap were used to treat the femoral stem long spiral fracture. (1) 24 artificial femoral shaft fractures were standardized into 4 experimental groups (n=6) and transverse fracture artificial femoral shaft. 3 bone was set as control group, and (2) the experimental group adopted "Vertex Nailing, VN", "Vertex Nailing with End Cap, VN+EC", "symmetrical nailing (Symmetrically Nailing, SN)", "symmetrical nailing + tail cap" fixed mode, transverse fracture pair The traditional symmetrical nailing was performed in the group (Control, Con) without tail cap; (3) the compression tests of four points, twists, 0 and 9 degrees were carried out by repeated measurements, and (4) to observe and compare the anisotropic flexural rigidity, rotational stiffness and compression stiffness of the whole femur, three, ESIN for two types of fracture of the femoral shaft of preschool children. A comparative study of vs transverse / short oblique fracture of spiral fracture. 21 cases of long spiral fractures of the femoral shaft of preschool children (2-7 years old) were treated by ESIN from January 2009 to March 2015, and they were compared with 59 cases of transverse / short oblique fractures treated with ESIN in the same period, and the general data of the two groups were analyzed, and the operation time was analyzed. Intraoperative bleeding, hospitalization expenses, fracture healing time, weight negative time and complications. Results: first, the results of convergence test and model verification showed that the model was effective. The stress nephogram showed that the fracture apex group was more supportive than the symmetrical nail group in the contact parts of the cortex and the elastic intramedullary nail (7.54MPa Vs 5.33 MPa), at the same time, the stress distribution around the fracture line is uniform, but the residual stress in the elastic intramedullary nail tail is also greater (177.29MPa vs 156.22MPa). The finite element simulation loading results show that the fracture vertex nailing can effectively improve the anti rotation ability of the femur, of which the internal rotation stiffness is increased by 175% (0.22 Nm/ degree vs 0.08 Nm/ degrees), and the internal rotation stiffness is raised. The high 92% (0.27 Nm/ vs 0.14 Nm/) and the compression resistance of the fracture apex were also superior. Two. Through the biomechanical experiment in vitro, the anti flexion and anti varus stiffness of group VN+EC were 1.79 + 0.19 Nm/mm and 1.12 + 0.22 Nm/mm, respectively. The fracture vertex nail was more than the other groups in the anti rotation group and the control group. Stronger (P0.05), and after the addition of the tail cap further enhanced the.9 degree simulated physiological position and 0 degree axial compression, the EN+EC group was able to provide similar compression stiffness (514.70 + 32.86vs 504.55 + 25.22294.99 + 23.91 vs298.18 + 17.33, Nm/mm) in the treatment of femoral stem long spiral fracture (Nm/mm), and significantly better than the other groups. Three, 80 cases (81 limbs) of femoral shaft fracture of preschool children were treated with ESIN, of which 21 cases of long spiral fracture (22 limbs), average age 4 + 1.37 years, average follow-up for 17 months (12~30 months). The average fracture healing time was 7.6 + 1.4 weeks, and the average full weight was 12.1 + 1.6 weeks. All cases were pulled out after 6~10 month fracture healing. In addition to the elastic intramedullary nail. Most of the children were followed up with equal length of lower limbs, normal gait, normal knee joint movement, no pain, 8 cases (3 cases of long spiral fracture) had the phenomenon of skin allergy "irritability", after pulling out intramedullary nail, 3 cases (1 cases of long spiral fracture) were over growth of the affected limbs. All cases were not. It was found that the treatment of long spiral fracture of femur in preschool children and "nail + tail cap" with ESIN have higher anti flexion, anti internal varus, anti rotation and compression performance and fracture fracture. Clinical studies have proved that this method is a safe and effective method for the treatment of long spiral fractures of the femur in preschool children. However, ESIN is not strong fixed. The paste or the support is fixed outside.
【学位授予单位】：第四军医大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R726.8
，

本文编号：1958429