单髁膝关节置换术后膝关节三维运动学特性研究

目的探讨单髁膝关节置换后膝关节与骨关节炎病变膝关节及正常膝关节在正常平地行走中的三维运动学差异。方法在瑞金医院骨科2011年3月至2012年5月间进行的7例单髁膝关节置换手术病例和10位健康人对照组进行步态分析比较。7例单髁病例中,男1例,女6例,平均年龄65．3岁（53～73岁）,步态分析时间距手术后平均7个月（4～12个月）,所有单髁膝关节置换均使用Oxford（BiometLtd）活动平台内侧单髁膝关节假体,手术病例对侧膝关节也存在内侧间隙骨关节炎并等待进行手术。10例健康人中,男5例,女5例,平均年龄56．8岁（53～6l岁）,所有健康人对照组均无髋膝关节疼痛和髋膝关节活动功能障碍病史。本研究采用红外运动捕捉系统（MX．F40,Vicon,OxfordUK）,对多点体表标记点进行步态数据记录,计算股骨相对于胫骨的旋转和移动运动学数据,比较单髁膝关节置换后膝关节在上述三维运动中与对侧病变膝关节和正常膝关节的差异。结果在步态周期内,单髁膝关节置换术后膝关节三维运动学表现与对侧病变膝关节及正常对照组膝关节均存在不同的差异。其中,在矢状面屈伸运动、水平面的内外旋运动、冠状面内外翻运动以及前后方向平移运动中,单髁置换后膝关节运动曲线都与正常膝关节更为接近。结论单髁膝关节置换术后,膝关节运动学表现上比对侧病变膝关节在旋转运动和平移运动中,更接近与正常膝关节的运动学特性。     

全膝置换术中预防股骨及胫骨假体旋转对位对线不良的研究进展

随着人口老龄化,我国需要进行人工全膝关节置换术(TKA)并可从中受益的病人将越来越多。在TKA术后,由于假体旋转而引起的假体对位对线不良,从而造成的髌股关节运动不良等并发症是膝关节翻修的重要原因,需要引起进一步的关注。膝关节假体旋转对位对线涉及到胫骨和股骨的正确定位、对线、截骨及假体的安放。在本文中,将对众多股骨及胫骨侧旋转对位对线的方法作一综述。     

应用内轴膝人工膝关节置换的进展

人工膝关节置换(TKA)是治疗膝关节骨关节炎的重要手段。然而置换后的膝关节运动学不同于自然膝关节运动学,常出现反向前移,是影响患者满意度提高的重要原因。内轴膝关节假体在设计上能更好地模拟自然膝关节的运动,为TKA假体提供了较好的选择。本文对内轴膝关节的基本特点和临床应用效果及进展作一综述。     

膝关节体内运动评估在前交叉韧带损伤重建中的应用

前交叉韧带功能缺失(ACLD)导致的关节运动学与动力学改变影响膝关节功能,甚至加剧关节磨损.这些改变无法通过前交叉韧带重建完全恢复.随着近年来光学运动捕捉系统、2D-3D配准技术及动态CT和MRI技术等在运动医学领域的应用,膝关节体内动态评估日益成熟.膝关节体内运动学分析对损伤机制研究、手术重建方式选择、术后康复指导及...     

全膝关节置换术股骨假体旋转力线研究进展

股骨假体旋转力线是影响全膝关节置换术预后的极其重要环节.以哪条轴线作为术中参照轴才能够最大程度地保证股骨假体旋转轴线对位准确,目前仍存有争议.该文就全膝关节置换术中各种股骨假体旋转定位参照轴的可靠性等作一综述.     

基于运动捕捉膝关节运动分析及临床常规评估进展

近年来,基于运动捕捉的膝关节运动学分析发展迅速,广泛用于探索膝关节疾病特征、治疗效果、随访分析等各个方面,其临床常规化十分具有前景。目前,基于运动捕捉系统的膝关节运动学分析主要应用于疾病特征探索,病例分析报道等,然而并未见临床常规化诊疗报道或者示范。步态采集设备型号各异、不同运动任务的结果无法对比及无规范动作标准等原因,制约膝关节步态分析临床常规化的发展与应用。本文将阐述基于运动捕捉的膝关节运动学步态发展现状及制约其临床常规化因素,有助于理解未来步态分析的临床实践和转化以及促进膝关节运动学分析临床常规化的应用。     

影响全膝关节置换术后关节活动度的相关因素分析

目的分析全膝关节置换术后关节活动度的相关影响因素,旨在探讨如何提高术后膝关节活动范围。方法回顾性研究2008年10月~2010年10月37例全膝关节置换术。术后1年25例膝关节屈曲度>90°的患者作为对照组,12例膝关节屈曲度<90°的患者作为实验组。两组根据年龄、性别、体重指数(BMI)、手术时间、术中出血和随访时间等进行配对病例对照研究分析影响因素。结果两组患者年龄、性别、手术时间、术中出血、随访时间及术前合并症比较,差异无统计学意义。手术前后两组膝关节屈曲度比较,差异有显著统计学意义(P<0.01)。手术前后两组的胫骨倾斜度与关节力线对位不良的比较,差异有统计学意义(P<0.05)。结论全膝关节置换术后膝关节活动度受肥胖、下肢力线对位情况和术后主动功能锻炼等因素影响,术中术后减少以上因素影响可以提高膝关节术后活动度。     

正常膝关节的运动学特性

膝关节是人体的主要负重运动关节,膝关节本身的解剖结构和周围稳定装置的复杂性决定了膝关节的运动绝非简单的铰链式屈伸运动,而是同时伴随着股骨髁向后移动及胫骨的轴向内旋等一系列复合的三维空间运动。了解正常膝关节的运动学特性对膝关节功能的正确评定、人工关节假体的设计和置换都具有重要意义。     

三维骨建模系统在人工全膝关节置换时旋转对位的作用

目的 为了进行人工全膝关节置换时假体旋转对位的量化研究,探讨三维骨建模的计算机辅助手术系统对量化操作的精确性和有效性. 方法 2002年11月 - 2003年6月,采用三维骨建模 Ceravision 系统对 21 例 21 膝保守治疗无效的三间隔骨性关节炎患者行人工全膝关节置换术.男5例5膝,女16例16膝;年龄64～79岁,平均 72.4 岁.左膝10例,右膝11例.主要临床表现为膝关节疼痛和活动受限.病程2～10年.14例膝内翻,7例膝外翻.根据相关的临床体检、影像学和导航系统资料,对术中假体旋转对位量值,并对术后3个月膝关节活动度、膝关节松弛度和髌骨稳定性进行分析. 结果 全部患者术后切口均Ⅰ期愈合.21 例患者均获随访12～16个月,平均13.3个月.术中股骨假体旋转对位内旋 1°～外旋 5°,胫骨假体旋转对位内旋 0°～外旋5°.其中膝内翻患者,股骨假体旋转对位外旋 1°～外旋5°,胫骨假体旋转对位外旋2°～外旋5°膝外翻患者,股骨假体旋转对位内旋1°～外旋4°,胫骨假体旋转对位内旋0°～外旋 4°.术后3个月膝关节活动度,最大屈膝度为 105～130°,平均 115°;膝关节额面松弛度,内侧 0.2～0.5 cm,平均 0.27 cm,外侧 1.0～2.5 cm,平均 1.7 cm.无膝痛、髌骨失稳和脱位等并发症发生. 结论 应用三维骨建模的计算机辅助手术系统,可针对患者个体精确地进行假体旋转对位.     

人工膝关节假体设计对全膝关节置换术后髌股关节功能的影响(中)

经典膝关节运动学认为，膝关节并不按固定轴线屈曲。在膝关节由伸直到屈曲的过程中，其屈曲轴线不断由股骨髁的前上方向股骨髁的后下方移动，即膝关节的瞬时旋转中心呈反写的“J”形（Jcurved instant center of rotation）。经典的反“J”形瞬时旋转中心理论町以圆满地解释为获得足够的活动度膝关节骨性结构必须满足的两个条件之一，即随着膝关节不断屈曲股骨后髁的曲率半径必须不断减小，以避免股骨后方与胫骨上端发生撞击。另一条件是膝关节屈曲过程中胫股关节的接触点必须不断后移，即经典膝关节运动学中认为的“后滚”。与此同时，“J”形瞬时旋转中心现象的存在，充分体现了生物界解剖与功能相适应的基本法则。随着膝关节逐渐屈曲，躯体中心远离膝关节，重力的力臂延长，对伸膝装置提出了更高的要求。“J”形瞬时旋转中心理论认为，膝关节屈曲过程中膝关节屈曲轴线不断由前上方向后下方移动。     

个体化导板辅助全膝关节置换运动学对线技术

大部分自然人群膝关节存在不同程度的生理内翻或外翻,而目前广泛应用的全膝关节置换机械学对线技术并没有充分尊重这种生理变异,而把下肢中立位对线作为对线目标。有学者认为这可能与膝关节置换较低的术后满意率相关。在此背景下出现了一种更为尊重自然膝关节解剖形态的对线方式——运动学对线,由于该方法可能有助于减少术中软组织松解,改善膝关节术后功能并提高病人的满意率,所以近年来受到广泛关注。作者医院是国内最早使用个体化截骨导板进行运动学对线膝关节置换的单位之一。本文总结了该技术的术前规划、手术技巧和陷阱、相关理论以及临床和实验室证据等方面内容,以帮助读者全面理解运动学对线技术。     

全膝关节置换术中下肢对线方式的研究进展

膝骨关节炎已成为当今老年人常见疾病之一,目前,对于终末期膝骨关节炎,行全膝关节置换术(total knee arthroplasty,TKA)是最为有效的治疗手段。在TKA中,下肢力线的有效恢复则是手术成功的关键因素之一,极大影响患者术后的临床效果及假体存活率。最早被提出、认可并被广泛应用于TKA的对线方式是机械对线。近年来,随着对下肢力线的深入研究及计算机技术的迅速发展,TKA对线技术实现了由“统一化”向“个性化”,二维向三维的转变,调整机械对线、解剖学对线、运动学对线、反向运动学对线、限制运动学对线及功能学对线等新的对线方式被相继提出,为外科医师提供了更多选择。但对于何种对线方式是最佳选择,目前尚未有定论。本文对目前TKA中各种对线方式的研究现状及优缺点进行总结阐述,旨在为临床上TKA中对线方式的选择提供一定参考。     

功能学对线机器人辅助膝关节置换术研究进展

膝关节的正确对线被认为是决定全膝关节置换术(total knee arthroplasty,TKA)后长期预后的最具影响的因素之一,为了达到正确的对准目标,已经建立了许多不同的对准理念和外科技术,如机械对线(mechanical alignment,MA)、运动学对线(kinematic alignment,KA)和功能学对线(functional alignment,FA)3种对线技术各有特点,MA注重实现肢体的中性对齐,伸展和屈曲时平行且相等的骨间隙;KA以恢复患者的天然关节线为目标,使关节水平和角度正常并使生理性软组织平衡得到改善,努力重现接近正常的膝关节功能;其中随着机器人辅助手术技术而发展起来的功能学对线FA,功能学对线是一种相对较新的对齐理念,它不仅考虑到机体的下肢生理对齐,而且还旨在实现屈伸平衡,同时尊重原生软组织包膜。既做到了术中精确的恢复原位关节线的平面和斜度,又兼顾了软组织平衡,是一种更佳的对线方式。因此,正确构建患者下肢力线,有助于恢复膝关节功能、缓解疼痛症状和延长假体使用寿命具有十分重要的意义。但与传统 TKA 相比,机器人辅助 FA-TKA 手术时间延长,这意味着术后感染发生概率可能性会更大,并且目前大多数研究报道的FA技术都是短期结果,对患者远期疗效尚不清楚,因此,需要长期的研究结果来支持这项技术的应用。     

Entwicklung der Knieendoprothetik

In this article the evolution beginning with the robotics of total knee arthroplasty to CT-based and kinematic navigation and patient-specific instruments is described. Thereby it is pointed out that in the early 1990s, CT imaging solely for the planning of a knee endoprosthesis was considered as obsolete radiation exposure and this led to the widespread development of kinematical systems.Also a patient specific planning tool based on CAD built acryl harz blocs existed at the time. There is an ongoing process of implanting total knee arthroplasties in a more exact position. Nowadays the new evolution of soft tissue balancing by using a kinematic alignment has put these efforts into perspective.     

Neutral mechanical alignment: Stickin’ with the one that brung ya- Affirms

Restoring the overall mechanical alignment to neutral has been the gold standard in total knee arthroplasty since the 1970s. Recently, there has been renewed interest in alternative alignment goals that place implants in a more “physiologic” position with the hope of improving clinical outcomes. However, placing components outside of the classic “safe zone” of ± 3° is controversial, as studies have shown increased risk of mechanical failure, especially in obese patient populations. This paper will outline mechanical and kinematic alignment and present the evidence for why mechanical alignment is still the gold standard in total knee arthroplasty.     

Early Outcomes of Kinematic Alignment in Primary Total Knee Arthroplasty: A Meta-Analysis of the Literature

Background

Kinematic alignment in total knee arthroplasty (TKA) seeks to more anatomically align the knee prosthesis to promote more physiological kinematics. However, there are questions about the durability, function, and complication rate of a non–mechanically aligned TKA. Therefore, the purpose of this study is to perform a systematic review and meta-analysis to evaluate early outcomes after kinematic alignment.

Optimising the trans-femoral prosthetic alignment for running, by lowering the knee joint

For amputees to perform an everyday task, or to participate in physical exercise, it is crucial that they have an appropriately designed functional prosthesis. The aim of this study was to investigate the optimal trans-femoral prosthetic alignment configuration for running. A case study design was implemented as the method to collect data on four male Paralympic level trans-femoral amputee runners. In total 28 synchronised 3D kinematic, kinetic, and temporal biomechanical measures were analysed. A new prosthetic alignment, in which the prosthetic knee axis was lowered longitudinally (moved distally), was evaluated for running. The performance of the symmetry indices and running time for a total of three new modified alignments were compared to the standard prosthetic alignment. The interlimb asymmetry was found to improve when the subjects ran on the modified prosthetic alignment, and most importantly a one way ANOVA found a statistically significant increase in running velocity. This study identified that for all four subjects, who used the same prosthetic components, lowering the prosthetic knee joint centre improved their interlimb symmetry, and subsequently their running velocity by an average of 26%.     

Neutral mechanical alignment: Stickin’ with the one that brung ya—Opposes

Total knee arthroplasty is a safe and reproducible procedure for the treatment of arthritis. Despite increased use and modern techniques, there remains up to a 20% rate of patient dissatisfaction for reasons unexplained in the literature. One hypothesis is that universally targeting a neutral, mechanical alignment rather than taking a more individualized approach to patient alignment may contribute to patient dissatisfaction. Constitutional varus and kinematic alignment techniques aim to match patient anatomy more closely in total knee arthroplasty and are discussed in detail in this review.     

Leg axis after computer-navigated total knee arthroplasty: a prospective randomized trial comparing computer-navigated and manual implantation

To compare the alignment after computer-navigated total knee arthroplasty, 52 patients were randomly allocated to 2 groups. Twenty-seven patients received a total knee arthroplasty with the aid of a kinematic computer-navigation system, and 25 patients received a total knee arthroplasty with the conventional method. Both groups were well balanced concerning demographic data and preoperative scores. At 3-month follow-up, the mechanical alignment of the leg reached the desired straight axis in more cases with the computer-navigated implantation. This difference was statistically significant. The femoral and tibial mechanical anteroposterior axis and the femoral and tibial sagittal tilt (slope) measured on sagittal x-rays were not significantly improved in this patient group.     

Technical considerations in total knee surgery. Management of patella problems

Patellofemoral symptoms are now the most common cause of aseptic knee revision; however, the majority of patello-femoral problems are self-limited and may be managed symptomatically and nonoperatively. A trial of anti-inflammatory medications, stretching exercises, and appropriate bracing is always indicated. Patellofemoral symptoms are usually related to mechanical malalignment of all three components of the total knee arthroplasty. Attention to the fundamental principles of total knee arthroplasty, including restoration of the bony mechanical alignment, soft tissue stability, and maintenance of the anatomic joint line, prevents many of the problems. Meticulous preoperative planning and anatomic placement of the component parts are important for a satisfactory long-term outcome. Present research is directed to providing kinematic analysis of the patellofemoral tracking mechanism and to minimizing patellofemoral contact stresses with appropriate new designs.