The effects of length and width of the stem on proximal humerus stress shielding in uncemented primary reverse total shoulder arthroplasty.

Introduction: To preserve humeral bone during RTSA, stems have been made shorter and cement avoided whenever possible. However, with the increased use of uncemented RTSA, a phenomenon comparable to the stress shielding of the hip has been described for the proximal humerus. The aim of this study was to investigate the influence of stem length and width on proximal humeral bone resorption after primary uncemented RTSA.

Blunt rupture of the biceps brachii muscle - The "parachute injury" in a wake surfer - A case report.

Case: A 40-year-old man fell while wake surfing and his left arm got tangled in the rope. This caused a closed complete rupture of the M. biceps brachii.

Iterative Metal Artifact Reduction in Head and Neck CT Facilitates Tumor Visualization of Oral and Oropharyngeal Cancer Obscured by Artifacts From Dental Hardware.

Rationale And Objectives: The purpose of this study was to evaluate the diagnostic utility of iterative metal artifact reduction (iMAR) in computed tomography (CT)-imaging of oral and oropharyngeal cancers when obscured by dental hardware artifacts and to determine the most appropriate iMAR settings for this purpose.

Materials And Methods: The study retrospectively enrolled 27 patients (8 female, 19 male; mean age 64±12.7years) with histologically confirmed oral or oropharyngeal cancer obscured by dental artifacts in contrast-enhanced CT.

Cemented vs. uncemented reverse total shoulder arthroplasty for the primary treatment of proximal humerus fractures in the elderly-a retrospective case-control study.

Background: Uncemented reverse total shoulder arthroplasty (RTSA) for the primary treatment of proximal humerus fractures (PHF) in elderly patients was introduced at our institution in 2017. Recent reports have raised concerns about increased rates of early bone resorption at the proximal humerus with uncemented fracture stems. The aim of this study was to find out whether there was any difference in functional or radiographic outcomes between cemented and uncemented RTSA for PHF.

Cellular Aspects of Muscle Specialization Demonstrate Genotype - Phenotype Interaction Effects in Athletes.

Introduction: Gene polymorphisms are associated with athletic phenotypes relying on maximal or continued power production and affect the specialization of skeletal muscle composition with endurance or strength training of untrained subjects. We tested whether prominent polymorphisms in genes for angiotensin converting enzyme (ACE), tenascin-C (TNC), and actinin-3 (ACTN3) are associated with the differentiation of cellular hallmarks of muscle metabolism and contraction in high level athletes.

Methods: Muscle biopsies were collected from of three distinct phenotypes; endurance athletes ( = 29), power athletes ( = 17), and untrained non-athletes ( = 63).

Pre-inflation from the multiverse: can it solve the quadrupole problem in the cosmic microwave background?

We analyze a quantized toy model of a universe undergoing eternal inflation using a quantum-field-theoretical formulation of the Wheeler-DeWitt equation. This so-called third quantization method leads to the picture that the eternally inflating universe is converted to a multiverse in which sub-universes are created and exhibit a distinctive phase in their evolution before reaching an asymptotic de Sitter phase. From the perspective of one of these sub-universes, we can thus analyze the pre-inflationary phase that arises naturally.

Advanced Modeled Iterative Reconstruction (ADMIRE) Facilitates Radiation Dose Reduction in Abdominal CT.

Rationale And Objectives: This study aimed to determine the potential degree of radiation dose reduction achievable using Advanced Modeled Iterative Reconstruction (ADMIRE) in abdominal computed tomography (CT) while maintaining image quality. Moreover, this study compared differences in image noise reduction of this iterative algorithm with radiation dose reduction.

Methods: Eleven consecutive patients scheduled for abdominal CT were scanned according to our institute's standard protocol (100 kV, 289 reference mAs).

Inter- and intra-operator reliability in patient-specific template positioning for total hip arthroplasty. A cadaver study.

Background: The implantation of the acetabular cup essentially determines the clinical outcome of total hip arthroplasty. To address this issue, the aim of this study was to build patient-specific instruments (PSIs) with various reference surfaces, followed by in vitro investigations to examine the inter- and intra-operator reliability as well as the overall precision of these patient-specific templates.

Methods: Seven human hemi-pelvis specimens were used for this study.

What if? Exploring the multiverse through Euclidean wormholes.

We present Euclidean wormhole solutions describing within the multiverse. The study is carried out in the framework of third quantisation. The matter content is modelled through a scalar field which supports the existence of a whole collection of universes.

Design considerations for a novel shape-memory-plate osteosynthesis allowing for non-invasive alteration of bending stiffness.

Biomechanical stimuli play a major role in fracture healing. Changing the fixation stiffness through the course of healing might accelerate bone healing and prevent healing complications. Shape memory alloy (SMA) based implants were developed to allow for non-invasive stiffness alteration during the fracture healing process.

Dose reduction potential of iterative reconstruction algorithms in neck CTA-a simulation study.

Objectives: This study aimed to determine the degree of radiation dose reduction in neck CT angiography (CTA) achievable with Sinogram-affirmed iterative reconstruction (SAFIRE) algorithms.

Methods: 10 consecutive patients scheduled for neck CTA were included in this study. CTA images of the external carotid arteries either were reconstructed with filtered back projection (FBP) at full radiation dose level or underwent simulated dose reduction by proprietary reconstruction software.

Implant impingement during internal rotation after reverse shoulder arthroplasty. The effect of implant configuration and scapula anatomy: A biomechanical study.

Background: Internal rotation after reverse shoulder arthroplasty is essential to perform fundamental daily living activities. The purpose of this study was to examine the impact of anatomical and implant related factors on impingement-free internal rotation of the glenohumeral joint.

Methods: CT-scans of 13 human shoulder specimens with implanted reverse shoulder prostheses were carried out and scapula neck length, lateral pillar angle, and implantation height of the metaglene were measured.

A Novel Pairwise Comparison-Based Method to Determine Radiation Dose Reduction Potentials of Iterative Reconstruction Algorithms, Exemplified Through Circle of Willis Computed Tomography Angiography.

Objectives: The aim of this study was to determine the dose reduction potential of iterative reconstruction (IR) algorithms in computed tomography angiography (CTA) of the circle of Willis using a novel method of evaluating the quality of radiation dose-reduced images.

Materials And Methods: This study relied on ReconCT, a proprietary reconstruction software that allows simulating CT scans acquired with reduced radiation dose based on the raw data of true scans. To evaluate the performance of ReconCT in this regard, a phantom study was performed to compare the image noise of true and simulated scans within simulated vessels of a head phantom.

Corrosion behavior, biocompatibility and biomechanical stability of a prototype magnesium-based biodegradable intramedullary nailing system.

Implants made of degradable magnesium alloys are a potential alternative to conventional orthopaedic implant materials, e.g. stainless steel or titanium.

Biomechanical evaluation of inferior scapula notching of reverse shoulder arthroplasty depending on implant configuration and scapula neck anatomy.

Purpose: The presence of inferior scapula notching is significantly affected by the anatomy the scapula and can be influenced by the glenosphere design and position and the onlay type.

Materials And Methods: A biomechanical study was undertaken with 13 human shoulder specimens in a robot-assisted shoulder simulator. Inferior scapula contact during adduction of the humerus was detected using a contact pressure film.

A nickel-titanium shape memory alloy plate for contactless inverse dynamization after internal fixation in a sheep tibia fracture model: A pilot study.

Background: Inverse dynamization has recently been proposed for the treatment of tibia non-unions. Nickel-titanium (NiTi) shape memory alloys (SMAs) may provide an opportunity for contactless non-invasive alteration of the stiffness of an implant after surgery.

Objective: The aim of this pilot study was to analyze the feasibility of the one way shape memory effect in a large animal as well as the feasibility of our ovine large animal fracture model.

A Novel Shape Memory Plate Osteosynthesis for Noninvasive Modulation of Fixation Stiffness in a Rabbit Tibia Osteotomy Model.

Unlabelled: Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME).

Hypotheses: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing.

Diaphragm Repair with a Novel Cross-Linked Collagen Biomaterial in a Growing Rabbit Model.

Background: Neonates with congenital diaphragmatic hernia and large defects often require patch closure. Acellular collagen matrices (ACM) have been suggested as an alternative to synthetic durable patches as they are remodeled by the host or could also be used for tissue engineering purposes.

Materials And Methods: 2.

Computed Tomography Angiography of Carotid Arteries and Vertebrobasilar System: A Simulation Study for Radiation Dose Reduction.

Computed tomography angiography (CTA) of carotid arteries and vertebrobasilar system is a standardized procedure with excellent image quality, but radiation exposure remains a matter of concern. The aim of this study is to examine to what extent radiation dose can be lowered in relation to a standard protocol by simulating examinations with lower tube currents applying a dedicated software.Lower tube current was simulated by a dedicated noise insertion and reconstruction software (ReconCT).

Automated tube voltage adaptation in head and neck computed tomography between 120 and 100 kV: effects on image quality and radiation dose.

Introduction: Low tube voltage allows for computed tomography (CT) imaging with increased iodine contrast at reduced radiation dose. We sought to evaluate the image quality and potential dose reduction using a combination of attenuation based tube current modulation (TCM) and automated tube voltage adaptation (TVA) between 100 and 120 kV in CT of the head and neck.

Methods: One hundred thirty consecutive patients with indication for head and neck CT were examined with a 128-slice system capable of TCM and TVA.

Whole body magnetic resonance angiography and computed tomography angiography in the vascular mapping of head and neck: an intraindividual comparison.

Introduction: The aim of the study was to compare the detectability of neck vessels with contrast enhanced magnetic resonance angiography (MRA) in the setting of a whole-body MRA and multislice computed tomography angiography (CTA) for preoperative vascular mapping of head and neck.

Methods: In 20 patients MRA was performed prior to microvascular reconstruction of the mandible with osteomyocutaneous flaps. CTA of the neck served as the method of reference.

MyCases-a portable application for radiologic case collections.

Radiologists come across interesting patient cases almost every day. This work proposes a novel case database server for quick and easy storage of such cases including whole image series, patient data, and annotations. Cases can be added to the database by saving DICOM images into a predefined directory on the local network.

Quantum gravitational contributions to the cosmic microwave background anisotropy spectrum.

We derive the primordial power spectrum of density fluctuations in the framework of quantum cosmology. For this purpose we perform a Born-Oppenheimer approximation to the Wheeler-DeWitt equation for an inflationary universe with a scalar field. In this way, we first recover the scale-invariant power spectrum that is found as an approximation in the simplest inflationary models.

Secondary reconstruction of posttraumatic enophthalmos: prefabricated implants vs titanium mesh.

Objective: To compare individually prefabricated computer-assisted designed/computer-assisted manufactured (CAD/CAM) glass-bioceramic implants with nonpreformed titanium meshes for orbital floor reconstruction in secondary correction of enophthalmos.

Methods: In a nonrandomized, comparative, prospective cohort study, 2 groups of 10 patients received secondary correction of enophthalmos with CAD/CAM implants in one group and titanium meshes in the other. Relative enophthalmometry and exophthalmometry data were assessed preoperatively, at the end of the operation, at day 90 postoperatively, and at day 365 postoperatively.

Validation of optical three-dimensional plagiocephalometry by computed tomography, direct measurement, and indirect measurements using thermoplastic bands.

The aim of the study was to validate optical three-dimensional surface imaging for plagiocephalometry by comparing it with established direct and indirect plagiocephalometric measurements. From head models with symmetric and asymmetric shapes, a number of distances were determined for plagiocephalometry. Data were acquired by optical three-dimensional surface imaging, direct and indirect measurements, and computed tomography.