骶髂关节脱位钉板内固定与关节拉力螺钉内固定两种置入方法的三维有限元分析

背景:有限元法能对复杂的结构、形态、载荷和材料力学性能进行应力分析比较,模拟的条件更接近正常,结果更加可信,已经是骨科生物力学研究中的重要手段。目的:以有限元分析方法建立骨盆骶髂关节(单侧)脱位模型,比较前路钉板内固定及骶髂关节拉力内固定治疗后的生物力学稳定性。方法:在正常骨盆三维有限元模型的基础上,截断骶髂关节间的骶髂前后韧带(包含骶髂骨间韧带)以及骶结节韧带和骶棘韧带等盆底韧带,造成骶髂关节脱位。分别在前路钉板内固定系统(共2块重建钢板6枚螺钉)及骶髂关节拉力螺钉内固定(2枚拉力螺钉)两种固定方法的模型上,加载后进行非线性有限元分析。计算该加载方式下的骨盆应力、应变及位移的分布情况。结果与结论:建立了高精度骨盆骶髂关节脱位两种内固定的三维有限元模型。通过应力应变云图分析与比较后发现,采用骶髂关节拉力螺钉内固定相对于前路钢板内固定移位的总位移小,应力分布均匀,无明显高度集中现象,固定强度更大,固定后的骨盆更稳定。利用有限元方法分析骨盆骶髂关节脱位两种内固定生物力学稳定性,具有较高真实性、精确度和可重复性,结果与其他生物力学实验结果相一致,能满足临床骨盆损伤研究的需要。     

骨盆前环骨折经皮空心拉力螺钉固定的生物力学研究

目的：通过骨盆生物力学的研究,为前环骨折提供可供选择的临床治疗方式。方法：15具防腐湿性尸体,随机分成三组每组5具。A组骨盆完整,行预试验;B、C两组制成前环骨折模型,B组采用空心拉力螺钉固定,C组采用重建钢板固定。各组均接受不超过500次的循环压力负荷,直至结构衰竭,经动态机械性能分析（DMA）并记录压应力和各方向位移。结果：A组在150N／3Hz模式下出现应力松弛,耻骨支间位移（0．7±0．32）mm;250N／5Hz负荷模式下发生结构衰竭,位移（3．0±0．88）mm。相同的压力／频率耦合模式下,发生松弛时B组位移（1．26±0．49）mm,C组位移（1．06±0．45）mm;发生衰竭时B组的应力为（1010．4±542．46）N,C组为（919．2±409．34）N。结论：拉力螺钉与重建钢板相比,应力足够坚强,基于骨盆的生物力学特点,能够改善前环骨折的治疗。     

垂直不稳定型骨盆骨折两种固定方法的生物力学研究

目的采用传统外固定架和改良外固定架两种外固定方法,研究固定后垂直不稳定型骨盆骨折的生物力学特性。方法7具骨盆标本,其中男性4具,女性3具,年龄17-38岁。制成垂直不稳定型骨盆骨折模型,对骶髂关节均采用前路钢板固定,再分别用传统外固定架及改良外固定架固定后,于静力位测试生物力学数据并进行比较。结果改良外固定架固定时：患侧骶髂关节应变为0-（806.5±76.8）με,骶髂关节纵向位移0-（3.9±0.6）mm,耻骨分离移位0-（5.0±1.3）mm,骨盆整体压缩率2.2%±0.5%,骨盆承受极限压力（1920.0±65.5）N;传统外固定架固定时：患侧骶髂关节应变为0-（1015.3±108.0）με,骶髂关节纵向位移0-（5.2±1.0）mm,耻骨分离移位0-（9.8±2.5）mm,骨盆整体压缩率2.9%±0.6%,骨盆承受极限压力（1513.7±165.7）N。结论改良外固定架固定结合内固定术式较传统术式更符合垂直不稳定型骨盆骨折稳定的要求,为临床提供了一些有参考价值的生物力学依据。     

改进型耻骨联合分离记忆合金内固定器的 生物力学特性

目的 探究改进型耻骨联合分离记忆合金内固定器生物力学特性。方法 采用10具骨盆标本,建立耻骨联合分离损伤模型,对照组复位后采用动力加压钢板固定,实验组复位后采用改进型耻骨联合分离记忆合金内固定器固定,比较两种内固定的生物力学稳定性。结果 两组模型均无松动,内固定无断裂。实验组耻骨联合在水平、前后、垂直3个方向的位移与对照组比较均明显减小（P＜0.05）。结论 改进型耻骨联合分离记忆合金内固定器对抗水平和前后方向拉力以及垂直剪切力均优于动力加压钢板。     

耻骨联合区域相关解剖学进展及内固定治疗的生物力学特征

文题释义：耻骨联合：是骨盆两个联结副弓在骨盆前部所汇合之处,由两侧耻骨内侧面构成,关节面由透明软骨覆盖,一较厚的纤维软骨盘连接,关节的周围有前、后、上、下四韧带。耻骨联合属于微动关节,参与构成骨盆环,维持骨盆环稳定。 耻骨联合分离：是指骨盆前方两侧耻骨纤维软骨联合处,因各种因素出现分离移位,表现耻骨联合距离增宽或上下脱位。 背景：耻骨联合分离损伤大多与严重骨盆骨折损伤一起发生。由于耻骨联合解剖位置深在,且治疗效果常不尽如人意,有必要进行相关解剖及生物力学研究,以便更好指导临床诊疗。 目的：总结分析耻骨联合解剖学特点,生物力学研究现状,为临床治疗耻骨联合分离提供一定裨益。 方法：在中国知网、维普、PubMed数据库上以“耻骨联合分离”及“生物力学”作为中文检索词、“separation of pubic symphysis”和“biomechanics”作为英文检索词检索;检索时间为1984年4月至2020年2月。通过标题及摘要选取相关文献, 并阅读参考文献的标题和摘要, 从中再次挑选相关文献,剔除重复文献。结果与结论：检索符合条件文献57篇,最终纳入文献33篇。①现解剖研究多集中于耻骨联合相关组成结构及周围韧带方面;②限于耻骨联合位置原因,未进一步深入研究,如周围韧带和肌肉起止点的精确分布,精确的神经和血液分布,还有待进一步研究;③对耻骨联合分离生物力学研究较少,且差异较大,有待深入研究达成共识;④伴随有限元发展,生物力学热点多集中在耻骨联合治疗方面;⑤因重建钢板和空心螺钉力学稳定性优良而做为耻骨联合分离常用固定方式,而经皮空心螺钉固定因其微创性成为今后发展趋势。ORCID: 0000-0001-9019-3392(宫玉锁)中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

后路单钉棒治疗骶髂关节脱位的生物力学特性及其有效性

背景：目前骶髂螺钉广泛应用于治疗骶髂关节脱位,但是生物力学性能较差,不能达到坚强内固定。 目的：探讨应用单钉棒治疗骶髂关节脱位的力学强度及临床疗效。 方法：①取成年防腐标本12具,男女各半,分别切断骶髂关节韧带及耻骨联合结构,制作骶髂关节脱位、耻骨联合分离模型,将标本随机等分为骶髂螺钉固定组和骨盆后路单钉棒固定组,分别采用骶髂螺钉固定和骨盆后路单钉棒固定方法固定。②设定单钉棒系统临床适应证,收集16例骶髂关节脱位患者的临床资料,采用Mears的影像评定标准和骨盆骨折Majeed疗效评分评定固定效果。 结果与结论：在相同载荷下,骶髂关节标本后路单钉棒固定组的位移、轴向刚度、极限载荷和屈服载荷均大于骶髂螺钉组(P < 0.05)。16例患者随访时间平均为23.2个月(3~45个月)。根据Mears的影像评定标准,固定后解剖复位13例,满意3例。骨盆骨折Majeed疗效评分为60~100分,平均82分;其中C1型骨折的疗效优良率为82%,C2型为80%。提示与骶髂螺钉比较,应用后路单钉棒治疗骶髂关节脱位,其内固定强度更为可靠,临床疗效也更满意。     

骨盆的形态特点与不稳定型骨折内固定治疗评价

目的　探讨根据骨盆的形态特点选择不同的内固定手术治疗不稳定型骨盆骨折的临床应用价值。 方法　65例不稳定型骨盆骨折,31例Tile B型骨折经前入路,将耻骨联合或耻骨支复位用重建钢板固定,其中8例合并髂骨骨折经髂窝入路将之复位用重建钢板固定;34例Tile C型骨折的前环损伤均采用与Tile B型骨盆骨折相同的方法处理,后环损伤的固定方法：17例骶骨骨折或骶髂关节脱位之中,复位后在透视引导下从后方经皮骶髂螺钉固定11例,经髂骨的螺栓固定4例,经后路在双侧髂骨后嵴之间用张力带钢板固定2例;9例骶髂关节骨折-脱位之中,经皮骶髂螺钉固定6例,钢板固定3例;8例合并髋臼骨折行重建钢板内固定。 结果　通过对术后骨盆X线测量骨折分离移位的最大距离,根据Matta评分标准：小于4 mm为优,占86.1%（56例）;4~10 mm为良,占7.7%（5例）;10~20 mm为可,占6.2%（4例）;大于20 mm为差（0例）。本组骨盆X线测量结果总优良率为93.8%。 结论 不稳定型骨盆骨折应在血流动力学稳定时尽早根据骨折的类型及骨盆的解剖形态特点选择合理的内固定手术方案。     

骶髂关节解剖型钢板的全骨盆三维有限元模拟

目的在高度仿真的完整骨盆三维有限元模型基础上,模拟使用新设计的解剖型钢板对骶髂关节骨折脱位进行固定,并与普通钢板的模拟固定进行对比,验证和分析新型钢板的性能.方法从CT精确重建髋骨和骶骨模型,采用专门的半自动流线型生物力学有限元网格划分器生成规则的体网格模型,并进一步建立骶髂关节的终板、软骨、关节接触面,和骨盆上的主要韧带组织及耻骨间盘.然后去掉一侧的骶髂关节韧带群模拟骨折脱位,使用新型的骶髂关节解剖型棒-板内固定系统进行固定模拟,同时使用普通钢板替代解剖型钢板建立对比模型,分别进行加载分析受力情况.结果通过使用新的解剖型钢板改进棒一板内固定系统,骶髂关节的最大相对位移值减小了约23%,骨盆主要传承负载区域的最大的应力值降低了约25%.结论新型的解剖型钢板有效地提高了骶髂关节棒-板内固定系统的力学性能,为骨盆骨折的治疗增加了一种更有效的新方法.     

耻骨联合分离程度与骶髂关节变化相关性研究

目的:探讨耻骨联合分离程度与骶髂关节变化之间的关系,通过耻骨联合的变化预测骶髂关节损伤程度.方法:防腐尸体骨盆8具,骨刀凿断耻骨联合,切断双侧骶棘,骶结节韧带和骶髂前韧带,制成开书型骨盆骨折,使耻骨联合分离至1、3、5、7 cm时,用螺旋CT扫描,用标准CAD测量软件计算骶髂关节开大的距离.结果:耻骨联合分离1、3、5、7 cm时,骶髂关节分离距离平均值分别为:左侧(6.93±0.44)、(9.63±0.21)、(11.64±0.33)、(14.35±0.29)mm,右侧(6.91±0.44)、(9.63±0.19)、(11.63±0.20)、(14.30±0.49)mm.耻骨联合分离3 cm与5 cm时,髓骼关节分离距有明显差异,P<0.05.耻骨联合分离与骶髂关节分离有相关性,r(左)=0.991,r(右)=0.992,P<0.01.回归方程:左骶髂关节分离距离(mm)=5.777+1.214×耻骨联合分离距离(cm),右骶髂关节分离距离(mm)=5.784+1.209×耻骨联合分离距离(cm).结论:骶髂关节分离随耻骨联合的分离程度增加,根据耻骨联合分离距离可预测骶髂关节变化,指导临床治疗.     

髋臼横断骨折双柱内固定的生物力学分析*

背景：骨盆髋臼骨折治疗的关键是精确的骨折复位和稳定的内固定。 目的：分析比较3种髋臼横断骨折双柱内固定手术的生物力学特性,找到固定效果最好的双柱内固定手术方法。 方法：建立各向异性的骨盆髋臼横断骨折模型,通过对最大位移、最大等效应力等评价指标的有限元综合分析,比较分析双柱螺钉、前柱螺钉后柱钢板、双柱钢板等3种双柱内固定方法在站立位置的生物力学性能差异。 结果与结论：有限元分析双柱螺钉固定最大位移1.827 mm,最大等效应力26.589 MPa;前柱螺钉后柱钢板固定最大位移2.080 mm,最大等效应力106.04 MPa;双柱钢板固定最大位移2.987 mm,最大等效应力200.37 MPa。3种双柱内固定方法稳定性最好的是双柱螺钉固定,最后是双柱钢板固定。      

Asymmetry of the internal connections of the striate cortex of the cat in the projection zone of the center of the field of vision

Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0–5°) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of “silent” zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field. Laboratory of Visual Physiology and Laboratory of Central Nervous System Morphology, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, 6 Makarov Bank, 199034 St. Petersburg, Russia. Translated from Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 82, No. 12, pp. 23–29, December, 1996.     

Effects of the lesion of the postcommissural part of the septum on the behavior of the rat.

The effects of the lesion of the postcommissural part of the septum on behavior of the rat has been studied. Results may be summarized as follows. An increase in the exploratory behavior in the open field which decreases rapidly; a decrease in the number of defecations in this test and a decrease in time leaving a dark environment for exploration. In the shuttle box test, no facilitation of the acquisition, but a permanent and quite significant increase in the intertrial activity has been found. We conclude that the lesions tend to decrease the emotivity of the subjects. An interpretation on the basis of the species -- specific defensive reactions explains the transitory and permanent effects of the lesions on the spontaneous activity.     

Counterpointing the functional role of the forebrain and of the brainstem in the control of the sleep-waking system

This paper reviews the lifetime contributions of the author to the field of sleep-wakefulness (S-W), reinterprets results of the early studies, and suggests new conclusions and perspectives. Long-term cats with mesencephalic transection show behavioral/polygraphic rapid eye movement sleep (REMS), including the typical oculo-pupillary behavior, even when the section is performed in kittens prior to S-W maturation. REMS can be induced as a reflex. Typical non-rapid eye movement S (NREMS) is absent and full W/arousal is present only after a precollicular section. The isolated forebrain (IF) rostral to the transection exhibits all features of W/arousal and NREMS [with electroencephalographic (EEG) spindles and delta waves], arousal to olfactory stimuli, and including the appropriate oculo-pupillary behaviors. These features also mature normally after neonatal transection. REMS is absent from the IF. After deprivation there is NREMS pressure and rebound in the IF, but the decerebrate cat only shows pressure for REMS. Most IF reactions to pharmacologic agents are within expectations, except for the tolerance/withdrawal effects of long-term morphine use which are absent. In contrast, these effects are supported by the brainstem (i.e. seen in the decerebrate cat). In cats with ablation of the telencephalon, or diencephalic cats, delta waves are absent in the thalamus. EEG thalamic spindle waves are seen triggering S for only 4-5 days after ablation. Therefore, true NREMS is absent in chronic diencephalic cats although pre- and postsomniac behaviors persist. These animals are hyperactive and show a pronounced, permanent insomnia; however, a low dose of barbiturate triggers a dramatic REMS/atypical NREMS rebound. Cats without the thalamus (athalamic cats), initially show a dissociation between behavioral hyperactivity/insomnia and the neocortical EEG, which for 15-20 days exhibits only delta and slower oscillations. Fast, low-voltage W rhythms appear later on, first during REMS, but spindle waves and S postures are absent from the start, such that these cats also display only atypical NREMS. Athalamic cats also show barbiturate-sensitive insomnia. Cats with ablation of the frontal cortices or the caudate nuclei remain permanently hyperactive. They also show a mild, but significant hyposomnia, which is permanent in afrontal cats, but lasts for about a month in acaudates. The polygraphic/behavioral features of their S-W states remain normal. We conclude and propose that: (a) the control of the S-W system is highly complex and distributed, but is organized hierarchically in a well-defined rostro-caudal manner; the rostral-most or highest level (telencephalon), is the most functionally complex/adaptative and regulates the lower levels; the diencephalic/basal forebrain, or middle level, has a pivotal role in inducing switching between S and W and in coordinating the lowest (brainstem) and highest levels; (b) W can occur independently in both the forebrain and brainstem, but true NREMS- and REMS-generating mechanisms exist exclusively in the forebrain and brainstem, respectively; (c) forebrain and brainstem S-W processes can operate independently from each other and are preprogrammed at birth; this helps understanding normal and abnormal polygraphic/behavioral dissociations in humans and normal dissociations/splitting in aquatic mammals; (d) NREMS homeostasis is present in the IF, but only REMS pressure after deprivation persists in the decerebrate cat; (e) the thalamus engages in both NREMS and W; (f) insomnia in diencephalic cats is the result of an imbalance between antagonistic W- and S-promoting cellular groups in the ventral brain (normally modulated by the telencephalon); (g) the EEG waves, which are signature for each S-W state, appear to truly drive the concomitant behaviors, e.g. a hypothetical human IF could alternate between behavioral NREMS and W/arousal/awareness; (h) a role for REMS is to keep the individual sleeping at the end of the self-limiting NREMS periods. The need for accelerating research on telencephaling NREMS periods. The need for accelerating research on telencephalic S-W processes and downstream control of the lower S-W system levels is emphasized.     

The development of the ligament of the head of the femur

The hip joints of 30 human male and female fetuses and stillborns between 20 mm and 350 mm crown-rump length were studied by light microscopy. The ligament of the head of the femur developed in situ as a condensation of mesenchyme at the end of the second month of intra-uterine life (IUL), and was vascularized by branches of acetabular vessels early in the fourth month. In the majority of fetuses older than 5.5 months IUL, vessels in the ligament passed a short way into the femoral head within cartilage canals, to supply a small region around the fovea capitis. The remainder of the head was supplied by vessels in canals from around the upper part of the neck. The ligament changed from predominantly cellular to fibrous during the last 4 months of IUL. This increase in strength suggested significant mechanical functions in utero: limitation of adduction-flexion and opposition to postero-superior dislocation were the most likely.     

Topical organization of the projections of neurons of the substantia nigra and the ventral field of the tegmentum of the midbrain to the head of the caudate nucleus of the cat

Neuroscience and Behavioral Physiology -     

Involvement of the striatum in the central regulation of the hormonal functions of the gonads

Studies reported here show that intrastriatal administration of corticoliberin to rats decreases the blood testosterone level. However, in conditions of chemical deficiency of dopaminergic transmission in the dorsal striatum induced by injection of 6-hydroxydopamine, the effect of this neurohormone did not appear. It is concluded that extrahypothalamic corticoliberin is involved in regulating the hormonal reproductive system acting via dopaminergic mechanisms. Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 85, No. 4, pp. 594–597, April, 1999.     

Ultrastructure of the endothelium of the drainage system of the eye

The endothelium of the ocular drainage system (Schlemm’s canal, collector tubules, and aqueous veins) in primary juvenile glaucoma undergoes degenerative dystrophic changes with compensatory hypertrophy and proliferation at the initial stages of the glaucomatous process and atrophy and desquamation at advanced and terminal stages. Progressive decrease in the pinocytous function of endotheliocytes, reduction of the protein-synthesizing and mitochondrial compartments of the cytoplasm, and formation of autophagosomes reflect the process of endotheliocyte degeneration in general. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 5, pp. 574–577, May, 2008