Low-Energy Pelvic Ring Fractures in the Elderly Population: Expected Outcomes and Associated Mortality Rates.

BACKGROUND: The aim of the study was to uncover mortality risk utilizing a retrospective review at a level I trauma center in addition to demographic factors. METHODS: Patients aged 65 and older with low-energy closed pelvic ring fractures treated non-operatively from 2007 to 2017 were queried from the level I trauma center database. Mortality rate and associated risks were calculated. RESULTS: The average age of all the patients included in this study who sustained a low-energy pelvic fracture was 83.1 years (± 7.5; 66 - 97). The mean length of stay was 4.6 days (± 4.4; 0 - 37). The mean number of comorbidities was 2.2. The 1-year mortality rate was 23%. The relative risk (RR) of 1-year mortality for low-energy pelvic fractures for ages 65+ did not statistically differ compared to the US population in 2016 (6.6%) (RR: 1.0; 95% CI). The 2+ comorbidities showed a statistical significance in the pelvic fracture population with a P value of 0.037. Race, sex, discharge disposition and length of stay did not reach statistical significance (P > 0.05). CONCLUSION: Low-energy pelvic injuries do not appear to increase rate of mortality compared to the US population. Fracture pattern, race, sex, discharge disposition and length of stay do not seem to have an effect on mortality. Elderly patients with an average age of 84.5 years and more than two comorbidities had higher rates of mortality; however, these patients were likely to sustain earlier mortality regardless of low-energy pelvic fracture.

Conceptual Framework for Assessing Ecosystem Health.

Over the past century, the environment of the Gulf of Mexico has been significantly altered and impaired by extensive human activities. A national commitment to restore the Gulf was finally initiated in response to the unprecedented Deepwater Horizon oil spill in 2010. Consequently, there is a critical need for an assessment framework and associated set of indicators that can characterize the health and sustainability of an ecosystem having the scale and complexity of the Gulf. The assessment framework presented here was developed as an integration of previous ecological risk- and environmental management-based frameworks for assessing ecosystem health. It was designed to identify the natural and anthropogenic drivers, pressures, and stressors impinging on ecosystems and ecosystem services, and the ecological conditions that result, manifested as effects on valued ecosystem components. Four types of societal and ecological responses are identified: reduction of pressures and stressors, remediation of existing stressors, active ecosystem restoration, and natural ecological recovery. From this conceptual framework are derived the specific indicators to characterize ecological condition and progress toward achieving defined ecological health and sustainability goals. Additionally, the framework incorporates a hierarchical structure to communicate results to a diversity of audiences, from research scientists to environmental managers and decision makers, with the level of detail or aggregation appropriate for each targeted audience. Two proof-of-concept studies were conducted to test this integrated assessment and decision framework, a prototype Texas Coastal Ecosystems Report Card, and a pilot study on enhancing rookery islands in the Mission-Aransas Reserve, Texas, USA. This Drivers-Pressures-Stressors-Condition-Responses (DPSCR4 ) conceptual framework is a comprehensive conceptual model of the coupled human-ecological system. Much like its predecessor, the ecological risk assessment framework, the DPSCR4 conceptual framework can be tailored to different scales of complexity, different ecosystem types with different stress regimes, and different environmental settings. Integr Environ Assess Manag 2019;15:544-564. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Distal Radius Skyline View: How to Prevent Dorsal Cortical Penetration.

Volar locked plating has become a standard treatment for operative stabilization of distal radius fractures. It is assumed that volar plating portends a low risk of extensor tendon irritation and rupture, especially when compared with dorsal plating constructs; however, extensor tendon tenosynovitis and rupture is a well-described complication after volar plating of the distal radius. Dorsal cortical penetration of screws may go unnoticed with traditional intraoperative fluoroscopic techniques and may contribute to extensor tendon irritation. This article presents the authors' experience with an additional fluoroscopic dorsal tangential radiograph helping the surgeon ascertain dorsal screw prominence following volar plate fixation. (Journal of Surgical Orthopaedic Advances.

Optimal Management of High-Energy Pilon Fractures.

The ideal treatment method for fibular fractures associated with high-energy pilon injuries remains unknown. In this investigation, the authors reviewed a consecutive series of 137 patients who sustained high-energy pilon injuries and assessed the effect of fibular fixation and timing on radiographic and clinical outcomes. At a mean follow-up of 18.7 months, the authors found that the presence or lack of fibular fixation did not have an effect on the timing or rate of union of the pilon fractures; similarly, there was no significant difference between these groups regarding the presence or development of coronal or sagittal malalignment intraoperatively or at final follow-up. Fibular union rates were also not significantly different between groups, but fibular fixation increased operative time in a statistically significant manner. Interestingly, when comparing fibular fixation during the temporization stage vs the definitive fixation stage, the authors found that early fixation of the fibular fracture also had no effect on alignment, healing, or complication rates. Fixation of the fibula during external fixation placement statistically increased operative time during temporization but did not significantly decrease operative time during definitive stabilization. The authors cannot recommend fibular fixation with all associated pilon fractures because the presence or timing of fibular fixation does not significantly change the radiographic outcomes, complication rate, or need for future surgical interventions. Future clinical analysis is needed to further delineate the indication for fibular fixation in this scenario.

Clinical Comparison of Minifragment Plates Versus Conventional Semitubular Plates for Fixation of Distal Fibula Fractures.

BACKGROUND: Although operative stabilization of unstable distal fibula fractures is frequently performed and discussed, the ideal implant and technique for these injuries is still debated. QUESTIONS/PURPOSES: The purpose of this study was to determine if minifragment plating of distal fibula fractures would clinically provide equivalent fixation and cost and minimize hardware prominence when compared with standard one-third tubular plating. PATIENTS AND METHODS: A retrospective review was conducted on 44 patients who had undergone operative stabilization of a displaced fibula fracture. Inclusion required fibula fixation with either a traditional one-third semitubular plate or a 2.7-mm minifragment plate. Retrospective review of the patient demographics, injury and surgical variables, and radiographs was completed by two surgeons not involved with the patients' original care. RESULTS: The minifragment group demonstrated equivalency in maintenance of fracture reduction relative to standard tubular plating. Both groups were able to maintain the talocrural angle with less than 1° of change from initial postoperative to final postoperative radiographs. No significant differences were seen in postoperative hardware irritation between groups. CONCLUSIONS: Use of a minifragment plating system for displaced fibula fractures appears to be safe but comes with the significant potential added cost of the technology. Interestingly, no significant differences were seen in implant-related irritation or implant removal, but further investigation with a larger study population would help better determine these outcomes.

Assessing Risks to Sea Otters and the Exxon Valdez Oil Spill: New Scenarios, Attributable Risk, and Recovery.

The Exxon Valdez oil spill occurred more than two decades ago, and the Prince William Sound ecosystem has essentially recovered. Nevertheless, discussion continues on whether or not localized effects persist on sea otters (Enhydra lutris) at northern Knight Island (NKI) and, if so, what are the associated attributable risks. A recent study estimated new rates of sea otter encounters with subsurface oil residues (SSOR) from the oil spill. We previously demonstrated that a potential pathway existed for exposures to polycyclic aromatic hydrocarbons (PAHs) and conducted a quantitative ecological risk assessment using an individual-based model that simulated this and other plausible exposure pathways. Here we quantitatively update the potential for this exposure pathway to constitute an ongoing risk to sea otters using the new estimates of SSOR encounters. Our conservative model predicted that the assimilated doses of PAHs to the 1-in-1000th most-exposed sea otters would remain 1-2 orders of magnitude below the chronic effects thresholds. We re-examine the baseline estimates, post-spill surveys, recovery status, and attributable risks for this subpopulation. We conclude that the new estimated frequencies of encountering SSOR do not constitute a plausible risk for sea otters at NKI and these sea otters have fully recovered from the oil spill.

Simultaneous Segmentation of Prostatic Zones Using Active Appearance Models With Multiple Coupled Levelsets.

In this work we present an improvement to the popular Active Appearance Model (AAM) algorithm, that we call the Multiple-Levelset AAM (MLA). The MLA can simultaneously segment multiple objects, and makes use of multiple levelsets, rather than anatomical landmarks, to define the shapes. AAMs traditionally define the shape of each object using a set of anatomical landmarks. However, landmarks can be difficult to identify, and AAMs traditionally only allow for segmentation of a single object of interest. The MLA, which is a landmark independent AAM, allows for levelsets of multiple objects to be determined and allows for them to be coupled with image intensities. This gives the MLA the flexibility to simulataneously segmentation multiple objects of interest in a new image. In this work we apply the MLA to segment the prostate capsule, the prostate peripheral zone (PZ), and the prostate central gland (CG), from a set of 40 endorectal, T2-weighted MRI images. The MLA system we employ in this work leverages a hierarchical segmentation framework, so constructed as to exploit domain specific attributes, by utilizing a given prostate segmentation to help drive the segmentations of the CG and PZ, which are embedded within the prostate. Our coupled MLA scheme yielded mean Dice accuracy values of .81, .79 and .68 for the prostate, CG, and PZ, respectively using a leave-one-out cross validation scheme over 40 patient studies. When only considering the midgland of the prostate, the mean DSC values were .89, .84, and .76 for the prostate, CG, and PZ respectively.

Treatment of unicameral bone cysts in pediatric patients with an injectable regenerative graft: a preliminary report.

BACKGROUND: Multiple treatment modalities exist for unicameral bone cysts (UBC), including steroid injection, autologous bone marrow injection, mechanical decompression, intramedullary fixation, curettage, and bone grafting. All have their own potential limitations such as high recurrence rates, cyst persistence, need for multiple procedures, and prolonged immobilization. A minimally invasive regimen consisting of curettage, decompression, and injection of a calcium sulfate-calcium phosphate (CaSO4-CaPO4) composite has been utilized at our institution in an attempt to obtain optimal results for the treatment of UBCs in the pediatric population. METHODS: We retrospectively evaluated 16 patients with pathologically confirmed UBC who were treated with curettage, decompression, and injection of a calcium sulfate-calcium phosphate composite between April 2006 and August 2010 at a single institution. The average age of the patients at time of surgical intervention was 9.4 years of age (range, 3 to 16 y). Average follow-up was 16 months (range, 6 to 36 mo). Radiographic healing, clinical outcomes, and complications were evaluated. RESULTS: Final follow-up radiographs demonstrated healing in 93.7% (15 of 16) of patients after a single procedure. Complete healing was observed in 14 of 16 patients and partially healed with a defect in 1 of 16 patients. One patient had a persistent cyst but did not wish to receive further treatment. All patients returned to full activities including sports on average at 3.1 months (range, 1 to 6 mo) and were asymptomatic on most recent follow-up. No postoperative complications, including refracture, were observed. CONCLUSIONS: Curettage, decompression, and injection of a calcium sulfate-calcium phosphate composite for UBC in the pediatric population demonstrates encouraging results with low recurrence rates and complications compared with conventional methods. LEVEL OF EVIDENCE: Case series, Level of Evidence IV.

Quantifying population-level risks using an individual-based model: sea otters, Harlequin Ducks, and the Exxon Valdez oil spill.

Ecological risk assessments need to advance beyond evaluating risks to individuals that are largely based on toxicity studies conducted on a few species under laboratory conditions, to assessing population-level risks to the environment, including considerations of variability and uncertainty. Two individual-based models (IBMs), recently developed to assess current risks to sea otters and seaducks in Prince William Sound more than 2 decades after the Exxon Valdez oil spill (EVOS), are used to explore population-level risks. In each case, the models had previously shown that there were essentially no remaining risks to individuals from polycyclic aromatic hydrocarbons (PAHs) derived from the EVOS. New sensitivity analyses are reported here in which hypothetical environmental exposures to PAHs were heuristically increased until assimilated doses reached toxicity reference values (TRVs) derived at the no-observed-adverse-effects and lowest-observed-adverse-effects levels (NOAEL and LOAEL, respectively). For the sea otters, this was accomplished by artificially increasing the number of sea otter pits that would intersect remaining patches of subsurface oil residues by orders of magnitude over actual estimated rates. Similarly, in the seaduck assessment, the PAH concentrations in the constituents of diet, sediments, and seawater were increased in proportion to their relative contributions to the assimilated doses by orders of magnitude over measured environmental concentrations, to reach the NOAEL and LOAEL thresholds. The stochastic IBMs simulated millions of individuals. From these outputs, frequency distributions were derived of assimilated doses for populations of 500,000 sea otters or seaducks in each of 7 or 8 classes, respectively. Doses to several selected quantiles were analyzed, ranging from the 1-in-1000th most-exposed individuals (99.9% quantile) to the median-exposed individuals (50% quantile). The resulting families of quantile curves provide the basis for characterizing the environmental thresholds below which no population-level effects could be detected and above which population-level effects would be expected to become manifest. This approach provides risk managers an enhanced understanding of the risks to populations under various conditions and assumptions, whether under hypothetically increased exposure regimes, as demonstrated here, or in situations in which actual exposures are near toxic effects levels. This study shows that individual-based models are especially amenable and appropriate for conducting population-level risk assessments, and that they can readily be used to answer questions about the risks to individuals and populations across a variety of exposure conditions.

Quantitative Assessment of Current Risks to Harlequin Ducks in Prince William Sound, Alaska, from the Exxon Valdez Oil Spill.

Harlequin Ducks (Histrionicus histrionicus) were adversely affected by the Exxon Valdez oil spill (EVOS) in Prince William Sound (PWS), Alaska, and some have suggested effects continue two decades later. We present an ecological risk assessment evaluating quantitatively whether PWS seaducks continue to be at-risk from polycyclic aromatic hydrocarbons (PAHs) in residual Exxon Valdez oil. Potential pathways for PAH exposures are identified for initially oiled and never-oiled reference sites. Some potential pathways are implausible (e.g., a seaduck excavating subsurface oil residues), whereas other pathways warrant quantification. We used data on PAH concentrations in PWS prey species, sediments, and seawater collected during 2001-2008 to develop a stochastic individual-based model projecting assimilated doses to seaducks. We simulated exposures to 500,000 individuals in each of eight age/gender classes, capturing the variability within a population of seaducks living in PWS. Doses to the maximum-exposed individuals are ∼400-4,000 times lower than chronic toxicity reference values established using USEPA protocols for seaducks. These exposures are so low that no individual-level effects are plausible, even within a simulated population that is orders-of-magnitude larger than exists in PWS. We conclude that toxicological risks to PWS seaducks from residual Exxon Valdez oil two decades later are essentially non-existent.

A Conceptual Model of Natural and Anthropogenic Drivers and Their Influence on the Prince William Sound, Alaska, Ecosystem.

Prince William Sound (PWS) is a semi-enclosed fjord estuary on the coast of Alaska adjoining the northern Gulf of Alaska (GOA). PWS is highly productive and diverse, with primary productivity strongly coupled to nutrient dynamics driven by variability in the climate and oceanography of the GOA and North Pacific Ocean. The pelagic and nearshore primary productivity supports a complex and diverse trophic structure, including large populations of forage and large fish that support many species of marine birds and mammals. High intra-annual, inter-annual, and interdecadal variability in climatic and oceanographic processes as drives high variability in the biological populations. A risk-based conceptual ecosystem model (CEM) is presented describing the natural processes, anthropogenic drivers, and resultant stressors that affect PWS, including stressors caused by the Great Alaska Earthquake of 1964 and the Exxon Valdez oil spill of 1989. A trophodynamic model incorporating PWS valued ecosystem components is integrated into the CEM. By representing the relative strengths of driver/stressors/effects, the CEM graphically demonstrates the fundamental dynamics of the PWS ecosystem, the natural forces that control the ecological condition of the Sound, and the relative contribution of natural processes and human activities to the health of the ecosystem. The CEM illustrates the dominance of natural processes in shaping the structure and functioning of the GOA and PWS ecosystems.

A Quantitative Ecological Risk Assessment of the Toxicological Risks from Exxon Valdez Subsurface Oil Residues to Sea Otters at Northern Knight Island, Prince William Sound, Alaska.

A comprehensive, quantitative risk assessment is presented of the toxicological risks from buried Exxon Valdez subsurface oil residues (SSOR) to a subpopulation of sea otters (Enhydra lutris) at Northern Knight Island (NKI) in Prince William Sound, Alaska, as it has been asserted that this subpopulation of sea otters may be experiencing adverse effects from the SSOR. The central questions in this study are: could the risk to NKI sea otters from exposure to polycyclic aromatic hydrocarbons (PAHs) in SSOR, as characterized in 2001-2003, result in individual health effects, and, if so, could that exposure cause subpopulation-level effects? We follow the U.S. Environmental Protection Agency (USEPA) risk paradigm by: (a) identifying potential routes of exposure to PAHs from SSOR; (b) developing a quantitative simulation model of exposures using the best available scientific information; (c) developing scenarios based on calculated probabilities of sea otter exposures to SSOR; (d) simulating exposures for 500,000 modeled sea otters and extracting the 99.9% quantile most highly exposed individuals; and (e) comparing projected exposures to chronic toxicity reference values. Results indicate that, even under conservative assumptions in the model, maximum-exposed sea otters would not receive a dose of PAHs sufficient to cause any health effects; consequently, no plausible toxicological risk exists from SSOR to the sea otter subpopulation at NKI.

Ecological significance of residual exposures and effects from the Exxon Valdez oil spill.

An ecological significance framework is used to assess the ecological condition of Prince William Sound (PWS), Alaska, USA, in order to address the current management question: 17 y following the Exxon Valdez oil spill (EVOS), are there any remaining and continuing ecologically significant exposures or effects on the PWS ecosystem caused by EVOS? We examined the extensive scientific literature funded by the Exxon Valdez Trustees or by ExxonMobil to assess exposures and effects from EVOS. Criteria to assess ecological significance include whether a change in a valued ecosystem component (VEC) is sufficient to affect the structure, function, and/or health of the system and whether such a change exceeds natural variability. The EVOS occurred on 24 March 1989, releasing over 250,000 barrels of crude oil into PWS. Because PWS is highly dynamic, the residual oil was largely eliminated in the first few years, and now only widely dispersed, highly weathered, or isolated small pockets of residual contamination remain. Many other sources of polycyclic aromatic hydrocarbons (PAHs) exist in PWS from past or present human activities or natural oil seeps. Multiple-lines-of-evidence analyses indicate that residual PAHs from EVOS no longer represent an ecologically significant exposure risk to PWS. To assess the ecological significance of any residual effects from EVOS, we examined the literature on more than 20 VECs, including primary producers, filter feeders, fish and bird primary consumers, fish and bird top predators, a bird scavenger, mammalian primary consumers and top predators, biotic communities, ecosystem-level properties of trophodynamics and biogeochemical processes, and landscape-level properties of habitat mosaic and wilderness quality. None of these has any ecologically significant effects that are detectable at present, with the exception of 1 pod of orcas and possibly 1 subpopulation of sea otters; however, in both those cases, PWS-wide populations appear to have fully recovered. Many other stressors continue to affect PWS adversely, including climate and oceanographic variability, increased tourism and shipping, invasive species, the 1964 earthquake, and overexploitation of marine resources, with associated cascading effects on populations of PWS fish and predators. We conclude that the PWS ecosystem has now effectively recovered from EVOS.