An experimental animal model of spinal root compression syndrome: an analysis of morphological changes of myelinated axons during compression radiculopathy and after decompression

The treatment of radicular pain is mainly empirical because there are only few experimental studies dealing with morphological changes during compression radiculopathy. The goal of the study was to investigate changes in the morphology of myelinated axons during spinal root compression and the influence of decompression in a new rat model. The number of myelinated axons and their diameter were measured at 1, 2, 5, and 8 weeks during compression of the dorsal spinal root. The same approach was applied for 1-week compression followed by decompression for 1 or 2 weeks and compression for 5 weeks followed by 3-week decompression. A decrease in the number of myelinated axons (particularly those of large diameters) occurred after compression for 1 week. Continued compression for up to 8 weeks resulted in centripetal increase in the number of myelinated axons and the persistence of a small fraction of large myelinated axons at the site of compression. After that time, a decreased number of axons and a reduced fraction of large myelinated axons occurred again. Decompression after 1-week compression caused a rapid increase in the number of both small and large myelinated axons within the spinal root including the site of compression. A small fraction of regenerated axons was found after 5-week compression followed by 3-week decompression. Finally, we investigated the time course of the temporary increase in the number of regenerated myelinated axons during dorsal root compression for up to 8 weeks. The efficacy of decompression was superior when applied one week after compression or after regress of the acute phase of aseptic inflammation associated with fragility of spinal root. The results of the study verify the need for early surgical decompression to prevent irreversible damage of the spinal roots.     

大鼠脊髓慢性压迫及减压后神经细胞凋亡及其相关基因的表达

目的：观察慢性压迫性脊髓损伤后及减压后神经细胞凋亡和Bcl-2mRNA，P53mRNA,CASPASE-3神经功能恢复的影响。方法：将55只同龄Wistar大鼠，置入后路渐进式压迫装置，制作成慢性压迫性脊髓损伤模型。随机分为假手术对照组（A组5只），慢性脊髓压迫组（B组25只），减压组（C组25只）。应用原原位末端脱氧核糖核苷酸转移酶介导dUTP标记（TUNEL）技术及原位杂交检测方法，观察各组细胞凋亡率及细胞凋亡相关基因Bcl-2mRNA、P53mRNA、CASPASE－3在慢性压迫性脊髓损伤后及减压后的表达，分别于损伤后及减压后1、3、7、14、28d对慢性脊髓损伤区进行细胞凋亡及原位杂交检测。结果：A、B、C三组均发现神经细胞凋亡及细胞凋亡相关基因Bcl-2mRNA、P53mRNA，CASPASE－3的表达，A、B、C三组细胞凋亡率及阳性细胞灰度值比较，差异有显著性意义（P＜0．05）。阳性细胞表达程度与细胞凋亡的减少及神经功能的恢复相一致。结论：慢性压迫性脊髓损伤可导致大量的神经细胞凋亡，同时激活内源性保护机制，使脊髓发生适应性改变，减压可能通过激活此机制而减轻神经细胞凋亡，起到保护作用。     

Clinical outcomes of percutaneous vertebroplasty for selective single segment dorsolumbar vertebral compression fractures

Overview of literature

Elderly patients sustaining a trivial fall may develop vertebral compression fractures if they are predisposed to any factor that leads to decreased bone mineral density. Such patients suffer with severe pain and disability during the early healing stages. Percutaneous Vertebroplasty is mainly done to provide immediate pain relief and also believed to offer stability to the compressed vertebra by preventing further collapse.

经皮穿刺椎体成形术的体外力学性能研究

目的 :探讨经皮椎体成形术对椎体力学强度的影响作用。方法 :4具完整老年女性胸腰段脊柱 (T11-L2 ) ,X线摄片无明显病理异常 ,用DEXA测定脊柱骨密度BMD ,将标本游离成单个椎体 ,将每例标本的 4个椎体随机选择 2个共 8个椎体进行骨水泥PMMA注射构成椎体成形术组 (A组 ) ,余 8个椎体为对照组 (B组 )。A组行椎体成形术注射加显影剂的低粘度骨水泥 5ml。注射后摄轴位X线片了解骨水泥分布情况。测试A组和B组椎体静态压缩下的最大抗压强度及刚度。结果 :所有椎体BMD的T值提示为中重度骨质疏松 (T值 - 3.15～ - 4 .6 6 ,平均 - 3.87)。A组注射 5ml骨水泥后轴位片示骨水泥分布面积皆大于 5 0 %。A组的最大抗压强度和刚度分别为 2 6 4 5± 4 78N和 1317± 2 81N/mm ;B组最大抗压强度 186 2± 6 2 0N ,刚度为 10 2 5± 2 33N/mm。两组比较最大抗压强度及刚度均存在显著性差异 (P <0 .0 5 )。结论 :骨质疏松椎体内注射骨水PMMA可显著改善其力学性能 ,临床应用经皮椎体成形术可达到强化椎体的目的。     

交锁髓内钉与加压钢板固定治疗胫骨骨折的疗效对比分析

目的评价交锁髓内钉与加压钢板固定两种疗法治疗胫骨骨折的疗效。方法将108例胫骨骨折患者随机采用交锁髓内钉或加压钢板固定治疗;观察两种方法的疗效、并发症。结果临床疗效:交锁髓内钉组优48例,加压钢板组优39例,x2=4.79,P<0.05;并发症:交锁髓内钉组7例,加压钢板组18例,x2=6.30,P<0.05。结论与加压钢板内固定治疗胫骨骨折相比,交锁髓内钉固定治疗胫骨骨折具有创伤小,功能恢复快,固定稳定性好,愈合率高、感染率低等优点,疗效满意,可以作为临床上优选方案之一。     

Estenia瓷树脂复合体制作冠桥的强度测试

目的:探讨Estenia瓷树脂复合体的强度,并与其他几种树脂材料进行比较,为临床选择冠桥树脂材料提供参考。方法:采用Estenia瓷树脂复合体体外模拟下颌第一磨牙单冠和第一磨牙缺失3个单位固定桥的形态,测试单冠的抗压强度和固定桥的抗弯强度,并与Artglass、Solidex、Targis3种树脂材料在相同实验方法下测试得到的结果作比较。结果:Estenia瓷树脂单冠的折裂最大载荷均值为600.20N,Estenia瓷树脂桥的折裂最大载荷均值为302.53N。结论:Estenia瓷树脂复合体的强度高于Artglass﹑Solidex和Targis树脂复合体。     

靶向药物洗脱支架压握过程的力学性能

目的 研究两种不同结构的药物洗脱支架（drug eluting stent, DES）压握过程的力学性能,以期对DES结构设计提供科学的指导。方法 采用Solidworks软件分别建立支架外表面没有刻槽的传统DES（I型支架）以及支架外表面有刻槽的靶向DES（II型支架）;通过ABAQUS有限元分析软件,对两种支架压握过程中的径向紧缩反弹比、轴向紧缩反弹比、压握不均匀性、残余应力分布等重要的力学性能指标进行分析。结果 同一紧缩外径条件下,两种支架径向紧缩反弹比、轴向紧缩反弹比以及压握不均匀性指数的差值分别在0.07%~0.12%、0.016%~0.033%、0.013%~0.048%之间,II型支架支撑体上存在面积更大的低应力区域。结论 相比传统DES支架,靶向DES支架在减少载药量的同时,力学性能并未降低,对心血管狭窄等疾病的治疗具有较好的临床应用前景。     

原发性骨质疏松椎体压缩性骨折的X线、MRI影像诊断价值分析

目的分析原发性骨质疏松椎体压缩性骨折的X线、MRI影像学特点。方法以2010年6月至2016年1月经影像学、临床或病理证实的100例椎体压缩性骨折患者为研究对象,其中原发性骨质疏松椎体压缩性骨折56例,设为观察组,均接受X线片、MRI检查,转移瘤继发性椎体压缩性骨折42例,设为对照组,均行MRI检查,X线检查者15例,对两组骨折患者X线、MRI影像特点观察并比较。结果 X线片图像特点:观察组检出椎体骨折70个,椎体形态方面以凹陷形为主,占65.71%;椎体骨密度多降低,占95.71%;椎管变形占11.43%;累及终板占31.43%;对照组检出椎体22个,椎体形态方面以楔形压缩为主,占54.55%;其次是凹陷形,占31.82%;溶骨型占81.82%;椎管狭窄占18.18%;累及终板占40.91%。MRI图像特点:观察组显示椎体后缘上角或下角后翘占97.14%;T1WI序列显示局限性低信号27个,T2WI脂肪抑制序列显示高信号41个;对照组显示圆隆状椎体后缘占96.15%;不规则结节状椎体旁软组织肿块38个;骨折病灶T1WI显示弥漫性低信号43个;T2WI脂肪抑制序列显示高信号48个;增强扫描显示明显强化。结论 X线、MRI在原发性骨质疏松与转移瘤继发性椎体压缩性骨折鉴别诊断中有重要价值。     

Functional testing in lumbar nerve root compression syndromes. An evaluation in patients with normal neurological findings

Summary A functional test using downhill walking was evaluated in relation to the myelopgraphical examination in 33 patients with a suspected lumbar nerve root compression syndrome despite normal neurological findings. Any changes of motor or reflex signs or of straight leg raising were accepted as test results. They were noted in a decision matrix and the positive and negative predictive value (PPV and NPV, respectively) calculated. The PPV of any deterioration of the neurological status resulting from the test as a sign of abnormal myelographical findings was calculated to be approximately 85 per cent, the corresponding NPVs being approximately 50 per cent. In its present form, this functional test is inadequate as a screening procedure in these patients.