【作者】 张明彦；

【导师】 李康华；

【作者基本信息】 中南大学 ， 外科学， 2012， 博士

【摘要】 踝关节韧带损伤是最常见的运动性损伤,其数量约占整个运动损伤的25%,其中内翻扭伤导致踝关节外侧副韧带(Lateral Collateral Ankle Ligament)的损伤又约占踝关节韧带损伤的85%。踝关节外侧副韧带是维持踝关节稳定的重要结构,尤以距腓前韧带Anterior Talofibular Ligament, ATFL)及跟腓韧带(Calcaneofibular Ligament,CFL)起主要稳定作用,其损伤可导致踝关节外侧不稳定,严重影响踝关节功能。同时CFL对距下关节也起到稳定作用,其损伤也会影响距下关节的功能。距下关节参与了踝关节多种运动的组成,如果距下关节受到损伤或不稳,也会影响踝关节的功能。相对容易损伤的外侧韧带,单独的踝关节内侧韧带损伤是不常见的,大部分三角韧带损伤或者合并了外踝骨折,或者合并了韧带联合损伤。国外学者Brostrom收集了281例急性踝关节扭伤的病例,内侧韧带扭伤仅仅只有3%。几乎所有的内侧韧带损伤病例都是部分韧带撕脱。国外学者Harper回顾了42例三角韧带完全断裂伤患者,都无一例外地合并了其他损伤。然而,强烈的外翻暴力仍然可以导致单独的三角韧带损伤。三角韧带损伤的3个主要机制分别是足的旋前-外展、旋前-外旋和旋后-外旋。尽管内侧三角韧带有着极低的损伤发生率,并且大部分都不需要修复,但三角韧带损伤常常带来明显的疼痛和功能障碍。学者Clanton认为,三角韧带损伤的病人会感到内踝不适,同时踝关节会呈现外翻和外展。病人往往会要求施行能够纠正旋转不稳定、距骨倾斜及在冠状面外翻成角的重建手术。胫后肌腱损伤导致的成人获得性平足症,女性发病率高于男性,尤其好发于60岁以上的老年人。疾病的临床特征是胫后肌腱和足内侧纵弓的功能不全.从而引起足后跟的外旋、中足的外展和前足的旋后。X线影像学特征是,随着畸形的发展,外侧第一跖骨-跗骨角不断增大,以及前后观上距舟关节接触面积的不断减小,其他关节也会发生类似畸形。Myerson改进了Johnson和Strom提出的胫后肌腱损伤的分类系统。他在原分类系统中加入了StageⅣ,即伴有三角韧带损伤,该损伤导致了距骨在踝穴的外翻倾斜。Stage R的平足症可以再细分为两个亚期,分别为柔软性平足症(StageⅣa)和僵硬性平足症(StageⅣb)。僵硬性平足症,常常伴有内侧足跟的滑动,需要行关节融合术治疗当Stage Ⅳ平足症合并有踝关节炎时,不管是关节融合还是关节置换,都需要额外对足的畸形进行纠正。然而,柔软性平足症可通过三角韧带重建技术来治疗。基于此,许多学者将精力投入到三角韧带重建术式的研究中。目前,文献中已经有几种三角韧带重建技术的报道。Wiltberger和Mallory描述了一种重建三角韧带的技术。他们在胫骨远端横断一半胫后肌腱,再纵向切开,肌腱远端仍然附着于生理附着点,近端则通过早已在凿通的内踝隧道,穿出的肌腱在隧道外自身缝合。Deland等则描述了用腓长肌腱移植的重建方法。他们在腓长肌腱止点上方切断腓长肌腱,将腓长肌腱通过距骨的骨隧道来到内踝,再通过内踝的骨隧道来到胫骨外侧,并固定肌腱于胫骨外侧。Kitaoka等进行了一项生物力学研究,研究三角韧带重建术在平足症畸形的作用。同侧的踇长伸肌腱被用来移植重建三角韧带,肌腱通过内踝和内侧楔骨的隧道,穿出后再自身缝合。Hintermann等评估了19例实施了平底足手术的患者,其中3例为三角韧带重建术。在这些重建术中,内踝和舟骨粗隆钻出骨隧道,把同侧游离的跖肌腱通过这些骨隧道,然后自身缝合。关节生物力学研究方法多种多样,包括动物实验、尸体实验和物理实验等。踝关节动物实验模型选材困难,而人体标本获取更是极为不易。随着电子计算机技术的发展,有限元分析(Finite element analysis, FEA)已经迅速发展成为一种现代计算方法。在仿真实验中,可以对模型材料参数进行实验条件仿真,模拟拉伸、弯曲、扭转等各种力学实验,以求解获得在不同实验条件下模型任意部位变形、应力/应变分布、内部能量变化、极限破坏分析等变化情况,由于有限元分析相较于传统研究方法拥有诸多优势,因此被迅速引入生物力学研究领域,成为传统经典生物力：学研究的有力补充。本文将根据踝关节的影像学图像资料,建立踝关节的三维有限元模型,并以有限元分析方法为手段,研究踝关节内侧三角韧带对踝关节的稳定作用,分析踝关节实施了上述四种重建方法后的运动学参数和肌腱韧带的生物力学参数。基于此目的,本课题组把工作分成以下三部分：第一章：人踝关节三维有限元模型建立及其有效性验证第二章：人踝关节内侧三角韧带完整和损伤的有限元分析第三章：人踝关节内侧三角韧带四种重建方法的有限元分析第一章人踝关节三维有限元模型建立及其有效性验证目的：建立一个包含胫腓骨下段、距骨、跟骨、足舟骨、内侧楔骨、踝关节软骨、距下关节软骨、踝关节外侧韧带、内侧三角韧带、距下关节韧带的较完整的踝关节三维有限元数学模型,为进一步研究踝关节内侧三角韧带提供基础通用工具,并验证其有效性。方法：采用计算机断层扫描(CT)和核磁共振成像(MRI)扫描同一青年男性的中立位右踝关节,将影像学图像保存为DICOM数据,并导入到逆向工程学软件MIMICS10.0.1,由CT数据逆向构建踝关节各组成骨的三维仿真几何模型,由MRI数据逆向建立踝关节和距下关节软骨三维仿真几何模型。使用MIMICS10.01自带的有限元前处理软件MAGICS9.9(?)各所有三维仿真几何模型进行表面平滑处理和表面网格重新优化后保存,导入有限元分析处理软件Ansys12.0,建立一个封闭的由shell93壳单元和solid92实体单元组成的较完整的踝关节三维有限元模型。利用Ansys里仅受压的link10杆单元模拟构建踝关节外侧韧带、内侧三角韧带、距下关节韧带,并对模型各部分赋予材料属性,即建成较完整的正常成人的踝关节三维有限元模型。使用有限元分析法模拟运算踝关节的前抽屉实验,所得结果与文献中相同实验工况的实验结果进行对照,验证踝关节有限元模型的有效性。结果：利用逆向工程学软件MIMICS10.01有限元分析软件Ansys12.0(?)顺利地建立了包含胫腓骨下段、距骨、跟骨、足舟骨、内侧楔骨和踝关节、距下关节软骨、踝关节内外侧韧带、距下关节韧带在内的人体踝关节的三维有限元模型。通过模拟计算踝关节的前抽屉实验,与文献中实验数据进行对照,验证了该模型的有效性。结论：本研究基于CT和MRI所建立的踝关节三维有限元模型的几何重建精确、逼真,可以顺利实施网格化,可有效的计算踝关节运动学参数和力学参数：第二章人踝关节内侧三角韧带完整和损伤的有限元分析目的：运用有限元分析方法研究人踝关节内侧三角韧带浅层和深层结构与踝关节稳定性的关系。方法：以建立的踝关节三维有限元模型为基础,模拟内侧三角韧带完整、浅层断裂、完全断裂3组模型,分别予以外旋或外翻力矩,运用有限元分析方法模拟运算3种模型在背屈-20°、-10°、0°、10°、20°五个不同角度时踝关节外旋和外翻的角度。将3组模型的实验结果数据进行比较,探讨内侧三角韧带浅层损伤和完全损伤对踝关节稳定性的影响。结果：踝关节在背屈-20°-20°范围内,三角韧带浅层断裂组的距骨外旋角相比正常组显著增大,而外翻角轻度增加(P<0.05)。三角韧带完全断裂组的距骨外翻角相比浅层断裂组显著增大,而外旋角仅轻度增加(P<0.05)。结论：三角韧带浅层结构可能主要维持踝关节的外旋稳定性。三角韧带深层结构可能主要维持踝关节的外翻稳定性。第三章人踝关节内侧三角韧带不同重建方法的有限元分析目的：运用有限元分析方法研究Wiltberger、Deland、Kitaoka、 Hintermann四种人踝关节内侧三角韧带重建方法的生物力学特性并进行比较,着重探讨四种重建术恢复踝关节稳定性的能力。方法：运用所建立的人踝关节三维有限元模型,模拟Wiltberger、 Deland、Kitaoka、Hintermann四种三角韧带重建模型,均分别予以外旋或外翻力矩,运用有限元分析方法模拟运算四种重建模型在背屈-20°、-10°、0°、10°、20°五个不同角度时踝关节外旋和外翻的角度。最后与韧带完整组在五个背屈角度下的数据进行对比,初步探讨在计算机模拟环境下哪种重建方法能更好的恢复踩关节的稳定性。结果：踝关节在背屈-20°-20°范围内,kitaoka组的外旋角度相比其他三组模型最接近韧带完整组(P<0.05),比完整组的外旋角度略大,而Deland组的外翻角度最接近韧带完整组,甚至小于韧带完整组(P<0.05)。结论：Wiltberger、Deland、Kitaoka、Hintermann四种三角韧带重建方法中,没有任何一种能完全恢复踝关节的外旋和外翻稳定性。其中,kitaoka法最大限度的恢复了踝关节的外旋稳定性,而Deland(?)去则完全恢复踝关节的外翻稳定性。更多还原

【Abstract】 Isolated medial ankle sprains are relatively uncommon, with most deltoid injuries occurring in combination with medial malleolus fractures or syndesmosis injuries. In Brostrom"s series of281acute ankle sprains, medial side ankle sprains constituted only3%. Nearly all of the medial-side injuries were partial ligament tears. In Harper’s review of42patients with complete deltoid ligament ruptures, all had other injuries. However, isolated injury to the deltoid ligament can occur during an eversion injury and several other conditions. The3most characteristic mechanisms of injury are pronation-abduction, pronation-external rotation, and supination-external rotation of the foot. In patients who have posterior tibial tendon disorder, trauma-and sports-related deltoid disruptions, and valgus talar tilting after triple arthrodesis or total ankle arthroplasty, the isolated injury of deltoid ligament can also be seen.Deltoid ligament injuries can be a significant source of pain and disability. According to Clanton, patients experience medial ankle discomfort and have slight valgus and abduction of the ankle with ambulation.Patients requiring a reconstructive operation typically exhibit rotatory instability as well as enhanced talar translation or valgus angulation in the coronal plane. Several approaches to deltoid reconstruction have been reported.Wiltberger and Mallory described a technique of reconstructing the deltoid by dividing the posterior tibial tendon longitudinally. The dorsal half of the tendon was left attached distally at the navicular, but transected proximally. A vertical drill hole was made in the medial malleolus through which the proximal end of the tendon was passed from plantar to dorsal and then sutured to itself.Deland et al described a technique for reconstruction in the setting of Stage IV posterior tibial tendon insufficiency. Their technique involves passing a peroneus longus tendon graft through a bone tunnel in the talus from lateral to medial and then through a second tunnel from the tip of the medial malleolus to the lateral tibia.Kitaoka et al described a deltoid ligament reconstruction technique in the setting of flatfoot deformity. The extensor hallucis longus tendon was harvested and passed through drill holes in the medial malleolus and medial cuneiform. It was then sutured back upon itself at both sites.Hintermann et al described a procedure for reconstruction of the deltoid ligament. Bone tunnels were created in the medial malleolus and navicular tuberosity. A free plantaris tendon autograft was harvested, placed through the bone tunnels, and sutured back on to itself.Though several techniques can be used for surgical reconstruction of the deltoid ligament, the ideal method is not known. The purpose of this study was to evaluate the biomechanical results of those deltoid ligament reconstructions using finite element analysis.In addition, the knowledge of stress inside the ligaments and reconstructed grafts which could help to better understand the biomechanical behavior of the reconstructed joint is extremely difficult in the experimental measurement. Therefore, in this paper the finite element analysis helps to assess this biomechanical parameter.Based on this, the study was divided into the following steps:Chapter One Development and validation of a three-dimensional finite element ankle model of humanObjective:To develop a three-dimentional finite element model of the intact human ankle and take the verification analysis in the kinematics of the model.Methods:An healthy ankle of a male (age25, height170cm and weight65kg) was scanned in neutral position using Computer Tomography(CT) and magnetic resonance image (MRI). The geometry of the skeletons of the ankle were rebuilt from the CT images and the articular cartilage from MRI images with Mimics10.01software. According to Mimics software, Magics9.9software which implemented in Mimics and Ansys software, a three-dimentional finite element ankle model was developed on the basis of CT and MRI images. The model consisted of the distal of the tibia and the fibula, the whole talus, the calcaneus bone, the navicular bone, the medial cuneiform bone, the articular cartilage, and the ligaments surrounding the ankle joint including the lateral ligaments and medial deltoid ligament complex. Bone structures were meshed with rigid surface elements due to their small strain compared to soft structures. Articular cartilage was meshed with3D tetrahedral deformable elements. Link elements that have only tension function capability were used to simulate ligaments and grafts bearing the tension load. The anterior drawer test of the talus was simulated in Ansys software to validate the model.Results:An effective and high simulative three-dimensional finite element model of the ankle including six bony structures, cartilage and nine principal ligaments surround the ankle joint complex was developed. The anterior drawer test of the talus in Ansys software validated the model compare to literatures.Conclusion:The three-dimensional finite element model of the ankle was effective so that it can be used to simulate the real ankle for the future study such as the kinematics and biomechanics of the ankle in the deficiency or reconstruction of the medial deltoid ligaments complex. Chapter two The finite element analysis of the intact and deficiency medial deltoid ligment in ankle model of humanObjective:To evaluate the kinematics and biomechanics of the ankles of which the medial deltoid ligament complex is nomal, the superficial deltoid and the whole deltoid is deficient respectively with finite element analysis.Methods:In addition to the intact ankle model, superficial deltoid-deficient, the whole deltoid-deficient models were simulated based on the intact finite elements ankle model. The forces in the ligaments and the kinematics of talus were predicted for an eversional or external torque through the range of ankle flexion in Ansys software.Results:When the superficial structure of the deltoid ligament complex is deficient, the talar tilt increased slightly under an eversional torque, however, the external rotational displacement of the talus increased drastically under an external torque(P<0.05). And, the difference of the external rotational displacement between the superficial deltoid-deficient and deltoid-deficient ankle was very small. However, the difference of the valgus angulation of the talus between them was tremendous relatively(P<0.05).Conclusion:This study showed that the superficial structure of deltoid ligament complex resist external rotation of the talus relative to the tibia mostly and the deep structure resists eversion of the one relatively. Chapter three The finite element analysis of the tenodesis reconstruction in ankle with medial deltoid ligment deficiency in ankle model of humanObjective:To evaluate the kinematics and biomechanics of the tenodesis reconstruction in ankle with deltoid ligament deficiency using finite element analysis.Methods:In addition to the intact ankle model, Wiltberger reconstruction, Deland reconstruction, Kitaoka reconstruction and Hintermann reconstruction models were simulated. The forces in the ligaments and grafts and the kinematics of talus were predicted for an eversional or external torque through the range of ankle flexion in Ansys software.Results:No reconstructions could completely restore the values for ankle stability and the stresses of the lateral ligaments to normality. But compatively, The Kitaoka procedure was most effective in limiting the external rotation(P<0.05), in addition to the Deland procedure, was in limiting the eversion(P<0.05). Conclusion:This study showed that Kitaoka has advantage with regard to rotational stabilities as well as ligaments stress in comparison with other methods. And the Deland procedure is good at the evertional stabilities in comparison with others.更多还原