Fracture mechanics of circular discs with a V-notch subjected to wedging

ObjectiveA method proposed for determining the fracture toughness (FT) of dental materials involves a ‘roller’ wedging open a V-notch in a cylindrical specimen. There are a number of problems with the design of this test and its mechanical analysis, and thus with the validity of the results obtained, were it to be used. Firstly, friction is ignored in calculating the horizontal wedging force. Secondly, the test specimen does not make use of a pre-crack at the notch tip. The aim of this study was to evaluate the effects of these factors on the FT calculated.MethodsAn analytical solution for the mode-I stress intensity factor (K_I) of the compact tension specimen, which bears some similarities, is taken to be applicable. The mechanics of the specimen has been reanalysed, with a finite-element study of the resultant stresses, and compared with the compact-tension test.ResultsThe assumed analytical solution can provide accurate estimates for K_I for the V notched specimen. However, the apparent agreement is due to the fortuitous combination of an overestimated horizontal wedging force and an underestimated stress singularity at the crack tip. In any case, ignoring friction will lead to an overestimate of FT.SignificanceIt is concluded that the test as presented is invalid.     

椎体成形术联合补肾健骨汤治疗老年骨质疏松性压缩骨折的临床效果

目的:分析椎体成形术联合补肾健骨汤治疗老年骨质疏松性压缩骨折的临床效果。方法:选择2016年9月-2019年4月本院收治的73例老年骨质疏松性压缩骨折患者,按随机数表法分为两组,对照组(36例)采用椎体成形术治疗,研究组(37例)在对照组的基础上加用补肾健骨汤治疗,对比两组临床效果、腰椎功能及疼痛度。结果:研究组治疗总有效率94.59%(35/37)比对照组高(P<0.05);研究组腰椎功能评分(16.36±1.69)分,明显比对照组优(P<0.05);研究组治疗后腰椎疼痛度为(3.13±0.23)分,明显比对照组低,差异具有统计意义(P<0.05)。结论:老年骨质疏松性压缩骨折采用椎体成形术联合补肾健骨汤治疗,可减轻疼痛度,改善腰椎功能,还能提高治疗效果,值得临床推广。     

推拿联合针灸治疗血瘀型腰椎间盘突出症的临床疗效观察

目的:观察推拿手法联合针灸对血瘀型腰椎间盘突出症的临床疗效。方法:选取2015年6月至2017年12月秦皇岛市中医医院收治的血瘀型腰椎间盘突出症患者100例作为研究对象,按照随机数字表法随机分为对照组和观察组,每组50例。对照组接受单纯针灸治疗,观察组在对照组基础上加用脊柱推拿手法,2组均以10次为1个疗程,连续治疗2个疗程。比较2组患者治疗前、治疗3 d、10 d后JOA评分系统(Japanese Orthopaedic Association Scores,JOA)、Oswestry功能障碍指数的变化、血小板计数、血浆凝血酶原时间(PT)、活化部分凝血酶原时间(APTT)、血栓弹力图及临床总有效率的变化、腰椎疼痛评分(VAS)、血清学指标、炎性因子的变化。结果:推拿手法联合针灸可明显改善血瘀型腰椎间盘突出症的JOA评分、Oswestry功能障碍指数及凝血状态,降低患者外周血SP、NPY、IL-1β、TNF-α水平,且具有时间依赖性。结论:推拿联合针灸可明显改善血瘀型腰椎间盘突出症症状,调节患者的高凝状态,该法具有一定的时间依赖性。     

基于数据挖掘的黄有荣教授治疗腰椎间盘突出症用药规律分析

目的应用数据挖掘的方法总结和分析黄有荣教授治疗腰椎间盘突出症的用药规律,为临床中医药治疗腰椎间盘突出症提供参考。方法收集、整理黄有荣教授首诊治疗腰椎间盘突出症的病例,对符合纳入标准的病例中使用的中药进行统计分析,运用SPSS20.0 for Windows统计软件对中药的频数、聚类规则进行分析,运用SPSS Modeler 14.1统计软件对药物用药规律进行数据挖掘。结果共有263份病例符合纳入标准,共使用中药210味,总计出现频次3582次,分析得出使用高频次药物有当归、牛膝、甘草、杜仲等33味中药;高频次药物组合主要包含当归与赤芍、当归与桃仁、牛膝与党参、当归与川芎等;治疗腰椎间盘突出症用药以补虚药、活血化瘀药、祛风湿药类药物为主,药物归经主要归肝、肾、脾经。结论黄有荣教授治疗腰椎间盘突出症以补益肝肾、活血化瘀为主,辅以祛风湿,通络止痛为治疗原则,独活寄生汤是其治疗的基础方剂,数据挖掘客观反映了黄有荣教授临床用药规律。     

Primary epidural lumbar Ewing sarcoma presenting as cauda equina syndrome in an adult patient who underwent surgical decompression: A case report

Ewing sarcoma (ES) is a rare primary neoplasm in the lumbar adult spine and may mimic a benign tumor. In this case, after a patient's three-month history of lower back pain and rapidly progressing leg numbness and weakness, magnetic resonance imaging (MRI) showed a mass in the third lumbar vertebra. At a two-month follow-up, imaging showed a fracture, compression and lesion enlargement. Decompression and fixation confirmed ES, and the patient began combined radiotherapy and chemotherapy. Two months postoperatively, residual ES was suspected on MRI. The patient underwent a second surgery, and histopathology confirmed necrosis. A six-month follow-up after the first surgery showed no tumor recurrence. This case supports the inclusion of ES in the differential diagnosis of pathologic spinal fracture. Early decompression and spinal fixation are critical for preserving neurologic and spinal functions in ES complicated by a compression fracture. Combined adjuvant radiotherapy and chemotherapy remain the standard therapeutic strategy.     

大鼠尾椎间盘退变造模器械的研发与应用

目的:研制一种简便、微创、针刺深度可控的大鼠椎间盘退变模型的造模器械。方法 :自行设计一种新型针刺大鼠尾椎间盘退变的造模器械,由C型套环和针筒两部分构成。取3月龄雄性SD大鼠20只,分为针刺组(10只)和对照组(10只),将造模器械的C型套环套在鼠尾上,用21G针对针刺组的大鼠尾椎Co6/7、Co8/9椎间盘分别行横贯(10mm)和半横贯穿刺(5mm);对照组大鼠尾椎无任何处理。造模前和造模后4周时对两组大鼠的尾部行X线片和MRI检查,在X线片上测量椎间盘高度,计算目标椎间盘高度指数(DHI)比;在MRI T2像上采用Pfirrmann评分评价目标椎间盘退变情况。再处死大鼠取目标椎间盘固定切片后行番红O染色,观察椎间盘退变情况;对非针刺节段尾椎间盘内注射造影剂(碘海醇)后,X线下显影并用针抽吸髓核组织。结果:造模过程中大鼠无死亡,术后无感染等并发症。向大鼠椎间盘注射碘海醇后造影显影良好,可以抽取一定量的髓核组织。造模后4周,针刺组Co6/7和Co8/9的DHI比分别为0.65±0.07和0.73±0.09、Pfirrmann退变评分分别为4.3±0.82和3.5±0.71分,对照组分别为0.98±0.02和0.97±0.02、1.1±0.32分和1.1±0.32分,两组同节段比较均有显著性差异(P0.05),针刺组两个节段间比较有显著性差异(P0.05),对照组两个节段间比较无显著性差异(P0.05)。番红O染色针刺组Co6/7髓核消失,与纤维环界限不清,终板骨化;针刺组Co8/9穿刺侧髓核和纤维结构紊乱,另一侧髓核与纤维环较完整;对照组Co6/7和Co8/9髓核、纤维环和终板形状完整,结构清晰。结论:造模器械穿刺可以成功建立大鼠尾椎间盘退变模型,且横贯穿刺较半横贯穿刺椎间盘退变重;利用该造模器械可以向椎间盘内注射造影剂或药物,抽取髓核。     

腹腔镜手术治疗小儿腰疝的临床研究

目的探讨腹腔镜手术在治疗小儿腰疝治疗中的安全性、可行性及优越性。方法本组9例小儿腰疝患儿,男4例,女5例;年龄1岁6个月至10岁,平均年龄4岁;7例发生于腰下三角,2例发生于腰上三角。6例发生于左侧腰部,3例发生于右侧腰部。均采用腹腔镜微创手术,行腹腔镜下腰疝修补术。结果本组9例患儿均成功完成腹腔镜手术,手术顺利,无术中大出血、无术中及术后输血、无意外损伤及围手术期死亡病例发生。手术效果好,治愈出院。平均住院时间5 d。术后随访1~8年,无明显远、近期并发症发生。结论腹腔镜手术是治疗小儿腰疝的安全、可靠的方法,具有创伤小,恢复快,美容效果满意等优势,值得临床推广。     

脊柱-骨盆矢状面参数与腰椎椎间盘突出症相关性研究进展

腰椎椎间盘突出症(LDH)是指腰椎椎间盘发生退行性病理改变,纤维环破裂,髓核组织从破裂处突出/脱出,刺激或压迫神经引起的以腰腿痛为主要症状的病变,给患者的工作生活带来一定影响。近年有研究发现,脊柱-骨盆矢状面参数与LDH密切相关,正常脊柱-骨盆形态可使身体处于最佳平衡状态,若发生改变则平衡状态被破坏,导致脊柱矢状面生物力学发生改变,从而加速脊柱退行性变[1-3]。本文查阅分析脊柱-骨盆矢状面参数与LDH的相关性研究,发现脊柱-骨盆矢状面失衡不仅与LDH的发生机制相关,且与其临床症状和预后也有关联,现综述如下。     

健康宣教联合心理护理在腰椎间盘突出症患者围术期的应用效果分析

目的探讨健康宣教联合心理护理在腰椎间盘突出症(LDH)患者围术期的应用效果。方法选取我院2018年6月至2019年6月实施手术治疗的90例LDH患者,随机分为观察组(n=45)和对照组(n=45)。对照组采用常规围术期护理,观察组在对照组基础上采用健康宣教联合心理护理。比较两组患者的SDS、 SAS、 VAS、 JOA评分以及护理满意度。结果护理7d后,观察组的SDS、 SAS评分均显著低于对照组(P <0.05);术后3个月,观察组的VAS评分显著低于对照组,JOA评分显著高于对照组(P均<0.05)。观察组的护理满意度显著高于对照组(P <0.05)。结论健康宣教联合心理护理应用于LDH患者围术期,能够减少患者的焦虑和抑郁情绪,缓解疼痛,提升护理满意度。