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

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。     

新型记忆合金节段内固定器治疗腰椎峡部裂的实验研究

目的 :设计一种治疗腰椎峡部裂的新型记忆合金节段内固定器 ,测试其材料力学特性 ,并评价其生物力学稳定性。方法 :测量 2 0具干燥完整成人腰椎标本获得数据 ,按数据采用镍钛记忆合金设计固定器并行材料力学测试。取 6具新鲜成人腰椎标本 ,先后形成正常脊柱组、峡部裂组、横突棘突钢丝捆绑组、钩螺钉固定组、Buck螺钉固定组、新研制记忆合金固定器固定组 6组实验模型。利用脊柱三维运动实验机 ,分别测试 6组的前屈 /后伸、左 /右侧弯及左 /右轴向旋转 6种运动的活动范围。结果 :材料力学测试表明其形态记忆功能良好 ,体温状态下会产生稳定可靠的回复力。 6组在前屈、后伸及左右旋转状态 ,峡部裂组稳定性最差 ,同其他 5组差别明显。而使用新研制记忆合金内固定器组可明显恢复腰椎稳定性 ,同正常脊柱组及其他 3种内固定组均无显著差别。另两种状态左右侧弯 6组均无显著性差别。结论 :新设计的内固定器符合腰椎的生物力学要求 ,较先前的半环状内固定器优势明显 ,具有很好应用前景     

腰椎椎弓崩裂CT征象的临床诊断价值

目的分析腰椎椎弓峡部裂的CT表现,探讨各个征象的诊断价值和意义.方法自可疑椎弓峡部裂脊椎的椎弓根的上缘至下一个椎弓根上缘,层厚2～3mm连续扫描.结果86例中发生L5椎弓峡部裂51例,L4者33例,L3,者2例.各种CT征象发现率为:环裂征91%,椎体前移征85%,双椎体征50%,椎管拉长征45%,双关节面征38%,葫芦征26%,游移征15%,磨旋征6%.结论环裂征是该病的特征性表现;双关节面征及葫芦征发现率较低,但特异性较高.椎管拉长征具有一定诊断价值,其它征象无论其发现率大小,均是该病的继发改变,不能作为确诊的直接依据.     

节段内固定治疗腰椎峡部裂的生物力学研究

在8具成人新鲜腰椎标本上,通过脊柱三维运动实验机,研究了横突棘突钢丝捆绑法、钩螺钉固定法及Buck螺钉固定法对峡部裂腰椎三维稳定性的影响。实验结果表明：三者均能显著地恢复脊柱的稳定性,且三者之间无显著差别。     

Conservative treatment for lumbar spondylolysis in children of elementary school age

PurposeLumbar spondylolysis in children of elementary school age has different characteristics from those of junior or senior high school patients. The purpose of the present study was to investigate the outcomes of conservative treatment for lumbar spondylolysis in patients of elementary school age.MethodsWe included 46 lesions in 32 consecutive patients of elementary school age with fresh cases of lumbar spondylolysis (5 girls and 27 boys; mean age, 11.3 years). We examined the relationship between bone union after conservative treatment and factors such as the CT axial staging, whether the lesion was unilateral or bilateral, whether the contralateral lesion was terminal stage, and the presence of spina bifida occulta.ResultsBone union was achieved in 33 lesions (72%) in 23 patients, whereas 13 lesions (28%) in 9 patients could not obtain bone union. The proportion of unilateral lesions with bone union was 13 of 13 (100%), significantly higher than that for bilateral lesions (20/33 lesions, 61%, p = 0.009). Of the 33 bilateral lesions, bone union was attained in 20 of 28 (71%) lesions without contralateral terminal stage, whereas bone union was not attained in any of 5 (0%) lesions with contralateral terminal stage, showing a significant difference between those with or without contralateral terminal stage (p = 0.005).ConclusionBilateral lesions and contralateral terminal stage are possible unfavorable factors to bone union in conservative treatment for patients of elementary school age with lumbar spondylolysis. Early diagnosis and treatment before the lesions become bilateral or progressive stage are important.     

Progressively Unstable C2 Spondylolysis Requiring Spinal Fusion: Case Report

Cervical spondylolysis is a rare condition defined as a corticated cleft at the pars interarticularis in the cervical spine. This is the case of C2 spondylolysis demonstrating progressive significant instability, which was successfully treated by anterior cervical discectomy and fusion (ACDF) with cervical anterior plate. We describe a 20-year-old female with C2 spondylolysis presenting with progressive worsening of neck pain associated with progressive instability at the C2/3 segment. The progression of instability was well-documented on flexion-extension cervical spine x-rays. She was successfully treated by C2/3 ACDF with anterior cervical plate. Her preoperative significant neck pain resolved immediately after the surgical intervention. She was completely free from neurological symptoms at 1-year postoperative follow-up. We also review the literature and discuss 24 reported cases with C2 spondylolysis. When planning treatment, we should make sure to differentiate this pathology from acute traumatic fracture, which is a hangman''s fracture. Assessment of C2/3 instability associated with neurological deficits is extremely important to consider management properly. C2/3 ACDF with cervical plate is biomechanically viable, less invasive, and provides adequate surgical stabilization for unstable C2 spondylolysis.     

Spinal disorders in childhood I: painful disorders

Back pain and spinal deformity are the most common presenting complaints of spinal disorders in childhood seen in a specialist orthopaedic spinal clinic. Many of the patients referred will have non-specific back pain, yet there are a multitude of significant and sinister pathologies of the spine along with extraspinal causes that should be considered and sought. Similarly most deformities will be either minor or idiopathic, yet specific underlying causes need to be excluded. The cornerstone of safe practice is a detailed, thorough and targeted history and examination. This article focuses on painful disorders.     

多层螺旋CT对腰椎峡部裂的诊断

目的研究腰椎峡部裂的矢状位重建诊断。方法对20例椎弓峡部裂的病例进行CT扫描和多平面重建，获得矢状位图像。随机选择3具经福尔马林固定过的腰椎标本直接矢状位扫描和横断位扫描，再将横断位扫描的图像重建成矢状位和三维图像。结果在直接矢状位上腰椎椎弓峡部显示良好，上、下关节突及椎弓峡部和椎弓根同时显示在同一图像上，矢状位重建图像与直接矢状位图像完全一致。在20例椎弓峡部裂病例中单腰椎19例，双腰椎1例，裂隙的形态及角度显示良好。结论矢状位重建可清晰的显示椎弓和椎弓峡部裂的形态特征。     

前后路联合手术治疗腰椎滑脱症

目的探讨应用后路椎弓根内固定系统联合前路椎体间植骨治疗重度腰椎滑脱症的临床疗效.方法应用后路SOCON提拉复位内固定系统复位并固定滑脱椎体,结合前路经腹膜外途径椎体间髂骨植骨治疗重度腰椎滑脱症20例.结果术后18例Ⅱ度椎体滑脱获得解剖复位,2例Ⅲ度脱位复位至Ⅰ度滑脱.经4～18个月随访,滑脱椎体复位无丢失,椎弓根螺钉无松动,椎体间骨融合牢固,椎间隙高度维持良好.结论SOCON提拉复位内固定系统可提供滑脱椎体满意的复位内固定作用,前路椎体间植骨融合率高,术后复位丢失率低.     

螺旋CT成像后处理在腰椎峡部裂中的应用

目的 探讨螺旋CT成像后处理在腰椎峡部裂诊断中的临床价值。方法 分析20例腰椎峡部裂最大密度投影(MIP)、多平面重组(MPR)、表面重建(SSD)重建图像的CT表现。结果MIP和MPR显示峡部裂艮好，20例38处均能显示，前者更清晰；SSD图像显示椎体滑脱良好，16例椎体滑脱均能显示；峡部断裂断端骨赘形成7例，纤维组织增生或骨痂形成6例，侧隐窝狭窄6例，黄韧带肥厚3例，椎间盘突出5例，椎间孔狭窄12例，斜轴位或矢状位MPR均能很好显示。结论 “断翼征”、“断柄征”，“断颈征”、“环裂征”是腰椎峡部裂特征性的CT表现，螺旋CT的多系列重建图像对峡部裂的诊断以及治疗方式的选择具有重要意义。