[Total Elbow Replacement - Implantation of the Latitude Prosthesis (Tornier)]

Due to technical progress, the indication for total elbow arthroplasty could be expanded in recent years. As a result, the demand regarding functionality and mobility of the replaced joint has risen as well. Elbow arthroplasty has to be considered as technically demanding. Only with detailed knowledge of this surgical procedure and its possible intraoperative pitfalls can one provide the best possible results. In this instructional video we explain the implantation of the Latitude elbow prosthesis (Tornier) putting emphasis on the correct approach as well as implantation of the prosthesis and subsequent wound closure.

[The assessment of biological maturation for talent selection - which method can be used?]

BACKGROUND

The biological maturity status plays an important role in sports, since it influences the performance level and the talent selection in various types of sport. More mature athletes are favorably selected for regional and national squads. Therefore, the biological maturity status should be considered during the talent selection process. In this context, the relative age effect (RAE), which exists when the relative age quarter distribution of selected sports groups shows a biased distribution with an over-representation of athletes born in the first months after the specific cut-off-date for the competition categories, represents another problem in the talent development. From an ethical point of view, discrimination of young talented kids does exist: the relatively younger athletes have little to no chance of reaching the elite level, despite their talents and efforts. The causal mechanisms behind the RAE are still unclear and have to be assessed. In this context, the biological maturation seems to be a possible influential factor for the existence of a RAE in sport, which has to be examined. Several methods for estimating the biological maturity status exist; however, they are often expensive and not practicable. Consequently, the aim of the present study was to assess the concordance of a simple, yet accurate method of estimating biological maturation (prediction equation of age at peak height velocity, APHV) of Mirwald and co-workers, and the gold standard method of estimating skeletal age (SA, the x-ray of the left wrist).

METHODS

In total, 75 Austrian students (40♂, 35♀) aged 10 - 13 years, were examined. Thirty of the participants (17♂, 13♀) were students of a well-known Austrian ski boarding school, and 45 (23♂, 22♀) of a non-sportive secondary modern school of the same region. The participants included in the study had not experienced a rupture of the carpal bones of the left wrist. Parents and participants were informed of the study aims, requirements and risks before providing written informed consent. The study was performed according to the Declaration of Helsinki. The study was approved by the Board for Ethical Questions in Science (Nr.: 2/2014) and the Institutional Ethics Review Boards for Human Research. For the prediction equations, the body height, the body mass and the sitting height were examined 8. The actual CA at time of measurement, and the leg length as the difference between body height and sitting height were calculated. These parameters were used to predict MO as time before or after PHV for boys and girls using the prediction equations of Mirwald et al. 19. According to Malina and Koziel 8, the participants were classified as late, on time (average) or early maturing on the basis of their APHV relative to the sample mean and standard deviation separated by sex. Participants within plus/minus the standard deviation of the mean were considered on time; participants with APHV > mean + standard deviation were classified late, while those with APHV < mean - standard deviation were classified early. An expert in pediatric endocrinology evaluated the x-rays of the left-hand wrist with the Greulich-Pyle-Method for assessing SA, the most widely used method of determining SA 24. The difference between SA and CA were calculated (= difference SA-CA). Consistent with other studies, the participants were divided into three groups according to their maturity status: on time or average maturity status was a SA within ±1 year of CA, late maturating was a SA behind CA of more than 1 year, and early maturating was a SA in advance of CA of more than 1 year 5 19 25. The most accurate method used to compare two methods of measurement is the Bland-Altman plot and the 95 % limits of agreement 26 27 28. Bland-Altman plots of the difference between difference in APHV (from the literature mean) and difference SA-CA (y-axis) and the mean of difference in APHV and difference SA-CA (x-axis) were performed. Approximately 95 % of the points in the plot should lie within the limits; then the concordance between the two methods of measurement is given 28. Additionally, intraclass correlation coefficients (ICC(3,1); two-way-mixed, total agreement) were calculated between difference in APHV and difference SA-CA. Chi²-tests were used to assess the difference in the percentage of pupils classified as on time, early or late maturing between the classifications based on the SA and on APHV, respectively. The level of significance was set at p < 0.05 and for highly significant at p < 0.01. All of the calculations were performed using PASW Statistics V.21.0.

RESULTS

Chi²-tests did not show any significant differences (p = 0.404) in the percentage of participants classified as on time, early or late maturing between the two classifications based on SA and on APHV, respectively, neither for the total sample, nor for the two groups ski racers and non-athletes. The Bland-Altman analysis showed that more than 95 % of the points in the plot lie within the limits; consequently, there is concordance between the two methods with regard to estimating biological maturation. The ICC(3,1) statistics showed a highly significant correlation: p = 0.002, ICC (95 % CI) = 0.48 (0.13 - 0.69).

CONCLUSIONS

The prediction equations to determine APHV seem to be a valid method of assessing the biological maturity status of youths aged 10 - 13 years. The percentage of pupils classified as on time, early or late maturing did not differ significantly between the classifications based on the two methods. Also the Bland-Altman analysis proved the concordance between the two methods. The RAE could be influenced and strengthened by the biological age in sports in which advantages in maturity parameters are important. Athletes born early in the selection year, who are also at the same time advanced in maturity, might be advantaged in the selection process. However, since the prediction equations seem to be valid, this method can be used in the future in the talent selection process in order to not disadvantage late-maturing athletes, which in turn could result in the reduction of the occurrence of the RAE in various types of sports in the future. In talent selection processes the growth spurt and the implemented changes in proportions between core and the extremities are often not considered; although it was shown that during this period, athletes showed poor performances in physical fitness. Since physical fitness is an important criterion in talent selection processes, athletes who go through their individual peak growth spurt at the time of selection have disadvantages due to the diverse proportions. As a consequence, it seems important to know the athlete's APHV in order to consider the variations in physical performance caused by developmental changes. The prediction equations to determine APHV include the leg length and sitting height in order to consider the diverse proportions between core and extremities; hence, this method seems to be accurate and should be implemented in the talent selection process.

Characterization of spatial coherence of synchrotron radiation with non-redundant arrays of apertures

A method to characterize the spatial coherence of soft X-ray radiation from a single diffraction pattern is presented. The technique is based on scattering from non-redundant arrays (NRAs) of slits and records the degree of spatial coherence at several relative separations from 1 to 15 µm, simultaneously. Using NRAs the spatial coherence of the X-ray beam at the XUV X-ray beamline P04 of the PETRA III synchrotron storage ring was measured as a function of different beam parameters. To verify the results obtained with the NRAs, additional Young's double-pinhole experiments were conducted and showed good agreement.

[Limits to arthroscopic treatment of degenerative triangular fibrocartilage complex lesions depending on the ulnar variance]

PURPOSE

The present prospective study investigated the influence of the static ulnar variance on the success of arthroscopic debridement of degenerative TFCC lesions.

PATIENTS AND METHODS

10 patients with an ulnar positive variance ("Ulna+") and 12 patients with ulnar neutral or ulnar negative variance ("Ulna-/0") were examined preoperatively (U0), as well as at 2 (U2) and 6 (U6) months after arthroscopic debridement of degenerative TFCC lesions and compared with each other. After the U2 investigation due to persistent complaints in 9 of 10 patients with an ulnar positive variance there was a need for further surgery, consisting of ulnar shortening osteotomy (USO). The following parameters were recorded in each case: pain at rest and with load, the summed wrist range of motion - consisting of extension and flexion, radial and ulnar deviation, pronation and supination - compared to the contralateral side, the strength of the affected hand compared to the contralateral side, the Mayo modified wrist score (MMWS), the Krimmer score and the DASH score. Preoperatively there were no significant differences between the 2 cohorts "Ulna+" and "Ulna-/0" except for the characteristic "pain at rest".

RESULTS

At 2 months postoperatively (U2), the results in the cohort "Ulna+" remained at a significantly or tendentially poorer level compared to the cohort "Ulna-/0". The subsequent surgical treatment of the subgroup "Ulna+" with USO led to almost complete approximation of the results at 6 months postoperatively (U6). In addition to this, with time (U6) within each subgroup there were tendential or significant improvements of all characteristics compared to the preoperative situation (U0). At U6 four of 22 patients were -unable to work.

CONCLUSION

Degenerative lesions of the TFCC can be treated successfully by arthroscopic debridement in cases of ulnar negative and ulnar neutral variance. Patients with ulnar positive variance and persistent complaints after debridement of the TFCC can be treated successfully with a secondary ulnar shortening osteotomy.

Glicerina bruta no suplemento e seus efeitos nas características da carcaça e nos componentes do peso vivo de cordeiros lactentes

Objetivou-se avaliar o efeito da porcentagem de glicerina bruta em suplementos sobre as características da carcaça e os componentes do peso vivo de cordeiros lactentes mantidos em pasto de azevém. Foram utilizados 32 cordeiros lactentes, distribuídos nos tratamentos: 0, 10, 20 e 30% de glicerina bruta na matéria seca, em substituição ao milho, no suplemento isoproteico (18% de PB na matéria seca) fornecido diariamente em quantidade equivalente a 2% do peso corporal. As porcentagens de glicerina bruta tiveram efeito linear decrescente sobre peso de carcaça quente, peso de carcaça fria, rendimento de carcaça quente e rendimento de carcaça fria, enquanto as perdas pelo jejum aumentaram. O peso da paleta e o peso do costilhar diminuíram, enquanto a proporção de perna aumentou com o incremento de glicerina bruta no suplemento. Na composição tecidual da paleta, observou-se que a gordura subcutânea, a gordura intermuscular e a gordura total da paleta decresceram linearmente segundo as porcentagens de glicerina bruta. Sobre os componentes do peso vivo, observaram-se diferenças nas proporções de pele, rúmen, omaso, intestino grosso, que aumentaram, enquanto a de gordura renal diminuiu linearmente. Conclui-se que o uso de glicerina bruta em até 30% em suplemento fornecido em comedouro privativo para cordeiros lactentes mantidos em pasto de azevém interfere nas características da carcaça e nos componentes corporais.

Personal protective equipment, hygiene behaviours and occupational risk of illness after July 2011 flood in Copenhagen, Denmark

Incidence of various diseases can increase following a flood. We aimed to identify professionals in Copenhagen who became ill after contact with 2 July 2011 floodwater/sediment and determine risks and protective factors associated with illness. We conducted a cohort study of employees engaged in post-flood management activities. Participants completed a questionnaire collecting information about demographics, floodwater/sediment exposure, compliance with standard precautions, and symptoms of illness. Overall, 257 professionals participated, with 56 (22%) cases. Risk of illness was associated with not washing hands after floodwater/sediment contact [relative risk (RR) 2∙45], exposure to floodwater at work and home (RR 2∙35), smoking (RR 1∙92), direct contact with floodwater (RR 1∙86), and eating/drinking when in contact with floodwater (RR 1∙77). Professionals need to follow standard precautions when in contact with floodwater/sediment, especially proper hand hygiene after personal protective equipment use and before eating/drinking and smoking.

Breakdown of the x-ray resonant magnetic scattering signal during intense pulses of extreme ultraviolet free-electron-laser radiation

We present results of single-shot resonant magnetic scattering experiments of Co/Pt multilayer systems using 100 fs long ultraintense pulses from an extreme ultraviolet (XUV) free-electron laser. An x-ray-induced breakdown of the resonant magnetic scattering channel during the pulse duration is observed at fluences of 5  J/cm(2). Simultaneously, the speckle contrast of the high-fluence scattering pattern is significantly reduced. We performed simulations of the nonequilibrium evolution of the Co/Pt multilayer system during the XUV pulse duration. We find that the electronic state of the sample is strongly perturbed during the first few femtoseconds of exposure leading to an ultrafast quenching of the resonant magnetic scattering mechanism.

Invited article: Coherent imaging using seeded free-electron laser pulses with variable polarization: first results and research opportunities

FERMI@Elettra, the first vacuum ultraviolet and soft X-ray free-electron laser (FEL) using by default a "seeded" scheme, became operational in 2011 and has been opened to users since December 2012. The parameters of the seeded FERMI FEL pulses and, in particular, the superior control of emitted radiation in terms of spectral purity and stability meet the stringent requirements for single-shot and resonant coherent diffraction imaging (CDI) experiments. The advantages of the intense seeded FERMI pulses with variable polarization have been demonstrated with the first experiments performed using the multipurpose experimental station operated at the diffraction and projection imaging (DiProI) beamline. The results reported here were obtained with fixed non-periodic targets during the commissioning period in 2012 using 20-32 nm wavelength range. They demonstrate that the performance of the FERMI FEL source and the experimental station meets the requirements of CDI, holography, and resonant magnetic scattering in both multi- and single-shot modes. Moreover, we present the first magnetic scattering experiments employing the fully circularly polarized FERMI pulses. The ongoing developments aim at pushing the lateral resolution by using shorter wavelengths provided by double-stage cascaded FERMI FEL-2 and probing ultrafast dynamic processes using different pump-probe schemes, including jitter-free seed laser pump or FEL-pump∕FEL-probe with two color FEL pulses generated by the same electron bunch.

Calpain mediates caspase-dependent apoptosis initiated by hydrogen peroxide in pancreatic acinar AR42J cells

Several studies have shown that oxidative stress induces apoptosis in many cellular systems including pancreatic acinar cells. However, the exact molecular mechanisms leading to apoptosis remain partially understood. This study aimed to investigate the role of the cytosolic cysteine protease calpain in H2O2-induced apoptosis in pancreatic AR42J cells. Apoptosis was evaluated using flow cytometric analysis of sub-G1 DNA populations, electron-microscopic analysis, caspase-3-specific αII-spectrin breakdown, and measuring the proteolytic activities of the initiator caspase-12 and caspase-8, and the executioner caspase-3. H2O2 induced an increase in the calpain proteolytic activity immediately after starting the experiments that tended to return to a nearly normal level after 8 h and could be attributed to m-calpain. Whereas no caspase-12, caspase-8 and caspase-3 activations could be detected within the first 0.5 h, significantly increased proteolytic activities were observed after 8 h compared with the control. At the same time, the cells showed first ultrastructural hallmarks of apoptosis and a decreased viability. In addition, αII-spectrin fragmentation was identified using immunoblotting that could be attributed to both calpain and caspase-3. Calpain inhibition reduced the activities of caspase-12, caspase-8, and caspase-3 leading to a decrease in the number of apoptotic cells. Immunoblotting analyses of caspase-12 and caspase-8 indicate that calpain may be involved in the activation process of both proteases. The results suggest that H2O2-induced apoptosis of AR42J cells requires activation of m-calpain initiating the endoplasmic reticulum stress-induced caspase-12 pathway and a caspase-8-dependent pathway. The findings also suggest that calpain may be involved in the execution phase of apoptosis.

Nanoscale spin reversal by non-local angular momentum transfer following ultrafast laser excitation in ferrimagnetic GdFeCo

Ultrafast laser techniques have revealed extraordinary spin dynamics in magnetic materials that equilibrium descriptions of magnetism cannot explain. Particularly important for future applications is understanding non-equilibrium spin dynamics following laser excitation on the nanoscale, yet the limited spatial resolution of optical laser techniques has impeded such nanoscale studies. Here we present ultrafast diffraction experiments with an X-ray laser that probes the nanoscale spin dynamics following optical laser excitation in the ferrimagnetic alloy GdFeCo, which exhibits macroscopic all-optical switching. Our study reveals that GdFeCo displays nanoscale chemical and magnetic inhomogeneities that affect the spin dynamics. In particular, we observe Gd spin reversal in Gd-rich nanoregions within the first picosecond driven by the non-local transfer of angular momentum from larger adjacent Fe-rich nanoregions. These results suggest that a magnetic material's microstructure can be engineered to control transient laser-excited spins, potentially allowing faster (~ 1 ps) spin reversal than in present technologies.

Ultrafast optical demagnetization manipulates nanoscale spin structure in domain walls

During ultrafast demagnetization of a magnetically ordered solid, angular momentum has to be transferred between the spins, electrons, and phonons in the system on femto- and picosecond timescales. Although the intrinsic spin-transfer mechanisms are intensely debated, additional extrinsic mechanisms arising due to nanoscale heterogeneity have only recently entered the discussion. Here we use femtosecond X-ray pulses from a free-electron laser to study thin film samples with magnetic domain patterns. We observe an infrared-pump-induced change of the spin structure within the domain walls on the sub-picosecond timescale. This domain-topography-dependent contribution connects the intrinsic demagnetization process in each domain with spin-transport processes across the domain walls, demonstrating the importance of spin-dependent electron transport between differently magnetized regions as an ultrafast demagnetization channel. This pathway exists independent from structural inhomogeneities such as chemical interfaces, and gives rise to an ultrafast spatially varying response to optical pump pulses.

A verocytotoxin-producing E. coli outbreak with a surprisingly high risk of haemolytic uraemic syndrome, Denmark, September-October 2012

Denmark faced an outbreak of verocytotoxin-producing E. coli (VTEC) O157:H7 infections in autumn 2012. Thirteen cases were diagnosed of which eight had haemolytic uraemic syndrome (HUS). Epidemiological investigations suggested ground beef as the vehicle of the outbreak. The outbreak strain had a rare toxin gene subtype profile: eae, vtx1a and vtx2a, and a high proportion of HUS (62%) among cases, a finding previously linked with the outbreak subtype profile. Toxin subtyping can be useful to identify high risk VTEC strains.

Endstation for ultrafast magnetic scattering experiments at the free-electron laser in Hamburg

An endstation for pump-probe small-angle X-ray scattering (SAXS) experiments at the free-electron laser in Hamburg (FLASH) is presented. The endstation houses a solid-state absorber, optical incoupling for pump-probe experiments, time zero measurement, sample chamber, and detection unit. It can be used at all FLASH beamlines in the whole photon energy range offered by FLASH. The capabilities of the setup are demonstrated by showing the results of resonant magnetic SAXS measurements on cobalt-platinum multilayer samples grown on freestanding Si(3)N(4) membranes and pump-laser-induced grid structures in multilayer samples.

Accuracy of linear intraoral measurements using cone beam CT and multidetector CT: a tale of two CTs

OBJECTIVES

The aim was to compare the accuracy of linear bone measurements of cone beam CT (CBCT) with multidetector CT (MDCT) and validate intraoral soft-tissue measurements in CBCT.

METHODS

Comparable views of CBCT and MDCT were obtained from eight intact cadaveric heads. The anatomical positions of the gingival margin and the buccal alveolar bone ridge were determined. Image measurements (CBCT/MDCT) were performed upon multiplanar reformatted data sets and compared with the anatomical measurements; the number of non-assessable sites (NASs) was evaluated.

RESULTS

Radiological measurements were accurate with a mean difference from anatomical measurements of 0.14 mm (CBCT) and 0.23 mm (MDCT). These differences were statistically not significant, but the limits of agreement for bone measurements were broader in MDCT (-1.35 mm; 1.82 mm) than in CBCT (-0.93 mm; 1.21 mm). The limits of agreement for soft-tissue measurements in CBCT were smaller (-0.77 mm; 1.07 mm), indicating a slightly higher accuracy. More NASs occurred in MDCT (14.5%) than in CBCT (8.3%).

CONCLUSIONS

CBCT is slightly more reliable for linear measurements than MDCT and less affected by metal artefacts. CBCT accuracy of linear intraoral soft-tissue measurements is similar to the accuracy of bone measurements.