人体膝关节股胫关节运动特性分析

目的　分析人体正常膝关节和人工膝关节高屈曲活动下股胫关节的运动,为膝关节运动特性研究、假体设计提供参考。 方法　选取健康志愿者,利用CT和MRI扫描数据建立正常全膝关节三维有限元模型以及TKA术后有限元模型,采取三束股四头肌肌力非同步变力加载,模拟人体下蹲运动,以分析股胫关节的相对运动特性,并检索相关研究结果以便对比分析。 结果　获得正常膝关节以及TKA术后人体下蹲过程中股骨相对胫骨的三维相对运动数据,结果表明,TKA术前、后股胫关节相对运动的总体趋势相近,同时在前后位移、远近位移、内外位移、内收外展和内外旋等最大值方面存在差异;同时通过对比分析TKA前后股胫关节相对运动以及相关文献数据,发现结果存在不同程度差异。 结论　究其原因,正常膝关节相对运动差异主要在于股胫关节各个运动方向上和不同屈曲度时约束程度的改变;人工膝关节相对运动差异主要来源于膝关节型面和结构的改变;同时与坐标系的定义、在体和离体的差异、负荷加载的差异相关。本研究针对人体正常膝关节和TKA术后膝关节股胫关节运动进行有限元仿真分析,对膝关节运动特性研究具有一定的参考价值。     

人体膝关节动态有限元模型及其在TKR中的应用

目的 研究膝关节高屈曲活动下运动和应力等的动态特征。为膝关节生物摩擦学研究提供相对运动和应力分布等生物力学数据 方法 建立包括人体主要骨与软组织的全膝关节置换前后的膝关节的动态有限元模型,对天然及全膝置换后膝关节下蹲运动和接触应力分布进行分析,并与相应的尸体实验的结果进行验证分析。结果 通过有限元分析,获得高屈曲膝关节的三维相对运动参数,胫股关节和髌股关节的接触位置和应力等动态力学参数。有限元分析结果表明,分别在膝关节过伸和高屈曲时,在胫骨高分子聚乙烯平台的胫骨平台轮柱和平台前部的交界处、胫骨平台内后方和轮柱后部三个区域发生较高的接触应力。这些也正是假体发生较高磨损率的区域 结论 所建立的有限元模型能够对于膝关节下蹲动作的运动、接触等力学行为进行评估,为临床膝关节全膝置换术、膝关节假体的摩擦学研究及其膝关节假体设计提供有力的分析工具。     

骑行时不同屈曲角度膝关节软骨受力分析

在对骑行人车系统动力学研究的基础上,分析在骑行周期内膝关节软骨的受力状态,以期获得关节软骨受力的规律,增加对骑行时膝关节生物力学特性的理解。基于有限元分析法,建立包括股骨、胫骨、腓骨、髌骨、关节软骨、半月板及韧带组织的人体全膝关节有限元模型。将骨组织刚体化,并对其施加屈曲位移边界条件,包括胫骨相对股骨的内旋、内收、前移和外移以及髌骨相对股骨的屈曲、内旋、内倾以及外移。通过显式动力学分析计算,获得膝关节屈曲60°、80°和100°相位,同时得到骑行状态上述屈曲位处膝关节软骨的应力分布。结果 通过有限元分析,获得骑行姿态下膝关节相关相位的力学分布规律。结果表明,相同载荷下,最大von-Mises应力出现在屈曲100°位置,股骨软骨应力增幅达71.25%,髌骨软骨增大29.36%;随着骑行屈曲角度的增加,胫股关节高应力区逐渐向膝关节后部转移,髌股关节软骨受力逐渐上移。骑行时高应力发生在膝关节屈曲角度较大位置,胫骨平台软骨后侧、髌骨软骨上侧承受更大应力。     

膝关节动态有限元模型的力学分析

背景：膝关节具有解剖结构复杂性,活动多样性的特点。目前人体膝关节的生物力学研究由于不能进行直接的人体实验而进展缓慢,在尸体上进行实验又不具备正常人体的生理环境,其实验结果并不准确。 目的：采用了工程学的有限元分析方法,在无创、活体的条件下,研究膝关节各部位的受力情况。 方法：利用CT图像建立膝关节的三维动态有限元模型,在膝关节0°-90°范围内分析前后交叉韧带和髌股关节的受力。 结果与结论：前交叉韧带在屈膝0°时张力最大,然后逐渐减小,在屈膝50°-90°之间无明显变化,而后交叉韧带恰恰相反,在屈膝0°-50°时变化不大,之后逐渐增大,屈膝90°时达到最大值。髌股关节受力分析发现,髌股关节的压力是随着角度逐渐增大的。提示膝关节动态三维有限元模型能够逼真模拟膝关节活动,研究正常人膝关节各部位的受力,是骨科生物力学分析的有效工具。     

人工膝关节的生物摩擦学特点

目的:探讨膝关节屈曲活动时的动态特征,为人工膝关节生物摩擦学的研究提供相对运动和应力分布等生物力学数据。方法:由第一作者采用电子检索的方式,在中国期刊全文数据库(CNKI:1994/2009)中检索有关人工膝关节运动及摩擦的文献,检索词为"膝关节假体,生物力学,磨损颗粒,仿生滑液"。排除较陈旧的文章及重复性研究,共检索到符合标准的文献22篇。结果:建立包括人体主要骨与软组织的全膝关节置换前后的膝关节的动态有限模型,通过有限元分析,获得与屈曲膝关节的三维相对运动参数,胫骨关节和髋股关节的接触位置和应力等动态力学参数。结论:人工膝关节磨损性能受到较多因素的影响,多数学者在研究这些因素时以单因素研究为主,对多因素研究较少而且研究主要集中于对实验结果的描述,很少有对关节运动及磨损机制进行深入研究的报道。对人工膝关节运动及摩擦性能的研究需要把运动学和力学与磨损状态结合起来,共同期待今后进行磨损状况的预测。     

膝关节矢状面机构模型

建立矢状面上膝关节二维机构模型，求解矢状面髌股关节求解屈膝过程中髌骨与股骨的接触点移动，髌骨倾角、髌韧带倾角变化，髌股关节功能角变化以及髌股接触力和髌韧带作用力的变化等髌股关节运动及动力学参数．依据膝关节主要组成部分的功能及相互间连接关系，以股胫关节交叉四连杆模型为基础，通过对髌股关节的几何描述及力平衡限定，并运用ADAMS软件进行分析计算，计算结果与文献实验结果吻合良好。     

正常髌股关节在体运动学研究回顾

髌骨轨迹不良被认为是引起髌股疼痛综合征的主要病理生理机制之一。本文回顾迄今已发表的正常髌股关节运动分析结果，介绍正常髌股关节在不同功能活动下的6自由度运动动态特征。髌骨内外移位、翻转、前后移位以及屈曲在不同的功能运动中都存在较为统一的运动模式。然而，不同测量方法限制了研究之间的深入比较。今后广泛运用动态磁共振成像（magnetic resonance imaging,MRI）或/和双平面正交荧光透视成像系统（dual fluoroscopic imaging system，DFIS），规范坐标系的建立或骨性形态参数的定义与使用，并增加实验的样本量，将有助于明确在体髌股关节6自由度运动的特征，完善对髌股关节动态功能的临床评价依据。     

膝关节病变的髌骨振动

利用行关节镜检查之便，在病人同意下，我们首先在体内证明了生理性髌股关节摩擦音（ＰＰＣ）讯号系由髌股关节的关节软骨摩擦而来。本文研究１７例（１７个膝关节）因运动伤害接受膝关节镜检查的病人和２４例（３６个膝关节）进行全人工膝关节置换的病人。将术前测量的ＰＰＣ讯号与手术所见关节病变比较。另外也包括了五例年青正常人和五例老年正常人ＰＰＣ，作为年龄对照组比较。正常人ＰＰＣ可以全程出现，均方根（ＲＭＳ）值６７．３ｍｖ；老年正常人为４３．９ｍｖ。有膝关节运动伤害而髌股关节完整者为４６．０ｍｖ。退化性关节炎病人ＲＭＳ平均值为１８．４ｍｖ、比其他各组的ＲＭＳ值小（Ｐ＜０．００１）。按病变情况可将ＰＰＣ讯号区分为三种类型：第一型只有膝关节弯曲伸直部分周期出现正常ＰＰＣ讯号，表示髌股轨道仍有软骨完好的地方。第二型为全周期ＰＰＣ讯号减小，表示退化性变化相当厉害，软骨多处磨损，但髌骨关节面尚属完好。第三型则全周期ＰＰＣ讯号消失表示退化性关节炎普及整个关节面，髌骨的软骨已磨损。ＰＰＣ量测简单、非侵袭性，可以判断髌股关节软骨病变的程度和范围，其临床应用潜力很大。     

膝关节参数在膝前疼痛中的意义

背景：膝关节参数如合适角异常对于膝前疼痛有统计学意义已在CT测量下证实,但是没有在临床手术实践中证实。 目的：通过对膝前疼痛患者髌骨X射线轴位片上的合适角、髌股指数、外侧髌股角、倾斜角等参数的测量,分析这些参数对膝前疼痛的诊断价值。 方法：纳入不同程度髌股关节软骨损伤的膝前痛患者50例患者的50个膝关节,测量髌骨X射线轴位片上合适角、髌股指数、外侧髌股角、倾斜角参数,同时与50例无膝前痛仅存在半月板损伤的50个膝关节进行比较。 结果与结论：髌骨X射线轴位片的合适角及髌股指数、倾斜角对于膝前疼痛有显著性差异,外侧髌股角无显著性差异。髌骨X射线轴位片的合适角、髌股指数对由髌股关节紊乱导致的膝前疼痛患者有重要的诊断治疗价值,是对髌股关节紊乱具有临床意义的有效参数。     

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。     

Age-related changes in kinematics of the knee joint during deep squat

Researchers frequently use the deep knee squat as a motor task in order to evaluate the kinematic performance after total knee arthroplasty. Many authors reported about the kinematics of a normal squatting motion, however, little is known on what the influence of aging is. Twenty-two healthy volunteers in various age groups (range 21-75 years) performed a deep knee squat activity while undergoing motion analysis using an optical tracking system. The influence of aging was evaluated with respect to kinematics of the trunk, hip, knee and ankle joints. Older subjects required significantly more time to perform a deep squat, especially during the descending phase. They also had more knee abduction and delayed peak knee flexion. Older subjects were slower in descend than ascend during the squat. Although older subjects had a trend towards less maximal flexion and less internal rotation of the knee compared to younger subjects, this difference was not significant. Older subjects also showed a trend towards more forward leaning of the trunk, resulting in increased hip flexion and anterior thoracic tilt. This study confirmed that some aspects of squat kinematics vary significantly with age, and that the basic methodology employed here can successfully detect these age-related trends. Older subjects had more abduction of the knee joint, and this may indicate the load distribution of the medial and lateral condyles could be different amongst ages. Age-matched control data are therefore required whenever the performance of an implant is evaluated during a deep knee squat.     

人工全膝关节置换术中髌股关节轨迹不良的处理策略及疗效

目的　总结人工全膝关节置换（total knee arthroplasty,TKA）术中,纠正髌股关节轨迹不良的方法及效果。 方法　2012年6月-2014 年12 月,对52例58膝TKA术中出现髌骨向外侧脱位倾向髌股关节轨迹不良的患者,针对发生原因,通过单纯调整髌骨内、外侧支持带张力,髌骨修整成形或调整胫骨假体位置等方法,或者联合应用上述两种或两种以上方法进行纠正。 结果 术中无拇指试验髌股关节轨迹恢复正常,术后髌骨未出现向外脱位倾向。术后切口均Ⅰ期愈合,2例因外翻明显,术中外侧支持带松解范围较大,术后出现关节积血,经对症处理后好转,无其他并发症发生。所有患者术后均获随访,随访时间 17-47个月,平均32个月。膝关节内、外翻畸形均获得矫正,4例残留 5-10°(平均8°）左右的屈曲畸形。随访末期KSS评分78-89分,平均84分,膝关节KSS功能评分为82-91分,平均86分。术后至随访期末X线片均显示人工关节位置正常,无松动及感染迹象。 结论 TKA术中出现髌股关节轨迹不良时,通过单纯调整髌骨内、外侧支持带张力,髌骨修整成形或调整胫骨假体等方法,或者联合应用上述两种或两种以上方法等进行调整,是处理髌股轨迹不良的有效方法,有利于术后膝关节的功能恢复。     

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.     

关节镜下外侧支持带松解内侧髌股韧带重建治疗复发性髌股关节脱位

目的　探讨关节镜辅助下外侧支持带松解联合内侧髌股韧带（medial patellofemoral ligament,MPFL）重建手术治疗复发性髌骨脱位的临床效果。 方法　对我院2012年1月-2015年1月收治的19例复发性髌骨脱位患者,采取关节镜辅助下行外侧支持带松解、内侧髌股韧带重建联合手术。术后定期随访,记录术前和术后影像学结果、Lysholm 膝关节功能综合评分和 Kujala 髌股关节评分,观察重建韧带长度变化。 结果　19例均获随访,时间( 25.7±8. 56) 月（12~48月）,术后无髌骨再脱位及恐惧征,无髌股关节疼痛加重,X线显示Q角在正常范围,膝关节CT（屈膝45°）显示患者髌骨外侧关节面张开角从术前平均（-1.2±6.8)°（-16°~8°）提高至术后(11.2±5.1)°（5°~18°）,较术前有显著性差异（P＜0.01）。术后1年Lysholm 评分及Kujala 髌股关节评分较术前有明显改善。重建韧带长度术后即刻平均为（57.81±6.76）mm,术后1年为（58.36±6.87）mm,无明显松弛。 结论　关节镜辅助下二联手术治疗复发性髌骨脱位,能有效恢复髌股关节位置和功能,预防复发,术后1年韧带无明显松弛,疗效满意。     

基于静态磁共振图像构建髌股关节准动态三维运动模型

目的　创建基于多屈膝角度静态膝关节磁共振图像,构建完整屈伸膝过程的髌股关节准动态三维模型的方法。 方法　选择1名健康成年男性,年龄30岁,体重65 kg,身高172 cm,对其右膝关节分别在0°、30°、60°、90°、120°5个屈膝角度进行MRI扫描,并将扫描结果以Dicom格式导入Mimics软件中,提取髌骨、股骨轮廓,重建五个屈膝角度的静态髌股关节三维模型,再将上述五个静态模型导入逆向工程软件Rapidform中进行同一坐标系的配准,利用三次样条插值算法,将离散静态髌股关节模型配准为动态三维运动模型。据此动态三维模型计算髌骨运动轨迹并与既往文献结果对比以验证模型的准确性。 结果　基于静态核磁共振图像可以快速构建准确而无辐射的髌股关节准动态三维运动模型,以此动态模型计算出的髌骨运动轨迹和髌股关节旋转轴与既往文献结果相一致。 结论　本方法成功构建了包含屈膝0°到120°间的完整髌股关节运动过程,在屈膝过程中,随着屈膝角度的增加,髌骨相对于股骨滑车不断俯屈,同时轻度的外倾和外旋。     

亚洲蹲和西方蹲的下肢关节运动学和肌肉激活比较

目的分析比较亚洲蹲和西方蹲动作中下肢关节运动学和肌肉激活程度的差异。方法以11名健康成年人为研究对象,采用三维运动捕捉系统、测力台和表面肌电同步采集两种下蹲动作的运动学、动力学和肌肉激活信息,并通过OpenSim计算下肢肌力。结果在膝关节弯曲角度峰值时刻,亚洲蹲骨盆前倾,而西方蹲骨盆后倾;此外,与亚洲蹲相比,西方蹲具有显著较小的髋关节屈角、较大的膝关节屈角、较大的髋关节外展角和内旋角。在自重深蹲的下降期和上升期中,西方蹲的比目鱼肌力峰值均显著大于亚洲蹲,西方蹲的胫骨前肌力均显著小于亚洲蹲,峰值时刻未见统计学差异。结论在亚洲蹲中,胫骨前肌激活和近侧端关节前屈可能有利于稳定;而在脚跟抬起的西方蹲中,比目鱼肌激活显著,但两者近端肌肉激活模式相同。研究结果为临床深蹲康复方案制定或深蹲训练方式的选择提供理论指导。     

Erratum to “Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty” [The Knee 27(5) (2020) 1534–1541]”

BackgroundThe purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA).MethodsFifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique 3° angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman’s rank correlation analysis.ResultsIntraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS.ConclusionSurgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.     

Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty

BackgroundThe purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA).MethodsFifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique three-degree angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis.ResultsIntraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS.ConclusionsSurgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.     

Patellar resurfacing has minimal impact on in vitro tibiofemoral kinematics during deep knee flexion in total knee arthroplasty

BackgroundWhile patellar resurfacing can affect patellofemoral kinematics, the effect on tibiofemoral kinematics is unknown. We hypothesized that patellar resurfacing would affect tibiofemoral kinematics during deep knee flexion due to biomechanical alteration of the extensor mechanism.MethodsWe performed cruciate-retaining TKA in fresh-frozen human cadaveric knees (N = 5) and recorded fluoroscopic kinematics during deep knee flexion before and after the patellar resurfacing. To simulate deep knee flexion, cadaver knees were tested on a dynamic, quadriceps-driven, closed-kinetic chain simulator based on the Oxford knee rig design under loads equivalent to stair climbing. To measure knee kinematics, a 2-dimensional to 3-dimensional fluoroscopic registration technique was used. Component rotation, varus-valgus angle, and anteroposterior translation of medial and lateral contact points of the femoral component relative to the tibial component were calculated over the range of flexion.ResultsThere were no significant differences in femoral component external rotation (before patellar resurfacing: 6.6 ± 2.3°, after patellar resurfacing: 7.2 ± 1.8°, p = 0.36), and less than 1° difference in femorotibial varus-valgus angle between patellar resurfacing and non-resurfacing (p = 0.01). For both conditions, the medial and lateral femorotibial contact points moved posteriorly from 0° to 30° of flexion, but not beyond 30° of flexion. At 10° of flexion, after patellar resurfacing, the medial contact point was more anteriorly located than before patellar resurfacing.ConclusionDespite the potential for alteration of the knee extensor biomechanics, patellar resurfacing had minimal effect on tibiofemoral kinematics. Patellar resurfacing, if performed adequately, is unlikely to affect postoperative knee function.