Reproducibility and diagnostic value of a new method using ratios to diagnose anterior atlanto-axial subluxation on plain radiographs

ObjectivesMeasures on conventional radiography are used to detect, especially in rheumatoid arthritis, upper cervical spine instabilities (CSIs) with the anterior and posterior atlanto-dental intervals (AADI and PADI) measurements. Our objective was to evaluate the diagnostic performance and reliability of AADIs and PADIs extrapolated based on ratios in assessing anterior atlanto-axial subluxation (aAAS) when plain radiographs do not allow the measures.MethodsRadiographies of 119 patients were randomly selected. Two blinded observers performed two measurements of the odontoid sagittal diameter (O), axis body base sagittal diameter (C2), AADI, PADI, Clark station and Ranawat index, and the AADI/O, AADI/C2, PADI/O and PADI/C2 ratios were calculated. The diagnostic value of AADI and PADI extrapolated from the AADI/O, AADI/C2, PADI/O and PADI/C2 ratios was evaluated using ROC curves, with AADI > 2.9 mm used as the gold standard.ResultsAmong the 119 patients, 12 patients had aAAS (AADI > 2.9 mm), 6 of them had severe aAAS (AADI > 8.9 mm and/or a PADI < 14 mm), and 6 patients had vertical AAS (Clarks station = 2 or 3 and/or Ranawat index < 13 mm). The AADI extrapolated from the AADI/O and AADI/C2 ratios has excellent intra- and inter-observer reproducibility. The diagnostic value of the extrapolated AADI was high for aAAS (sensitivity 92%; specificity of 100%) and severe aAAS (sensitivity75%; specificity 100%). The diagnostic value of the extrapolated PADI was good but lower than the diagnostic value of the extrapolated AADI.ConclusionExtrapolated AADI can be used instead AADI to detect aAAS and severe aAAS.     

人腰背筋膜的动态响应

本研究对人胸腰段脊柱的粘弹特性作了观察，对两组４０～８５岁的人体胸腰椎标本作了单轴拉伸断裂试验。根据解剖学纤维方向（即尾内侧和尾外侧方向）来选择两组标本。以五种不同的应变速率来判断标本的生物力学特性。获得每组标本的最大断裂应力、应变和杨氏模量。结果表明，两种解剖方向之间各种生物力学参数均无显著差异。然而，实验发现最大断裂应力、应变和杨氏模量随应变速率增加而增加。应变速率大于３／秒，则断裂应变和杨氏模量保持不变，提示已达到上限。     

单侧多节段后部结构切除对腰椎旋转稳定性影响的生物力学研究

目的：研究多节段脊柱后部结构对腰椎旋转稳定性的影响。方法：选用７具成人新鲜尸体脊柱标本（Ｌ１～Ｓ１），采用单侧多节段逐步切除腰椎后部结构的方法，形成７种状态，从单侧多节段开窗至全椎板及双侧小关节切除等。通过脊柱三维运动试验机施加１０Ｎｍ的扭转载荷，使脊柱产生左、右轴向旋转运动。结果：全椎板加双侧小关节部分切除后，腰椎旋转稳定性受到显著影响。结论：除小关节骨性结构及关节囊外，椎板及后部韧带结构对维持腰椎旋转稳定性亦有重要作用     

腰椎板切除对腰椎稳定性影响的实验研究

本文以人体新鲜尸体的完整腰椎为实验标本，采用生物力学测定的方法对切除不同节段腰椎椎板后，腰椎稳定性所受影响进行了定性、定量的研究。从而得出结论，腰椎椎板切除将影响腰椎的稳定性。但稳定性破坏的大小，不随腰椎板节段切除的多少而变化。     

无蹼壁虎半阴茎组织学研究

目的 :无蹼壁虎半阴茎形态学特征及意义 ;方法 :用光镜组织学及组织化学对无蹼壁虎半阴茎进行研究 ;结果 :研究发现半阴茎短且分叉 ,具以下几个特点 :①前方有舌状突起及小刺状结构 ;②有开放精沟 ,ALP(碱性磷酸酶 )反应阳性 ;③半阴茎后 1 /3具明显的海绵组织 ;④后方借纵形牵引肌与肛后囊相连。结论 :无蹼壁虎半阴茎与其他爬行动物的有一定的差异性 ,这是与它的生活习性及系统演化上所出的位置是相适用的。     

The R-zero line: a new kinematic concept of the lumbar spine

Summary A new kinematic concept is described that relates to the notion that the lumbar spine behaves as a complete structure. This concept is called the R-zero line and represents kinematically the neutral position of the lumbar spine between anteflexion and retroflexion. The clinical significance of this parameter is evaluated in normal individuals and in patients with a symptomatic herniated disc at L4–5, with a symptomatic herniated disc at L5–S1, and with spondylolysis/spondylolisthesis. The results of this study show that the R-zero line has a characteristic configuration in all four test groups.     

脊柱骨巨细胞瘤及其外科治疗

目的：研究脊柱骨巨细胞瘤的影像学特点,探讨手术方式及其预后的影响。方法：５６例均行手术治疗,早期实施单纯肿瘤病灶切除术,后期施行肿瘤整块切除术和病椎次全切除术,同时给予坚强的内固定。结果：术后所有患者局部疼痛均有不同程度的缓解,７７．３％的患者神经体征得到改善。随访４２例（平均随访５年４个月）中预后良好无复发者２５例（５９．５％）,局部仍有瘤灶存在但病变不超过术前者１１例（２６．２％）,病变扩大,     

下颈椎后路固定方法的力学比较

目的：评价不同于颈椎后路内固定器的生物力学性能。方法：应用５具新鲜尸体颈椎标本（Ｃ２￣Ｃ７）建立脱位模型后,依次用棘突钢丝、侧块螺钉、自制螺钉、椎弓根螺钉固定,用材料试验机测算其垂直压缩刚度,前后水平剪切刚度和左右水平剪切刚度。结果：棘突钢丝的垂直压缩刚度和前后剪切刚度虽较完整颈椎增大,但无显著性差异（Ｐ〉０．０５）,而左右剪切刚度尚较完整颈椎减小（Ｐ〈０．０５）。侧块螺钉、自制螺钉和椎弓根螺钉的     

沈氏装置稳定性的生物力学评价

评价沈氏经椎弓根内固定装置的生物力学稳定性。方法采用５具新鲜尸体脊柱标本,制造Ｌ１损伤模型,测量并比较标本在完整状态,损伤状态、沈氏装置固定、沈氏装置疲劳及ＣＤ装置固定下的Ｔ１２和Ｌ２之间的三维运动范围,并将沈装置与ＣＤ装置固定下的运动范围进行,经统计学处理,评价沈氏装置的稳定性。