后路椎弓根内固定系统治疗胸腰椎爆裂骨折的疗效及分析

目的探讨后路椎弓根内固定系统治疗胸腰椎爆裂骨折的疗效。方法收集66例胸腰椎爆裂骨折并接受后路椎弓根内固定系统治疗的患者,观察其术前、术后Frankel分级、视觉模拟评分、患者椎体前缘压缩率及Cobb’s角变化。结果与术前相比,术后患者Frankel分级、视觉模拟评分、患者椎体前缘压缩率及Cobb’s角均明显改善（P〈0．05）,随访1年发现患者椎体前缘压缩率及Cobb’s角与术后差异无统计学意义（P〉0．05）。结论后路椎弓根内固定是治疗胸腰椎爆裂骨折的良好方法。     

后路钉棒内固定治疗胸腰段椎体骨折37例体会

目的:探讨应用后路钉棒系统内固定治疗胸腰段椎体骨折的临床疗效。方法:回顾性分析某院采取脊柱后正中入路椎管探查减压或单纯钉棒系统内固定治疗胸腰段椎体骨折37例。结果:37例患者均获6～24个月随访,脊髓神经功能均获得明显改善,按Frankel分级(除A级1例无改善外)均有1～3级的神经功能恢复。Cobb角由术前平均28.3°恢复到术后平均4°。结论:后路钉棒系统具有疗效确切、手术创伤小、操作简单、固定可靠、安全性高等优点。     

急性间歇性血卟啉病的中枢神经系统损害临床及影像特点分析

目的 分析急性间歇性血卟啉病中枢神经系统损害的临床及影像学特点,探讨其可能的发生机制.方法 回顾分析北京协和医院1991-2011年收治住院的6例出现中枢神经系统损害的急性间歇性血卟啉病患者,以及文献报道的13例出现中枢神经系统损害的急性间歇性血卟啉病患者的临床及影像学资料.结果 北京协和医院6例患者的中枢神经系统损害表现包括痫性发作,意识障碍,皮质盲等.脑电图出现慢波增多或正常.脑脊液检查蛋白稍高或正常.神经影像学表现为两组,一组(4例)为皮质及皮质下白质病变,以白质受累为主.另一组(2例)为对称性深部灰质核团病变.文献中13例患者中枢神经系统损害症状包括急性意识障碍,幻觉,痫性发作,皮质盲等.神经影像学表现与北京协和医院报道的病例相似,此外有2例患者仅表现为脑叶皮质受累,无白质受累表现.结论 急性间歇性血卟啉病可以造成中枢神经系统,周围神经系统,自主神经系统损害,中枢神经系统损害的影像学可以表现为皮质及皮质下白质损害,脑深部灰质核团损害,或者仅累及皮质,无白质损害.其发生存在多种可能的机制,应早期正确诊断及治疗.     

Polarity-specific high-definition transcranial direct current stimulation of the anterior and posterior default mode network improves remote memory retrieval

BackgroundPrevious studies show that activity in the posterior default mode network (pDMN), including the posterior cingulate cortex and the precuneus, is correlated with the success of long-term episodic memory retrieval. However, the role of the anterior DMN (aDMN) including the medial prefrontal cortex is still unclear. Some studies show that activating the medial prefrontal cortex improves memory retrieval while other studies show deactivation of the medial prefrontal cortex in successful retrieval of episodic memories, suggesting a possible functional dissociation between the aDMN and pDMN.ObjectiveIn the current study, we aim to causally explore this probable dissociation using high-definition transcranial direct current stimulation (HD-tDCS).MethodsWe perform a randomised double-blinded two-visit placebo-controlled study with 84 healthy young adults. During Visit 1 they learn 75 Swahili-English word-associations. Seven days later, they randomly receive either anodal, cathodal or sham HD-tDCS targeting the pDMN or aDMN while they recall what they have previously learned.ResultsWe demonstrate that anodal stimulation of the pDMN and cathodal stimulation of the aDMN, equally improve the percentage of Swahili-English word-associations recalled 7 days after learning.ConclusionsModulating the activity in the aDMN and pDMN causally affect memory retrieval performance. HD-tDCS of the aDMN and pDMN shows that anodal stimulation of the pDMN and cathodal stimulation of the aDMN increases memory retrieval performance one week after the learning phase. Given consistent evidence, it is highly likely that we are increasing the activity in the pDMN with anodal pDMN stimulation. However, it is not clear if cathodal HD-tDCS targetting aDMN works via decoupling from the pDMN or via indirectly disinhibit pDMN.     

人眼后皮质前玻璃体囊袋的光相干断层扫描影像特征观察

目的观察人眼后皮质前玻璃体囊袋(PPVP)的OCT影像特征。方法回顾性临床研究。2012年5月至2017年2月于成都市第三人民医院眼科行OCT检査发现PPVP的受检者107名173只眼纳入研究。行频域OCT(SD-OCT)、扫频光源OCT(SS-OCT)检査分别为103、70只眼。SD-OCT检査采用德国Heidelberg公司Spectralis OCT仪进行。SS-OCT检查采用日本Topcon公司DRI OCT仪的玻璃体增强扫描模式。观察PPVP不同类型OCT成像差异以及影像特征。结果所有受检眼SD-OCT.SS-OCT检查均可见PPVP结构清晰,表现为黄斑区前弱反射船形腔隙,前界为玻璃体胶原,后界为玻璃体皮质;PPVP鼻侧存在一弱反射的无凝胶区域(Martegiani区),两者之间存在连接通道。其形态特点两种检查方式所见相似,但SS-OCT对PPVP的成像更清晰。结论人眼PPVP的OCT影像特征为黄斑区前弱反射船形腔隙,前界为玻璃体胶原,后界为玻璃体皮质;其鼻侧存在Martegiani区。     

Posterior approaches to the ankle – an analysis of 3 approaches for access to the posterior malleolar fracture

BackgroundAn anatomical study to determine what degree of access to the posterior distal tibia could be gained by using 3 different approaches; the posterolateral, the posteromedial and the medial posteromedial approaches.MethodsA comparison study, between the anatomical dissection of 7 fresh frozen cadaveric lower legs and image analysis of CT data of posterior malleolar fractures from a prospectively collected database was conducted. All fractures have been classified using the Mason and Molloy classification.ResultsIn comparing the posterior malleolar fracture fragment width to distal tibia width, the posterolateral fragment encompasses 60.1% (95% CI 56.8, 63.3) of the total width of the tibia. If the posteromedial fragment is included the fragments encompass the entire distal tibia (100%). In type 3 fractures, 81.4% (95% CI 75.5, 87.1) of the distal tibia width is involved.When comparing the fracture width to the approach, no approach achieves a complete exposure of the type 2B or 3 fracture patterns. The overall surface area of the type 2B and 3 fractures, is significantly greater than all the approaches. Considering the lateral to medial extent of the fracture, the posterolateral fragment mean width is 33% greater than what can be exposed by the posterolateral approach (mean 24.9 vs 16.8 mm). In type 2B and 3 fractures, the horizontal exposure reduces to 39.8% and 47.6% respectively. In comparison, the PM approach exposes 47.6% of the type 2B fracture pattern and 57.1% of the type 3 fracture pattern and allows a preferable angle for hardware insertion. The MPM approach does not expose any of the posterolateral fragments in this study, however it does expose 92% (mean 21.9 vs. 23.8 mm) of the medial to lateral width of a posteromedial fragment of a type 2B fracture.ConclusionEach approach allows access to different parts and amounts of the posterior tibia. An understanding of and utilisation of these approaches can lead to adequate exposure for fixation of most posterior malleolus fracture patterns seen.     

Updates of pathologic myopia

Complications from pathologic myopia are a major cause of visual impairment and blindness, especially in east Asia. The eyes with pathologic myopia may develop loss of the best-corrected vision due to various pathologies in the macula, peripheral retina and the optic nerve.Despite its importance, the definition of pathologic myopia has been inconsistent. The refractive error or axial length alone often does not adequately reflect the ‘pathologic myopia’. Posterior staphyloma, which is a hallmark lesion of pathologic myopia, can occur also in non-highly myopic eyes. Recently a revised classification system for myopic maculopathy has been proposed to standardize the definition among epidemiological studies. In this META-PM (meta analyses of pathologic myopia) study classification, pathologic myopia was defined as the eyes having chorioretinal atrophy equal to or more severe than diffuse atrophy.In addition, the advent of new imaging technologies such as optical coherence tomography (OCT) and three dimensional magnetic resonance imaging (3D MRI) has enabled the detailed observation of various pathologies specific to pathologic myopia. New therapeutic approaches including intravitreal injections of anti-vascular endothelial growth factor agents and the advance of vitreoretinal surgeries have greatly improved the prognosis of patients with pathologic myopia. The purpose of this review article is to provide an update on topics related to the field of pathologic myopia, and to outline the remaining issues which need to be solved in the future.     

Focal hole versus screw stimulation to prevent false negative results in detecting pedicle breaches during spinal instrumentation

ObjectiveWe describe a stimulus-evoked EMG approach to minimize false negative results in detecting pedicle breaches during lumbosacral spinal instrumentation.MethodsIn 36 patients receiving 176 lumbosacral pedicle screws, EMG threshold to nerve root activation was determined using a focal probe inserted into the pilot hole at a depth, customized to the individual patients, suitable to position the stimulating tip at the point closest to the tested nerve root. Threshold to screw stimulation was also determined.ResultsMean EMG thresholds in 161 correctly fashioned pedicle instrumentations were 7.5 mA ± 2.46 after focal hole stimulation and 21.8 mA ± 6.8 after screw stimulation. Direct comparison between both thresholds in individual pedicles showed that screw stimulation was always biased by an unpredictable leakage of the stimulating current ranging from 10 to 90%. False negative results were never observed with hole stimulation but this was not true with screw stimulation.ConclusionsFocal hole stimulation, unlike screw stimulation, approaches absolute EMG threshold as shown by the lower normal limit (2.6 mA; p < 0.05) that borders the upper limit of threshold to direct activation of the exposed root.SignificanceThe technique provides an early warning of a possible pedicle breakthrough before insertion of the more harmful, larger and threaded screw.     

关节镜双后内入路与切开手术治疗急性单纯后交叉韧带胫骨止点撕脱骨折早期疗效对比

目的:比较关节镜双后内入路与切开手术治疗急性单纯后交叉韧带胫骨止点撕脱骨折的疗效差异。方法:回顾性分析2016年6月至2020年6月经手术治疗的52例急性单纯性后交叉韧带胫骨止点撕脱骨折患者的临床资料,按手术方案不同分为两组,关节镜组27例患者行关节镜双后内入路手术治疗,其中男16例,女11例,年龄19~52(34.9±9.2)岁;切开复位组25例患者行膝关节后内侧切口手术治疗,其中男14例,女11例,年龄18~54(33.7±8.4)岁。观察并比较两组患者手术时间、切口长度、术中出血量、住院时间、住院费用、术后愈合情况、并发症以及术后12个月Lysholm、IKDC评分。结果:两组患者均顺利完成手术,无血管、神经损伤。52例均获得随访,时间6~24(15.0±1.7)个月。关节镜组手术时间、住院费用大于切开复位组(P<0.05);关节镜组术中出血量、切口长度、住院时间小于切开复位组(P<0.05);关节镜组和切开复位组术后12个月Lysholm评分分别为(95.9±1.7)分和(86.4±1.2)分,均较术前的(49.1±2.3)分和(48.9±1.1)分显著提高(P<0.05);关节镜组和切开复位组术后12个月IKDC总分分别为(96.9±1.5)分和(87.1±1.4)分,均较术前的(47.6±4.1)分和(48.1±3.9)分显著提高(P<0.05);关节镜组术后12个月膝关节Lysholm、IKDC评分均高于切开复位组(P<0.05)。结论:关节镜双后内入路治疗急性单纯后交叉韧带胫骨止点撕脱骨折,早期效果满意,疗效优于传统开放手术,具有创伤小、恢复快、操作简便等优点。