Late in-the-bag spontaneous IOL dislocation: risk factors and surgical outcomes

AIM: To evaluate the possible predisposing risk factors for late in-the-bag spontaneous IOL dislocations and to study the early surgical and visual outcomes of repositioning and exchange surgeries.METHODS: Medical and surgical records of 39 eyes of 39 patients who underwent IOL repositioning or exchange surgery for dislocation between 2010 and 2018 were reviewed. Possible predisposing risk factors and some characteristics of late in-the-bag spontaneous IOL dislocations;outcomes of IOL repositioning and exchange surgeries, including visual acuity, refractive status before and after surgery and postoperative complications were evaluated.RESULTS: The predisposing factors for late in-the-bag spontaneous IOL dislocations were pseudoexfoliation [PEX;12/39(30.8%)], previous vitreoretinal surgery [7/39(17.9%)], axial myopia [3/39(7.7%)], both PEX and axial myopia [1/39(2.6%)], both previous vitreoretinal surgery and axial myopia [2/39(5.1%)] and uveitis (1/39(2.6%))The mean interval between cataract and dislocation surgery was 7.23 y, greater in PEX positive group(8.63 y). The mean best corrected visual acuity(BCVA) improved significantly after dislocation surgery(P<0.001) and also improved significantly after exchange surgery(P=0.001). The mean value of spherical equivalant decreased significantly after dislocation surgery(P=0.011), whereas corneal astigmatism increased but this difference was not significant after dislocation surgery and exchange surgery(P=0.191, P=0.074, respectively).CONCLUSION: The most prevelant risk factors for late inthe-bag spontaneous IOL dislocations are PEX, previous vitreoretinal surgery and axial myopia. In the management of IOL dislocations, exchange surgery with small corneal incision seemed effective with improved BCVA and safety with low postoperative complications.

Surgical Repair of Dorsal Capsulo-Ligamentous Complex for Dislocation of the Thumb Carpometacarpal Joint

Background: Acute dislocation of the thumb carpometacarpal (CMC) joint is a rare and challenging injury, and its treatment remains controversial. The purpose of the study was to evaluate the clinical outcome after surgical repair of the dorsal capsulo-ligamentous complex. Materials and methods: Eight patients with a mean age of 39.8 years (range, 23 - 56 years) treated for the thumb CMC joint were treated in our hospital between 2008 and 2018. The ruptured dorsal capsulo-ligamentous complex was repaired using suture anchors in all patients, and the joint was immobilized with a Kirschner wire pinning and splint for 3 weeks. The clinical outcome was assessed by measuring the range of motion of the thumb CMC joint and the Japanese Society for Surgery of the Hand version of the Quick Disability of the Arm, Shoulder, and Hand (Q-DASH-JSSH) score. Results: The mean radial abduction of the thumb CMC joint was 66°, and the volar abduction was 63°. The mean Q-DASH-JSSH score was 4.8 (range, 0 - 15.6). There were no cases of infection, nerve disturbance, or osteoarthritis. Anatomical reduction was observed in seven patients at the final follow-up and in a rugby football player at 6 months of follow-up;however, subluxation of the thumb CMC joint at 12 months of follow-up due to reinjury was observed. Conclusion: Surgical repair of the dorsal capsulo-ligamentous complex with suture anchors is a reliable and simple treatment for acute unstable dislocation of the thumb CMC joint.

Repair of Complex Post-Traumatic Facial Dislocations: Indications, Therapeutic Difficulties and Results at Treichville University Hospital, Abidjan, Cote d’Ivoire

Introduction: Complex post-traumatic facial disfigurements are caused by civilian or ballistic trauma. Their repercussions are functional, aesthetic and psychological. The initial emergency or secondary management of facial damage is difficult. The objective is to report, through the clinical observation of three patients, the results of the management of complex facial dislocations in a context of limited technical resources. Patients and methods: Three complex post-traumatic facial dislocations were managed between May 2006 and June 2017. Results: Primary treatment and secondary repair were established on a case-by-case basis. Local autoplasty was the indication of choice. Multidisciplinary management resulted in satisfactory functional and cosmetic outcomes. Two of the patients were lost to follow-up before the end of treatment. Discussion: The complete management of facial dislocations remains difficult and complex, in an extreme exercise situation. In an emergency, the priority is to save the life of the injured person. Several factors are involved in the therapeutic decision: the choice of the maxillofacial reconstruction technique, the availability of the technical platform, the financial capacity and the psychological state of the patient and his entourage. Sequential and multidisciplinary treatment gives satisfactory results in terms of morphology, function and aesthetics, despite the limited technical resources available. Psychological support is an essential complement for successful socio-professional and family reintegration.

Electronic structure & yield strength prediction for dislocation-Mo complex in the γ phase of nickel-based superalloys

Molybenum＇s effects when added in the γ phase of nickel-based superalloys were studied using the lattice Green＇s function multiscale method. The electronic structure of the dislocation-Mo complex was analyzed and hybridization was found to contribute to the strengthening. Moreover, by combining the interaction energies calculated from two scales, the yield stress was theoretically predicted at 0 K and finite temperature.

INTERACTION OF A SCREW DISLOCATION IN THE INTERPHASE LAYER WITH THE INCLUSION AND MATRIX

The interaction of a screw dislocation in the interphase layer with the circular inhomogeneity and matrix was dealt with . An efficient method for multiply connected regions was developed by combining the sectionally subholomorphic function theory, Schwatz symmetric principle and Cauchy integral technique. The Hilbert problem of the complex potentials for three material regions was reduced to a functional equation in the complex potential of the interphase layer, resulting in an explicit series solution . By using the present solution the interaction energy and force acting dislocation were evaluated and discussed.

Interaction between a screw dislocation and an elastic elliptical inhomogeneity with interfacial cracks

The elastic interaction between a screw dislocation and an elliptical inhomogeneity with interfacial cracks is studied. The screw dislocation may be located outside or inside the inhomogeneity. An efficient complex variable method for the complex multiply connected region is developed, and the general solutions to the problem are derived. As illustrative examples, solutions in explicit series form for complex potentials are presented in the case of one or two interfacial cracks. Image forces on the dislocation are calculated by using the Peach-Koehler formula. The influence of crack geometries and material properties on the image forces is evaluated and discussed. It is shown that the interfacial crack has a significant effect on the equilibrium position of the dislocation near an elliptical-arc interface. The main results indicate, when the length of the crack goes up to a critical value, the presence of the interfacial crack can change the interaction mechanism between a screw dislocation and an elliptical inclusion. The present solutions can include a number of previously known results as special cases.

A SCREW DISLOCATION IN A THREE-PHASE COMPOSITE CYLINDER MODEL WITH INTERFACIAL RIGID LINES

The problem of the elastic interaction between a screw dislocation and a three-phase circular inclusion with interracial rigid lines （anti-cracks） is investigated. An efficient and concise method for the complex multiply connected region is developed, with which explicit series form solutions of the complex potentials in the matrix, and the interphase layer and inclusion regions are derived. Based on the complex potentials, the image force on the screw dislocation is then calculated by using the Peach-Koehler formula. The equilibrium position of the dislocation is discussed in detail for various rigid line geometries, interphase layer thicknesses and material property combinations. The main results show that the interracial rigid lines exert a significant perturbation effect on the motion of the screw dislocation near the circular inclusion surrounded by an interphase layer.

A Piezoelectric Screw Dislocation Interacting with an Elliptical Piezoelectric Inhomogeneity Containing a Confocal Elliptical Rigid Core

The electro-elastic interaction between a piezoelectric screw dislocation and an elliptical piezoelectric inhomogeneity, which contains an electrically conductive confocal elliptical rigid core under remote anti-plane shear stresses and in-plane electrical load is dealt with. The anaJytical solutions to the elastic field and the electric field, the interracial stress fields of inhomogeneity and matrix under longitudinal shear and the image force acting on the dislocation are derived by means of complex method. The effect of material properties and geometric configurations of the rigid core on interracial stresses generated by a remote uniform load, rigid core and material electroelastic properties on the image force is discussed.

Unilateral spontaneous lens absorption and dislocation of the empty capsular bag into the anterior chamber

Cases involving spontaneous aphakic change in the visual axis are rare in Outpatient Clinics. However, we can often ascertain the past events affecting the patient＇s eye by examining its current status. The placement of the dislocated internal material of the lens, the remnant lens capsular bag status, lens and zonular status of the contralateral eve.

ANALYSIS OF A SCREW DISLOCATION INSIDE A CIRCULAR INCLUSION WITH INTERFACIAL CRACKS IN PIEZOELECTRIC COMPOSITES

The electroelastic interaction of a screw dislocation inside a circular inclusion with inteffacial cracks in piezoelectric composite materials under anti-plane shear and in-plane electric loads at infinity is investigated. The general solution to this problem was obtained by means of Riemann-Schwarz＇ s symmetry principle integrated with analysis of singularities of corresponding complex potentials. As a typical example, closed form expressions of the complex potentials and electroelastic field components in the matrix and inhomogeneity regions were derived explicitly when the interface contains a single crack. The image force acting on the screw dislocation was calculated by using the generalized Peach-Koehler formula. The influence of interfacial crack geometry and piezoelectric material property combinations upon the image force was discussed in detail. The results show that interfacial crack has a significant perturbation effect on the image force and the equilibrium position of the screw dislocation. The presence of the interfacial crack can change the direction of the image force when the length of the crack goes up to a critical value. The obtained explicit solutions can be used as Green＇s functions to study the problem on the interaction between interfacial cracks and arbitrary shape crack inside the inclusion. The present solutions can lead to previously known results as the special case.

Analysis of a piezoelectric screw dislocation inside an elliptical inhomogeneity with confocal rigid line in piezoelectric material

This paper deals with the electro-elastic coupling interaction between a piezoelectric screw dislocation which is located inside the elliptical inhomogeneity and an electrically conductive confocal rigid line under remote anti-plane shear stresses and in-plane electrical loads in piezoelectric composite material. The analytical-functions of the complex potentials, stress fields and the image force acting on the piezoelectric screw dislocation are obtained based on the principle of conformal mapping, the method of series expansion, the technical of analytic continuation and the analysis of singularity of complex potentials. The rigid line and the piezoelectric material property combinations upon the image force and the equilibrium position of the dislocation are discussed in detail by the numerical computation.

Dislocation stability in three-phase nanocomposites with imperfect interface

Interface imperfection can significantly affect the mechanical properties and failure mechanisms as well as the strength and toughness of nanocomposites. The elastic behavior of a screw dislocation in nanoscale coating with imperfect interface is studied in the three-phase composite cylinder model. The interface between inner nanoin- homogeneity and intermediate coating is assumed as perfectly bonded. The bonding between intermediate coating and outer matrix is considered to be imperfect with the assumption that interface imperfection is uniform, and a linear spring model is adopted to describe the weakness of imperfect interface. The explicit expression for image force acting on dislocation is obtained by means of a complex variable method. The analytic results indicate that inner interface effect and outer interface imperfection, simultaneously taken into account, would influence greatly image force, equilibrium position and stability of dislocation, and various critical parameters that would change dislocation stability. The weaker interface is a very strong trap for glide dislocation and, thus, a more effective barrier for slip transmission.

In-situ TEM investigation on the evolution of He bubbles and dislocation loops in Ni-based alloy irradiated by H_(2)^(+)&He^(+)dual-beam ions

The synergistic evolution mechanisms of He bubbles and dislocation loops under 30 keV H_(2)^(+)&He^(+)dual-beam ions irradiation at 650℃ in the Ni-based alloy GH3535,which is the most promising candidate structure material for molten salt reactors(MSRs),were revealed via in-situ TEM.The nucleation,merg-ing,and change in the size of the dislocation loops and He bubbles were characterized in detail to study the influences of irradiation fluence and pre-existing dislocation loops on their evolutions.The number density of both the He bubbles and dislocation loops increases rapidly and subsequently saturates,whereas their size continuously increases with the increasing ion fluence.Pre-existing dislocation loops with strong absorption characteristics grow preferentially and suppress the nucleation of dislocation loops during the dual-beam ions irradiation.Moreover,the bubbles tend to nucleate within the dislocation loops to form bubble-loop complexes,and then decrease in their number density.The details of the un-faulting processes of the Frank loops were discussed,where the energy difference between the two types of loops as well as the evolution of the inside Shockley dislocation loops dominates the unfaulting be-havior.The several evolution stages of the loop-punching mechanism are revealed,and the emitted loops can directly form perfect loops as well as unfault the neighboring Frank loops.The He bubbles inside the loops provide corresponding stress for the formation of rhombic loops,which can achieve rapid growth and sweep ability by merging with the neighboring loops.Additionally,its dissociation to Shockley dis-location can unfault the Frank loops along their slip direction.Among the four Frank loop variations,the edge-on Frank loop variations have the highest growth rate,followed by the perfect loop.The related mechanisms based on in-situ experimental observation are discussed in depth.

肱二头肌长头腱脱位分型与其周围组织结构损伤的关系

目的 探讨肱二头肌长头腱(LHBT)脱位分型及其常规磁共振成像(MRI)表现。方法 回顾性收集31例LHBT脱位患者MRI资料,分析不同脱位类型间LHBT、喙肱韧带外侧部(LCHL)、喙肱韧带内侧部-盂肱上韧带复合体(MCHL-SGHL)、肱横韧带(THL)、肩胛下肌腱(SSC)及冈上肌腱(SSP)撕裂率差异性及其MRI表现。结果 31例患者中,半脱位14例,全脱位17例(Ⅰ型10例,Ⅱ型6例,Ⅲ型1例),2组以上结构撕裂数依次分别为9例与11例;4例与13例;11例与16例;5例与16例;8例与17例;10例与11例。其中LCHL、THL及SSC撕裂率低于全脱位组(P均<0.05),且所有结构撕裂率在全脱位亚型间差异均无统计学意义(P均>0.05)。结论 LHBT脱位常合并自身及其固定结构的撕裂,诊断时应仔细全面观察。

25G PPV联合IOL睫状沟缝合固定置换术治疗IOL囊袋复合体脱位于玻璃体腔

目的:评估25G玻璃体切割(PPV)联合人工晶状体(IOL)睫状沟缝合固定置换术治疗IOL囊袋复合体脱位于玻璃体腔的临床效果。方法:回顾性分析我院2015-01/2020-01应用25G玻璃体切割联合IOL睫状沟缝合固定置换术治疗IOL囊袋复合体完全脱位于玻璃体腔的患者21例21眼的临床资料。结果:所有患者术中均顺利取出脱位的IOL复合体,未出现医源性视网膜损伤,术中发现视网膜裂孔4眼,视网膜格子样变性2眼,分别予以视网膜激光光凝。随访6~18mo,BCVA(LogMAR)由术前的0.40±0.30提高到术后的0.33±0.25(P=0.040)。所有病例末次随访BCVA均达到术前BCVA。术后等效球镜度与术前IOL屈光度预测值相差的绝对值≤0.75D。末次随访时所有患者IOL位置良好,未发生视网膜脱离等并发症。结论:25G玻璃体切割联合IOL睫状沟缝合固定置换手术是治疗IOL囊袋复合体脱位安全有效的方法。

错位的中心性深圳福田中心区立体步行系统研究

通过空间设计网络分析(sDNA)工具,文章研究了深圳福田中心区南片区9个大型商业综合体植入城市立体步行系统前后的空间结构变化情况,并通过现状与规划设计方案的对比,分析了建筑与城市空间的内外联动对立体步行系统可达性分布模式的影响.研究旨在以复杂空间系统的局部与整体关系为中心区立体步行系统的现状诊断和方案评估提供一个研判视角.

夹杂与基体对界面层螺旋位错的干涉效应

研究圆形夹杂与基体对有限厚度界面层螺旋位错的干涉问题· 结合复变函数的分区亚纯函数理论、施瓦兹对称原理与柯西型积分运算,发展了多连通域联结问题的一个有效分析方法,将3个区域应力函数的联结问题化归为界面层应力函数的函数方程,并求得了显式级数解· 利用该结果。

压电螺位错与含界面裂纹圆形涂层夹杂的干涉

研究位于基体或夹杂中任意点的压电螺型位错与含界面裂纹圆形涂层夹杂的电弹耦合干涉问题．运用复变函数方法,获得了基体,涂层和夹杂中复势函数的一般解答．典型例子给出了界面含有一条裂纹时,复势函数的精确级数形式解．基于已获得的复势函数和广义Peach-Koehler公式,计算了作用在位错上的像力．讨论了裂纹几何条件,涂层厚度和材料特性对位错平衡位置的影响规律．结果表明,界面裂纹对涂层夹杂附近的位错运动有很大的影响效应,含界面裂纹涂层夹杂对位错的捕获能力强于完整粘结情况;并发现界面裂纹长度和涂层材料常数达到某一个临界值时可以改变像力的方向．解答的特殊情形包含了以往文献的几个结果．

三柱理论对中足复杂骨折脱位手术治疗的指导意义

目的探讨三柱理论对中足复杂骨折脱位临床诊疗的指导作用。方法 2013年1月-2017年9月成都市第一人民医院骨科共收治24例中足复杂损伤患者,女8例,男16例;年龄18～57岁,平均41岁;按解剖三柱分类:内侧柱6例,内侧柱合并中间柱6例,累及三柱12例。采用跨关节长钢板坚强固定内侧柱及中间柱,克氏针弹性固定外侧柱,术中根据固定需要配合使用螺钉。骨折后伴有内侧柱足舟骨或外侧柱骰骨短缩者,需要撑开复位,跨关节钢板固定,必要时植骨,重建各柱的长度,维系足弓正常结构与功能。术后通过影像学及临床检查随访,采用X线片评估中足对位对线及骨折愈合情况。依据Mariland足部评分量表评估疗效,采用VAS疼痛评分量表评估损伤部位疼痛程度。结果治疗后随访12个月。24例中1例内侧柱因足舟骨粉碎骨折长度未充分恢复,术后出现跛行,内固定取出后步态恢复正常;其他23例均取得满意疗效,足弓正常负重,行走功能正常,未见钢板螺钉失效、感染等情况发生。末次随访患者足部X线复查示中足骨折均骨性愈合,中足结构正常、稳定,对位对线正常;Mariland足部评分平均94(70～98)分:优19例,良2例,可3例;平均VAS评分为1.2(0～2)分。结论在三柱损伤理论的指导下及时手术治疗中足复杂骨折,术中精准解剖复位,根据不同的固定强度选择不同的方式固定内侧柱、中间柱及外侧柱,恢复足弓正常解剖结构及功能,术后早期功能锻炼,可获得满意的临床效果。

改良四通路玻璃体切割在人工晶状体后脱位治疗中的应用(英文)

目的:报道改良四通路玻璃体切割术治疗 1 例后房型人工晶状体后脱位。方法:一位青年性白内障患者,双眼白内障术后均发生人工晶状体后脱位,其 1 眼应用改良四通路玻璃体切割技术将人工晶状体复位,另 1 眼应患者的要求而未行手术治疗。结果:术中和术后未发生任何并发症,患者术眼视力迅速回复,术后 14mo 最佳矫正视力为 0.5;而未行手术治疗的另 1 眼发生全视网膜脱离,仅残余手动视力。结论:改良四通路玻璃体切割术是治疗人工晶状体后脱位的一个好选择。