Isolated Volar Radioulnar Joint Dislocation With Associated Ulnar Styloid Fracture.

Isolated volar dislocation of the distal radioulnar joint is a rare occurrence and is commonly missed. The mechanism of injury typically involves hypersupination. True lateral radiographs are difficult to obtain as patients are usually limited with wrist pronation and supination, resulting in a high miss rate. We describe a 32-year-old male who presented to the emergency department (ED) with pain and swelling of the posteromedial aspect of the right wrist after punching a wall one hour prior to presentation. Examination revealed soft tissue tenderness and mild edema at the right distal ulna with an associated deformity, best visualized at the volar aspect of the right wrist. Active range of motion was limited with right wrist flexion and extension, secondary to pain and edema. Right wrist supination and pronation strength and range of motion were limited due to the patient's tenderness on examination. Peripheral nerve function and vascular examination were normal. Initial radiographs of the right hand, wrist, and forearm did not reveal a fracture or dislocation. A musculoskeletal computed tomography (CT) scan of the right hand and wrist revealed an avulsion fracture of the ulnar styloid with volar displacement of the ulna. Analgesia was achieved with an ultrasound-guided ulnar nerve block, and the right wrist was successfully reduced. This report highlights the difficulty in obtaining a diagnosis of an isolated volar dislocation of the distal radioulnar joint. We recommend obtaining a musculoskeletal CT scan in the setting of an inconclusive radiograph and incongruent physical examination. Analgesia can also be achieved with an ulnar nerve block under ultrasound guidance.

Incidence of Emergency Department Visits for Electric Rental Scooters Using Detailed Ridership Data.

INTRODUCTION: Electric scooter (e-scooter) rental usage has increased exponentially around the country, expanding to more than 120 cities by the end of 2018. Early attempts to capture the safety effects of widespread adoption of this technology have been hampered by lack of accurate ridership data. Here we describe a 17-month evolution of ridership characteristics in St. Louis, Missouri, and the frequency of e-scooter rental-related injuries serious enough to require an emergency department (ED) visit over this time frame; we also provide estimates of incidence rates of injuries based on company ridership data. METHODS: We performed a combination retrospective chart review and prospective questionnaire-based analysis of adult e-scooter rental-related ED visits in both downtown St. Louis Level 1 trauma centers during the first 17 months of e-scooter rental usage (August 2018-December 2019). The retrospective portion focused on demographics, alcohol use, helmet use, disposition, operative repair, and temporal and severity markers. The prospective portion focused on more detailed crash and rider data. Finally, we used ridership data from both e-scooter rental companies in St. Louis to estimate incidence and temporal trends. RESULTS: A total of 221 patients had e-scooter rental-related ED visits. The median age of our population was 31 years with 58.8% male and 53.8% White. There were no deaths. Ninety-two patients were found to have fractures with 38% requiring surgery. Of the 21 patients diagnosed with head injury, five had an intracranial bleed. Overall incidence of ED visits related to e-scooters was 2.1 per 10,000 trips and 2.2 per 10,000 miles with the number of ED visits by month closely correlated with the number of rides per month (Pearson correlation coefficient = 0.95). CONCLUSION: The number of e-scooter rental-related injuries seen in St. Louis trauma centers was relatively low and correlated closely with overall number of rides. The number of injuries decreased and were less severe from 2018 to 2019 with infrequent intracranial injuries and a large percentage of fractures requiring operative repair.

Cardiovascular Histopathology of a 11-Year Old with Mucopolysaccharidosis VII Demonstrates Fibrosis, Macrophage Infiltration, and Arterial Luminal Stenosis.

Mucopolysaccharidosis type VII (MPS VII) is caused by ß-glucuronidase deficiency, resulting in lysosomal accumulation of glycosaminoglycans (GAGs) and multisystemic disease. We present cardiovascular gross and histopathology findings from a 11-year-old MPS VII male, who expired after developing ventricular fibrillation following anesthesia induction. Gross anatomic observations were made at autopsy; postmortem formalin-fixed paraffin-embedded samples of the carotid artery, aorta, myocardium, and valves were sectioned and stained with hematoxylin-eosin, Verhoeff-Van Gieson, CD68, and trichrome stains. Gross heart findings include an enlarged, dilated heart, mitral valve prolapse with thick, shortened chordae tendinae, and thickened aortic valve cusps. The aorta contained raised intimal plaques mimicking conventional atherosclerosis. Cardiac myocytes included hypertrophic nuclei, subendocardial fibrosis, and increased interfascicular collagen. Coronary lumens were 40-70% stenosed by fibrointimal hyperplasia containing storage material-laden cells, CD68+ macrophages, and fragmented elastin laminae. Similar findings were visualized in aortic intimal plaques. We confirm that arterial plaques, elastin fragmentation, and activated CD68+ macrophage infiltration occur in human MPS VII, consistent with previously observed findings in murine and canine MPS VII. We also confirm ultrasonographically observed carotid intimal-medial thickening is an in vivo correlate of histopathologic vascular fibrointimal hyperplasia. MPS VII patients should be regularly monitored for cardiac disease, with methods such as Holter monitors and stress testing; MPS VII-directed treatments should effectively address cardiovascular disease.

Shrink-induced single-cell plastic microwell array.

The ability to interrogate and track single cells over time in a high-throughput format would provide critical information for fundamental biological understanding of processes and for various applications, including drug screening and toxicology. We have developed an ultrarapid and simple method to create single-cell wells of controllable diameter and depth with commodity shrink-wrap film and tape. Using a programmable CO(2) laser, we cut hole arrays into the tape. The tape then serves as a shadow mask to selectively etch wells into commodity shrink-wrap film by O(2) plasma. When the shrink-wrap film retracts upon briefly heating, high-aspect plastic microwell arrays with diameters down to 20 µm are readily achieved. We calibrated the loading procedure with fluorescent microbeads. Finally, we demonstrate the utility of the wells by loading fluorescently labeled single human embryonic stem cells into the wells.

Shrink-film configurable multiscale wrinkles for functional alignment of human embryonic stem cells and their cardiac derivatives.

A biomimetic substrate for cell-culture is fabricated by plasma treatment of a prestressed thermoplastic shrink film to create tunable multiscaled alignment "wrinkles". Using this substrate, the functional alignment of human embryonic stem cell derived cardiomyocytes is demonstrated.

Sequential shrink photolithography for plastic microlens arrays.

Endeavoring to push the boundaries of microfabrication with shrinkable polymers, we have developed a sequential shrink photolithography process. We demonstrate the utility of this approach by rapidly fabricating plastic microlens arrays. First, we create a mask out of the children's toy Shrinky Dinks by simply printing dots using a standard desktop printer. Upon retraction of this pre-stressed thermoplastic sheet, the dots shrink to a fraction of their original size, which we then lithographically transfer onto photoresist-coated commodity shrink wrap film. This shrink film reduces in area by 95% when briefly heated, creating smooth convex photoresist bumps down to 30 µm. Taken together, this sequential shrink process provides a complete process to create microlenses, with an almost 99% reduction in area from the original pattern size. Finally, with a lithography molding step, we emboss these bumps into optical grade plastics such as cyclic olefin copolymer for functional microlens arrays.

Shrink-film microfluidic education modules: Complete devices within minutes.

As advances in microfluidics continue to make contributions to diagnostics and life sciences, broader awareness of this expanding field becomes necessary. By leveraging low-cost microfabrication techniques that require no capital equipment or infrastructure, simple, accessible, and effective educational modules can be made available for a broad range of educational needs from middle school demonstrations to college laboratory classes. These modules demonstrate key microfluidic concepts such as diffusion and separation as well as "laboratory on-chip" applications including chemical reactions and biological assays. These modules are intended to provide an interdisciplinary hands-on experience, including chip design, fabrication of functional devices, and experiments at the microscale. Consequently, students will be able to conceptualize physics at small scales, gain experience in computer-aided design and microfabrication, and perform experiments-all in the context of addressing real-world challenges by making their own lab-on-chip devices.

Unconventional low-cost fabrication and patterning techniques for point of care diagnostics.

The potential of rapid, quantitative, and sensitive diagnosis has led to many innovative 'lab on chip' technologies for point of care diagnostic applications. Because these chips must be designed within strict cost constraints to be widely deployable, recent research in this area has produced extremely novel non-conventional micro- and nano-fabrication innovations. These advances can be leveraged for other biological assays as well, including for custom assay development and academic prototyping. The technologies reviewed here leverage extremely low-cost substrates and easily adoptable ways to pattern both structural and biological materials at high resolution in unprecedented ways. These new approaches offer the promise of more rapid prototyping with less investment in capital equipment as well as greater flexibility in design. Though still in their infancy, these technologies hold potential to improve upon the resolution, sensitivity, flexibility, and cost-savings over more traditional approaches.

Shrink film patterning by craft cutter: complete plastic chips with high resolution/high-aspect ratio channel.

This paper presents a rapid, ultra-low-cost approach to fabricate microfluidic devices using a polyolefin shrink film and a digital craft cutter. The shrinking process (with a 95% reduction in area) results in relatively uniform and consistent microfluidic channels with smooth surfaces, vertical sidewalls, and high aspect ratio channels with lateral resolutions well beyond the tool used to cut them. The thermal bonding of the layers results in strongly bonded devices. Complex microfluidic designs are easily designed on the fly and protein assays are also readily integrated into the device. Full device characterization including channel consistency, optical properties, and bonding strength are assessed in this technical note.