距骨缺血性坏死的有限元分析

背景：对距骨缺血性坏死的具体临床治疗,目前仍有很大争议。 目的：观察不同程度距骨坏死时,距骨滑车关节面上的应力及其分布变化。 方法：利用8具踝关节标本建立踝关节三维有限元模型,通过改变各模型距骨坏死的体积分析距骨滑车关节面压应力与其分布的变化规律,计算出距骨缺血性坏死可能诱发踝足创伤性关节炎或出现距骨塌陷的临界坏死体积。 结果与结论：实验成功建立了踝关节三维有限元模型。分析发现距骨内、外侧坏死程度比较小时,距骨滑车关节面应力分布变化不大;当内侧距骨坏死体积达到(26.6±1.5)%,外侧距骨坏死体积达到(35.0±2.5)%时,距骨坏死组织与正常骨组织边界区域出现应力集中的现象,其应力区域呈不规则形,提示,此时诱发踝足创伤性关节炎或发生距骨体塌陷的危险性很高,应手术治疗。     

胫骨远端关节面缺损有限元模型的生物力学分析

背景：采用有限元分析法进行骨与关节的生物力学研究得到了广泛应用,但是关于胫骨远端关节面缺损有限元分析,国内外少见关于此类的报道。 目的：建立踝关节的三维有限元模型,制作胫骨远端关节面不同面积的缺损,并模拟在不同位相下胫骨远端关节面发生形变、位移情况,预测胫骨远端关节面缺损的最大允许程度和探讨踝关节创伤性关节炎的力学发病机制。 方法：通过对1名正常成年男性踝关节的多排螺旋 CT扫描,获得连续断层图片,导入Mimics 医学建模软件生成实体模型后,应用大型通用有限元分析软件ANSYS13.0进行网格划分、材料属性赋值生成有限元模型。约束边界条件,模拟踝关节远端轴向受力,得出在不同位相下胫骨远端关节面有限元模型上的应力分布与位移结果。 结果与结论：建立人体踝关节有限元模型总单元数为157 990,总节点数为193 801。3个位相,都是随着胫骨远端缺损面积的增大,接触面积逐渐减小,尤其是跖屈位在缺损直径13 mm的面积时,变化最为明显;3个位相的接触面积,在中立位接触面积最大;在中立位和背屈位都是随着胫骨远端关节面缺损面积的增大,应力峰值逐渐增大,都是在11-13 mm以后应力峰值明显增大;在中立位和背屈10°位,主要集中在后内和后外象限;在跖屈10°位,变化比较复杂,在11-13 mm,随着缺损面积的增大应力峰值变化明显增大,到13 mm应力峰值达到最大值。所以,胫骨远端关节面的最大缺损直径可认为是11-13 mm。胫骨远端关节软骨及骨床缺损直径超过11-13 mm的圆面积,关节功能将受到影响。     

利用有限元分析技术探讨后踝骨折的治疗方案

目的通过踝关节三维有限元模型,研究静止站立位后踝骨折后胫距关节面的应力变化及位移趋势,为后踝骨折的治疗提供理论依据。方法以一套正常人体站立位踝关节CT图像为原始数据,应用有限元建模技术,建立带有关节软骨的踝关节三维有限元模型,对模型的有效性进行验证。通过对后踝关节面进行分区、切割,模拟计算后踝不同骨折范围条件下施加正常应力时的关节软骨接触面积、最大接触应力、平均接触应力、最大位移等参数。结果随着骨折范围的增加,胫骨软骨接触面积呈逐渐减小趋势,胫骨软骨的平均接触应力值逐渐增大,胫骨相对位移增加。胫距关节的应力区主要集中在踝穴的外侧及前外侧,当后踝骨折面积超过1／3时,关节负重区面积明显缩小,关节位移趋势增加。结论后踝骨折面积超过1／3时,关节接触面积明显减小,应力变化明显增加,关节位移趋势增加,预后不佳,具有手术复位固定的指征。     

踝关节内翻的有限元力学分析

背景：近年来,骨科生物力学领域的研究不断成熟和发展,研究方法多采用有限元分析软件。作者检索文献发现国内外学者对于踝关节的研究也日益增多,但是所见研究均为静态状态,而且对于非中立位相踝关节损伤的研究鲜有报道。 目的：对已建立的踝关节数字模型进行有限元力学分析,观察踝关节在不同内翻角度时,其组成骨在不同空间维度上的位移、剪切力变化及应力变化规律,探讨内翻时踝关节的损伤机制。 方法：经Mimics、Geomagic和Ansys处理后,生成的踝关节三维数字模型导入软件Ansys中,经过约束条件、施加载荷、求解试算等阶段,对不同内翻角度时的踝关节各组成骨进行有限元分析。 结果与结论：实验模拟了踝关节内翻角度在10°,15°,20°,25°,30°,45°,60°,70°,80°,85°的10种不同工况,分别对踝关节进行有限元力学分析,得到其各组成骨在不同空间维度上发生的位移、剪切力和应力分布情况。分析数据,发现其所发生位移、所受应力及剪切力均随着内翻角度的增加不断增加,最大应力分布区即外踝、距骨滑车髁间线外侧部,为临床上最常见发生骨折的部位。随着内翻角度的增加,距骨x轴上发生的位移增加,从而影响整个踝关节的应力分布。     

以内踝前血管为蒂胫骨远端内侧骨膜瓣移位术的应用解剖

目的：为内踝前血管胫骨远端内侧骨膜瓣移位术提供解剖学依据。方法：30侧经动脉灌注红乳胶成年下肢标本，观测内踝前动脉的来源、走行、分支分布、邻近吻合及胫骨远端内侧面的骨膜血管结果：内踝前动脉起于胫前动脉或足背动脉，紧邻胫骨前肌腱内侧行向前内，在楔骨内缘与足底内侧动脉浅支．或跗内侧动脉后行支形成吻合。动脉滞途发出3～6支外径为03～1．0mm的内踝骨膜支，分布内踝区骨膜，并与其它来源的胫骨远端内侧而骨膜动脉相吻合。结论：以内踝前血管为蒂的胫骨远端内侧骨膜瓣，顺行移位可修复胫骨远端骨不连，顺行或逆行移位可用于修复距骨颈骨折和距骨体缺血性坏死。     

成人踝关节关节面的应用解剖学观测

目的观测成人踝关节的相关形态学指标,为踝关节损伤修复、关节置换等提供解剖学依据,同时积累国人人体解剖学资料。方法利用游标卡尺、量角器、求积仪等,对53具成人骨骼的完整踝关节进行形态学测量。结果踝关节面积：腓骨踝关节面面积（3．70±0．41）cm2,胫骨踝关节面面积（2．50±1．56）cm2,距骨滑车面积（10．60±1．87）cm2,距骨内踝关节面面积（2．20±1．86）cm2、外踝关节面面积（3．30±0．61）cm2。距骨滑车测量：距骨滑车关节凹深度（0．30±0．18）cm;内、外侧唇的高度分别为（0．50±0．21）am、（0．90±0．12）cm;前缘宽度（2．70±0．33）cm;后缘宽度（2．00±0．58）cm。踝关节各面间以及与下肢轴线的交角：内、外踝关节面与距骨滑车平面交角分别为（109．00°±1．58°）、（116．00°±1．21°）;内、外踝关节面与下肢轴线交角分别为（18．00°±1．08°）、（26．00°±1．36°）。结论踝关节损伤修复、关节置换等均应以踝关节的形态学参数为依据方能达到良好的疗效。     

距骨滑车关节面的形态对踝关节稳定性的影响

目的：探讨距骨滑车关节面的形态对踝关节稳定性的影响。方法：用电子数显游标卡尺测量了９３副（男５１，女４２）距骨滑车上关节面前、后宽和内、外侧面长４项指标，数据用ＳＰＳＳ软件处理。结果：距骨滑车面上面前宽男２９．４±２．８ｍｍ、女２７．４±２．６ｍｍ；后宽男２２．６±２．４ｍｍ、女２０．６±２．７ｍｍ；内踝面长男３２．９±３．０ｍｍ、女３０．９±２．５ｍｍ；外踝面长男２９．２±２．５ｍｍ、女２７．２±２．４ｍｍ。距骨滑车上面的前宽与后宽、内踝面长与外踝面长均具有显著性差异。结论：当踝关节跖屈时，处于一种相对不稳定性状态，易损伤。     

带血管蒂胫骨远端骨膜瓣的临床解剖学研究

目的：为设计带血管蒂胫骨远端骨膜瓣提供解剖学依据。方法：30侧经动脉灌注红乳胶成年下肢标本，观测胫骨远端内侧面、前外侧面骨膜血管的起源、走行、分支分布及与邻近动脉的吻合关系。结果：胫骨远端内侧面骨膜血管来自内踝前动脉的骨膜支3～6支，外径0．3～1．0mm。胫骨远端前外侧面骨膜血管来自外踝前动脉的骨膜支1～3支，外径0．4～0．8mm；腓动脉穿支降支的骨膜支2～4支，外径0.5～1.0mm。内踝前动脉在楔骨内缘与足底内侧动脉浅支、跗内侧动脉吻合；腓动脉穿支降支循外踝前外侧下行与外踝前动脉吻合，并沿腓骨短肌腱的前缘前行，终支与跗外侧动脉、跟外侧动脉相吻合。结论：以内踝前血管为蒂的胫骨远端内侧骨膜瓣和以外踝前血管为蒂的胫骨远端前外侧骨膜瓣，可移位修复距骨颈骨折不连和距骨体缺血性坏死。     

有限元法分析不同固定方式在胫骨远端粉碎性骨折骨愈合中的生物力学差异

背景：胫骨远端粉碎性骨折伴软组织损伤的治疗具有挑战性，新型逆行胫骨髓内钉、外置接骨板是重要的治疗手段，但其在骨折愈合不同时期、不同负重情况时的骨折端应变、应力遮挡情况未见报道。目的：通过有限元分析法探讨骨折愈合不同时期逆行髓内钉及外置接骨板的生物力学差异，为临床应用及康复锻炼提供科学参考。方法：利用1名40岁健康男性的胫骨CT数据，建立胫骨远端粉碎骨折的有限元模型，构建胫骨逆行髓内钉、外置接骨板固定模型及骨痂模型并根据骨折的固定原则进行装配。使用ANSYS软件进行有限元分析，比较骨折愈合不同时期时逆行髓内钉及外置接骨板2种固定方式的骨折端位移、胫骨应力遮挡、骨痂应力、胫骨及固定装置应力分布情况。结果与结论：(1)胫骨骨折端相对位移随着骨折愈合的进行逐渐减小，在术后3个月后位移明显减少；术后0,1个月，外置接骨板组的垂直位移及总位移均大于逆行髓内钉组，2种固定方式的Z轴位移(水平内外侧位移)均较X、Y轴位移明显，且接骨板模型的Z轴位移差异最明显；2种固定方式的Z轴位移最大位置均位于胫骨外侧，位移最小位置均位于胫骨内侧；(2)骨折愈合的应力遮挡率随骨折时间延长而逐渐降低；逆行髓内钉的应力遮...     

股骨上段应力状态分析

采用光弹性实验方法，对股骨上段模型进行应力分析，结果表明：①股骨头部较颈部应力小．颈部内侧下方应力较大为压应力，其外侧上方为拉应力，呈现出们心受压状态；②股骨距部位是股骨上段的主要承载区，该处承受较大压应力，其应力分布与骨小梁走向及股骨距处皮质增厚一致，③股骨干上段受力状态近似梁弯曲，其内外侧皮质均承受较大应力，内侧压应力幅值大于外侧拉应力。     

Biomechanically important articular surfaces in the talocrural joint.

The authors investigated the influence of relations between the utile areas of the articular faces in ankle joint in medial twisting of the foot. For their investigation they used the material from the Institute of Anatomy "Drago Perovi?", Institute of Pathology and Institute for Forensic medicine of the Medical Faculty of Zagreb. Investigations were performed in articular faces of the tibia, fibula and talus on the left and right legs of the adults. Mutual comparing of the joint faces, their areas and altitudes, angles between the medial malleolus and tibia, and the altitudes of the medial and lateral malleolus has shown great individual differences. According to these results the authors concluded that the disproportion of the articular bodies caused habitual medial twisting of the foot. The importance and the role of ligaments, muscles and joint capsule were not the object of this investigation. The obtained results are a contribution to the functional anatomy of the ankle joint, and to the clinical pathology of this region.     

成人小腿胫腓骨的应用解剖学观测

目的观测成人小腿胫、腓骨的相关形态学指标,为小腿骨折固定、自体骨移植提供解剖学依据,同时积累人体解剖学资料。方法利用游标卡尺、角规、求积仪,对52具成人出土骨骼（100侧）完整的小腿胫腓骨（左52侧、右48侧）进行形态学测量。结果成人胫骨长（35．7±1．77）cm、滋养孑L距内踝尖距离（23．8±1．46）cm、滋养孔时钟位左侧11时（5±0．25）分、右侧12时（1±0．22）分,腓切迹长（2．6±0．59）cm、宽（2．7±0．63）cm、深（0．6±0．22）cm,胫骨内踝关节面面积（2．5±1．56）cm2、下关节面面积（8．6±1．02）cm2;腓骨长（35．2±1．72）cm、滋养孔距外踝尖距离（19．3±2．04）cm、滋养孔时钟位左侧12时（2±0．21）分,右侧11时（58±0．17）分,腓骨头关节面面积（1．4±0．51）cm2,踝关节面面积（3．7±0．41）cm2,外踝沟长（2．6±0．59）cm、宽（2．7±0．63）cm、深（0．6±0．22）cm;内、外踝尖高度差（1．88±0．42）cm。结论胫腓骨骨折的固定方式、固定装置的选择,自体骨移植以及骨、关节的重建均应以两骨的形态学为依据方能达到良好的治疗效果。     

Biomechanical topography of human ankle cartilage

The material properties of normal cadaveric human cartilage in the ankle mortice (tibiotalar articulation) were evaluated to determine a possible etiologic mechanism of cartilage injury of the ankle when an obvious traumatic episode is not present. Using an automated indentation apparatus and the biphasic creep indentation methodology, creep indentation experiments were performed in five sites in the distal tibia, one site in the distal fibula, and eight sites in the proximal talus of 14 human ankles (seven pairs). Results showed significant differences in the mechanical properties of specific human ankle cartilage regions. Topographically, tibial cartilage is stiffer (1. 19 MPa) than talar cartilage (1.06 MPa). Cartilage in the anterior medial portion of the tibia has the largest aggregate modulus (H _A =1.34 MPa), whereas the softest tissue was found to be in the posterior lateral (0.92 MPa) and the posterior medial (0.92 MPa) regions of the talus. The posterior lateral ridge of the talus was the thickest (1.45 mm) and the distal fibula was the thinnest (0.95 mm) articular cartilage. The largest Poisson's ratio was found in the distal fibula (0.08). The lowest and highest permeability were found in the anterior lateral regions of the astragalus (0.80 × 10⁻¹⁵ m⁴N⁻¹sec⁻¹) and the posterior medial region of the tibia (1.79 × 10⁻¹⁵ m⁴N⁻¹sec⁻¹), respectively. The anterior and posterior regions of the lateral and medial sites of the tibia were found to be 18–37% stiffer than the anatomically corresponding sites in the talus. The biomechanical results may explain clinically observed talar dome osteochondral lesions when no obvious traumatic event is present. Cartilage lesions in a repetitive overuse process in the ankle joint may be related to a disparity of mechanical properties between the articulating surfaces of the tibial and talar regions.     

可吸收螺钉置入固定简单外踝骨折的有限元分析

BACKGROUND: Compared with the metal screws, absorbable screws have more obvious advantages, such as does not have to conduct internal fixation removal, non-metallic components, no influence on the magnetic resonance imaging of patients after implantation, relatively simple operations, namely drilling-tapping-screws fixation, more in line with the principles of minimally invasive in orthopedics. OBJECTIVE: To investigate the biomechanical characteristics of absorbable screw fixation in repair of simple lateral malleolus fractures by means of finite element technology. METHODS: The three-dimensional model of simple lateral malleolus fractures and absorbable screw model were established, and then fixed according to standard orthopedic surgical techniques. The reference load when the load bearing of fibulotalar joint reaching the peak value in a normal adult gait cycle was loaded. The stress distribution and displacement of fibula and absorbable screws were analyzed. RESULTS AND CONCLUSION: There were totally 38 542 units, 8 790 nodes in the single screw fixation model. When the articular facet of lateral malleolus loading 300 N, the maximum stress of screws was 89.35 MPa, the maximum displacement was 0.5 mm, the maximum displacement of the distal fracture was 0.5 mm. When the articular facet of lateral malleolus loading 450 N, the maximum stress of screws was 152.58 MPa, the maximum displacement was 0.59 mm, the maximum displacement of the distal fracture was 0.77 mm. There were totally 43 115 units, 9 496 nodes in the double screws fixation model. When the articular facet of lateral malleolus loading 300 N, the maximum stress of screws was 38 MPa, the maximum displacement was 0.44 mm, the maximum displacement of the distal fracture was 0.44 mm. When the articular facet of lateral malleolus loading 450 N, the maximum stress of screws was 66.68 MPa, the maximum displacement was 0.48 mm, the maximum displacement of the distal fracture was 0.49 mm. The experiment verified the biomechanical feasibility of absorbable screw fixation in repair of simple lateral malleolus fractures. For simple involving only the lower lateral fibular fracture, absorbable screw fixation is entirely feasible, and usually requires at least two screws to maintain the stability of the articular surface of the reset.       

跟骨内翻畸形对踝关节应力变化三维有限元分析

目的通过踝关节三维有限元模型的建立,模拟正常负重应力状态下随着跟骨内翻角度的增大,对踝关节的损伤模式的变化。方法取一名28岁男性志愿者,基于踝关节CT的数据建立包括骨骼、软组织和关节囊,考虑材料的非线性和关节接触的踝关节的三维有限元模型。采用统一的模型和方法,志愿者人体重量为60 kg,单腿站立,总加力600 N,垂直朝下,跟踪跟骨内翻角度从4~°、8~°、11~°、14~°的变化共四种情况力学表征形式,关注对踝关节应力分布的影响进行对比分析。应用有限元分析软件(Abaqus6 v6.14,DS System公司,法国)。结果踝关节应力集中区域在内踝与对应距骨关节面的凹陷区域,其次是外侧。距骨应力集中区域在距骨顶与内踝接触位置的区域,其次是外侧。我们发现4种情况下分析结果显示趋势一致,符合线性力学分析基本规律。结论跟骨内翻畸形负重应力集中固定在内踝、距骨接触位置,随着跟骨内翻畸形角度的增大,局部所承载的应力负荷增大,成正相关。跟骨手术治疗时跟骨内翻角变异应控制在患者跟骨生理内翻角+2°内。     

Three‐dimensional analysis of talar trochlea morphology: Implications for subject‐specific kinematics of the talocrural joint

Three‐dimensional (3D) behavior of the talocrural joint is primarily determined by the articular surface morphology of the talar trochlea and tibiofibular mortise. However, morphological features of the anterior and posterior regions of the talar trochlea remain unclear. The objectives of this study were to evaluate anterior and posterior radii of the medial and lateral talar trochlea and to estimate subject‐specific kinematics of the talocrural joint. Fifty dry tali were scanned using computed tomography to create 3D bone models. Radii of curvature of the anterior and posterior region at both the medial and lateral trochlea were calculated. Orientations of the dorsiflexion and plantarflexion axis passing through the centers of the circles fitted to the anterior region of the medial and lateral trochlea and through the centers of the circles fitted to the posterior region of the medial and lateral trochlea were evaluated, respectively. The anterior radius of the medial trochlea was significantly smaller than that of the lateral trochlea by a mean of 7.8 mm (P < 0.001). The posterior radius of the medial trochlea was larger than that of lateral trochlea in 30 samples (60%) and vice versa in 20 samples (40%). Unilateral asymmetric shape of anterior trochlea would induce external rotation of the talus during ankle dorsiflexion, whereas bilateral asymmetric shape of posterior trochlea would induce opposite axial rotations among subjects during ankle plantarflexion, which would help the physical therapists to restore talocrural joint motions to ideal state for patients with ankle injuries. Clin. Anat. 29:1066–1074, 2016. © 2016 Wiley Periodicals, Inc.