【作者】 余正红；

【导师】 钟世镇； 蔡谞； 李义凯；

【作者基本信息】 南方医科大学 ， 人体解剖与组织胚胎学， 2008， 博士

【摘要】 膝关节损伤和疾病常见多发,致残率高,人工膝关节表面置换术(TKA)是目前公认对晚期患者唯一确切有效的治疗方法。总的来说,TKA通过切骨获得假体的对位,通过软组织平衡达到良好的对线和稳定,使患者膝关节恢复到无痛、稳定、活动功能良好的状态。合适的假体选择+正确的安装以及关节周围软组织平衡的恢复是手术成功的关键。众多学者对膝关节进行了的大量研究,尤以股骨远端为首的膝骨性结构研究较为完善,假体设计和截骨安装技术相对成熟。目前,临床一致公认术中软组织平衡是TKA成功与否的技术关键和难点,也是影响TKA疗效的最主要因素。重要的神经、血管和伸膝装置的处理方法及损伤与否与术后疗效密切相关。临床有关TKA切口选择、软组织平衡的技术和方法存在大量的严重分歧,基本上是术者各凭经验、感觉进行手术。因此,部分患者术后出现不同程度的各种并发症。临床实践和文献复习发现,其根本原因在于TKA相关应用解剖学资料尚不系统和全面,尤以基于国人的相关研究未见系统报道。首先,有关膝关节神经支配缺乏详尽、深入的应用解剖学研究,导致临床很难解释清楚患者膝关节疼痛的复杂原因与机制;导致部分患者被过度治疗,使“TKA前症状”患者过早接受置换术;或导致部分TKA术后患者部分疼痛存留或遗留部分神经支配功能障碍。其次,膝关节血管分布、走行特点与TKA入路选择,以及如何尽量减少术中出血和术后膝部血供严重损害等密切相关,也缺乏针对性系统研究。最后,也是最重要的,TKA术中软组织平衡存在以下问题:①有关TKA术中软组织平衡的概念模糊,缺乏清楚、一致的认知。平衡什么?具体哪些软组织?目前没有明确界定。②对软组织平衡术所进行松解的结构及松解次序缺乏足够的试验依据。并且表述混乱,没有按照标准的解剖学术语、规范,容易导致理解困难和错误。③膝关节周围韧带结构各自的形态学特征与功能不清楚,尤其缺乏针对TKA术中操作特点的研究。④不同的韧带结构被松解后,不仅对不同屈膝角度上膝内、外翻稳定性、旋转稳定性将产生影响,而且将导致关节间隙发生不同程度的增宽。但其对TKA等间隙的技术产生的影响,一直被忽略不计,导致术中很难准确达到等间隙技术要求。部分术者因此反复加大松解的范围和程度,最终导致关节线位置和关节稳定性等改变,从而影响术后关节功能和假体寿命。本课题通过①膝标本的解剖观察、测量和膝部动脉三维重建,了解膝关节神经、血管走行、分布特点,及其与TKA术中操作的关系,为TKA入路选择、术中神经、血管保护等提供形态学依据和参考数据。②膝标本的解剖观察、测量,了解伸膝装置、交叉韧带复合体、外侧副韧带复合体、内侧副韧带复合体及腘肌—肌腱复合体、半膜肌腱复合体及髌内、外侧支持带、关节囊等结构的形态学特征、空间几何位置,测量与膝关节置换术中操作相关参数值。③新鲜膝标本上模拟TKA术中软组织松解,并将状态在计算机上真实再现,分析、比较对韧带结构松解前后关节运动学、关节间隙距离等的影响。④重建包括骨、软骨、半月板、主要韧带的膝关节三维模型,为建立模拟自然膝的膝关节有限元分析模型奠定基础。方法:1.巨微解剖:72例防腐固定、8例新鲜冷冻保存的成人下肢标本,在手术显微镜(放大6×和10×)下,用显微外科器械仔细逐层解剖,观察以下方面内容并对部分标本进行TKA置换模拟手术:①分离出大腿及膝部神经,观察其形态特征和分布范围,测量其中较粗大的神经干直径。②在其中2例新鲜完整正常人体下肢标本上,按标准流程操作模拟TKA手术过程。观察容易损伤腓总神经的操作步骤中,何种体位、操作、器械插入深度与方向可能牵拉、挤压、挫伤腓总神经。③观察膝关节血管走行、分布特点,及其与TKA入路选择、术中操作的关系,分析深静脉血栓形成的解剖机制。④观察膝前区:伸膝装置的结构组成、形态学特征与髌股关节软组织平衡的关系。⑤观察膝内侧区:内侧副韧带复合体、半膜肌腱复合体、关节囊等结构的组成、形态学特征、空间几何位置,测量与膝关节置换术中韧带松解的相关参数值。⑥观察膝外侧区及后外侧角:外侧副韧带复合体、腘肌—肌腱复合体、后外侧区关节囊等结构的形态学特征、空间几何位置,测量与膝关节置换术中韧带松解的相关参数值。2.膝关节动脉系统三维重建:新鲜完整下肢标本1例,以聚甲基丙烯酸甲酯+朱砂+增塑剂等配成合适浓度进行动脉灌注后,行薄层CT(层厚0.499mm)扫描,取膝部671层用Mimics10.0软件重建膝部动脉血供系统。3.膝关节相关结构的三维重建:新鲜完整下肢标本1例,对膝关节部分行伸直位薄层CT(387层,层厚0.299mm)和MRI扫描(64层,1.479mm),Mimics10.0和Geomagic Studio 8软件分割、配准,重建膝关节骨—软骨—半月板—主要韧带模型。4.膝内侧支持结构软组织平衡的生物力学研究:新鲜完整成人膝关节保本6例,行CT轴位扫描后,按各自编号重建膝关节骨性结构及两端包埋块模型,保存.stl文件。每个标本依次按:完整,松解一(松解ACL+MCL前纵部,距离到胫骨鹅足下,宽15mm,模拟TKA术中膝前内侧部分支持结构松解),松解二(ACL+MCL前纵部+后斜部+后内侧关节囊,保留半膜肌止点部分)3种处理顺序进行松解。标本固定于脊柱三维运动测量仪,分别在屈膝0°、30°、45°、60°、90°时,胫骨上端施加外翻力矩10N.cm。RealScan USB Scanner model 200激光扫描系统扫描、保存每一测试工况的.pmjx图像文件。导入Geomagic Studio 8,利用包埋块标志与相应标本的CT重建.stl文件股骨、胫骨分别配准,在膝三维重建模型上还原试验状态,保存为.wrp文件,并测量每一工况股骨内上髁至胫骨内侧缘中点的在Y、Z轴距离,比较不同工况关节间隙距离变化(Z轴)和股骨相对胫骨位移变化(Y轴)。再将每一标本同一处理的各不同角度工况分别与完整屈膝0°位配准,测量外翻(Z轴)和伴随旋转(Y轴)的变化。结果:1.膝关节神经分布特征:膝关节的神经分布可分为浅、深2层。浅层为皮神经,部分干较粗,容易形成皮神经瘤。深层可以分为伸膝肌支关节支组成的髌上区组,隐神经分支组成的内侧及髌下区组,腓总神经关节支组成的后外侧区组,腘丛神经组成的腘区组4组。4组神经在关节囊外分布有重叠交叉,但各自分布区域基本明确;在关节内均分布到滑膜,通过滑膜的延伸覆盖整个关节腔表面。深层的隐神经膝关节支、腓总神经膝关节支和股内侧肌支膝关节支等神经支粗约1mm,位置表浅且固定,具有选择性切断的可行性。2.TKA术中医源性腓总神经损伤原因:标本模拟手术过程证实,术中可能导致腓总神经损伤的高危操作依次为:①松解股骨后外侧关节囊、腓肠肌外侧头时,助手自后向前环抱提拉股骨远端将腓总神经压迫贴近股骨后外侧骨面大大增加腓总神经挫伤几率,且术后多为其深、浅支同时出现症状。②外侧Hoffman板钩放置位置偏于外侧副韧带后侧或深度过大,钩尖部在运动中容易划伤腓总神经,术后多为深支或浅支的不全损伤。③安装假体试模后,为纠正残余屈曲角度,强力完全伸直或过伸,容易导致腓总神经牵拉伤。3.膝关节血管的解剖观测和三维重建:①股动脉、腘动脉、胫前动脉和股深动脉等血管的分支在膝部交通、吻合,形成可分为髌网、股骨外侧髁和内侧髁网、髌下网等的膝关节血管网。膝关节置换术,经股肌下/经股肌入路时股内侧肌斜头(VMO)动脉是防止神经、股动脉损伤的安全标志。膝下外侧动脉容易损伤,应注意保护。②重建了膝关节的骨性结构和血管的3D模型。重建的三维图像可以直观形象生动的体现膝关节血管主要分支的空间位置关系,并可按各种方向任意旋转演示。③腘血管丛被腘区发出膝上内/外侧动静脉、腓肠肌内外侧头血管丛、膝中动静脉膝下内、外侧动静脉等分支呈上、中、下固定,限制其前后向位移。TKA术中胫股关节前后向脱位导致术中血管壁张力过高,内膜撕裂是TKA术后腘区深静脉血栓形成的主要原因。腓肠肌外侧头止点存在变异时,这种效应更加明显。4.伸膝装置的解剖特征:髌前三层不同走向的纤维膜性结构包被伸膝装置。股外侧肌腱、股内侧肌、股最内侧肌与股直肌腱分别成33.50°±6.19°、54.5°±8.20°、78.60°±8.52°角。股四头肌腱扩张部向下扩展形成髌内、外侧支持带(MPR、LPR)。膝关节肌为独立肌肉,是膝关节重要的滑移装置并维持髌骨内侧稳定结构。TKA术中维持髌内侧支持带、股最内侧肌完整和有助于防止髌股关节并发症。5.膝内侧稳定结构的解剖特征:膝关节内侧面支持结构包括内侧副韧带复合体(MCL complex)和半膜肌复合体等结构,可分为3层。MCL前纵部由2层纤维膜构成,止于胫骨平台关节面下5～7cm。后斜部纤维与其深方第3层(内侧关节囊)融合,被半月板、冠状韧带固定。半膜肌腱鞘和半膜肌腱的9附丽处加强膝关节后内侧区域,肌腱介于MCL浅层与深层之间。第三层(关节囊层)止于胫骨平台内侧缘中点关节面下0.8～1.5cm骨面,并与半膜肌腱横行的止点部相融合。6.膝外侧结构解剖特征:PLCC主要包括3层结构。浅层包括:髂胫束、外侧副韧带(LCL)、腓肠腓骨韧带、弓状韧带(arcuate ligament)。中层(图1-6-2)包括:腘肌腱复合体(腘肌腱、腘腓韧带)、腘胫筋膜和腘半月板筋膜。深层:外侧关节囊韧带(中1/3外侧关节囊)、外侧半月板后角、外侧冠状韧带、关节囊的后外侧部分。7.膝内侧软组织平衡标本试验研究:松解MCL前纵部和ACL后,对屈膝60°、90°(11.19°±2.05°,P=0.045)外翻稳定性影响最显著;其伴随旋转的增加也最大(P＜0.001)。松解MCL后斜部和后侧关节囊主要在屈膝≤30°时产生显著影响:膝伸直位时外翻增加8.65°±1.54°(P＜0.001);屈膝30°时12.09°±2.77°(P＜0.001);伴随外旋增加主要在屈膝0°～20°有显著性差异。8.膝关节相关结构的三维重建:结合CT、MRI图像分别对骨、软组织结构显影清楚的优点。将CT、MRI数据导入Mimics 10.01软件,分别建立并保存膝关节骨性结构、软骨、半月板等3D模型。将这些模型文件导入Geomagic 8进行修饰、配准、融合。成功建立了包含骨、软骨、半月板、前后交叉韧带的膝关节三维模型。结论:1.膝关节神经支配在关节外有明显的区域性,而在关节内成网状分布。全膝关节置换术、膝关节镜下清理术通过切除滑膜、切断关节支而消除疼痛。局部去神经化术对消除或缓解膝关节外疼痛有合理的解剖机制。选择性的局部去神经化术对治疗确诊局部皮神经瘤形成或神经支卡压等关节外源性疼痛具有可行性。2.TKA术中松解后外侧关节囊、腓肠肌外侧头时,应该避免助手自后向前环保股骨远端向上提拉。注意Hoffman板钩防止位置、插入方向及其深度。避免强力过伸膝关节。有助于减少术后腓总神经麻痹的发生。3.结合CT/MRI、计算机图像处理、3D重建技术,可以直观立体再现膝关节结构及其血供特点,为临床手术入路选择提供直观的参考。TKA术后深静脉血栓形成与术中血管牵拉损伤有关。4.TKA术中术中防止膝关节肌内侧束撕裂有重要意义。对股最内侧肌止点和髌股横韧带准确分层缝合有利于髌骨软组织平衡。5.TKA内侧软组织平衡宜于采用“spreader”剥离松解,纠正内翻畸形主要在于骨膜下剥离MCL复合体胫骨侧止点;纠正屈曲畸形主要在于松解股骨端内后侧关节囊和胫骨侧半膜肌横行止点。内侧间隙紧张发生在屈膝＜30°时,松解MCL前纵部至关节面下超过6cm;在屈膝30°～60°时,松解MCL后斜部和半膜肌横行止点,在屈膝＞60°时,增加松解后侧关节囊。6.LCL和腘肌腱复合体、外侧关节囊韧带是膝后外侧角中主要的稳定结构。外翻畸形＜30°时,外侧结构软组织平衡宜于按以下次序逐步松解:切断外侧关节囊韧带、松解髂胫束,在股骨远端彻底松解后外侧关节囊,腘腓韧带。外翻畸形＞30°,应用高限制性假体时,可以松解外侧所有结构;或行股骨外侧髁截骨滑移,应用非高限制性假体。7.基于MRI、CT图像,可以准确分割重建膝关节韧带、肌肉、软骨、半月板等相关结构。主要创新点:1.对膝关节神经分布进行了较系统的解剖学研究,探讨了膝部疼痛机制的神经解剖学因素,有助于阐释膝关节疼痛的复杂机制,提高临床诊断水平和优化相应治疗策略选择。2.针对膝关节置换术中软组织平衡,对膝关节相关韧带结构进行了较系统的针对性应用解剖研究和主要结构功能的生物力学研究,为TKA相关术中操作提供了形态学基础和理论依据。3.对膝关节血管分布进行了系统的解剖观察并三维重建,结合神经分布、韧带等相关结构的研究结果,为TKA入路选择提供应用解剖基础。探讨了TKA术后深静脉血栓形成的解剖学机制,提出了预防措施。4.采用改良方法对血管进行灌注,血管柔软,不影响关节屈伸。可行多体位连续螺旋CT/MRI扫描,血管显影清楚,伪影少,能做到计算机快速三维重建并立体显示,摸索了一种血管研究新方法。5.采用结合Realscan扫描、CT重建,重建了膝关节软骨—半月板—韧带等结构,实现了膝关节运动学信息三维还原与测量,不仅提高了测量精度,还能测量既往难以获得的信息。更多还原

【Abstract】 Background:Knee is the biggest joint of the human kind.Knee disorders are common, especially the knee osteoarthritis affecting the old victims seriously.It is a leading cause of disability and has a formidable societal and public health impact.Total knee arthroplasty(TKA) has been documented to be the most beneficial management for these advanced stage sufferers.In TKA,achieving appropriate alignment in the coronal and sagittal planes by correctly cutting bone and soft tissues balancing is the keystone to success.In summery,correcting deformity,relieving pain and normal dynamic knee kinematics restoration were dependent on accurate soft tissue balancing (STB).The therapeutic effect was correlated closely to the management of blood vesseles,nerves and ligaments of knee.A great quantity of studies about these issues had been executed.Even though the advanced prothesis was companied with skilled operation technique now,soft tissue balancing was viewed generally as the most difficult procedure in TKA.There were considerable disputes about incision and technique of STB in clinic.Most of the orthopedist executed TKA with oneself experience and "feel".Therefore,diversity complications shown up in some victims were reasonable.Our clinical practice and literatures review suggested that these disagreements fundamentally impute to the insufficient of relational clinical anatomy documents about TKA,especially in our country.Although the morphological features of distal femur and proximal tibia had been clear,the documents about soft tissues were insufficient now.First,the basic purpose of TKA was relievate pain.But because of the innervation of knee joint was unclearly,the cause and mechanism of the complex arthronalgia was unclear.Therefore,some patients were executed TKA early to relievate pain,some ones remained different extent functional impairment of nerves postoperation.Second,approaches of TKA were related to the morphological features and distribution of nerves and blood vessel closely.It was benefit to diminish unnecessary hurt of never and blood vessel with appropriate approach.Third,and the capital,many issues about soft tissue balancing of TKA puzzled us today:(1)The concept of soft tissue balancing or soft tissue balance was ambiguity and inconsistent. What was it to balance? What the tissues were? No clearly answer to them.(2)How to achieve soft tissue balance? Kinds of Ligament releasing skill relation to soft tissue balancing were not reported with standard anatomy technical terms.These presentations were difficult to understand,even leaded to mistake sometimes.(3)Why and where to release these ligament?The function and morphological characters of these ligament complexs of knee were not clear.No sufficiency evidence was provide to answer which one should to be release and where should to do.(4)What the impact on dynamic knee kinematics after ligament released? Several studies suggested that influenced not only on the varus-valgus stability and internal-external rotation stability of knee,but also on the wide of joint gap.Furthermore,the effect was related intimately to the flexion angle of knee joint.It was known to all that over-released ligament should change the joint line and result in malfunction.Objectives:Our study had done some research to aim directly at above- mentioned.(1)To provide anatomical basis of the approach,nevers and blood vessels protection of TKA.(2) To provide anatomical and biomechanic basis of soft tissues balancing in TKA.(3)To explore a useful and practical method for three-dimensional reconstruction of the blood vessels,ligaments,articular cartilage and menisci of knee. Methods:1.Macromicrodissection:8 fresh adult human cadaveric knees and 80 formal-dehyde-fixed ones were executed with microsurgical techniques.①The innervation morphological features in knee joint and the relations between the nerves and surrounding tissues were observed and measured.The possibility of neurotomy to treat the arthronalgia of knee joint was observed.The relations of innervation to the exposures in TKA were explored.②2 fresh adult human cadaveric knees had taken TKA,to observe the risk factors of peroneal nerve palsy in operation.③The distribution morphological features and the relation to the approach and operation techniques in TKA of knee joint bloodes were observed.④Anterior region of knee: Morphological features were observed,and the data were measured for realignment of the extensor mechanism of the knee joint in total knee arthroplasty (TKA).⑤Medial area of knee:The morphological features of the structures and each part of them were observed,and the relation to the soft tissue balancing techniques in TKA had been explored.⑥Lateral region and angulus posteriolateralis of knee:The morphological features of each part of the structures were observed,and the relation to the soft tissue balancing techniques in TKA had been explored.2.Three-dimensional reconstruction of the blood vessels:CT data of 1 adult knee joint specimen which the artery had been perfused by contrast medium were harvested.The bone and artery structures of knee were 3D reconstructed using Mimics10.01.3.Three-dimensional reconstructions of the bone and ligaments,articular cartilage and menisci:387 slices of CT data(0.299 mm interval) and 64 slices of MRI data (1.497mm interval) of an adult knee joint specimen were harvested.The structures such as bone,articular cartilage,meniscus and ACL/PCL of knee joint were reconstructed using 3D reconstruction software Mimics and reverse-engineering software Geomagic 8.4.Biomechanics study of the medial supporting structures:6 fresh knee specimens were embedded by Polymethylmethacrylate(PMMA) both the superior and inferior ends,and reconstructed 3D reconstruction.The positions of them in test were got by a 3D laser scan.The movement parameters of knee joint were calculated(precision 0.01mm and 0.01°) with Geomagic 8 through 3D laser scan and CT 3D reconstruction. The valgus and rotation laxity and width of joint gap were calculated.Result:1.Innervation of knee:The innervation pattern of the study was similar to that of Horner’s.But our study suggested that the innervation of knee joint had two layer groups:the superficial layer group and the profunda layer group.The superficial layer were composed of the cutaneous nerves which may form nerve tumor easily.The profunda layer group could be divided into 4 groups which comprised different articular branches respectively.Although them had some extent superimpose innervation outside the articular capsule,each one had its special distribution area. With the coverage and extension of synovial membranes,an extensive network of somatic nerve and autonomic nerve formed inside knee joint.The articular branches of saphenous nerve,common peroneal nerve and the muscular branches of quadriceps muscle never were mostly about 1mm thickness,so could be located easily.2.Risk factors for common peroneal nerve in TKA:Cadaver knees TKA suggested the dangerous handlings include the belows in turn.①Lifting distal femur by encircle dragging could rise risk of common peroneal nerve.②It was risk for common peroneal nerve to set Hoffman crook not paralleling longitudinal axis of tibia or posterior the lateral collateral ligament.③Excessive extened knee joint when the prosthesis had been fixed.3.Arteriovenous of knee:①Branches of femoral artery and popliteal artery and anterior tibial artery,also of deep femoral artery formed blood vessel strainer.As a safe marker for femoral artery in total knee arthroplasty,the musculoarticular branch should be preserved wherever possible if the subvastus approach was used.The lateral inferior genicular artery should be preserved carefully.②3D models of bone-blood vessel structures were constructed using angiography-irrigated CT scanning data.The transparence demonstrations were carried out using both Mimics and 3ds max methods.It demonstrated the position relations and 3D morphology clearly.And it displayed the regional blood supply clearly.③Risk of thrombogenic:The popliteal AtV was fixed by its branches.The endomembran of these veins was prone to be teared by hyperextension while the tibia dislocating forwards and backwards in TKA. Such kind of endomembran hurts leads to popliteal vascular plexus thrombogenic.The risk of thrombogenic was highlighted when the insertion of caput laterale musculi gastrocnemii tendon has variation.4.The extensor mechanisim were wraped up by trilaminar prepatellar fibrous soft tissues of different arrangement.The angles of the vastus lateralis tendon and the vastus medialis obliquus muscle(VMO) fibers to the rectus tendon were 33.5 and 78.6,respectively.The pavilion of quadriceps tendon spreaded downward and formed the lateral and medial patellar retinaculum.The medial patellofemoral ligament (MPFL)was about 47.6 mm long and 12mm(8-26 mm) wide.The subcrureus was an independent muscle which acted as a frift structure and a medial stabilizer of patellar.5.The medial area supporting structures of knee were composed of the medial collateral ligament complex and semimembranous muscle complex which could be divided into three layers.Anterior portions of the medial collateral ligament stopped anterior-medial tibia,inferior to the tibial plateau 50-60mm.The posterior oblique portions one mixed the third layer together,and fixed by medial meniscus and coronary ligament.The tendinous sheath and tendon of semimembranous muscle strengthened post-medial area of knee,and could be divided into 9 parts.Furthermore, the tendon intervened the superficial layer and deep layer of MCL.The third layer (articular capsule)stopped inferior to tibial plateau 0.8-1.5cm.6.The posterolateral comer complex was consisted of 3 layers of structure. Superficial layer included iliotibial tract,lateral collateral ligament,popliteofibular ligament and arcuate ligament.Stratum medium had popliteus-tendon complex, popliteus-tibia fascia and popliteus-niscus fascia.Deep layer was consisted of lateral capsule ligament,posterior hom of lateral meniscus,lateral coronary ligament and lateral articular capsule.7.Release of the anterior portion of MCL and ACL produced valgus and rotation laxity at 60°and 90°(11.19°±2.05°,P=0.045)flexion.Release of the posterior oblique portion and posterior capsule produced moderate laxity at from full extension to 30°flexion.Complete medial collateral ligament release increased laxity significantly in flexion and extension both.8.With the merit of CT to demonstrate the bone structure well,segmentation and 3D reconstruction of bone were performed using Mimics 10.01 in CT data.Documents of bone was saved.The registration was performed after the 3d models which reconstructed by MRI and CT separately were imported in the software Geomagic to transform the coordinate of CT data which enabled the CT model be fit for the MRI image.With the merit of MRI to demonstrate the soft tissue structure well, segmentation and 3D reconstruction of meniscus,atricular cartilage and ACL/PCL were performed using Mimics 10.01 in MRI data.The 3D models of these structures were imported to Geomagic software to 3D modification to let the structure smooth. The articular cartilage models were imported into CT image again to testify the region of the segmentation.Finally,the 3D knee joint model with bone,meniscus, ACL/PCL and articular cartilage was reconstructed.Conclusion:1.The extrinsic innervation of knee joint could be divided into different groups. Oppositly,reticulate innervation inside joint.Arthronalgia could be relieved by resecting the membrane synovialis and articular braches through total knee arthroplasty or arthroscopy.Denervation have the rational anatomical foundation to relieve the pain in patellofemoral joint.Selective denervation technique may be effective to some extrinsic source pain due to the regional cutaneous nerve neoplasia or nerve branch compression.2.Lifting distal femur by encircle dragging should be avoid while peeling posterolateral joint caps and caput laterale musculi gastrocnemii.The location, inserting orientation and depth of Hoffman crook should be taken care of.Avoid hyperextension of the knee.3.Combining the image technology such as CT,MRI with computer image processing and 3D reconstruction and registration technologies,the direct-viewing bone and arteries of knee joint could be achieved to benefit surgery approach choice. The deep venous thrombosis after TKA was related to vessels injury by excess drag.4.The key procedure of soft tissue balancing in TKA was to suture the VMO and MPFL accurately,and loosen the vastus lateralis tendon or the lateral patellar retinaculum if necessary.Protection of the subcrureus is significant in TKA.5.It was benefit to achieve soft tissue balancing of medial structure in TKA with "spreader" skill.The key to correct yams deformity was to release the MCL complex at the tibia.To correct flexion deformity should be concentrate on medial-posterior articular capsule at the femoral and the lateropusion tendon branch of the semimembranous muscle at the tibia.If the medial joint gap tension happened at flexion＜30°,release of the anterior part of MCL.At flexion 30°～60°,release of the posterior oblique part of MCL and the lateropusion tendon branch of the semimembranous muscle.At flexion＞60°,increase release of the posterior articular capsule.6.The fundamental stabilizer of posterolateral corner of knee was lateral collateral ligament complex and popliteus-tendon complex.To achieve soft tissue balancing of medial structure in TKA,when the valgus deformity＜20°,sequence release of lateral capsule ligament,lateral articular capsule,iliotibial tract,popliteofibular ligament and arcuate ligament.7.With the merit of CT and MRI,it is realizable to reconstructe 3D knee joint model with bone,meniscus,ACL/PCL,articular cartilage and blood vessel.更多还原