Biologics in Spine Fusion.

Achieving fusion in spine surgery can be challenging because of patient factors such as smoking and diabetes. The consequences of pseudarthrosis can be severe, including pain, instability, and additional surgery. Autologous iliac crest bone graft is the historical standard for augmenting spine fusion, providing high rates of fusion throughout the cervical, thoracic, and lumbar spine. Harvest of autologous iliac crest bone can be associated with comorbidities and this has led to development of alternative biologic materials to enhance spine fusion. Substitutes include various forms of allograft products including decellularized allograft; demineralized bone matrix; synthetic materials including bioactive glass; and autologous and allograft mesenchymal stem cells. Bone morphogenetic proteins can be efficacious for fusion but have significant risks and are not suitable for all spine procedures. There is a wide variety of utilization of biologics for spine fusion that are influenced by spinal region, surgeon preference, surgical training, health system formulary, and cost.

Injections for Knee Osteoarthritis: Corticosteroids, Viscosupplementation, Platelet-Rich Plasma, and Autologous Stem Cells.

This article reviews the benefits of corticosteroid, viscosupplementation, platelet-rich plasma, and autologous mesenchymal stem cell injections for the treatment of patients with knee osteoarthritis. Integrating injections into both clinical and surgical practices is complicated given existing health insurance reimbursement policies. This review describes the outcomes associated with these interventions and appropriate methods of navigating the existing reimbursement pathways to help providers implement these treatments into their practices.

Hyperglycemia enhances function and differentiation of adult rat cardiac fibroblasts.

Diabetes is an independent risk factor for cardiovascular disease that can eventually cause cardiomyopathy and heart failure. Cardiac fibroblasts (CF) are the critical mediators of physiological and pathological cardiac remodeling; however, the effects of hyperglycemia on cardiac fibroblast function and differentiation is not well known. Here, we performed a comprehensive investigation on the effects of hyperglycemia on cardiac fibroblasts and show that hyperglycemia enhances cardiac fibroblast function and differentiation. We found that high glucose treatment increased collagen I, III, and VI gene expression in rat adult cardiac fibroblasts. Interestingly, hyperglycemia increased CF migration and proliferation that is augmented by collagen I and III. Surprisingly, we found that short term hyperglycemia transiently inhibited ERK1/2 activation but increased AKT phosphorylation. Finally, high glucose treatment increased spontaneous differentiation of cardiac fibroblasts to myofibroblasts with increasing passage compared with low glucose. Taken together, these findings suggest that hyperglycemia induces cardiac fibrosis by modulating collagen expression, migration, proliferation, and differentiation of cardiac fibroblasts.

Connecting Molecular Exchange Dynamics to Stress Relaxation in Phase-Separated Dynamic Covalent Networks.

A suite of phase separated dynamic covalent networks based on highly tunable dynamic benzalcyanoacetate (BCA) thia-Michael acceptors are investigated. In situ kinetic studies on small molecule model systems are used in conjunction with macroscopic characterization of phase stability and stress relaxation to understand how the molecular dynamics relate to relaxation modes. Electronic modification of the BCA unit strongly impacts the exchange dynamics (particularly the rate of dissociation) and the overall equilibrium constant (Keq) of the system, with electron-withdrawing groups leading to decreased dissociation rate and increased Keq. Critically, below a chemistry-defined temperature cutoff (related to the stability of the hard phase domains), the stress relaxation behavior of these phase separated materials is dominated by the molecular exchange dynamics, allowing for networks with a tailored thermomechanical response.

Engineering Lipophilic Aggregation of Adapalene and Adamantane-Based Cocrystals via van der Waals Forces and Hydrogen Bonding.

Lipophilic aggregation using adamantanes is a widely exploited molecular property in medicinal and materials chemistry. Adamantanes are traditionally installed to molecular units via covalent bonds. However, the noncovalent installation of adamantanes has been relatively underexplored and presents the potential to bring properties associated with adamantanes to molecules without affecting their intrinsic properties (e.g., pharmacophores). Here, we systematically study a series of adamantanecarboxylic acids with varying substitution levels of methyl groups and their cocrystals with bipyridines. Specifically, single-crystal X-ray diffraction shows that while the directionality of single-component adamantanes is notably sensitive to changes in methyl substitution, hydrogen-bonded cocrystals with bipyridines show consistent and robust packing due to π-stacking predominance. Our observations are supported by Hirshfeld surface and energy framework analyses. The applicability of cocrystal formation of adamantanes bearing carboxylic acids was used to generate the first cocrystals of adapalene, an adamantane-bearing retinoid used for treating acne vulgaris. We envisage our study to inspire noncovalent (i.e., cocrystal) installation of adamantanes to generate lipophilic aggregation in multicomponent systems.

The autonomic effects of cardiopulmonary decompression sickness in swine using principal dynamic mode analysis.

Methods to predict onset of cardiopulmonary (CP) decompression sickness (DCS) would be of great benefit to clinicians caring for stricken divers. Principal dynamic mode (PDM) analysis of the electrocardiogram has been shown to provide accurate separation of the sympathetic and parasympathetic tone dynamics. Nine swine (Sus scrofa) underwent a 15-h saturation dive at 184 kPa (60 ft. of saltwater) in a hyperbaric chamber followed by dropout decompression, whereas six swine, used as a control, underwent a 15-h saturation dive at 15 kPa (5 ft. of saltwater). Noninvasive electrocardiograms were recorded throughout the experiment and autonomic nervous system dynamics were evaluated by heart rate series analysis using power spectral density (PSD) and PDM methods. We observed a significant increase in the sympathetic and parasympathetic tones using the PDM method on average 20 min before DCS onset following a sudden induction of decompression. Parasympathetic activities remained elevated, but the sympathetic modulation was significantly reduced at onset of cutis and CP DCS signs, as reported by a trained observer. Similar nonsignificant observations occurred during PSD analysis. PDM observations contrast with previous work showing that neurological DCS resulted in a >50% reduction in both sympathetic and parasympathetic tone. Therefore, tracking dynamics of the parasympathetic tones via the PDM method may allow discrimination between CP DCS and neurological DCS, and this significant increase in parasympathetic tone has potential use as a marker for early diagnosis of CP DCS.

Interrupted oxygen pre-breathing and decompression outcomes in swine.

BACKGROUND: Rescue from a disabled submarine may result in substantial risk for severe decompression sickness (DCS) among survivors. Oxygen prebreathe (OPB) before rapid decompression has been shown to significantly reduce risk or delay onset for severe DCS in animals. However, the duration of this benefit remains unknown and might even be lost if a delay between the prebreathe period to initiation of recompression therapy allows for nitrogen reaccumulation. METHODS: We hypothesized that the benefit of OPB would be lost following subsequent periods of air interruption in a 70-kg swine saturation model. Following OPB of 45 or 60 min with varying periods (30, 45, 60 min) of air interruption, 61 swine exposed to 2.7 ATA for 22 h were rapidly decompressed. Swine without OPB served as negative controls and swine treated with 45 min of OPB without air interruption served as positive controls. RESULTS: Comparing experimental groups for Type II DCS incidence showed OPB120/60 being the only experimental group (11%) statistically different than the negative control group OPB0 (80%). Log rank tests comparing Type II DCS free survival only showed statistically significant differences for OPB45/60 compared to positive control group OPB45, while, more importantly, demonstrating a significant difference for OPB120/60 compared to that approximated for OPB45, indicating a significant reversal of the air interruption effects with longer OPB on Type II DCS disease free survival. DISCUSSION: Based on these findings we concluded that the protective effects of OPB against severe DCS are reduced with increasing periods of air interruption.

Online Virtual Patient Cases vs. Weekly Classroom Lectures in an Internal Medicine Clerkship: Effects on Military Learner Outcomes.

INTRODUCTION: Virtual patient cases (VPCs), a type of simulated, interactive electronic learning, are a potentially important tool for military health care providers in austere or pandemic settings to maintain skills but need more validation. Our military internal medicine clerkship is spread across military treatment facilities around the country and has 15 weekly live student lectures, but students randomly miss the first, second, or third 5 weeks due to their psychiatry clerkship. We hypothesized that VPCs would be an adequate replacement for lost lectures. MATERIALS AND METHODS: We compared live lectures to a web-based VPC and analyzed the academic outcomes of 734 students from 2015 to 2022. RESULTS: Using our end-of-clerkship Script Concordance Test (SCT) as the primary outcome, there was no significant difference in performance between the 2 learning methods (VPC, 63.9% correct; lectures 63.2%, P = .27). After controlling for gender, baseline knowledge, and the total number of VPCs completed, there was still not a statistically significant difference between teaching methods (F(1,728) = 0.52, P = .47). There was also no significant differences in all other clerkship outcomes including National Board of Medical Examiner and Objective Structured Clinical Examination scores. CONCLUSION: VPCs appear noninferior at teaching clinical reasoning as measured by SCT. VPCs might be substituted for traditional, live lectures in clerkships when time or other resources are limited, in austere environments such as military deployments, or during conditions limiting interpersonal contact such as pandemics but are not a complete substitution for in-person learning.

A geopositioned and evidence-graded pan-species compendium of Mayaro virus occurrence.

Mayaro Virus (MAYV) is an emerging health threat in the Americas that can cause febrile illness as well as debilitating arthralgia or arthritis. To better understand the geographic distribution of MAYV risk, we developed a georeferenced database of MAYV occurrence based on peer-reviewed literature and unpublished reports. Here we present this compendium, which includes both point and polygon locations linked to occurrence data documented from its discovery in 1954 until 2022. We describe all methods used to develop the database including data collection, georeferencing, management and quality-control. We also describe a customized grading system used to assess the quality of each study included in our review. The result is a comprehensive, evidence-graded database of confirmed MAYV occurrence in humans, non-human animals, and arthropods to-date, containing 262 geo-positioned occurrences in total. This database - which can be updated over time - may be useful for local spill-over risk assessment, epidemiological modelling to understand key transmission dynamics and drivers of MAYV spread, as well as identification of major surveillance gaps.

Diversity and clinical impact of Acinetobacter baumannii colonization and infection at a military medical center.

The epidemiology of Acinetobacter baumannii emerging in combat casualties is poorly understood. We analyzed 65 (54 nonreplicate) Acinetobacter isolates from 48 patients (46 hospitalized and 2 outpatient trainees entering the military) from October 2004 to October 2005 for genotypic similarities, time-space relatedness, and antibiotic susceptibility. Clinical and surveillance cultures were compared by amplified fragment length polymorphism (AFLP) genomic fingerprinting to each other and to strains of a reference database. Antibiotic susceptibility was determined, and multiplex PCR was performed for OXA-23-like, -24-like, -51-like, and -58-like carbapenemases. Records were reviewed for overlapping hospital stays of the most frequent genotypes, and risk ratios were calculated for any association of genotype with severity of Acute Physiology and Chronic Health Evaluation II (APACHE II) score or injury severity score (ISS) and previous antibiotic use. Nineteen genotypes were identified; two predominated, one consistent with an emerging novel international clone and the other unique to our database. Both predominant genotypes were carbapenem resistant, were present at another hospital before patients' admission to our facility, and were associated with higher APACHE II scores, higher ISSs, and previous carbapenem antibiotics in comparison with other genotypes. One predominated in wound and respiratory isolates, and the other predominated in wound and skin surveillance samples. Several other genotypes were identified as European clones I to III. Acinetobacter genotypes from recruits upon entry to the military, unlike those in hospitalized patients, did not include carbapenem-resistant genotypes. Acinetobacter species isolated from battlefield casualties are diverse, including genotypes belonging to European clones I to III. Two carbapenem-resistant genotypes were epidemic, one of which appeared to belong to a novel international clone.

Prevention of infections associated with combat-related eye, maxillofacial, and neck injuries.

The percentage of combat wounds involving the eyes, maxillofacial, and neck regions reported in the literature is increasing, representing 36% of all combat-related injuries at the start of the Iraq War. Recent meta-analysis of 21st century eye, maxillofacial, and neck injuries described combat injury incidences of 8% to 20% for the face, 2% to 11% for the neck, and 0.5% to 13% for the eye and periocular structures. This article reviews recent data from military and civilian studies to support evidence-based recommendations for the prevention of infections associated with combat-related eye, maxillofacial, and neck injuries. The major emphasis of this review is on recent developments in surgical practice as new antimicrobial studies were not performed. Further studies of bacterial infection epidemiology and postinjury antimicrobial use in combat-related injuries to the eyes, maxillofacial, and neck region are needed to improve evidence-based medicine recommendations. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections associated with Combat-related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Executive summary: Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society.

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society.

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications, and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

A descriptive analysis of dengue in Peace Corps Volunteers, 2000-2019.

BACKGROUND: Peace Corps Volunteers (PCVs) are a unique expatriate population at risk for dengue. Previous studies examined travelers or lacked demographic information about expatriates. We examined dengue incidence among PCVs before and after deployment of an electronic medical record (EMR) to assess temporal and demographic factors. METHODS: Dengue cases within Peace Corps' Epidemiologic Surveillance System from 2000 to 2019 were identified using a standard case definition, and two timeframes were compared: pre-EMR 2000-2015 and post-EMR 2016-2019. RESULTS: Annual infections occurred in a roughly 3-year cyclic pattern from 2007 to 2019. Incidence rate decreased from 1.35 cases per 100 dengue Volunteer-years (95% CI 1.28-1.41) in 2000-2015 to 1.25 cases (95% CI 1.10-1.41) in 2016-2019. Among PCVs who served from 2016 to 2019, the majority of infections occurred in females and 20-29 year olds, and 7% were medically evacuated. Among PCVs who served from 2015 to 2019, 21% were hospitalized in-country. CONCLUSIONS: Among PCVs, a non-significant decrease in dengue incidence occurred from 2000-2015 to 2016-2019. Annual infection rates peaked every three years, offering opportunities for targeted prevention efforts. Dengue infection in PCVs appears to mimic the overall demographic of Peace Corps. Expatriates like PCVs are at an increased risk for dengue infection compared to short-term travelers.

Dengue Virus Infections among Peace Corps Volunteers in Timor-Leste, 2018-2019.

Dengue is an ongoing health risk for Peace Corps Volunteers (PCVs) working in the tropics. On May 2019, the Peace Corps Office of Health Services notified the Centers for Disease Control and Prevention (CDC) of a dengue outbreak among PCVs in Timor-Leste. The purpose of this investigation was to identify the clinical, demographic, and epidemiological characteristics of PCVs with dengue and recommend dengue preventive measures. To identify PCVs with dengue and describe disease severity, the medical records of PCVs reporting fever during September 2018-June 2019 were reviewed. To identify factors associated with dengue virus (DENV) infection, we administered a questionnaire on demographics, travel history, and mosquito avoidance behaviors and collected blood specimens to detect the anti-DENV IgM antibody to diagnose recent infection. Of 35 PCVs in-country, 11 (31%) tested positive for dengue (NS1, IgM, PCR), eight requiring hospitalization and medical evacuation. Among 27 (77%) PCVs who participated in the investigation, all reported having been recently bitten by mosquitoes and 56% reported being bitten most often at home; only 16 (59%) reported having screens on bedroom windows. Nearly all (93%) PCVs reported using a bed net every night; fewer (70%) reported using mosquito repellent at least once a day. No behaviors were significantly associated with DENV infection. Raising awareness of dengue risk among PCVs and continuing to encourage mosquito avoidance behavior to prevent dengue is critical. Access to and use of measures to avoid mosquito bites should be improved or implemented. Peace Corps medical officers should continue to receive an annual refresher training on dengue clinical management.

Oxygen breathing accelerates decompression from saturation at 40 msw in 70-kg swine.

INTRODUCTION: Submarine disaster survivors can be transferred from a disabled submarine at a pressure of 40 meters of seawater (msw) to a new rescue vehicle; however, they face an inherently risky surface interval before recompression and an enormous decompression obligation due to a high likelihood of saturation. The goal was to design a safe decompression protocol using oxygen breathing and a trial-and-error methodology. We hypothesized that depth, timing, and duration of oxygen breathing during decompression from saturation play a role to mitigate decompression outcomes. METHODS: Yorkshire swine (67-75 kg), compressed to 40 msw for 22 h, underwent one of three accelerated decompression profiles: (1) 13.3 h staged air decompression to 18 msw, followed by 1 h oxygen breathing, then dropout; (2) direct decompression to 18 msw followed by 1 h oxygen breathing then dropout; and (3) 1 h oxygen prebreathe at 40 msw followed by 1 h mixed gas breathing at 26 msw, 1 h oxygen breathing at 18 msw, and 1 h ascent breathing oxygen. Animals underwent 2-h observation for signs of DCS. RESULTS: Profile 1 (14.3 h total) resulted in no deaths, no Type II DCS, and 20% Type I DCS. Profile 2 (2.1 h total) resulted in 13% death, 50% Type II DCS, and 75% Type I DCS. Profile 3 (4.5 h total) resulted in 14% death, 21% Type II DCS, and 57% Type I DCS. No oxygen associated seizures occurred. DISCUSSION: Profile 1 performed best, shortening decompression with no death or severe DCS, yet it may still exceed emergency operational utility in an actual submarine rescue.

Tibial Intramedullary Nail From a Suprapatellar Approach in a Semi-Extended Position.

An intramedullary nail is a common and reliable treatment option for diaphyseal tibial fractures. One such approach for this technique is suprapatellar. This video shows the surgical technique of a tibial nail through a suprapatellar approach in a semi-extended position in a 22-year-old man with a distal third tibial shaft fracture.

The Production of Antibiotic Cement Beads.

The use of antibiotic beads in open fracture cases can lead to decreased rates of infection and surgeon production is associated with significant time and cost savings. This video demonstrates production of antibiotic impregnated polymethylmethacrylate beads used in the setting of a grade IIIB open tibial shaft fracture.

Psychosis following mycoplasma pneumonia.

Extrapulmonary manifestations of Mycoplasma pneumoniae are well described, including a subset of central nervous system (CNS)-associated syndromes. In pediatric populations, frequencies of CNS sequelae occur in 0.1% to 7% of patients. Neurologic illness associated with M. pneumoniae, such as meningitis, encephalitis, polyradiculitis, Guillain-Barre, and stroke have been reported; however, the incidence of M. pneumoniae-associated organic brain syndrome is rare. We present the case of a 20-year-old midshipman with acute psychosis following resolution of M. pneumoniae pneumonia and review 6 other adult cases found in the literature. M. pneumoniae remains one of the most common causes of respiratory illnesses in the military recruit setting and therefore should always be suspected as an organic cause of mental status changes in young persons such as recruits, cadets, and midshipmen particularly with antecedent respiratory illnesses.

Radial Head Replacement Through a Kocher Approach.

PURPOSE: Radial head fractures are some of the most common elbow fractures. Fractures with 3 or more fracture fragments have been shown to have worse outcomes when treated with open reduction and internal fixation (ORIF). Radial head replacement offers an alternative treatment for those more comminuted radial head fractures. METHODS: Three-part radial head fractures make anatomical reduction more difficult to obtain with ORIF. Radial head fractures requiring replacement have shown good clinical outcomes. As a result, radial head arthroplasty offers a good treatment option for 3-or-more-part radial head fractures. RESULTS: This video presents a case of a radial head arthroplasty for a 3-part radial head fracture in a 23-year-old man. The radial head implant provides a smooth and concentric surface for articulation with the capitellum while providing stability to the elbow. CONCLUSIONS: Radial head replacement provides a good alternative to ORIF, producing similar elbow range of motion and providing good stability compared with the contralateral elbow.