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本实验采用8具新鲜尸体腰椎功能单位,通过脊柱三维运动实验机施加最大载荷为10,ON.m的6种力偶,使脊柱产生前屈/后伸、左/右侧弯和左/右轴向旋转运动。经立体摄像计算机图像处理得到L2~3节段的运动范围(ROM),中性区(NZ)和弹性区(EZ)等参数。将完整标本测量的结果为自身对照组,然后在L2~3节段依次切除左侧小关节1/3、1/2和全部。作t检验和方差分析单侧小关节切除对腰椎三维运动的影响。结果表明:单侧小关节切除1/3后ROM增加不显著(P>0.05),不影响脊柱的稳定;小关节全切除后后伸、左侧弯和右旋的ROM增加显著(P<0.05)。小关节切除1/2后ROM虽然增加不显著,但经方差分析与小关节全切的结果无显著差异,说明小关节切除范围超过1/2将导致脊柱失稳。 相似文献
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腰椎小关节是脊柱连接的重要关节,具有限制脊柱前屈前移运动,抵抗压缩、剪切及旋转等各种形式负荷的功能。外伤、异常的应力等因素均可导致该关节的退行性变和损伤。小关节病变是临床上引起下腰痛的一个重要原因,目前调查认为,15%~45%的慢性非特异性下腰痛与小关节病变有关[1] 相似文献
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腰椎节段形态对峡部、小关节应力及小关节接触力影响的有限元分析 总被引:1,自引:0,他引:1
目的:探讨腰椎形态结构变化对峡部裂性滑脱及小关节退变的作用和意义。方法:采用改良的“非种子区域分割方法”及非平行“最佳切割平面”等一系列新型计算机辅助设计(CAD)方法精确建立包括椎间盘高度、腰椎小关节角、椎间盘前凸角改变的L4~L5活动节段有限元模型;在2700N轴向压缩载荷条件下,分别对各有限元模型的峡部、小关节应力、小关节接触力以及椎间盘负载进行测试。结果:压缩载荷下,腰椎活动节段峡部、小关节等效应力及小关节接触力随椎间盘高度的减小而减小,随小关节角的增大而增加,随椎间盘前凸角的增加而减小。结论:椎间盘高度、腰椎小关节角、椎间盘前凸角等形态结构变化对腰椎节段有限元模型的峡部、小关节应力及小关节接触力有明显的影响。提示腰椎峡部应力性骨折及小关节退变的发生与椎间盘高度、腰椎小关节角、椎间盘前凸角等解剖形态因素有关。 相似文献
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不同运动负荷下腰椎应力的三维非线性有限元分析 总被引:8,自引:2,他引:6
目的:利用三维非线性有限元分析,研究1500N压力和15Nm弯矩下的脊椎前屈、后伸、侧弯和扭转运动时腰椎应力分布,探讨腰椎运动损伤的力学机制.方法:基于L3-L4节段的CT扫描数据建立有限元模型.根据腰椎三关节复合体结构,观察椎间盘膨出内陷尺度、纤维环应力水平、小关节负荷水平及后部结构等效应力分布来评价运动负荷导致的力学变化. 结果:压力和前屈负荷引起椎间盘前部受压膨出,后伸和侧弯负荷引起椎间盘在后部和后外侧部膨出.扭转不仅引起单侧小关节高负荷承载,还造成椎间盘后外侧区纤维环应力集中.后伸时小关节负荷虽低于扭转,但高于侧弯和前屈.椎弓根和椎弓峡部在压力和后伸负荷下等效应力较高.结论:椎间盘对压力的耐受性好于拉力,椎间盘后外侧区是各负荷下变形最大的区域,该部纤维环易于出现高应力而失败.小关节对腰椎活动特性有重要作用,扭转、后伸和高压力负荷引起小关节承受高负荷和小关节应力失败有关.椎弓根和椎弓峡部以及椎体前上部皮质骨区在屈伸和压力负荷下容易出现与应力相关的破坏. 相似文献
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腰椎小关节综合征的CT诊断 总被引:9,自引:2,他引:7
目的 评价CT对腰椎小关节综合征的诊断价值。方法 回顾分析 64例小关节综合征的CT表现。男 5 3例 ,女 11例。年龄 3 9~ 70岁 ,平均 5 4.5岁。结果 腰椎小关节异常的主要CT表现为 :(1)小关节突增生、肥大及骨赘形成 ,并导致关节间隙、侧隐窝、椎间孔及椎管狭窄。 (2 )关节面硬化 ,硬化骨质内囊样低密度区及关节面边缘缺损。 (3 )关节腔内“真空”现象 ,小关节不对称及关节半脱位。结论 CT可充分地显示椎小关节的解剖结构和病理改变 ,为小关节病的诊断提供了可靠的影像学根据 相似文献
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《中国中西医结合影像学杂志》2017,(4):423-425
目的 :探讨椎小关节空间趋向性与退行性腰椎滑脱(degenerative lumbar spondylolisthesis,DLS)之间的关系。方法 :选择300例患者,分为:L_(4~5)DLS组89例,L_5~S_1DLS组156例,无腰椎间盘突出和椎管狭窄的对照组55例3组。均采用CT扫描,测量3组L_(3~4)、L_(4~5)、L_5~S_1节段头尾侧小关节角并进行比较分析。结果:DLS组头侧的小关节角较尾侧为大(P0.05);滑脱组头尾侧的差异较对照组更显著。各节段的小关节角,经配对t检验,DLS组和对照组比较差异均有统计学意义。结论:在退行性滑脱患者中,小关节角的增大说明了小关节由冠状位向矢状位的一种空间趋向的变化,这在小关节头侧表现得较显著,尤其是在腰椎滑脱的患者中,这为腰椎滑脱的病因预测提供了一种方法。 相似文献
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目的 比较胸腰椎骨折后路单节段椎弓根钉固定与结合骨水泥强化固定的生物力学效果.方法 在8具新鲜小牛胸腰椎标本(T11~L3)的L1椎体上制作不完全爆裂骨折模型.标本依次行单节段椎弓根钉固定及单节段椎弓根钉固定+骨水泥强化固定.对标本施加扭矩为4 Nm的疲劳载荷共2 000次,加载频率为0.5 Hz.经脊柱三维运动测量系统测量完整、骨折、固定和周期性加载后固定节段前屈、后伸、左侧屈、右侧屈、左旋转和右旋转运动时固定节段的角位移运动范围(ROM).结果 两种固定状态及疲劳后各方向ROM均明显小于正常及骨折状态(P<0.05);单节段椎弓根钉固定结合骨水泥强化固定状态前屈、后伸、侧屈、旋转ROM分别为0.40°、0.53°、0.86°、0.55°,疲劳后前屈、后伸、侧屈、旋转ROM变化值分别为0.10°、0.07°、0.19°、0.08°,均小于单纯单节段椎弓根钉固定组,尤其在旋转和前屈方向,差异有统计学意义(P<0.05).结论 两种固定方式均可重建脊柱骨折的即刻稳定性并具有良好的抗疲劳载荷效果.但在前屈和旋转方向,单节段椎弓根钉固定并骨水泥强化优于单纯单节段椎弓根钉固定. 相似文献
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CT诊断腰椎小关节综合征的价值 总被引:5,自引:0,他引:5
目的分析腰椎小关节综合征的CT表现,探讨CT对该病的诊断价值.材料和方法回顾性分析59例腰椎小关节综合征的CT表现.结果腰椎小关节综合征小关节异常主要包括小关节增生肥大、骨赘形成、关节间隙变窄、小关节真空现象,小关节半脱位、关节囊钙化及两侧小关节不对称以及侧隐窝狭窄,椎间盘真空征及轻度腰椎退行性滑脱.结论CT扫描可对腰椎小关节综合征诊断提供可靠影像学依据,对改进临床诊断和治疗腰腿痛有重要意义. 相似文献
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One of the factors of the successful military career guidance Cadet schools students is preserving and promoting their health. Medical support of children and adolescents aged 10-17 years should include the full range of medical and preventive measures defined for this group. The state of providing outpatient care for pupils at the Cadet School in St. Petersburg was studied. These results show that full medical care in accordance with the standards can be based only on children's health clinics. It is important that the organization of medical support pupils cadet schools should be cooperate with civilian health care. 相似文献
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V. A. Serezhenkov I. A. Moroz G. A. Klevezal A. F. Vanin 《Applied radiation and isotopes》1996,47(11-12)
ESR-spectrometry was used to investigate radiation-induced paramagnetic centers in enamel of mammals: carnivores (polar bear and fox), ungulates (reindeer, European bison, moose), and man. Values at half the microwave power saturation of the radiation signal, P1/2, evaluated at room temperature, was found to range from 16 to 26 mW for animals and man. A new approach to discrimination of the radiation induced signal from the total ESR spectrum of reindeer enamel is proposed. ‘Dose-response’ dependencies of enamel of different species mammals were measured within the dose range from 0.48 up to 10.08 Gy. Estimations of ‘radiosensitivity’ enamel of carnivores and ungulates showed good agreement with radiosensitivity enamel of man by ESR method. 相似文献
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Analysis of the results of the international comparison of activity measurements of a solution of Fe
The results of an international comparison of activity measurements of a solution of 55Fe organized by the BIPM in 2005 are reported and analysed. This exercise, which follows the procedures of the CIPM mutual recognition arrangement to update older comparisons, is a renewal of the comparison organized by the BIPM that took place in 1978. A EUROMET comparison was organized in 1996 specifically to compare activity measurements of a 55Fe solution by means of liquid-scintillation techniques. Results of these three comparisons are presented and discussed in this paper.
The radionuclide solution was provided by the NPL, which also distributed the samples to the participants. The activity of the ampoules was measured by 16 laboratories using 12 methods producing 25 results. Some general considerations on uncertainty assessments pertaining to the different techniques used are drawn. The outcome of four different estimators is compared from which the presence of at least one outlier can be confirmed. Further measurements should be made to try to reduce the discrepancy between the results. To date the outcome of the present comparison does not show an improvement to that of the 1996 comparison. 相似文献
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D Gasparini 《La Radiologia medica》1987,73(4):304-309
A new method of non-surgical treatment of varicocele syndrome is described: it consists in sclerotherapy of spermatic vein by trans-femoral percutaneous catheterization with balloon-catheters. In 8 cases venous thrombosis has been induced by direct electric clotting. The techniques and a 6 months follow-up are discussed. It is pointed out that this procedure should be considered as the method of choice for tubular lesions and sub-fertility prophylaxis in young people and in childhood. 相似文献
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目的探讨延迟性脾破裂误漏诊原因和预防措施.方法回顾性分析总结12例延迟性脾破裂中的诊断和误漏诊的经验与教训.结果本组延迟性脾破裂的误漏诊5例(41.66%).对多发伤与脾破裂并存可能认识不足,外伤史轻微或伤员隐瞒外伤史,缺乏腹痛-缓解-突然再腹痛的典型病史,缺乏“对冲性脾破裂”力学分析和整体化诊断思路等为其误漏诊的主要原因.结论详细的外伤史和全面系统检查,重视腹以外多发伤掩盖腹内脏器伤及延迟性脾破裂可能.确立外伤-腹内脏器伤-脾破裂整体化诊断思路.不间断地辅以B超检查脾形态学变化和腹内有无积液,腹腔穿刺确定有无血腹、X线胸腹部检查观察左侧胸肋角和膈肌运动情况、必要时CT检查以尽早发现脾包膜下血肿,降低延迟性脾破裂误漏诊率. 相似文献