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Background Reverse shoulder arthroplasty (RSA) is a valuable solution for patients with shoulder pain or injury primarily due to a rotator cuff tear or secondary to traumatic events. Nevertheless, several complications are known to appear, with the most frequent being scapular notching (SN) on the inferior and posterior scapular neck. Controversial data exist about the clinical relevance of SN. Since further consequences are still not clearly understood, we aimed to provide more clarity on which factors, especially external rotation (ER), contribute to the appearance and progress of notching. Methods Constant Score (CS), Subjective Shoulder Value (SSV), flexion, abduction, and ER were evaluated retrospectively in 153 shoulders of 147 patients (mean age 79±7.7 years; 62% women) who underwent RSA between 2005 and 2010. Anteroposterior radiographs were evaluated before and 1, 2, 3, and 5 years after RSA for SN according to the Sirveaux classification. The evaluation was performed by two independent surgeons. Spearman’s coefficient and t-test were used. Results CS, SSV, flexion, and abduction increased significantly 1 year after RSA compared to before (all p

This study was to determine face and construct validity of a new virtual reality-based shoulder arthroscopy simulator which uses passive haptic feedback.Fifty-one participants including 25 novices (20 shoulder arthroscopies) and 26 experts (100 shoulder arthroscopies) completed two tests: for assessment of face validity, a questionnaire was filled out concerning quality of simulated reality and training potential using a 7-point Likert scale (range 1-7). Construct validity was tested by comparing simulator metrics (operation time in seconds, camera and grasper pathway in centimetre and grasper openings) between novices and experts test results.Overall simulated reality was rated high with a median value of 5.5 (range 2.8-7) points. Training capacity scored a median value of 5.8 (range 3-7) points. Experts were significantly faster in the diagnostic test with a median of 91 (range 37-208) s than novices with 1177 (range 81-383) s (p 0.0001) and in the therapeutic test 102 (range 58-283) s versus 229 (range 114-399) s (p 0.0001). Similar results were seen in the other metric values except in the camera pathway in the therapeutic test.The tested simulator achieved high scores in terms of realism and training capability. It reliably discriminated between novices and experts. Further improvements of the simulator, especially in the field of therapeutic arthroscopy, might improve its value as training and assessment tool for shoulder arthroscopy skills.II.

Background Combined single-stage reverse total shoulder arthroplasty (RTSA) plus latissimus dorsi transfer (LDT) has been reported to be a reliable treatment for pseudoparalysis of elevation and external rotation caused by irreparable rotator cuff tears. Secondary LDT in patients with pseudoparalysis of external rotation after previous RTSA has not yet been studied. Methods Ten patients were treated with LDT at a mean of 27 months (range, 4-134 months) after RTSA. Standard LDT was performed in 4 patients and a LDT plus teres major transfer according to L'Episcopo in 6 patients. All patients had preoperative and postoperative clinical evaluation, including the assessment of the Constant score and the subjective shoulder value. Results RTSA increased the preoperative mean relative Constant score from 26% (range, 11%-67%) to 51% (range, 20%-100%; P = .05). At a mean of 49 months (range, 23-67 months) after additional LDT, the relative Constant score further increased to 58% (range, 34%-100%; P = .141), remaining significantly superior to the score before RTSA ( P = .021). The mean subjective shoulder value was 15% (range, 0%-30%) before and 44% (range, 20%-70%) after RTSA ( P = .273) and was 56% (range, 20%-90%) after LDT ( P = .686), a significant overall improvement of the state of the shoulder compared with before RTSA ( P = .042). Mean active flexion increased from 36° (range, 0°-130°) to 86° (range, 10°-140°) after RTSA ( P = .024) and to 109° (range,70°-140°) after LDT ( P = 0.017 compared with pre-LDT; P = .011 compared with pre-RTSA). Mean active external rotation decreased from 0° (range, –80° to 50)° to –18° (range, –50°to 10)° after RTSA ( P = .079) and was improved to 2° (–40° to 40)° after LDT ( P = .24 compared with pre-LDT; P =.865 compared with pre RTSA). Conclusion Secondary LDT significantly improves active mobility in patients with residual dysfunction after RTSA.

Accurate knowledge of the morphology of the human brain is required for minimally or non-invasive surgical interventions. On the (sub-)cellular level, brain tissue is generally characterized using optical microscopy, which allows extracting morphological features with a wide spectrum of staining procedures. The preparation of the histological slices, however, often leads to artifacts resulting in imperfect morphological data. In addition, the generation of 3D data is time-consuming. Therefore, we propose synchrotron radiation-based micro computed tomography (SRmicroCT) avoiding preparation artifacts and giving rise to the 3D morphology of features such as gray and white matter on the micrometer level. One can differentiate between white and gray matter without any staining procedure because of different X-ray absorption values. At the photon energy of 10keV, the white matter exhibits the absorption of 5.08 cm(-1), whereby the value for the gray matter corresponds to 5.25 cm(-1). The tomography data allow quantifying the local strains in the histological images using registration algorithms. The deformation of histological slices compared to the SRmicroCT in a 2D-2D registration leads to values of up to 6.3%. Mean deformation values for the Nissl-stained slices are determined to about 1%, whereas the myelin-stained slices yield slightly higher values than 2%.

Summary QUESTIONS UNDER STUDY: The A(H1N1)pdm09 influenza virus is a highly contagious pathogen which caused the 2009 influenza pandemic. The virus is known to affect mainly younger people and may be a problem in crowded living conditions. The aim of the study was to describe a major A(H1N1)pdm09 outbreak in a Swiss military boot camp and to develop suggestions for similar future situations. METHODS: Retrospective chart analysis of a A(H1N1)pdm09 outbreak between 14 December and 23 December 2010. Symptoms, signs and lab parameters were documented. RESULTS: 105 of 750 male recruits were affected by the outbreak. All nasopharyngeal swabs of 16 patients with high fever were tested positive. Common clinical symptoms included high fever, myalgia and bronchitis with persistent cough and throat aches. Fever progression typically occurred in two peaks within three days. Median length of stay at the infirmary was 3 days (range: 0.5–9 days). CONCLUSION: A(H1N1)pdm09 has become a ubiquitous seasonal virus in the region. Complications were uncommon and non life threatening. In the event of new influenza outbreaks, hygienic and containment measures must be quickly and correctly implemented, in order to avoid an epidemic. This should also be considered in non-military settings like school camps or in retirement homes.

Before investigating human brains post mortem, the first preparation step is often formalin fixation of the brain. As the brain consists of inhomogeneous tissues, the fixation leads to a three-dimensional strain field within the tissue. During the single case MR-based investigation of the brain, first, the starting point with the brain post mortem but still within the cranium, was examined. Then 13 MR data sets were acquired over a fixation period of 70 days and compared to the initial data set. Based on affine registration of the data sets, the global volume shrinkage was found to be 8.1%. By means of a non-rigid registration additional maximal local volume strains of 32% were determined.

Cancer belongs to the primary diseases these days. Although different successful treatments including surgery, chemical, pharmacological, and radiation therapies are established, the aggressive proliferation of cancerous cells and the related formation of blood vessels has to be better understood to develop more powerful strategies against the different kinds of cancer. Angiogenesis is one of the crucial steps for the survival and metastasis formation of malignant tumors. Although therapeutic strategies attempting to inhibit these processes are being developed, the biological regulation is still unclear. This study concentrates on the three-dimensional morphology of vessels formed in a mouse tumor xenograft model post mortem. Synchrotron radiation-based micro computed tomography (SRμCT) could provide the necessary information that is essential for validating the simulations. Using mouse and human brain tissue, the different approaches to extract the vessel tree from SRμCT data are discussed. These approaches include corrosion casting, the application of contrast agents such as barium sulfate, tissue embedding, all of them regarded as materials science based. Alternatively, phase contrast tomography was used, which gave rise to promising results but still not reaches the spatial resolution to uncover the smallest capillaries.

The microstructure of brain tissues becomes visible using different types of optical microscopy after the tissue sectioning. This preparation procedure introduces stress and strain in the anisotropic and inhomogeneous soft tissue slices, which are several 10 μm thick. Consequently, the three-dimensional dataset, generated out of the two-dimensional images with lateral submicrometer resolution, needs algorithms to correct the deformations, which can be significant for mellow tissue such as brain segments. The spatial resolution perpendicular to the slices is much worse with respect to the lateral sub-micrometer resolution. Therefore, we propose as complementary method the synchrotron-radiation-based micro computed tomography (SRμCT), which avoids any kind of preparation artifacts due to sectioning and histological processing and yields true micrometer resolution in the three orthogonal directions. The visualization of soft matter by the use of SRμCT, however, is often based on elaborate staining protocols, since the tissue exhibits (almost) the same x-ray absorption as the surrounding medium. Therefore, it is unexpected that human tissue from the pons and the medulla oblongata in phosphate buffer show several features such as the blood vessels and the inferior olivary nucleus without staining. The value of these tomograms lies especially in the precise non-rigid registration of the different sets of histological slices. Applications of this method to larger pieces of brain tissue, such as the human thalamus are planned in the context of stereotactic functional neurosurgery.