Epidemiology of Diagnosed Age-related Macular Degeneration in Germany: An Evaluation of the Prevalence Using AOK PLUS Claims Data

INTRODUCTION

Epidemiologic data on age-related macular degeneration (AMD) are mainly based on cohort studies, including both diagnosed and undiagnosed cases. Using health claims data allows estimating epidemiological data of diagnosed subjects with AMD within the health care system using diagnosis codes from a regional claims database (AOK PLUS) to estimate the prevalence and incidence of non-exudative and exudative AMD in Germany.

METHODS

Patients with AMD were identified among AOK PLUS insured patients based on at least two outpatient, ophthalmologic or one inpatient H35.3 diagnoses for the years 2012 to 2021. Patients without continuous observation in a calendar year were excluded. Prevalence was assessed, and 1-year cumulative incidence was determined by the number of newly diagnosed patients divided by the number of individuals at risk. For 2020 and 2021, the AMD stage was assessed by diagnostic subcodes for non-exudative and exudative AMD, respectively. For 2012 to 2019, patient numbers were estimated based on the average proportions of non-exudative AMD and exudative AMD, respectively, in 2020 and 2021. Incidence and prevalence numbers were then extrapolated to Germany.

RESULTS

Between 2012 to 2021, the prevalence of diagnosed AMD cases remained relatively stable among approximately 3.27 million AOK PLUS insured persons, ranging from 0.96% (minimum in 2021) to 1.31% (maximum in 2014) for non-exudative AMD, about twice as high as for exudative AMD (min-max: 0.53-0.72%). The age- and sex-adjusted projections amounted to 644,153 diagnosed non-exudative and 367,086 diagnosed German patients with exudative AMDs in 2021. The 1-year cumulative incidence for non-exudative and exudative AMD, respectively, ranged from 122,427-142,932 to 46,092-86,785 newly diagnosed cases.

CONCLUSION

The number of diagnosed cases with AMD in Germany has increased slightly over the past decade. For the first time, patient counts with non-exudative and exudative AMD were approximated for Germany based on a representative, large-scale database study.

[Diagnosis and Management of Late-Onset Pompe Disease]

Pompe disease is a lysosomal storage disorder, with onset between the first weeks after birth and adulthood, depending on its phenotype. It can affect multiple organ systems and presents itself with a wide variety of symptoms. Thus, recognizing Pompe disease is difficult. Especially since enzyme replacement therapy for Pompe disease was introduced (in Germany in 2006), early diagnosis by means of enzyme activity determination from dried blood spot analysis and genetic verification has become important for outcome and quality of life. When facing an obscure muscular disorder, it is crucial to consider Pompe disease. This article provides an overview about Pompe disease and focuses on the diagnosis of the late onset type. The most important aspects of interdiciplinary care for patients with Pompe disease are presented. Additionally, it contains a section focusing on psychosocial challenges for children with Pompe disease and their families, which may include mental disorders and social retreat, and gives advice on how to support parents of affected children.

Myocardial work in hypertrophic cardiomyopathy - a new non-invasive parameter for segmental myocardial function?

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): DFG

Introduction

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiac disease. Alcohol septal ablation (PTSMA) is an established treatment option for patients with intracavitary obstruction. In non-obstructive patients, measurement of myocardial work (MW) using pressure strain loops was introduced as a new non-invasive tool to estimate myocardial performance.

Purpose

In this preliminary study, we compared global constructive work (GCW) and global wasted work (GWW) as well as the respective values for the septal- and lateral-basal segments in HOCM after successful PTSMA and non-obstructive HCM.

Methods

We included 12 patients (4 women, mean age 59.1 ± 17.6 years) with non-obstructive (maximal left ventricular gradient <30 mmHg; mean 10.6 ± 6.2 mmHg) HCM. 7 (58%) patients (subgroup A) had successful gradient reduction by PTSMA ≥3 months before analysis, whereas 5 patients had non-obstructive HCM (subgroup B). Using echocardiographic measurements of longitudinal strain and non-invasive measurements of peripheral- and calculated (PWA) central blood pressure (BP) as left ventricular systolic pressure (LVSP), we estimated and compared GCW and GWW as well as constructive work (CW) and wasted work (WW) of septal-basal and lateral-basal segments.

Results

In subgroup B, NTproBNP was significant higher than in subgroup A (2050 ± 1957 vs. 552 ± 845 pg/ml; p < 0.05). There were no differences between both subgroups in maximal septal thickness (20.7 ± 2.9 mm (A) vs. 22.2 ± 3.6 mm) and left atrial volume (91.6 ± 33.0 (A) vs. 114.0 ± 49.8 ml (B)). Using the measured peripheral BP as LVSP, GCW (1653 ± 347 (A) mmHg% vs 1641 ± 698mmHg%) and GWW (171 ± 89mmHg% (A) vs. 200 ± 126 mmHg%) showed no differences between both subgroups. Compared to published data of a healthy population, values of GCW were lower and values of GWW higher in HCM. Comparison in segmental analysis in subgroup A showed lower CW in septal-basal than in lateral-basal segments (1032 ± 385mmHg% vs. 1929 ± 699 mmHg%). In the subgroup B the finding was the same pattern (1024 ± 504mmHg% vs. 2301 ± 1069 mmHg%). In contrast, WW showed no difference between basal-septal and lateral-basal segments in both subgroups.

Conclusions

Our preliminary data show decreased GCW and increased GWW in HCM patients without obstruction at rest. As expected, we found lower CW in septal-basal segments than lateral-basal in patients after PTSMA with basal-septal-induced therapeutic infarction. Surprisingly, we found the same pattern in non-obstructive HCM patients. This finding might be one pathophysiological reason for not developing LVOT obstruction, which should be investigated in further detail.

Systematic review of oral and craniofacial findings in patients with Fabry disease or Pompe disease

Fabry disease and Pompe disease are rare lysosomal storage disorders that belong to a heterogeneous group of more than 200 distinct inborn metabolic diseases. Mutations followed by loss of function of enzymes or transporters that are localised in the acidic environment of the lysosome may result in degradation of many substrates, such as glycosaminoglycans, glycosphingolipids, glycogen, cholesterol, oligosaccharides, glycoproteins, and peptides, or the excretion of the products degraded by the lysosome. Our aim was to identify the oral signs and symptoms of Fabry disease and Pompe disease from a systematic review made using MEDLINE/PubMed, and a hand search for relevant articles, following the PRISMA guidelines. Both diseases show various craniofacial and oral changes, including supernumerary teeth, dental agenesis, angiokeratoma, and telangiectases in Fabry disease; and macroglossia, teeth fusion, and taurodontism in Pompe disease. Common clinical signs of Fabry disease include hyposalivation, hypohidrosis, and xerophthalmia, and a generally reduced physical resilience was apparent in patients with Pompe disease. Oral and craniofacial changes in patients with both diseases extend over their entire lifetime and can be detected even in an infant. Lysosomal storage diseases should be taken into consideration in the differential diagnosis of relevant diverse symptoms, because treatment, when available, is most effective when started early. The main therapeutic concepts are enzymatic replacement for Pompe disease, whereas patients with Fabry disease require additional oral chaperone treatment or enzyme replacement.

Abstract P4-01-10: The analysis of cell-free DNA and circulating tumor cells from one blood tube might empower treatment decisions in metastatic breast cancer patients

Background: The detection and characterization of circulating tumor cells (CTCs) as one of the analytes in liquid biopsy has been considered as surrogate marker to improve treatment decisions in metastatic breast cancer (MBC). In addition, cell-free tumor DNA (ctDNA) released by tumor cells and harboring tumor-associated variants is further discussed to give additional information for therapeutic options. Thus, CTC and ctDNA analysis from the same blood tube is desired. To test usability of plasma, generated after CTC isolation from whole blood for ctDNA analysis, we analyzed ctDNA from 42 hormone receptor-positive/HER2-negative MBC patients (pts) for the detection of tumor-associated variants (plasma isolated straight from whole blood) and compared the results for similarities and differences of the detected variants in a subgroup of these pts to those, obtained from plasma generated after CTC selection (taken from a separate tube).

Methods: 4 ml plasma of all MBC pts and 4 ml plasma obtained after immunomagnetic isolation of CTCs from 2x5ml blood [AdnaTest EMT-2/Stem Cell Select (n=17pts) followed by multimarker qPCR] were used for the analysis of cell-free DNA (cfDNA) applying the QIAamp MinElute ccfDNA Kit. A total of 30ng - 60ng cfDNA was applied for library construction using the QIAseq Targeted DNA Panel for Illumina with integrated unique molecular identifiers. Sequencing was executed on the NextSeq® 500 platform (Illumina, US). Data were analyzed using the QIAseq Targeted Sequencing Data Analysis Portal, the Biomedical Genomics Workbench and the Ingenuity Variant Analysis. All materials used were manufactured by QIAGEN, Germany.

Results: In the total cohort of 42 pts, most variants of all analyzed genes were detected in the MUC16 gene (31.2%). ERBB2, EGFR and AR (androgen receptor) also showed high numbers of variants (11.6%, 11.0% and 8.9%, respectively) with a majority detected pathogenic variants (47.7%) in AR. 92% of all detected variants showed an allele frequency of <5% and some of the detected MUC16, ERBB2 and AR mutations significantly correlated with overall survival. Comparing the plasma results from a separate blood draw with the results from plasma samples after CTC selection in a subgroup of 17/42 pts, no significant difference was found for cfDNA concentration but variability within the cohort. Whereas the variant comparison of ctDNA isolated from both plasma sources showed great concordance, additional variants (around 15%) were exclusively found in one of the two matched samples. Interestingly, in the variant population exclusively found in ctDNA isolated after CTC isolation, the relative amount of pathogenic variants was increased compared to the variant fraction only found in ctDNA from plasma of a separate blood tube. Results obtained for frequently overexpressed CTC transcripts in this subgroup included genes involved in the PI3K signaling pathway as well as ERBB2 and ERBB3 in about 30% of the pts.

Conclusion: We here present a feasible workflow for CTC and ctDNA evaluation for expression and mutation analysis from the same blood sample. These data emphasize that the use of different liquid biopsy analytes can empower treatment decisions of MBC pts in the future.

Citation Format: Kasimir-Bauer S, Bittner A-K, Hoffmann O, Hauch S, Sprenger-Haussels M, Storbeck M, Benyaa K, Hahn P, Mach P, Tewes M, Kimmig R, and Keup C. The analysis of cell-free DNA and circulating tumor cells from one blood tube might empower treatment decisions in metastatic breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-10.

Decompression for cervical disc herniation using the full-endoscopic anterior technique

OBJECTIVE

Resection of a cervical disc herniation using a full-endoscopic technique with an anterior approach.

INDICATION

Fresh disc herniation with monoradicular symptoms in the upper extremity.

CONTRAINDICATIONS

Pure neck pain, cervical myelopathy, older and calcified disc herniations, higher grade of instability and deformity.

SURGICAL TECHNIQUE

Introduction of a guidewire and dilatator to a cervical disc using an anterior approach. Under full-endoscopic view, preparation of the posterior parts of the annulus, opening of the annulus and posterior longitudinal ligament and resection of the herniated fragment from the epidural space.

POSTOPERATIVE MANAGEMENT

Immediate mobilisation, isometric/coordinative exercises, functional exercises from week 3, building up strength from week 6.

RESULTS

A total of 120 patients were operated using the full-endoscopic or microsurgically assisted technique and were followed up for 24 months. Significant improvement was achieved in both groups. The group of full-endoscopic operated patients returned to work significantly earlier and 89% of all patients would undergo the operation again.

[Distal radius fracture of the adult : Diagnostics and therapy]

Fractures of the distal radius are very common. The majority of patients are elderly females. High impact trauma are often responsible for fractures in young men. Clinical and radiological diagnostics, including computer-assisted tomography (CAT) scan, are generally sufficient. The indication for conservative treatment is still recommended for specific fracture patterns. Application of palmar locking plates after open reduction proved to be efficacious for the majority of fracture patterns. Furthermore, precise detection and treatment of concomitant lesions are mandatory in order to prevent complications.

Teaching and assessment of communication skills in undergraduate dental education - a survey in German-speaking countries

INTRODUCTION

Teaching communication is perceived to be of importance in dental education. Several reports have been published worldwide in the educational literature describing modifications of the dental curriculum by implementing the teaching of communication skills. Surveys which evaluate the current state of training and assessment of communication skills in dental education in different countries exist already in some countries, but little information is available about German-speaking countries.

MATERIAL AND METHODS

In a cross-sectional study with the aim of a census, all 36 dental schools in Germany (30), Austria (3), and Switzerland (3) were surveyed.

RESULTS

The present survey revealed that at 26 of the 34 dental schools (76%), communication skills training has been implemented. Training of communication skills mainly takes place between the 6th and the 9th semester. Ten schools were able to implement a partly longitudinal curriculum, while the other sites only offer stand-alone courses. Of the 34 dental schools, six assess communication skills in a summative way. Three of those schools also use formative assessments for their students. Another seven sites only use formative assessment. From the various formats of assessment, OSCE is mentioned most frequently.

CONCLUSION

The necessity to train and assess communication skills has reached German-speaking dental schools. The present survey allows an overview of the training and assessment of communication skills in undergraduate dental education in German-speaking Europe.

[Joint infections of the hand]

Joint infections of the hand may lead to irreversible lesions and impairment of hand function due to early cartilage damage. Furthermore, persistent infections which are not treated immediately can cause osteitis and/or spread systemically. Finger joints are prone to infection due to bite wounds or crush and sharp injuries. Whereas the wrist is often affected in patients with immunosuppression or chronic diseases, such as diabetes mellitus. If diagnosis and therapy are delayed, joint damage may be inevitable. Therefore, urgent treatment of the infected joint is imperative to preserve the function of the hand. This article reviews the current diagnostics and treatment of joint infections of the hand.

[Compression of the median nerve by chronic palmar dislocation of the lunate due to carpal collapse]

Carpal tunnel syndrome is among the most frequently diagnosed forms of peripheral nerve compression. Carpal tunnel syndrome due to carpal collapse that had progressed over decades, with a palmarly dislocated lunate, is rare. Hints of past trauma to the wrist going back decades should prompt further radiological examination in case of recurrent median nerve compression. With sufficient preoperative evaluation, the causes can be accurately detected and treated. Therefore, precise and complete history-taking is mandatory. Conclusions on further diagnostics that can be drawn from the latter must be consistently implemented to enable adequate therapy.

[Epidemiology of Dupuytren's disease]

Dupuytren's disease is a chronic disease of the elderly. Assuming that life expectancy will increase considerably in the coming decades, Dupuytren's disease will gain more medical and socioeconomic relevance. In addition to well-known familial and genetic causes, other environmental factors (nicotine, diabetes, alcohol, trauma, work) are discussed. Knowledge of all factors and their influence on the onset and severity of the disease is important for diagnosis, therapy, and prevention of the disease.

[Percutaneous needle aponeurotomy for Dupuytren's contracture]

Dupuytren disease is a benign fibroproliferative disease of the palmar aponeurosis, which can cause considerable functional deficiencies for the person concerned. Partial aponeurectomy is the gold standard in primary surgery. Because it is minimally invasive and has short recovery and low complication rates, the importance of needle aponeurotomy under specific indications has been increasing in the last years. Needle aponeurotomy is a cost-effective treatment with low complication rates. The revision rate compared to partial aponeurectomy is higher. Under consideration of specified indications, needle aponeurotomy is an alternative treatment option.

Numerical simulation of micro-particle rotation by the acoustic viscous torque

We present the first numerical simulation setup for the calculation of the acoustic viscous torque on arbitrarily shaped micro-particles inside general acoustic fields. Under typical experimental conditions, the particle deformation plays a minor role. Therefore, the particle is modeled as a rigid body which is free to perform any time-harmonic and time-averaged translation and rotation. Applying a perturbation approach, the viscoacoustic field around the particle is resolved to obtain the time-averaged driving forces for a subsequent acoustic streaming simulation. For some acoustic fields, the near-boundary streaming around the fluid-suspended particle induces surface forces on the nonrotating particle that integrate into a non-zero acoustic viscous torque. In the equilibrium state, this torque is compensated by an equal and opposite drag torque due to the particle rotation. The rotation-induced flow field is superimposed on the acoustic streaming field to obtain the total fluid motion around the rotating particle. In this work, we only consider cases within the Rayleigh limit even though the presented numerical model is not strictly limited to this regime. After a validation by analytical solutions, the numerical model is applied to challenging experimental cases. For an arbitrary particle density, we consider particle sizes that can be comparable to the viscous boundary layer thickness. This important regime has not been studied before because it lies beyond the validity limits of the available analytical solutions. The detailed numerical analysis in this work predicts nonintuitive phenomena, including an inversion of the rotation direction. Our numerical model opens the door to explore a wide range of experimentally relevant cases, including non-spherical particle rotation. As a step toward application fields such as micro-robotics, the rotation of a prolate ellipsoid is studied.

Self-assessment of competencies in dental education in Germany - a multicentred survey

INTRODUCTION

The aim was to assess the competencies of undergraduate dental students in Germany in the domains team competence, communicative competence, learning competence and scholarship.

MATERIALS AND METHODS

The survey was conducted at 11 dental schools that are equally distributed all over Germany. Competencies were assessed with the Freiburg Questionnaire to Assess Competencies in Medicine (FCM). A short version of the FCM was used in this study. This short form included the four domains: team competence (three items), communicative competence (eight items), learning competence (five items) and scholarship (four items). Students had to rate each item twice: first with regard to the respondent's current level of competence and second with regard to the level of competence that respondents think is required by their job. All items were rated on a five-point Likert scale (1 'very much' and 5 'not at all'). Responsible lecturers from all selected dental schools received another questionnaire to answer the questions whether the FCM domain corresponding learning objectives were taught at the respective dental school.

RESULTS

A total of 317 undergraduate students from 11 dental schools in their last clinical year participated. The response rate varied between 48% and 92%. Cronbach's α for the FCM scales addressing the current level of competencies ranged from 0.70 to 0.89 and for the scales measuring the presumed level of competencies demanded by their job ranged from 0.72 to 0.82. The mean values of the scales for the assessment of the presumed level of competencies demanded by the job were significantly lower compared to the mean values of the scales for the current level of competencies (P < 0.001 in all analyses). We found large differences between the two levels - in terms of 'standardised response means' (SRM) - in the domains team competence (SRM 1.34), learning competence (SRM 1.27) and communicative competence (SRM 1.18). Overall, the learning objectives that correspond to the assessed domains of competencies were taught to 19.6% completely, to 55.4% partially and to 25% not at all at the participating dental schools.

CONCLUSION

The results of the present survey revealed that the participating students perceived deficiencies in all domains of competencies. These results indicate that the assessed domains are still barely integrated into dental medicine curricula in Germany and that further research in this field is needed.

[How Congruent is the Rating of the Results of Flexor Tendon Injury Repairs Using the Scores by Buck-Gramcko, Strickland, and the American Society for Surgery of the Hand?]

PURPOSE

Scores are essential for comparing function after flexor tendon reconstructions. The Buck-Gramcko Score, the Strickland Score and the ASSH (American Society for Surgery of the Hand) Score are the most commonly applied rating systems. The purpose of this study is to evaluate these systems and their interchangeability.

METHOD

Based on an unrestricted metacarpophalangeal (MCP) joint of 0-0-90° or limited range of motion of the MCP joint of 0-30-90°, the scores of the 3 rating systems were assessed and graphically displayed for each possible finger position regarding proximal (PIP) and distal (DIP) interphalangeal joints.

RESULTS

Based on an unrestricted MCP joint, the scores of the 3 rating systems differed in 24-33% of the obtained values, depending on the sum of joint flexion and extension deficits of the aforementioned PIP and DIP joints. If the range of motion was restricted to 0-30-90° in the MCP joint, differing values were only observed in 16-19% of the obtained values. In extreme cases, scores for the same clinical presentation may thus be "excellent", "fair" or "poor", depending on which system has been used.

CONCLUSION

The different rating systems for the evaluation of flexor tendon reconstruction are neither identical nor adjustable. Therefore, consensus or at least a recommendation is needed regarding the system to be used. It may even be necessary to develop a generally accepted rating system to compare studies. In the meantime, the readings of the active and passive range of motion of all joints of the affected finger/thumb ought to be published in studies to compare and validate the results.

[Malformations of hand and forearm : Conspicuous postpartum]

Many congenital malformations of the hand and forearm, e. g. polydactyly, thumb duplication, syndactyly and radial aplasia, are already evident at birth and newborns are promptly referred to specialized departments. In contrast, orthopedic surgeons are often confronted with malformations of the hand and forearm, which gradually become clinically conspicuous during growth. This review article focuses on these specific malformations, which regularly upset the patients in practice and in most cases the parents even more so. In addition to the diagnostics and differential diagnostics, the conservative and surgical treatment options are presented.

[Proximal carpal row carpectomy]

OBJECTIVE

Resection of the proximal carpal row, termed proximal row carpectomy (PRC), is performed in order to treat pathologies of the proximal carpal row or radiocarpal joint between the scaphoid and scaphoid facet. It entails the articulation of the capitate and the lunate facet.

INDICATIONS

Lunate necrosis, carpal collapse, joint infection with concomitant intercarpal ligament lesions.

CONTRAINDICATIONS

Severe cartilage lesions of the lunate facet and the capitate, wrist capsule laxity, rheumatoid arthritis, neuromuscular dysbalance of the wrist-covering soft tissue structures.

SURGICAL TECHNIQUE

Dorsal approach to the wrist, incision of the third and fourth extensor compartments, resection and coagulation of the dorsal interosseous nerve, usage of a ligament-sparing capsule incision, identification of the proximal carpal row and inspection of cartilage of the lunate facet and capitate, mobilization and excision of the lunate, scaphoid and triquetrum, articulation of lunate facet and capitate is controlled clinically and fluoroscopically, wound closure, application of plaster slabs.

POSTOPERATIVE MANAGEMENT

Immobilization of the wrist on plaster slabs for 2 weeks, removal of sutures after 14 days.

RESULTS

PRC is a surgical procedure with few complications. Satisfactory range of motion and grip strength could be preserved without limiting function of the upper extremity. Postoperative osteoarthritis of capitate and lunate facet did not correlate with the good clinical outcome.

[Fractures of the proximal interphalangeal joint: Diagnostic and operative therapy options]

Joint fractures of the fingers often entail operative interventions in contrast to extra-articular fractures. These types of fracture are inclined to dislocate in addition to the actual fracture. The proximal interphalangeal (PIP) joint in particular often shows comminuted fractures due to the long leverage of the finger and a relatively small diameter of the joint. The clinical examination, X-ray diagnostics and if necessary computed tomography allow the classification into stable and unstable fractures. Unstable fractures must be treated by surgical reduction and fixation. A multitude of operative techniques are available for these mostly complicated fractures. The foremost goal is a stable osteosynthesis of the fracture with repositioning of the dislocation, which enables early physiotherapy in order to prevent tendon adhesion and contracture. This article presents the different types of PIP joint fractures, their specific surgical treatment and postoperative treatment regimens.

Numerical simulation of acoustofluidic manipulation by radiation forces and acoustic streaming for complex particles

The numerical prediction of acoustofluidic particle motion is of great help for the design, the analysis, and the physical understanding of acoustofluidic devices as it allows for a simple and direct comparison with experimental observations. However, such a numerical setup requires detailed modeling of the acoustofluidic device with all its components and thorough understanding of the acoustofluidic forces inducing the particle motion. In this work, we present a 3D trajectory simulation setup that covers the full spectrum, comprising a time-harmonic device model, an acoustic streaming model of the fluid cavity, a radiation force simulation, and the calculation of the hydrodynamic drag. In order to make quantitatively accurate predictions of the device vibration and the acoustic field, we include the viscous boundary layer damping. Using a semi-analytical method based on Nyborg's calculations, the boundary-driven acoustic streaming is derived directly from the device simulation and takes into account cavity wall vibrations which have often been neglected in the literature. The acoustic radiation forces and the hydrodynamic drag are calculated numerically to handle particles of arbitrary shape, structure, and size. In this way, complex 3D particle translation and rotation inside experimental microdevices can be predicted. We simulate the rotation of a microfiber in an amplitude-modulated 2D field and analyze the results with respect to experimental observations. For a quantitative verification, the motion of an alumina microdisk is compared to a simple experiment. Demonstrating the potential of the simulation setup, we compute the trajectory of a red blood cell inside a realistic microdevice under the simultaneous effects of acoustic streaming and radiation forces.

Acoustophoresis of disk-shaped microparticles: A numerical and experimental study of acoustic radiation forces and torques

Disk-shaped microparticles experience an acoustic radiation force and torque in an ultrasonic standing wave. Hence, they are translated by the acoustic field, an effect called acoustophoresis, and rotated. The torque effect is also known from the "Rayleigh disk" which is described in literature for sound intensity measurements. In this paper, inviscid numerical simulations of acoustic radiation forces and torques for disks with radius ≪ wavelength in water are developed in good agreement with former analytical solutions, and the dependence on disk geometry, density, and orientation is discussed. Experiments with alumina disks (diameter 7.5 μm), suspended in an aqueous liquid in a silicon microchannel, confirm the theoretical results qualitatively at the microscale and ultrasonic frequencies around 2 MHz. These results can potentially be applied for the synthesis of disk-reinforced composite materials. The insights are also relevant for the acoustic handling of various disk-shaped particles, such as red blood cells.

[Percutaneous needle aponeurotomy for Dupuytren's disease]

OBJECTIVE

Percutaneous transverse aponeurotomy of the cord by using a hypodermic needle as a scalpel blade in order to improve function of the hand.

INDICATIONS

Symptomatic flexion contracture with positive table top test caused by a single, palpable cord within the palm (primarily Tubiana stages I and II).

CONTRAINDICATIONS

Multiple, infiltrating or broad-based cords within the palm; irritated skin conditions; exclusive digital cord localization; recurrence after aponeurectomy; previous surgical intervention at the site of interest, digital nerve lesions; lack of patient compliance.

SURGICAL TECHNIQUE

Pinpoint surface anesthesia is obtained by injecting each portal area subdermally with 0.1 ml of local anesthetic. These applications start from distally to proximally within the palm while the most distal injection site is located proximal to the distal palm crease. Then the needle tip is introduced perpendicular to the cord. Sawing movements through the cord are performed transversely. While passively extending the contracted finger, the cord is held under tension which guarantees safe cutting. Patients are encouraged to report immediate pain sensation or numbness in order to prevent injuries to neurovascular structures and active finger flexion excludes tendon lesions during the procedure. Introducing the needle tip may be performed at several sites along the cord, if necessary, from distal to proximal at least 5 mm apart with prior pinpoint surface anesthesia. Finally, cautious passive stretching may be done after each release.

POSTOPERATIVE MANAGEMENT

Bandaging allowing immediate motion; application of a hand-based extension splint-glove during the night for 3-6 months.

RESULTS

Recurrence rate was 53% in 15 retrospectively examined patients after a mean interval of 40 months postoperatively.

[The Linburg-Comstock phenomenon: a review]

Simultaneous flexion of thumb and fingers is described as the Linburg-Comstock phenomenon. Congenital and acquired coupling of the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) tendons is the reason for this clinical entity. Additionally, coupling of the FPL and the flexor digitorum superficialis II or III has been described. The coupling can be between the muscles, the tendon sheaths or the tendons themselves. Asymptomatic and symptomatic coupling should be differentiated. In general symptomatic congenital or acquired coupling demands surgical intervention. We report about a 35-year-old patient with a congenital asymptomatic coupling of FPL and FDP-II who suffered a distorsion of the thumb. Afterwards she complained of pain and strength loss. An accessory tendon of 3 mm in diameter and 3.5 cm length between FPL and FDP-II was identified during surgery. The patient recovered completely after resection of this coupling.

[Symptomatic carpal coalition of scaphoid, trapezium and trapezoid with coexisting ipsilateral hypoplasia of the thumb]

We present the case of a 54-year-old woman with symptomatic coalition of scaphoid, trapezium and trapezoid as well as a coexisting ipsilateral hypoplasia of the thumb.

Modeling and optimization of acoustofluidic micro-devices

We investigate how the combination of numerical simulation tools and optimization routines can be used to design micro-devices. Experimental devices that are designed in this way can only provide optimal performance if the simulation model, used in the optimization procedure, reflects the real device characteristics accurately. Owing to this fact, the modeling of acoustofluidic devices is summarized. The mathematical formulation of the optimization problem, the parameterization of the device design and the implementation of the optimization loop is addressed alongside with practical recommendations for the chosen genetic algorithm optimization. In order to validate the implementation, an optimized planar resonator is compared with the optimal geometry given in the literature. The optimization of a typical 3D micro-device shows that devices can be designed to generate any desired acoustic mode shape at maximum pressure amplitude. The presented automatic design approach is of great practical relevance for the development of highly optimized micro-devices and it can speed up and facilitate the design-process in the growing field of acoustofluidics.

[Isolated capitate fractures in the frontal plane]

Isolated fractures of the capitate in the frontal plane are both very rare and most of the time very discreet. There is a great risk to miss such fractures with potential longterm consequences. The following report of two independent patients highlights the importance of computed tomography in order to verify fractures and initiate adequate treatment.

Gemcitabine and oxaliplatin with or without cetuximab in advanced biliary-tract cancer (BINGO): a randomised, open-label, non-comparative phase 2 trial

BACKGROUND

Gemcitabine plus a platinum-based agent (eg, cisplatin or oxaliplatin) is the standard of care for advanced biliary cancers. We investigated the addition of cetuximab to chemotherapy in patients with advanced biliary cancers.

METHODS

In this non-comparative, open-label, randomised phase 2 trial, we recruited patients with locally advanced (non-resectable) or metastatic cholangiocarcinoma, gallbladder carcinoma, or ampullary carcinoma and a WHO performance status of 0 or 1 from 18 hospitals across France and Germany. Eligible patients were randomly assigned (1:1) centrally with a minimisation procedure to first-line treatment with gemcitabine (1000 mg/m(2)) and oxaliplatin (100 mg/m(2)) with or without cetuximab (500 mg/m(2)), repeated every 2 weeks until disease progression or unacceptable toxicity. Randomisation was stratified by centre, primary site of disease, disease stage, and previous treatment with curative intent or adjuvant therapy. Investigators who assessed treatment response were not masked to group assignment. The primary endpoint was the proportion of patients who were progression-free at 4 months, analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00552149.

FINDINGS

Between Oct 10, 2007, and Dec 18, 2009, 76 patients were assigned to chemotherapy plus cetuximab and 74 to chemotherapy alone. 48 (63%; 95% CI 52-74) patients assigned to chemotherapy plus cetuximab and 40 (54%; 43-65) assigned to chemotherapy alone were progression-free at 4 months. Median progression-free survival was 6·1 months (95% CI 5·1-7·6) in the chemotherapy plus cetuximab group and 5·5 months (3·7-6·6) in the chemotherapy alone group. Median overall survival was 11·0 months (9·1-13·7) in the chemotherapy plus cetuximab group and 12·4 months (8·6-16·0) in the chemotherapy alone group. The most common grade 3-4 adverse events were peripheral neuropathy (in 18 [24%] of 76 patients who received chemotherapy plus cetuximab vs ten [15%] of 68 who received chemotherapy alone), neutropenia (17 [22%] vs 11 [16%]), and increased aminotransferase concentrations (17 [22%] vs ten [15%]). 70 serious adverse events were reported in 39 (51%) of 76 patients who received chemotherapy plus cetuximab (34 events in 19 [25%] patients were treatment-related), whereas 41 serious adverse events were reported in 25 (35%) of 71 patients who received chemotherapy alone (20 events in 12 [17%] patients were treatment-related). One patient died of atypical pneumonia related to treatment in the chemotherapy alone group.

INTERPRETATION

The addition of cetuximab to gemcitabine and oxaliplatin did not seem to enhance the activity of chemotherapy in patients with advanced biliary cancer, although it was well tolerated. Gemcitabine and platinum-based combination should remain the standard treatment option.

FUNDING

Institut National du Cancer, Merck Serono.

[Text mining, a method for computer-assisted analysis of scientific texts, demonstrated by an analysis of author networks]

Searching for relevant publications is becoming more difficult with the increasing number of scientific articles. Text mining as a specific form of computer-based data analysis may be helpful in this context. Highlighting relations between authors and finding relevant publications concerning a specific subject using text analysis programs are illustrated graphically by 2 performed examples.

[A 15-year-old adolescent presenting both Madelung deformity with Vickers' ligament and additional palmaris profundus muscle]

The palmaris profundus muscle is a rare entity which has been mentioned in association with nerve compressions. Madelung deformity is based both on an osteochondral lesion of the distal radial physis and often on the Vickers' ligament which originates around the lunate and inserts proximally in the radial physis. A 15-year-old right-handed female adolescent suffered from symptomatic left-sided Madelung deformity with Vickers' ligament and additional palmaris profundus muscle.

[Idiopathic palmar vein thrombosis of the fingers - rare but relevant]

Idiopathic thrombosis of palmar finger veins is rare and women suffer from it almost exclusively. Synovial cysts, epidermoid inclusion cysts, giant cell tumours and haemangiomatous lesions should be considered in the process of diagnosis. We present a 56-year-old woman with idiopathic and symptomatic thrombosis of palmar finger veins. Using the palmar approach the painful veins were identified and excised completely. An uncomplicated wound healing has followed with completely unrestricted and painless range of motion. Surgical excision of the finger vein thrombosis should be considered if there is continuing pain.

[Spontaneous fixation of MP-joint of the index finger in flexion]

Spontaneous fixations of MP-joints of fingers and thumbs are rare and are often a challenging task for hand surgeons. We present a 25-year-old female office employee with a fixed painless MP-joint of the left index finger in 90° flexion with normal PIP- und DIP-joint range of motion. Using the palmar approach to the MP-joint the entrapped accessory collateral ligament which was constrained by a prominent radial condylus could be identified. Operative removal of the prominence has released the joint. An uncomplicated wound healing has followed with completely unrestricted range of motion. If a closed reduction should be considered, it ought to be done cautiously without anaesthetics. A failed -reduction entails an operative revision using the palmar approach.

[Diagnostic value of preopratively performed MRI regarding lesions of the scapholunate ligament in clinical routine]

PURPOSE

The purpose of this retrospective study was to examine the sensitivity and specificity of preoperatively performed MRI of the wrist in identifying tears of the scapholunate ligament. Additionally, these findings were then compared with findings from a subsequently performed -arthroscopy of the wrist.

PATIENTS AND METHODS

The study was based on the MRI records of 401 patients who received MRI examinations between January 2004 and April 2012 in the context of ulnar-sided wrist pain. Subsequently, all patients received an arthroscopy of the wrist. The study included 218 male and 183 female patients with an average age of 42.4±14.3 years (range 12-84 years). The MRI examinations were conducted in various techniques and with various sequences. The MRI findings were evaluated by 88 experienced radiologists. The arthroscopies were performed by 16 experienced hand-surgeons who had seen the MRI results prior to the surgical intervention. -Arthroscopic findings were compared with MRI records and used as the benchmark.

RESULTS

Only 31 of 98 arthroscopically verified cases of a torn scapholunate ligament could be identified in an MRI examination. In contrast, MRI could correctly diagnose an intact ligament in 269 out of 276 arthroscopically verified cases. When compared with arthroscopy MRI sensitivity and specificity were 32% and 98%, respectively. In 91 out of 401 MRI examinations the use of a dedicated surface coil was recorded. In 66 out of 401 MRI examinations the use of contrast medium was documented. MRI specificity slightly improved upon use of contrast medium.

CONCLUSION

The comparison of MRI vs. arthroscopic sensitivity and specificity in the detection of scapholunate tears on a sufficiently large group of patients showed MRI to be a reliable method in excluding scapholunate ligament tears. Outside of clinical study conditions, however, it was found to be an unsuitable method in identifying and classifying scapholunate ligament tears. The high MRI sensitivity found by other studies could not be confirmed in our study.

Three-Month Evaluation of Vital Tooth Bleaching Using Light Units—A Randomized Clinical Study

The aim of this study was to evaluate the color stability of vital bleaching using a halogen unit, laser, or only chemical activation up to three months after treatment. A total of 60 patients were divided into three groups, and their teeth were bleached with 38% hydrogen peroxide using three methods: acceleration of the bleaching process with halogen (eight minutes), laser (30 seconds), or chemical activation only. All teeth were bleached a maximum of four times (4 × 15 minutes) until a change of six shade tabs took place. The color was evaluated both visually and with a spectrophotometer before bleaching, immediately after bleaching, and one and three months after bleaching. Directly after bleaching, the use of halogen showed better results than laser (p≤0.05). One and three months after bleaching, no significant difference was found between the tested methods relative to the shade change, independent of the method of shade evaluation (p&gt;0.05). As far as the color stability is concerned, bleaching with halogen resulted in stable color throughout the three months (p&gt;0.05), whereas the other two methods resulted in whiter teeth after one and three months compared with the color directly after bleaching (p≤0.05). Bleaching with laser needed more time than halogen for the desired shade change (p≤0.05). Although directly after treatment bleaching with halogen resulted in better results, one and three months after bleaching the kind of acceleration used in the bleaching process did not have any effect on the esthetic results.

Acoustofluidics 19: ultrasonic microrobotics in cavities: devices and numerical simulation

Acoustic radiation forces are increasingly used for the handling of micron sized particles (cells, functionalized beads, etc.) suspended in a fluid in the chamber of a manipulation device. The primary radiation forces arise as a nonlinear effect when an acoustic wave interacts with a particle. For specific robotic applications, precise control of the acoustic field in the cavity is important, which is excited, for example, by piezoelectric transducers attached to the device. Based on Gor'kov's potential the relevant forces on spherical particles can be computed. The field can be controlled by varying the excitation parameters: chamber and electrode configuration, as well as frequency, amplitude and phase of the excitation and their modulation. In the first part of the present tutorial, a number of examples are described: displacement and rotation of particles in micro machined chambers and macroscopic transport of particles in a larger chamber. In the second part, numerical tools (Finite Volume Method, COMSOL) are used to model the interaction of the acoustic field with a particle beyond a Gor'kov potential: viscosity, effects of walls near particles and acoustic radiation torque to rotate the particle. Excellent agreement between the various methods has been found.