股骨远端几何学和解剖学的相关性研究

目的 研究正常膝关节远端股骨关节面解剖标本和X线片的对应关系.方法 用侧位X线照相技术检测了10个新鲜尸体标本和10个志愿者的正常膝关节.测量这些圆弧表面的半径、圆弧所对的圆心角以及它们的圆心之间的距离,并且把髌股关节和股胫关节侧位X线片上看到的关节的模型和股骨远端表面的解剖学结构相对应.测量所得数值用SAS软件进行分析,P＜0.05为差异有统计学意义.结果 RA、RP和XY每两者之间有显著的相关性.角C和角D呈负相关,和角F呈正相关,角D和角F呈负相关.RA和RP呈正相关;角F呈现出更显著的统计学相关性,且呈负相关.结论 内侧副韧带和后交叉韧带可以看作内侧股胫关节的内侧副韧带,外侧副韧带和前交叉韧带可以看作外侧股胫关节的外侧副韧带.     

不同体位加载下肱骨外侧髁的应力分析研究

目的 从生物力学角度研究肱骨外侧髁在不同体位加载下的应力分布规律，探讨其骨折发生机制。方法 分别制造儿童肱骨外侧髁三维有限元及光学弹性模型，模拟伸屈肘及前臂旋前、中立、旋后和内外翻等多种体位加载，计算分析和观察相应部位的应力分布状况。结果 半屈肘位时肱骨外侧髁区平均应力值最大，而伸肘时的伸肌腱作用节点应力值大于外侧髁区。内翻位伸肌腱作用下，肱骨外侧髁上部为拉应力条纹，内侧髁上部为压应力条纹。结论 半屈肘位时易发生以尺桡骨撞击力与重力的上下剪切作用为主的肱骨外侧髁骨折；伸肘内翻位时，以伸肌腱牵拉为主的弯力偶矩可拉脱外侧髁形成骨折。肱骨外侧髁骨折的复位可利用伸肌腱的牵拉作用，而固定则尽量避免伸肌腱的牵拉。     

对微小种植体及其骨组织生物力学的三维有限元分析

目的建立微小种植体及其支持骨组织的三维有限元模型,以期为微小种植体的设计和临床应用提供科学的理论依据。方法采用SOLIDWORKS专业三维制图软件和ANSYSworkbench有限元软件,建立不同方向载荷的5个三维有限元模型,分别在模型上计算出不同方向载荷微小种植体-骨界面的Von-Mises应力及位移分布状况。结果在不同载荷方向150g正畸力下,微小种植体Von-Mises应力及位移的分布均集中于种植体颈部骨皮质区,种植体的Von-Mises应力值及位移值均较小,随着与种植体长轴夹角角度的增大,种植体的Von-Mises应力峰值分别为0.612、3.118、4.103、4.809、5.159MPa,呈明显的增加趋势,位移峰值分别为0.695、0.126、0.137、0142、0.158μm。结论在不同载荷方向150g正畸力下,微小种植体Von-Mises应力及位移的分布均集中于种植体颈部骨皮质区,种植体的Von-Mises应力值及位移值均较小,微小种植体可以安全地承载不同方向150g正畸力作用,特别是与种植体长轴夹角较小方向的力。     

CT结合逆向工程技术建立上颌第一磨牙全瓷冠三维有限元模型

目的 建立上颌第一磨牙全瓷冠三维有限元模型.方法 将在体上颁第一磨牙经CT扫描及图像处理后,应用Mimics软件和Imageware软件建立三维几何模型,预备出基牙和全瓷冠各层,然后导入有限元分析软件Abaqus软件中生成实体模型.结果 建立了上颌第一磨牙全瓷冠三维有限元模型,总节点为60160个,4面单元数为186 328个.结论 所构建的模型结构完整,单元划分精细,能够较精确地模拟实体状态,为进一步的生物力学研究提供了基础.     

手术胫骨平台骨折28例临床分析

胫骨内外两侧平台关节面呈鞍形。侧位观,平台关节面略呈凸形。正面观略呈凹形,胫骨隆突位于内外两侧平台之间,为非关节面区。此处由前向后顺序附有内侧半月板前角、前交叉韧带、外侧半月板前角、胫骨棘、外侧半月板后角、内侧半月板后角和后交叉韧带。胫骨上端周围皮质骨较薄弱。胫骨平台的关节软骨下皮质骨较股骨髁相对薄弱,暴力使两骨相撞时,常引起胫骨平台骨折,膝关节外侧容易遭受侧方暴力,故多见外侧平台骨折。     

个性化膝关节假体设计的形态学初探

目的:通过比较胫骨模型和胫骨半月板模型,优化膝关节假体。方法:对健康成人志愿者进行CT及MRI扫描,导入Mimics软件中建立三维模型,再导入ANSYS软件中,通过定义单元类型、选择材料属性和划分网格及力学分析,比较胫骨模型和胫骨半月板模型应力分布的区别。结果:成功对半月板进行三维立体测量,通过比较胫骨模型和胫骨半月板模型,提出了优化膝关节假体的新构想。结论:基于Mimics及ANSYS软件,成功构建了胫骨模型和胫骨半月板模型,对比分析可得,胫骨半月板模型在稳固膝关节及减少摩擦上优于胫骨模型,为个性化假体设计及3D打印提供仿真基础。     

摇椅弓及牙列和牙周组织三维有限元模型的建立

目的建立下颌牙列、牙周组织及相应不同角度,不同弧形深度的0.018英寸×0.025英寸下颌标准弓形摇椅弓的三维有限元模型,并将其形成一个整体,为分析其生物力学性质提供一个可信的数学模型。方法通过螺旋CT扫描,采用ANSYS有限元软件建模。结果获得较理想的三维有限元模型,包括下牙列、牙周膜、牙槽骨和各工况摇椅弓,共2 709个节点,1 969个单元。结论该模型有较好的力学和几何学相似性,所包含数据可以进行摇椅弓作用下牙齿的受力状况和牙周组织应力分布分析。     

显微根尖手术术后即刻及愈合模型的生物力学对比分析

目的 评估不同牙根切除长度对上颌中切牙显微根尖手术术后即刻及术后愈合后生物力学行为的影响。方法 通过三维逆向建模的方法建立上颌中切牙三维实体模型，并通过计算机辅助设计建立不同牙根及周围骨组织切除长度的显微根尖手术术后即刻及术后愈合的三维有限元模型。对模型施加约束及载荷，分析显微根尖手术术后即刻及术后愈合后牙周膜和皮质骨等效应力分布、大小以及模型位移的变化。结果 无论是术后即刻还是术后愈合的模型，随着牙根切除长度的增加，牙周膜等效应力峰值、皮质骨等效应力峰值及模型的位移峰值均增加。术后愈合模型的牙周膜等效应力峰值、皮质骨等效应力峰值及模型的位移峰值虽较正常牙齿有所上升，但较术后即刻模型下降。结论 显微根尖手术术后即刻应避免咬合力，对于牙根切除长度较长的病例应对牙齿做出固定，并避免咬合受力以降低牙周支持组织及牙槽骨的等效应力，待根尖牙槽骨愈合后再去除固定。     

上颌中切牙氧化锆桩核的三维有限元分析

目的通过三维有限元法研究不同长度、直径氧化锆桩核冠模型的应力分布,为氧化锆桩核修复的临床病例选择提供理论依据。方法采用Micro-CT扫描、DICOM标准数据建模法及Mimics、Pro/E软件建立不同长度、直径的上颌中切牙氧化锆桩核全冠模型共5组,在中切牙牙冠模型舌侧切缘下2mm与牙长轴成45°角施加100N载荷,用ANSYSWorkbench有限元分析软件计算各实验组桩核上的最大主应力、等效应力。结果各组模型氧化锆桩核冠应力分布模式无差别;最大主应力峰值除在舌侧加载区集中外,还位于根管内桩的舌侧中1/3;等效应力峰值位于根管内桩的唇侧中1/3。随着桩的直径减小,其应力峰值减小;桩长度增加时,其应力峰值降低。结论在一定范围内,氧化锆桩核直径越小,产生的应力越小,但过细的桩容易弯曲折断;在一定范围内,增加桩的长度可以减小应力。临床应根据牙体髓腔大小合理进行桩道预备。     

多层螺旋CT多平面和三维重组在膝关节骨折中的临床应用价值

目的 探讨高分辨螺旋电子计算机断层扫描（CT）轴位扫描,多平面重组与三维图像在膝关节骨折中的临床应用价值.方法 30例膝关节外伤患者,经X线片检查后行高分辨螺旋CT及多平面重组与三维图像处理.分析骨折线的走行,骨折片的移位与关节面的关系,对关节的解剖进行立体分析.结果 X线片发现骨折25例,未诊断骨折3例,可疑骨折2例.高分辨螺旋CT（HRCT）源图像发现骨折28例.多平面重组与三维图像的阅读结果为30例患者均清晰显示骨折.结论 X线片在膝关节外伤检查时有漏诊,且不能观察关节面的损伤情况;而多平面重组＋三维图像成像则能全面显示,是目前膝关节骨折最理想的检查方法.     

氟罗沙星葡萄糖注射液致膝关节损伤

1名62岁女性患者,因急性细菌性痢疾给予静脉滴注氟罗沙星葡萄糖注射液100ml(0.4g),1次/d。第3天患者出现周身肌肉、关节酸痛,体检:左侧膝关节、踝关节肿胀,腓肠肌内侧头外压痛阳性,关节活动时诱发疼痛。B超显示左膝关节积液,MRI示左膝关节前交叉韧带损伤、关节腔积液、关节周围软组织肿胀。实验室检查:血沉130mm/h、C反应蛋白42mg/L。立即停用氟罗沙星,给予关节制动、局部理疗,复查B超左侧膝关节恢复正常。3个月后,复查血沉、C反应蛋白均恢复正常。     

多种影像学技术在胫骨平台骨折诊断中的应用价值

目的：评价普通X线、多层螺旋CT（MSCT）三维重建和MRI在胫骨平台骨折诊断中的临床应用价值。方法收集我院胫骨平台骨折患者37例,全部患者均行膝关节DR正侧位、MSCT三维重建和MRI检查,对其影像资料进行汇总分析。结果 DR漏诊4例,分型错误2例;MSCT三维重建1例未见明确骨折线,而造成分型错误;MRI分型均与术后分型一致,但对于显示交叉韧带附着点撕脱骨折、骨折粉碎程度及碎骨块移位情况,DR与MRI没有MSCT三维重建满意;所有病例MRI显示均合并有不同程度的膝关节损伤,其中骨挫伤26例,关节软骨损伤33例,半月板损伤27例,前交韧带损伤24例,后交韧带损伤14例,内侧副韧带损伤19例,外侧副韧带损伤9例,髌韧带损伤7例,关节囊积液35例。结论普通X线、MSCT三维重建和MRI等多种影像学检查技术结合应用,既能提高胫骨平台骨折诊断及分型,又能对关节软骨、半月板、肌腱韧带等软组织损伤情况做出判断,完善对膝关节损伤情况了解,为临床制定治疗方案和术后膝关节功能的恢复具有重要意义。     

Effects of intraarticular injection of halopredone diacetate on the articular cartilage of rabbit knees: a comparison with methylprednisolone acetate

Halopredone diacetate, which is a new synthetic corticosteroid drug showing local retention, and methylprednisolone acetate in common clinical use were injected into the knee joints of adult rabbits to compare the effects of the two drugs on the articular cartilage. The dosage of one injection was 1.75 mg (H-1 group) and 8.75 mg (H-5 group) for halopredone diacetate and 1.4 mg (M-1 group) and 7.0 mg (M-5 group) for methylprednisolone acetate. The drugs were injected into the right knee joint once a week, 12 times in total. One week after the last injection, the steroid crystals remaining in the knee joint were observed in all rabbits in the H-1 and H-5 groups. White deposits were seen locally on a part of the cartilage in all the rabbits in the H-1, H-5, and M-5 groups but not in the M-1 group. These white deposits were observed as cystic lesions by light microscopy and contained abundant hydroxyapatite. Other histologic findings in the articular cartilage included fissure, hypocellularity, and a decrease of proteoglycan in each group. However, no distinct difference was noted between the H-1 group and the M-1 group as regards the histological-histochemical grades of the cartilage on the medial tibial condyle or in the electron microscopic findings of the cartilage on the medial femoral condyle. The same was true for the H-5 and M-5 groups. These results show that repeated intraarticular injections of these two drugs cause severe cartilage lesions to the same degree, except for the intracartilaginous white deposits of rabbit knees.     

The role of joint nerves and mast cells in the alteration of vasoactive intestinal peptide (VIP) sensitivity during inflammation progression in rats

The present study examined the peripheral effects of vasoactive intestinal peptide (VIP) on rat knee joint blood flow during acute and chronic inflammation. The involvement of joint nerves and synovial mast cells on these effects was also investigated. Prior to blood flow assessment, animals were deeply anaesthetised with ethyl carbamate (urethane; 2 mg kg(-1) i.p.). Local application of VIP (10(-13)-10(-9) mol) onto the capsular surface of normal rat knee joints caused a dose-dependent increase in synovial perfusion with an ED50 of 1.2 x 10(-11) mol. The dilator effect of the peptide was transient with the maximal response occurring approximately 1 min after drug administration. VIP-induced vasodilatation was blocked by co-administration of the VIP receptor antagonist VIP(6-28) (10(-9) mol). The inhibitory effect of the antagonist was consistent across the entire VIP dose range (P=0.01). The vasoresponsiveness to VIP was significantly attenuated in acutely inflamed joints; however, surgical denervation of acutely inflamed knees re-established the vasodilator effect of the neuropeptide. Topical application of VIP to 1- and 3-week adjuvant monoarthritic knees produced a hyperaemic response, which was not significantly different from normal (P=0.06 and 0.73 for 1- and 3-week adjuvant treated joints, respectively). Stabilisation of synovial mast cells by disodium cromoglycate (cromolyn) pretreatment did not alter the vasoresponsiveness to VIP in acute or chronically inflamed joints. The vasodilatatory effect of VIP is lost during acute knee joint inflammation and this abrogated effect is neurally dependent. In the chronic phase of knee joint inflammation, VIP-mediated hyperaemia recovers to normal levels. Synovial mast cells do not influence the vasomotor effects of exogenously applied VIP in inflamed knee joints.     

低场强磁共振梯度回波和脂肪抑制成像在膝关节损伤中的临床应用——附120例分析

目的 探讨低场强磁共振梯度回波和脂肪抑制成像在膝关节损伤中的临床应用.方法 120例患者经低场强MR不同序列检查,显示半月板、韧带、关节囊、关节软骨及关节面骨质等受损情况.结果 低场强MRI常规序列加脂肪抑制和梯度回波序列对内外侧半月板损伤,前、后交叉韧带,侧副韧带撕裂及关节软骨和骨质损伤的显示率高,诊断准确可靠,是膝关节损伤最佳的检查手段.     

股骨近端防旋髓内钉不同进钉点治疗外侧壁破裂型 股骨转子间骨折的有限元分析

摘要：目的 运用有限元法探讨股骨近端防旋髓内钉（PFNA）不同进钉点治疗外侧壁破裂型股骨转子间骨折的 生物力学。方法 基于志愿者髋部 CT 资料,通过 Mimics、Geomagic 等软件提取和优化右侧股骨三维模型,导入 Solidworks软件中与PFNA模型装配不同进钉点并分割模拟不同外侧壁骨折线得到3个A模型（股骨外侧壁粉碎,内 侧支撑存在）和3个B模型（股骨外侧壁粉碎,内侧支撑缺失）,导入Abaqus软件中设置材料参数、边界条件等后运算, 查看模型的Von Mises云图。结果 A模型中外侧壁上部进钉形成应力集中,中部进钉移位较大,下部进钉应力分布 均匀且移位较小;B模型外侧壁上部进钉移位较大,中部进钉应力较大且应力集中,下部进钉应力分散且移位较小。 结论 PFNA在外侧壁下部进钉治疗外侧壁破裂型股骨转子间骨折的生物力学效果最佳。     

P2X receptor-mediated excitation of nociceptive afferents in the normal and arthritic rat knee joint

1. We tested the hypothesis that functional P2X receptors are present on peripheral terminals of primary afferent articular nociceptors in the rat knee joint. Neural activity was recorded extracellularly from the medial articular nerve innervating the knee joint in rats anaesthetized with pentobarbitone.
2. The selective P2X receptor agonist, αβ methylene ATP (αβmeATP), and the endogenous ligand, ATP, caused a rapid short-lasting excitation of a sub-population of C and Aδ nociceptive afferent nerves innervating normal knee joints when injected intra-arterially or intra-articularly, and this effect was antagonized by the non-selective P2 receptor antagonist PPADS.
3. Induction of a chronic (14–21 days) unilateral inflammatory arthritis of the knee joint using locally injected Freund''s adjuvant neither increased or decreased responsiveness of joint nociceptors to αβmeATP or ATP.
4. Our results support the hypothesis that αβmeATP-sensitive P2X receptors are expressed on peripheral nociceptive afferents in the rat knee joint suggesting that they may be involved in the initiation of nociception and pain.

     

带血管蒂双叶筋膜瓣移位膝关节治疗血友病性膝关节病(附1例报告)

目的介绍一种带血管蒂双叶筋膜瓣移位于膝关节治疗血友病性关节病的新方法。方法用膝最上动脉的关节支和隐支为蒂的双蒂筋膜瓣包绕清理后的股胫和髌股关节。结果术后随访1.5～2.5年,双膝关节疼痛消失,膝关节活动度右术前10°,术后110°,左术前20°,术后120°。按美国膝关节学会人工关节置换术后疗效评定标准,运动、功能综合评定优良率达92%。结论带血管蒂双叶筋膜瓣移位于膝关节内,具有关节稳定性好,手术简单,创伤小,并发症少,效果好等优点。     

In vivo effects of CB2 receptor-selective cannabinoids on the vasculature of normal and arthritic rat knee joints

BACKGROUND AND PURPOSE: Cannabinoids (CBs) are known to be vasoactive and to regulate tissue inflammation. The present study examined the in vivo vasomotor effects of the CB2 receptor agonists JWH015 and JWH133 in rat knee joints. The effect of acute and chronic joint inflammation on CB2 receptor-mediated responses was also tested. EXPERIMENTAL APPROACH: Blood flow was assessed in rat knee joints by laser Doppler imaging both before and following topical administration of CB2 receptor agonists. Vasoactivity was measured in normal, acute kaolin/carrageenan inflamed and Freund's complete adjuvant chronically inflamed knees. KEY RESULTS: In normal animals, JWH015 and JWH133 caused a concentration-dependent increase in synovial blood flow which in the case of JWH133 was blocked by the selective CB2 receptor antagonist AM630 as well as the transient receptor potential vanilloid-1 (TRPV1) antagonist SB366791. The vasodilator effect of JWH133 was significantly attenuated in both acute and chronically inflamed knees. Given alone, AM630 had no effect on joint blood flow. CONCLUSION AND IMPLICATIONS: In normal joints, the cannabinomimetic JWH133 causes hyperaemia via a CB2 and TRPV1 receptor mechanism. During acute and chronic inflammation, however, this vasodilatatory response is significantly attenuated.