膝关节三维有限元模型建立和验证及模拟后交叉韧带重建术

目的建立健康成年人膝关节三维有限元模型并进行验证,在此基础上建立模拟后交叉韧带单束重建术的股骨、胫骨隧道和移植物模型,为进一步分析奠定基础。方法以MRI作为数据源,运用医学制图软件Mimics,逆向工程软件Geomagic studio、Solidworks及有限元分析软件Abaqus,参考大量有关实验的文献报道,建立所需三维有限元模型。验证模型:模拟膝关节在屈曲0°情况下,对股骨施加后向134 N集中力,得出胫骨股骨相对位移及主要韧带受力分布与已报道文献进行比较;模拟膝关节屈曲0°情况下,加载垂直方向395 N集中力(单腿站立时下肢受力),得出软骨及半月板von Mises应力并与已报道文献进行比较。结果建立的膝关节三维有限元模型包括股骨下段、胫腓骨上段、髌骨、股骨软骨、胫骨软骨、髌骨软骨、髌韧带、内外侧半月板、前后交叉韧带、内外侧副韧带,几何形状良好。模型验证:股骨相对胫骨前后、远近及内外方向上位移分别为4.52 mm、0.35 mm和1.12 mm,此时韧带应力主要分布在前交叉韧带股骨附着处和体部且股骨附着处最大,与类似实验报道结果一致,且与临床结论前交叉韧带主要限制胫骨前移、在股骨附着处易发生断裂一致;半月板承担主要应力且内侧大于外侧,主要分布在内缘,最大应力值为1.65 MPa,其次胫骨软骨最大应力为1.05 MPa,股骨软骨应力最小,主要受力部位在内侧,为0.78 MPa;与已报道文献及尸体解剖力学实验结果一致,验证了该模型的有效性,在此基础上模拟建立后交叉韧带单束解剖重建股骨、胫骨隧道和移植物模型,基本可以满足有限元分析的需要。结论采用MRI图像建立膝关节三维有限元模型切实可靠,能很好地模拟膝关节解剖结构及后交叉韧带重建术中的股骨、胫骨隧道并满足生物力学的研究。     

内侧副韧带不同程度损伤时膝关节的应力变化

背景:膝关节内侧副韧带损伤易导致继发性的半月板及软骨损伤,长期慢性损害会引起骨关节炎的发生。目前,关于内侧副韧带断裂所致半月板及关节软骨损伤的力学研究较少。目的:探讨膝关节内侧副韧带不同程度损伤对膝关节半月板及软骨生物力学的影响。方法:选择一名健康志愿者行膝关节CT和MRI检查,获取其影像资料,将扫描数据依次导入Mimics、Geomagic及Solidworks软件,经配准融合后建立正常膝关节三维模型,并在此基础上模拟出膝关节内侧副韧带不同程度损伤的模型,共分为4组,包括:①内侧副韧带完整;②内侧副韧带深层断裂;③内侧副韧带浅层断裂;④内侧副韧带完全断裂。最后导入Ansys软件,对膝关节施加3种模式载荷:①股骨顶端施加10 N·m外翻力矩;②股骨顶端施加4 N·m内旋力矩;③股骨顶端施加4 N·m外旋力矩。分析4组模型在不同载荷下对膝关节生物力学的影响。结果与结论:①在膝关节伸直位,对膝关节施加10N·m外翻力矩时,内侧副韧带不同程度损伤后外侧半月板总体应力均增加,关节软骨应力变化不明显,并且当内侧副韧带浅层出现断裂后外侧半月板应力峰值明显增大;②在膝关节伸直位,对膝关节施加4 N·m内旋力矩时,内侧副韧带不同程度损伤后内外侧半月板总体应力均增加,当内侧副韧带浅层出现断裂时半月板应力峰值从内侧半月板前角转移至外侧半月板前角;③在膝关节伸直位,对膝关节施加4 N·m外旋力矩,内侧副韧带不同程度损伤后外侧半月板应力峰值较内侧半月板增加更明显,关节软骨应力变化较小;④结果表明,膝关节处于伸直状态下,膝关节内侧副韧带浅层断裂继发半月板损伤的风险远大于内侧副韧带深层断裂,而外侧半月板较内侧半月板更易受到损伤;内侧副韧带浅层和深层对膝关节的旋转稳定性均有重要作用。     

膝关节后外侧结构生物力学的有限元分析

背景：有限元分析作为一种数值分析手段,适用于三维人体结构力学模型的生物力学分析。 目的：采用有限元分析膝关节后外侧结构主要韧带(外侧副韧带、腘肌腱和腘腓韧带)的生物力学特点。 方法：建立人膝关节包括后外侧结构的三维有限元模型,在模型上施加胫骨的前后向力、内外翻力矩、内外旋力矩,观察膝关节后外侧韧带在完整和缺失时的应力响应。 结果与结论：膝关节后外侧结构对限制膝关节的内翻、外旋和胫骨后移有重要作用,而对限制胫骨前移、外翻和内旋的作用并不明显。膝关节后外侧结构损伤对膝关节的稳定性有明显影响。在膝关节后外侧结构中起主要作用的是外侧副韧带,其次是腘肌腱,而腘腓韧带在后外侧结构中起辅助作用。     

不同屈曲状态下肘关节内侧副韧带生物力学的有限元分析

通过建立肘关节三维有限元模型,研究内侧副韧带维持肘关节稳定性的作用。本文基于正常人体肘关节计算机断层扫描(CT)图像数据,运用逆向工程方法建立肘关节三维几何模型。在有限元前处理软件中根据解剖学结构直接构建韧带和关节面软骨,并为模型赋予材料及接触。通过将处于中立0°位的肘关节仿真与试验数据对比,验证了模型的有效性。继而计算肘关节中立位分别屈曲15、30、45、60、75、90、105、120、135°时内侧副韧带的应力大小及分布。结果表明肘关节在不同屈曲角度受力时,内侧副韧带前束承受的应力最大,后束次之,斜束承受的应力最小,数值趋于0。由此可以推断,肘关节内侧副韧带在维持肘关节稳定方面,前束起主导作用,后束起辅助作用,斜束起的作用最小。本研究可为由内侧副韧带损伤所引起的肘关节不稳定的临床治疗提供理论依据。     

基于CT和MRI膝关节有限元模型建立与不同载荷下生物力学特性分析

基于CT和MRI图像数据建立膝关节有限元模型,采用六面体网格对不同载荷系统下人体膝关节生物力学特性进行研究,并进行有效性验证。建立膝关节有限元模型包括:股骨、胫骨、髌骨、腓骨、股骨软骨、胫骨软骨、腓骨软骨、半月板、前后交叉韧带、内外侧副韧带、髌韧带和股四头肌腱等。对膝关节施加1 kN轴向压缩载荷、134 N后向抽屉力和5、10、15 N[?m内翻力矩和外翻力矩,分析膝关节内软骨和半月板的接触应力和接触面积,股骨内外翻倾角以及位移变化情况。在1 kN压缩载荷和134 N抽屉力作用下,股骨软骨、内外侧半月板和内外侧胫骨软骨的接触应力峰值分别为4.47、3.25、2.83、2.70、2.53 MPa,Von Mises应力峰值分别为2.22、2.44、2.25、2.07、1.64 MPa。股骨相对胫骨前向位移为4.19 mm。施加5、10、15 N[?m内翻和外翻力矩时,股骨内翻和外翻倾角分别为3.49°、4.48°、4.91°和3.22°、3.62°、4.01°。随着力矩的线性增大,膝关节各组成部分的应力呈非线性变化趋势。膝关节软骨、半月板和韧带的研究结果符合其生物力学特性,与前人数值分析和实验研究结果相一致,可为临床膝关节生理病理分析和治疗提供一定的理论依据。     

人体全膝关节精细有限元模型建立及有效性验证

近年来利用数字三维模型对人体全膝关节进行生物力学分析在国内外迅速发展,但是缺乏完整精细的膝关节有限元模型;同时对所建立模型的验证也比较单一,仅从韧带或者软骨受力单方面进行有效性的验证,导致模型的实用性和广泛性受到限制。目的以一种创新、高效的方法三维重建精细人体膝关节有限元模型,包括股骨、胫骨、髌骨、腓骨、股骨软骨、胫骨软骨、髌骨软骨、腓骨软骨、半月板、交叉韧带、侧韧带、髌韧带等组织结构,并对整体模型有效验证。方法利用CT和MRI医学影像,使用Mimics、3-Matic、Geomagic、Solidworks、Abaqus软件获得完整、精细的人体膝关节模型;在内外髁中点施加1 000 N竖直向下载荷,分析膝关节内外间室的力学分布及软骨的力学响应;以胫骨平台髁间隆起为参考施加134 N前向推力,模拟临床中的抽屉实验(ADT),获取各韧带组织的生物力学响应,并与现有人体实验及模型对比。结果 1 000 N载荷下,股骨软骨最大Mises应力值为2.514 MPa,半月板最大Miese应力值为7.693 MPa,胫骨软骨最大Mises应力值为1.848 MPa,均分布于膝关节的内侧;内外侧软骨接触面积分别为476.080 8 mm~2和338.446 8 mm~2;内外腔室分别承担总载荷的60.57%和39.43%。134 N载荷下,胫骨平台前端的位移量为5.687 mm;前十字交叉韧带(ACL)最大Mises应力值为28.030 MPa,后十字交叉韧带(PCL)最大Mises应力值为16.730 MPa,内侧副韧带(MCL)最大Mises应力值为4.511 MPa,外科韧带(LCL)最大Mises应力值为3.751 MPa;交叉韧带与股骨止点的最大Mises应力值为15.270 MPa。结论建立的精细膝关节三维模型很好地重塑了人体膝关节相关生物力学特性;该精细膝关节模型仿真结果与现有实验数据非常接近,证明了模型的有效性;完整、有效的精细全膝关节有限元模型将为植入物手术、人体运动分析、康复研究等打下基础。     

电针治疗膝骨性关节炎患者上下楼梯的三维有限元分析

针对电针治疗膝骨性关节炎患者上下楼梯运动生物力学特性改变进行有限元仿真研究,对比分析膝关节生物力学行为改变与电针治疗疗效的相关性。基于CT和MRI图像数据,结合Mimics和Geomagic医学图像处理软件,建立人体膝关节下楼梯屈曲15°和上楼梯屈曲50°时的三维有限元模型,模型包括股骨、胫骨、腓骨、内外侧半月板、股骨软骨、内外侧胫骨软骨结构等。通过临床力学实验,测取电针治疗前后膝关节所受支反力、力矩,并施加于所建立的有限元模型,对比分析治疗前后半月板及关节软骨的应力分布情况。膝骨性关节炎在电针治疗后,内外侧半月板、股骨软骨、内外侧胫骨软骨的应力均得到不同程度的恢复,与治疗前相比,下楼梯屈曲15°时最大应力值分别减小0.543、0.236、0.194、0.239和0.327 MPa,上楼梯屈曲50°时分别减少0.253、0.31、0.227、0.112和0.122 MPa,软骨的应力峰值趋向于正常值,应力分布范围也更接近于正常膝关节,且关节内侧软骨及半月板比外侧受到的负荷大,软骨应力比更接近于正常值,这与临床上内侧型膝骨性关节炎患者多于外侧型患者的现象相符合,从而证明电针治疗可影响膝关节中力的传递,使病变膝关节的应力吸收能力得到改善和提高。电针治疗膝骨性关节炎能有效改善关节软骨的压应力,使关节内力平衡得到恢复,延缓关节软骨退变,促进关节软骨的修复;电针治疗下膝关节生物力学特性的研究,可为膝关节临床治疗和评价提供理论依据。     

前交叉韧带损伤膝关节侧副韧带长度的变化(英文)

背景:侧副韧带对膝关节的稳定性起着重要的作用,通过2D/3D图像配准技术可以实现膝关节的运动还原并获得前交叉韧带损伤后生理屈曲过程中内侧副韧带和外侧副韧带长度变化规律。目的:对前交叉韧带损伤膝关节侧副韧带长度变化进行运动还原体内稳定性研究。方法:选择单侧膝关节前交叉韧带断裂而对侧正常的8例患者,在生理负重屈曲采集0°,15°,30°,60°和90°时的相互垂直的2D图像,与CT(3D)图像在虚拟X射线投射系统进行2D/3D图像配准,还原膝关节不同角度时的股骨和胫骨相对3D位置关系,并通过韧带止点还原的方法对内侧副韧带、外侧副韧带进行韧带长度分析,并对比两侧。结果与结论:内侧副韧带损伤后在0°,15°和30°患膝内侧副韧带长度较健膝增加;内侧副韧带损伤后在0°、15°和30°患膝外侧副韧带长度较健膝减少,差异均有显著性意义(P0.05)。结果提示,在0°、15°和30°,前交叉韧带损伤后患膝内侧副韧带长度较健膝增加,而外侧副韧带长度较健膝缩短。     

不同屈曲角度时内侧髌股韧带重建的有限元分析

背景：内侧髌股韧带重建是目前治疗髌骨外侧脱位最常用的方法，最终目的是将髌骨调整到正常的解剖位置，恢复髌骨轨迹，目前内侧髌股韧带重建的主要核心问题在于其股骨端固定点的选取上。目的：运用有限元方法分析膝关节不同屈曲角度时重建内侧髌股韧带对髌骨的限制作用，模拟不同股骨端固定点重建内侧髌股韧带对髌骨的限制作用，为内侧髌股韧带重建时股骨端固定点的选取提供帮助。方法：依据提取的膝关节CT与MRI数据建立包含骨骼及软组织的膝关节有限元模型，在模拟膝关节30°与60°屈曲角度时，选取不同的股骨端固定点构建内侧髌股韧带，比较不同点位时髌股关节间接触应力与接触面积，以及对髌骨横向约束力的大小。对不同屈曲角度时相同股骨端固定点所构建的内侧髌股韧带等长性进行验证，以研究各种内侧髌股韧带重建位置的效果。结果与结论：(1)建立了30°与60°屈曲角度时膝关节的三维有限元模型，构建了不同股骨端固定点的内侧髌股韧带，不同屈曲角度时相同股骨端位置构建的内侧髌股韧带具有可用的等长性；(2)对髌骨向外侧施加位移后，在横向方向上，不同股骨端固定点构建的内侧髌股韧带对髌骨产生了不同的横向约束力，在前端10 mm处时横向约束力最...     

膝关节屈伸运动形态的有限元分析

背景:三维有限元分析在骨科中被广泛应用,在膝关节屈曲运动中的研究不多。目的:对膝关节屈曲运动的生物力学特性进行三维有限元分析。方法:建立膝关节的三维有限元模型以及膝关节屈曲30°,60°以及120°时的三维有限元模型,分析膝关节不同屈曲位股骨前移情况、股骨内移情况、胫骨内旋情况和胫骨内翻情况。结果与结论:(1)股骨前移:在膝关节屈曲30°,60°和120°时股骨均出现后移,膝关节屈曲60°时的股骨后移值大于屈曲30°和屈曲120°(P0.05);膝关节屈曲120°股骨后移值大于屈曲30°,但差异无显著性意义(P0.05);(2)股骨内移:在膝关节屈曲30°时股骨外移,在膝关节屈曲120°时膝关节内移,膝关节屈曲120°时股骨内移值明显大于屈曲30°和屈曲60°时(P0.05);膝关节屈曲30°和屈曲60°时外移值比较差异无显著性意义(P0.05);(3)胫骨内旋:在膝关节屈曲30°,60°和120°时胫骨均出现内旋,3者比较差异均无显著性意义(P0.05);(4)胫骨内翻:在膝关节屈曲30°,60°和120°时胫骨均出现内翻,其中屈曲120°时胫骨内翻不明显,膝关节屈曲60°时胫骨内翻度数最大,明显高于屈曲120°时(P0.05);膝关节屈曲30°时胫骨内翻度数大于屈曲120°时,但差异无显著性意义(P0.05);(5)结果表明,膝关节在屈曲60°时股骨后移最明显,膝关节屈曲120°时股骨内移值最大,膝关节屈曲30°和屈曲120°时胫骨内旋明显,膝关节屈曲60°时胫骨明显内翻。     

Structure and Function of the Healing Medial Collateral Ligament in a Goat Model

In this study knee joint function with a healing medial collateral ligament (MCL) at six weeks was examined with a robotic/universal force-moment sensor testing system during the application of two loading conditions: (1) 5 N m valgus moment and (2) 67 N anterior load. Additionally the structural properties of the femur–MCL–tibia complex and the mechanical properties of the MCL substance were determined by uniaxial tensile tests. The histological appearance of the healing MCL was also observed. At 30° and 60° of knee flexion, valgus rotation of the healing knee was significantly increased compared to the sham. The in situ force in the healing MCL was significantly lower (34±17 N vs 54±12 N) at the same flexion angles (50±10 N vs 62±7 N). The anterior translation of the knee had returned to normal values at 30° and 60° of knee flexion. However, no differences could be found between the corresponding in situ forces in the healing MCL at all flexion angles examined during application of an anterior load. The stiffness of the healing group (52.5±19.4 N/mm) was significantly lower than the sham group (80.3±26.4 N/mm) (p < 0.04). The modulus of the healing group was also significantly decreased (p < 0.05). The findings suggest that the tensile properties of the healing goat MCL and valgus knee rotation have not returned to normal at six weeks after an isolated MCL rupture, however, anterior translation appeared to return to sham levels. © 2001 Biomedical Engineering Society. PAC01: 8719St     

女性全身关节过度活动患者跳深着陆时膝关节应力分析

目的 分析全身关节过度活动(generalized joint hypermobility, GJH)女性患者与健康女性在跳深着陆中膝关节软骨、半月板von Mises应力分布差异。方法 采集女性GJH患者与女性健康受试者在跳深着陆缓冲阶段垂直地面反作用力(vertical ground reaction force, VGRF)峰值时刻的膝关节运动学与地面反作用力特征,通过逆动力学计算膝关节反作用力,并将膝关节沿股骨长轴方向的合力作为载荷;基于1名女性膝关节三维有限元模型,分别对2组受试者跳深着陆过程进行数值仿真,计算膝关节软骨与半月板von Mises应力及应力分布。结果 在跳深着陆VGRF峰值时刻,GJH组和对照组膝关节屈曲、外翻角度具有统计学意义(P<0.05)。相比于对照组,GJH组膝关节屈曲角度降低、外翻角度增加;在跳深着陆中,GJH组膝关节内部承受应力更大且胫股关节内、外侧室负重区应力分布不均衡,其股骨软骨外侧髁外侧、外侧胫骨软骨前部/中部外侧以及外侧半月板前角、体部外侧缘为应力集中部位。结论 女性GJH患者因膝关节活动范围增大、关节囊松弛,导致在跳跃类项目中膝关节...     

A comparison of tibiofemoral and patellofemoral alignment during a neutral and valgus single leg squat: an MRI study

BackgroundThe etiology of anterior knee pain is not well understood. Recently, excessive hip adduction and internal rotation have been cited as possible factors. However, how these altered hip mechanics affect the patellofemoral joint is still unclear.ObjectiveTo compare the three-dimensional tibiofemoral and patellofemoral alignment between a neutral squat and one performed with increased hip adduction and internal rotation. We aimed to examine the relationships between the three-dimensional tibiofemoral and patellofemoral alignment during a neutral and valgus squat. Finally, we aimed to determine the relationship between two-dimensional and three-dimensional measures of patellofemoral alignment.Methods10 healthy subjects were recruited for this study. Knee and patellar kinematics in a neutral squat and one performed with hip adduction and internal rotation were measured using a open, upright, magnetic resonance imaging unit. Both single leg squats were performed at 30° of knee flexion.ResultsThere was a significant correlation between knee external rotation and lateral patellar translation, and between knee abduction and lateral patellar translation. Moderate relationships were found between the 2D and 3D measures but these were not statistically significant.ConclusionThe valgus squat resulted in greater knee external rotation in all subjects. Although mean patellar mechanics were not different in the valgus squat, lateral patellar translation increased as knee external rotation increased. Lastly, 2D measures of patellofemoral alignment only provide moderately fair surrogates for 3D measures.     

UKA假体后倾角安装位置对衬垫磨损的影响

目的 研究单髁膝关节置换(unicompartmental knee arthroplasty,UKA)假体不同后倾角度安装对膝关节承载、运动及衬垫磨损的影响。 方法 联合 UKA 骨肌多体动力学模型、有限元模型和磨损模型,分析固定式 UKA 假体 5种后倾角安装位置情况对术后膝关节力和运动、衬垫接触应力、线性磨损深度和体积磨损量的影响。 结果 后倾角 0°时,衬垫的最大 von Mises 等效应力为 24. 84 MPa,接触应力为 47. 61 MPa,5百万次循环(million cycle, MC)周期的磨损量为 47. 29 mm3。 随着 UKA 胫骨假体后倾角的增加,步态周期内旋和后移运动均增大,摆动相的内侧关节力增大,5 MC 磨损周期后衬垫 von Mises 等效应力与接触应力显著减小,衬垫的磨损面积、最大线性磨损深度和体积磨损量随之减少。 相对于后倾角 0°,后倾角为 3°、5°、7°时衬垫的线性磨损深度分别减小了 17. 8% 、19. 2% 、20. 6% ;衬垫体积磨损量分别下降了 24. 5% 、30. 9% 、34. 3% 。 结论 UKA 假体考虑后倾角安装超过 3°时会显著增加步态周期内旋运动和后移运动,减小聚乙烯衬垫关节面的磨损。     

The effect of tibiofemoral loading on proximal tibiofibular joint motion

The human proximal tibiofibular joint (PTFJ) and its relationship to overall knee joint mechanics have been largely unexplored. This study describes force/displacement data from experiments done on four human cadaveric knee specimens and general conclusions obtained with the help of a statistical modeling technique. Specimens were rigidly affixed at the tibia to a force plate and the femur was attached to a custom made device allowing for manual load application. Motion of the fibular head was tracked relative to the tibial plateau by means of reflective markers and a high speed digital camera synchronized with the force plate data stream. Each specimen was subjected to a range of loading conditions and a quadratic regression model was created and then used to predict the specimen's response to standardized loading conditions and compare these across specimens. Statistical analysis was performed with a three-factor analysis of variance with repeated measures. Proximal tibiofibular joint motion was largest in the anterior-posterior direction with translations of 1-3 mm observed during a range of physiological loading conditions. The applied internal-external rotation moment had a significant effect on proximal tibiofibular joint translation (P < 0.05). Effects of varus-valgus loading and flexion angle were seen in some specimens. This study demonstrates that substantial proximal tibiofibular joint motion can occur in physiologic loading states. Preservation of proximal tibiofibular joint function, and anatomical variations which affect this function, may need to be considered when designing surgical procedures for the knee joint.     

Contact stresses in the knee joint in deep flexion

The contact stresses in the knee that arise from activities involving deep flexion have not been given due consideration in view of social and cultural practice amongst many Asians that frequently cause the engagement of these activities. Excessively large stresses (>25 MPa) can cause cartilage damage and may be the precursor to the development of degenerative disease of the joint. In this study, forces in the knee derived from previous studies of human walking and squatting were applied to five cadaver knees that underwent quasi-static mechanical testing. This was conducted using a materials-testing machine and a custom-made apparatus that allowed secure and consistent loading of the knee specimen in flexion beyond 120 degrees. A thin-film electronic pressure transducer was inserted into the cadaver tibiofemoral joint space to measure force and area. Throughout the various positions simulating specific phases of walking, it was found that stresses peaked to 14 MPa (standard deviation was 2.5 MPa). In deep flexion, the peak stresses were significantly larger by over 80%, reaching the damage limits of cartilage. The results from this biomechanical study suggest that the adequacy of articular cartilage to support loads in the knee joint during deep flexion may be questionable.     

The effect of anterolateral ligament reconstruction on knee constraint: A computer model-based simulation study

BackgroundTo determine the influence of anterolateral ligament reconstruction (ALLR) on knee constraint through the analysis of knee abduction (valgus) moment when the knee is subjected to external translational (anterior) or rotational (internal) loads.MethodsA knee computer model simulated from a three-dimensional computed tomography scan of healthy male was implemented for this study. Three groups were designed: (1) intact knee, (2) combined Anterior Cruciate Ligament (ACL) and Antero-Lateral Complex (ALC) deficient knee, and (3) combined ACL and Antero- lateral Ligament (ALL) reconstructed knee. The reconstructed knee group was subdivided into four groups according to attachment of reconstructed anterolateral ligament to the femoral epicondyle. Each group of simulated knees was placed at 0°, 10°, 20°, 30°, 40° and 50° of knee flexion. For each position an external anterior (drawer) 90-N force or a five-newton meter internal rotation moment was applied to the tibia. The interaction effect between the group of knees and knee flexion angle (0–50°) on knee kinematics and knee abduction moment under external loads was tested.ResultsWhen reconstructed knees were subjected to a 90-N anterior force or a five-newton meter internal rotation moment there was significant reduction in anterior translation and internal rotation compared with deficient knees. Only the ALLR procedure using posterior and proximal femoral attachment sites for graft fixation combined with ACL reconstruction allowed similar mechanical behavior to that observed in the intact knee.ConclusionsCombined ACL and ALLR using a minimally invasive method in an anatomically reproducible manner prevents excessive anterior translation and internal rotation. Using postero-proximal femoral attachment tunnel for reconstruction of ALL does not produce overconstraint of the lateral tibiofemoral compartment.     

In vivo kinematic comparison before and after mobile-bearing unicompartmental knee arthroplasty during high-flexion activities

BackgroundMany patients who undergo unicompartmental knee arthroplasty (UKA) have an expectation that their knee flexion would increase following its replacement. Additionally, the survival rate of mobile-bearing UKA (MB-UKA) is high. However, the effect on the patient's kinematics remains unknown. This study aimed to clarify the kinematic effect of MB-UKA knees during high-flexion activities by comparing the in vivo kinematics before and after surgery.MethodsA squatting motion was performed under fluoroscopic surveillance in the sagittal plane before and after MB-UKA. To estimate the spatial position and orientation of the knee, a two-dimensional/three-dimensional registration technique was used. The femoral rotation and varus–valgus angle relative to the tibia and anteroposterior (AP) translation of the medial and lateral side of the femur on the plane perpendicular to the tibial mechanical axis in each flexion angle were evaluated.ResultsRegarding the varus–valgus angle, the preoperative knees indicated a significant varus alignment compared with the postoperative knees from 10° to 60° of flexion. There were no significant differences in the femoral rotation angle, AP translation, and kinematic pathway before and after MB-UKA in the mid-flexion of the range of motion.ConclusionThere were differences between the varus–valgus knee kinematics before and after MB-UKA, from 10 to 60° of flexion, but no difference from midrange of flexion to deep flexion. In addition, the rotational knee kinematics before and after MB-UKA was not significantly different.     

UKA 关节线安装误差对膝关节接触力学和运动学影响

目的 针对单髁膝关节置换(unicompartmental knee arthroplasty, UKA)内侧假体松动和外侧关节软骨退化问题,通过骨肌多体动力学方法研究不同生理活动中UKA关节线安装误差对膝关节接触力学和运动学的影响。方法 以内侧自然关节线为0 mm误差,分别考虑±2 mm、±4 mm、±6 mm共6种关节线安装误差情况,建立7个内侧UKA置换的骨肌多体动力学模型,对比研究步行和下蹲运动中膝关节接触力学和运动学的变化。结果 在步行步态周期70%时,相比于0 mm误差UKA假体关节线升高2 mm时内侧假体接触力增大127.3%,外侧软骨接触力减少12.0%;在UKA假体关节线降低4 mm时内侧假体接触力接近0 N,外侧软骨接触力增大10.1%;胫股关节总接触力在关节线升高和降低2 mm时分别增大19.7%和减小14.2%。在下蹲屈膝100°时,相比于0 mm误差膝关节内侧假体接触力和胫股骨关节总接触力在UKA假体关节线升高2 mm时分别增大31.6%和11.1%,在UKA假体关节线降低2 mm时分别减小24.5%和8.5%,而膝关节外侧软骨接触力变化不大。同时,在步行步态...