Missed Visits Predict Recurrence in Idiopathic Clubfoot.

BACKGROUND: Congenital talipes equinovarus, also known as "clubfoot," is a common congenital deformity. While reported relapse rates vary widely, relapse continues to be a common problem faced in the treatment of this condition. The objective of this study is to assess relationships between demographic/socioeconomic factors, follow-up, and rates of relapse in our population of clubfoot patients. METHODS: Retrospective chart review was conducted for patients undergoing treatment for idiopathic clubfoot from February 2012 to December 2022 at a tertiary children's hospital. Records were analyzed for follow-up adherence and recurrence in the Ponseti method, in addition to patient demographic and socioeconomic factors. Statistical analysis was performed to evaluate associations between recurrence, missed clinical visits, and demographic/socioeconomic factors of interest. RESULTS: Ninety-five patients were included in the study [74.7% male (N=71) and 25.2% female (N=24)]. A total of 64.2% (N=61) of patients developed recurrence during their treatment. Recurrence rates differed significantly by reported bracing noncompliance >1 month (35/46 vs. 26/49, P =0.019), having missed 1 or more clinical visits (38/61 vs. 8/34, P < 0.001), Medicaid or equivalent insurance type (41/56 vs. 20/39, P =0.028), non-white race (47/66 vs. 14/29, P =0.032, higher Social Deprivation Index score (56.13 vs. 41.06, P =0.019). Significant variables were analyzed using a multivariate logistic regression analysis (MVLR). After MVLR, having 1 or more missed clinical visits (OR 4.462, 95% CI: 1.549-12.856) remained significantly associated with increased rates of recurrence. Primary language preference and distance to the hospital were not associated with recurrence. CONCLUSIONS: Higher SDI scores, non-white race, Medicaid insurance, and missed clinical follow-up visits were all associated with increased rates of recurrence for clubfoot patients. Using an MVLR model, missed clinical follow-up visits remained independently associated with increased recurrence rates. LEVEL OF EVIDENCE: Level 2-retrospective, prognostic study.

Acute Compartment Syndrome in Pediatric Patients on Extracorporeal Membrane Oxygenation Support.

BACKGROUND: When acute compartment syndrome (ACS) occurs in pediatric patients requiring venoarterial extracorporeal membrane oxygen (VA ECMO) support, there is little data to guide surgeons on appropriate management. The purpose of this study is to characterize the presentation, diagnosis, timeline, and outcomes of patients who developed this complication. METHODS: This is a single-center retrospective case series of children below 19 years old on VA ECMO support who subsequently developed extremity ACS between January 2016 and December 2022. Outcomes included fasciotomy findings, amputation, mortality, and documented function at the last follow-up. RESULTS: Of 343 patients on VA ECMO support, 18 (5.2%) were diagnosed with ACS a median 29 hours after starting ECMO. Initial cannulation sites included 8 femoral, 6 neck, and 4 central. Femoral artery cannulation was associated with an increased risk of ACS [odds ratio=6.0 (CI: 2.2 to 15), P <0.0001]. In the hospital, the mortality rate was 56% (10/18). Fourteen (78%) patients received fasciotomies a median of 1.2 hours after ACS diagnosis. Only 4 (29%) patients had all healthy muscles at initial fasciotomy, while 9 (64%) had poor muscular findings in at least 1 compartment. Patients with worse findings at fasciotomy had a significantly longer duration between ischemia onset and ACS diagnosis. Patients required a median of 1.5 additional procedures after fasciotomy, and only 1 (7%) developed a surgical site infection. Of the 7 surviving fasciotomy patients, 2 required amputations, 3 developed an equinus contracture, 1 developed foot drop, and 3 had no ACS-related deficits. Four patients did not receive fasciotomies: 3 were deemed too ill and later died, and 1 was diagnosed too late to benefit. The only surviving nonfasciotomy patient required bilateral amputations. CONCLUSIONS: Pediatric ECMO-associated ACS is not exclusive to patients with femoral artery cannulation. The majority of fasciotomy patients were diagnosed with ACS after muscle necrosis had already started. We were unable to definitively conclude whether fasciotomies provide better outcomes. There is a need for increased awareness and earlier recognition of this rare yet potentially devastating complication. LEVEL OF EVIDENCE: Level IV-retrospective case series.

The Novel Use of the Lateral Scanogram to Detect Cruciate Deficiency in Children With Congenital Femoral Deficiency.

Congenital femoral deficiency (CFD) is often associated with cruciate ligament deficiency. The lateral scanogram may be a potential solution to some limitations for detecting instability associated with cruciate ligament deficiency. This qualitative case study identified two children with congenital femoral deficiency who were assessed with a lateral scanogram and had their results correlated to the clinical examination and MRI. Both cases identified a child with congenital femoral deficiency, one with a total leg length discrepancy (LLD) of 12 cm and the next with 6.5 cm. The weight-bearing lateral scanogram revealed anterior tibial translation, indicating knee instability. Both patients will undergo anterior cruciate ligament (ACL) reconstruction prior to limb lengthening. The lateral scanogram is a useful imaging modality that is capable of detecting anterior tibial translation, and thereby knee instability, in children with congenital femoral deficiency. Larger studies utilizing and evaluating the benefits of lateral scanograms are warranted.

Half-pin Breakage in Multiplanar External Fixators Used for Pediatric Deformity Correction.

BACKGROUND: Pediatric patients with leg length discrepancies and complex deformities may require multiplanar external fixators for correction. We have encountered 4 cases of half-pin breakage with the Orthex hexapod frame. The purpose of this study is to report factors associated with half-pin breakage and compare various deformity correction characteristics between 2 hexapod frames - Taylor Spatial Frame (TSF) and Orthex. METHODS: Pediatric patients with lower extremity deformities treated with an Orthex or TSF at a single tertiary children's hospital between 2012 and 2022 were included for retrospective review. Variables compared between frame groups include frame configuration, half-pin/wire fixation, length achieved, angular correction, and frame time. RESULTS: There were 23 Orthex frames (23 patients) and 36 TSF (33 patients) included. Four Orthex and zero TSF had proximal half-pin breakage. The Orthex group was younger on average (10 vs. 12 y, P =.04*) at the time of frame placement. The majority (52%) of Orthex frames were used for simultaneous lengthening and angular correction, while the majority (61%) of TSF was used for only angular correction. Orthex had more half-pins used for proximal fixation (median 3 vs. 2, P <0.0001*) and more frames with nonstandard configuration (7 (30%) vs. 1 (3%), P =0.004*). Orthex group had a longer total frame time (median 189 vs. 146 days, P =0.012*) and longer time required for regenerate healing (117 vs. 89 d, P =0.02*). There were no significant differences in length gained, angular correction, or healing index between Orthex and TSF. Nonstandard configuration, increased number of proximal half-pins, younger age at index surgery, and increased lengthening were associated with pin breakage. CONCLUSIONS: This is the first study to report half-pin breakage while using multiplanar frames in pediatric lower extremity deformity correction. The Orthex and TSF groups consisted of significantly different patients and frame configurations, making it difficult to identify any specific cause for pin breakage. This study shows that pin breakage is likely caused by multiple factors and is associated with the increased complexity of deformity correction. LEVEL OF EVIDENCE: Level III-Retrospective Comparison Study.

Simulating the effects of long-distance dispersal and landscape heterogeneity on the eco-evolutionary outcomes of range expansion in an invasive riverine fish, Tench (Tinca tinca).

Predicting how quickly populations expand their range and whether they will retain genetic diversity when they are introduced to new regions or track environmental conditions suited to their survival is an important applied and theoretical challenge. The literature suggests that long-distance dispersal, landscape heterogeneity and the evolution of dispersal influence populations' expansion rates and genetic diversity. We used individual-based spatially explicit simulations to examine these relationships for Tench (Tinca tinca), an invasive fish expanding its geographical range in eastern North America since the 1990s. Simulated populations varied greatly in expansion rates (1.1-28.6 patches year-1 ) and genetic diversity metrics, including changes in observed heterozygosity (-19 to +0.8%) and effective number of alleles (-0.32 to -0.01). Populations with greater dispersal distances expanded faster than those with smaller dispersal distances but exhibited considerable variation in expansion rate among local populations, implying less predictable expansions. However, they tended to retain genetic diversity as they expanded, suggesting more predictable evolutionary trajectories. In contrast, populations with smaller dispersal distances spread predictably more slowly but exhibited more variability among local populations in genetic diversity losses. Consistent with empirical data, populations spreading in a longer, narrower dispersal corridor lost more neutral genetic variation to the stochastic fixation of alleles. Given the unprecedented pace of anthropogenic environmental change and the increasing need to manage range-expanding populations, our results have conservation ramifications as they imply that the evolutionary trajectories of populations characterised by shorter dispersal distances spreading in narrower landscapes are more variable and, therefore, less predictable.

Genetic diversity and structure of a recent fish invasion: Tench (Tinca tinca) in eastern North America.

Introduced and geographically expanding populations experience similar eco-evolutionary challenges, including founder events, genetic bottlenecks, and novel environments. Theory predicts that reduced genetic diversity resulting from such phenomena limits the success of introduced populations. Using 1900 SNPs obtained from restriction-site-associated DNA sequencing, we evaluated hypotheses related to the invasion history and connectivity of an invasive population of Tench (Tinca tinca), a Eurasian freshwater fish that has been expanding geographically in eastern North America for three decades. Consistent with the reported history of a single introduction event, our findings suggest that multiple introductions from distinct genetic sources are unlikely as Tench had a small effective population size (~114 [95% CI = 106-123] individuals), no strong population subdivision across time and space, and evidence of a recent genetic bottleneck. The large genetic neighbourhood size (220 km) and weak within-population genetic substructure suggested high connectivity across the invaded range, despite the relatively large area occupied. There was some evidence for a small decay in genetic diversity as the species expanded northward, but not southward, into new habitats. As eradicating the species within a ~112 km radius would be necessary to prevent recolonization, eradicating Tench is likely not feasible at watershed-and possibly local-scales. Management should instead focus on reducing abundance in priority conservation areas to mitigate adverse impacts. Our study indicates that introduced populations can thrive and exhibit relatively high levels of genetic diversity despite severe bottlenecks (<1.5% of the ancestral effective population size) and suggests that landscape heterogeneity and population demographics can generate variability in spatial patterns of genetic diversity within a single range expansion.

Tibial Osteomyelitis Caused by Morganella morganii After External Fixation for Limb Length Discrepancy in a Pediatric Patient: A Case Report and Literature Review.

Morganella morganii is a facultative, anaerobic rod Gram-negative enteric bacterium. Few cases are documented of musculoskeletal infection. We present a case of a 9-year-old boy with osteomyelitis 1 year after index external fixation for leg length discrepancy. Our patient initially presented with wound drainage at his distal medial tibia fixation site but had negative radiographs. Initial antibiotic treatment failed after 1-month follow-up, and cultures revealed M. morganii. He underwent incision and drainage with external fixator removal, and the antibiotic regimen changed after a susceptibility panel. Symptoms were alleviated after 30 days with the new antibiotic regimen, and the patient was put back on his original schedule for limb lengthening through external fixation. A new methicillin-sensitive Staphylococcus aureus occurred at the same site 2.5 years later but was easily treated, and the 3-year follow-up showed no other recurrences or complications.

Does the stabilization of the calcaneocuboid joint with Steinmann pin in Evans osteotomy affect its incidence of arthritis?

PURPOSE: This study aims to determine the effect of retaining a Steinmann pin in the calcaneocuboid joint on its rates of arthritis following Evans calcaneal osteotomy lengthening procedure. The study hypothesized that leaving the pin across the calcaneocuboid joint post-operatively would lead to higher rates of arthritis. METHODS: This is a retrospective review of patients under 18 years of age who underwent Evans osteotomy at our hospital from January 2015 to May 2020. The Patients were stratified into 2 groups: Group 1 (pin was left post-operatively across the joint and removed on follow-up) and Group 2 (pin was removed during surgery). Demographic data were recorded, including age, sex, and body mass index. Calcaneocuboid arthritis was determined by radiographic imaging at least one-year follow-up. Time to pin removal, size of the pin and graft, and subluxation were analyzed as possible risk factors for arthritis. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated. RESULTS: 39 patients were included in the study: 24 patients had the pin removed post-operatively, and 15 had the pin removed intra-operatively. There were no significant differences between the 2 groups regarding body mass index, age, sex, or laterality. Calcaneocuboid arthritis rates were significantly higher in the Group 1 than Group 2 (12(50%) vs. 2(13.3%), respectively; p = 0.02). On multivariate regression, both age (OR, 1.305 [95%CI: 1.009-1.696]; p = 0.044) and leaving the pin in the joint postoperatively (OR, 7.661 [95%CI: 1.208-48.570]; p = 0.031) were found as risk factors for arthritis at follow-up. The mean time to pin removal, the size of the pin, and the size of the graft were not found to be significant predictors of arthritis (p > 0.05). CONCLUSIONS: This study shows that leaving the Steinmann pin in the calcaneocuboid joint in children post-operatively is associated with an increased risk of developing early radiographic signs of calcaneocuboid joint arthritis.

Defining the volume of consultations for musculoskeletal infection encountered by pediatric orthopaedic services in the United States.

OBJECTIVE: Adequate resources are required to rapidly diagnose and treat pediatric musculoskeletal infection (MSKI). The workload MSKI consults contribute to pediatric orthopaedic services is unknown as prior epidemiologic studies are variable and negative work-ups are not included in national discharge databases. The hypothesis was tested that MSKI consults constitute a substantial volume of total consultations for pediatric orthopaedic services across the United States. STUDY DESIGN: Eighteen institutions from the Children's ORthopaedic Trauma and Infection Consortium for Evidence-based Study (CORTICES) group retrospectively reviewed a minimum of 1 year of hospital data, reporting the total number of surgeons, total consultations, and MSKI-related consultations. Consultations were classified by the location of consultation (emergency department or inpatient). Culture positivity rate and pathogens were also reported. RESULTS: 87,449 total orthopaedic consultations and 7,814 MSKI-related consultations performed by 229 pediatric orthopaedic surgeons were reviewed. There was an average of 13 orthopaedic surgeons per site each performing an average of 154 consultations per year. On average, 9% of consultations were MSKI related and 37% of these consults yielded positive cultures. Finally, a weak inverse monotonic relationship was noted between percent culture positivity and percent of total orthopedic consults for MSKI. CONCLUSION: At large, academic pediatric tertiary care centers, pediatric orthopaedic services consult on an average of ~3,000 'rule-out' MSKI cases annually. These patients account for nearly 1 in 10 orthopaedic consultations, of which 1 in 3 are culture positive. Considering that 2 in 3 consultations were culture negative, estimating resources required for pediatric orthopaedic consult services to work up and treat children based on culture positive administrative discharge data underestimates clinical need. Finally, ascertainment bias must be considered when comparing differences in culture rates from different institution's pediatric orthopaedics services, given the variability in when orthopaedic physicians become involved in a MSKI workup.

Closed Reduction of Pediatric Distal Radial Fractures and Epiphyseal Separations.

BACKGROUND: Sedated, closed reduction of a displaced distal radial fracture followed by cast immobilization is indicated in cases of unacceptable alignment on post-splint imaging. The aim of this procedure is to obtain acceptable reduction and cast immobilization for fracture-healing. DESCRIPTION: The patient is positioned supine with the injured arm on the image intensifier. Adequate sedation is achieved with conscious sedation, general anesthesia, or regional anesthesia (hematoma block). The radial or ulnar translation is corrected with in-line traction. The wrist is typically hyperdorsiflexed, and traction is applied to the distal fragment. The distal fragment is then walked up and over as axial traction is applied and the wrist is brought from extension to flexion. The reduced wrist is held in a position of gentle flexion and slight ulnar deviation, and post-reduction fluoroscopy in anteroposterior and lateral views is obtained. A long-arm cast is applied by first applying a short-arm cast and a 3-point mold. Minimal cast padding is utilized to obtain the optimal "cast index." The wrist is re-imaged on the fluoroscopy device to obtain anteroposterior and lateral views. ALTERNATIVES: Alternative treatments include cast immobilization in situ, closed reduction and percutaneous pinning, and open reduction and internal fixation. RATIONALE: Closed reduction and cast immobilization is a low-risk procedure that has a high rate of union with acceptable alignment without the risk of an additional surgical procedure. EXPECTED OUTCOMES: The long-arm cast is maintained for 6 weeks, and radiographs are obtained at 1 and at 2 weeks postoperatively to confirm maintained alignment. It is advisable to instruct the patient not to put anything down the cast because this can result in skin breakdown. Additionally, care must be taken on removal of the cast. Cast saws should be kept sharp and be replaced frequently. There are commercially available "zip sticks" and other such devices to prevent cast-saw burns that should be utilized if cast technicians or residents are assisting in the removal. Following removal of the cast, we recommend wrist-motion exercises be performed 3 times daily. If the fracture line is clearly visible on radiographs, a removable wrist splint is utilized for another 2 to 4 weeks. A full return to activity is expected at 3 months. Some residual deformity is acceptable if the remodeling capacity is excellent at the distal aspect of the radius. However, the tolerance for malreduction decreases as the patient ages, if the deformity worsens, or if there is a deformity further from the physis. IMPORTANT TIPS: Particular attention should be given to the median nerve sensory component. The thumb, index, and long fingers are assessed for sensation and compared with the 2 ulnar digits. Acute carpal tunnel syndrome is possible in children who have distal radial fractures.Waterproof cast padding is not recommended in cases in which a closed reduction is performed because such padding does not provide good protection to the skin with adequate cast molding.After reduction is obtained, no additional traction should be applied. If an assistant applies traction with the wrist in extension, reduction can be lost, so it is preferred to maintain the wrist in slight flexion while placing the cast.Although it is beneficial to hold the fracture in the cotton-loader position, this position should not be exaggerated because this position can cause excessive pressure on the carpal tunnel.The median nerve passes through the carpal tunnel and is often at risk because of hematoma formation as a result of a distal radial fracture.A cast index of 0.8 or more has been found to have an increased risk of failure of closed treatment. The cast index is the ratio of sagittal (measured on a lateral view) to coronal (measured on an anteroposterior view) width from the inside edges of the cast at the fracture site.Keeping cast saw blades sharp, using saws attached to vacuum devices, and cooling the blade while in use can prevent cast-saw burns.Zip sticks can be utilized to protect the skin but can sometimes be difficult to get under the cast.It is important to remember that swelling will occur following fracture reduction. The cast should not be wrapped tightly. Consideration should be given to bivalving the cast at the time of reduction and overwrapping after a few days when acute swelling has improved.Vigilance for growth arrest is necessary in patients with fractures of the distal aspect of the radius. This can occur in up to 4% to 5% of cases and is more common with reduction, particularly late reduction. Radiographic screening 6 to 12 months after the injury can help identify an early arrest.

A new approach to the biological monitoring of freshwater systems: Mapping nutrient loading in two South African rivers, a case study.

Excessive addition of nitrogen (N) has threatened aquatic ecosystems for decades. Traditional water quality and biological monitoring assessment tools are widely used for monitoring nutrient loads and ecosystem health, but most of these methods cannot distinguish between different types and sources of pollution. This is a challenge, particularly when dealing with non-point sources of anthropogenic nitrogen inputs into freshwater systems. Recent laboratory studies using stable isotopic ratios (δ15N and C/N) of aquatic macrophytes (duckweed: Spirodela spp.) have shown successful differentiation and mapping between different N-sources and further, showed abilities to act as early warning indicators for environmental N-loading. Therefore, the aim of this study was to field test the potential of stable isotopic values of transplanted Spirodela spp. to map temporal and spatial N-loading variation and determine the main sources of N-loading in two river systems in the Eastern Cape Province of South Africa, using previously grown, isotopically calibrated and transplanted Spirodela plants, collected over a 13-month sampling period. Nitrogen isotopic values (δ15N) of Spirodela plants traced environmental N-loading and identified pollution hotspots and sources through time and space over a wide range of nutrient gradients. δ15N isotopic values of Spirodela spp. provided detailed dynamics on N-loading, therefore supporting its utilisation in the biological monitoring of ecosystem health and the early detection of eutrophication in freshwater systems.

Modeling Top-Down and Bottom-Up Drivers of a Regime Shift in Invasive Aquatic Plant Stable States.

The evidence for alternate stable states characterized by dominance of either floating or submerged plant dominance is well established. Inspired by an existing model and controlled experiments, we conceptually describe a dynamic that we have observed in the field using a simple model, the aim of which was to investigate key interactions of the shift between invasive floating and invasive submerged plant dominance, driven by the rapid decomposition of floating plants as a consequence of herbivory by biological control agents. This study showed that the rate of switch between floating and submerged invasive plant dominance, and the point in time at which the switch occurs, is dependent on the nutrient status of the water and the density of biological control agents on floating plant populations. Therefore, top-down invasive plant biological control efforts using natural enemies can affect systems on a wider scale than the intended agent - plant level, and can be significantly altered by bottom-up changes to the system, i.e., nutrient loading. The implications of this are essential for understanding the multiple roles invasive plants and their control have upon ecosystem dynamics. The results emphasize the importance of multi-trophic considerations for future invasive plant management and offer evidence for new pathways of invasion. The model outputs support the conclusion that, after the shift and in the absence of effective intervention, a submerged invasive stable state will persist.

Species succession and the development of a lacustrine fish community in an ephemeral lake.

Here, we present a gillnet survey of Lake Liambezi a 370 km2 shallow ephemeral floodplain lake situated in north-eastern Namibia, which is fed irregularly by the upper Zambezi and Kwando Rivers during years of high flooding. The lake dried up in 1985 and, with the exception of sporadic minor annual inundation events, remained dry until 2007. We describe the temporal succession of fish species over an 8 year period from initial inundation 2007 to maturation in 2014. The succession of the fish community did not follow the typical pattern of opportunistic strategists during colonisation, to periodic strategists that are eventually succeeded by equilibrium strategists. Instead, the evolution of the fish community was characterised by three distinct phases. The first phase involved the inundation and colonisation of the lake in 2007, followed by its decline until the floods that filled the lake in 2009. During this phase the lake was colonised by fishes from the adjacent upper Zambezi and Chobe River floodplains. Fish communities predominantly comprised floodplain specialists including the barbs Enteromius paludinosus and Enteromius poechii, the mormyrid Marcusenius altisambesi and catfishes Schilbe intermedius and Clarias gariepinus. The filling of the lake in the March 2009 floods marked the beginning of the second, successional phase. The barbs declined in abundance and the alestid Rhabdalestes maunensis underwent explosive population growth between 2009 and 2010, but populations crashed equally rapidly and were replaced by Brycinus lateralis which, together with S. intermedius went on to dominate the fish community 2011-2014. Larger, slower growing tilapiine cichlids increased steadily in abundance and became the dominant components in a 2700 t y-1 artisanal fishery that developed on the lake. The fish community in the ephemeral Lake Liambezi is clearly influenced by numerous factors including connectivity, lake level fluctuations, competition and the effects of fishing, which may disrupt typical succession processes in floodplain ecosystems.

Who Gets Compartment Syndrome?: A Retrospective Analysis of the National and Local Incidence of Compartment Syndrome in Patients With Supracondylar Humerus Fractures.

PURPOSE: Although acute compartment syndrome (ACS) is associated with pediatric supracondylar humerus (SCH) fractures, there are limited data describing its incidence and risk factors. The purpose of our study was to report the local and national incidence of ACS with SCH and floating elbow (concomitant SCH and forearm) fracture patterns and the associated risk factors. METHODS: We retrospectively queried data for SCH fracture patients over a 4-year period from our institution (a level I pediatric trauma center) and the National Trauma Data Bank (NTDB). Data on demographics, mechanism of injury, open versus closed fracture, length of stay, presence or absence of forearm fractures, and incidence of traumatic compartment syndrome were analyzed. The student t and χ tests were utilized for group comparisons of continuous and categorical variables, respectively. Logistic regression was used to identify risk factors for compartment syndrome. Results are summarized as means with SD or odds ratios (OR) with 95% confidence intervals (CI). Statistical significance was set at P<0.05. RESULTS: At our institution, 839 patients with SCH fractures met inclusion criteria. In total, 814 (97.02%) patients (average age, 5.96±2.58 y) sustained isolated SCH fractures during the indicated timeframe. SCH fractures with an associated forearm fracture were identified in 25 (2.98%) patients (average age, 7.00±3.03 y). Three patients (0.36%) with isolated SCH fractures were observed to have compartment syndrome. No compartment syndromes were identified in the patients with floating elbows.Within the same time period, the NTDB identified 31,234 SCH fractures met inclusion criteria. Of those, 31,167 patients had isolated SCH fractures (average age, 5.5±2.7 y). In total, 67 of the SCH patients (0.2%, P<0.0001) had documented ACS (average age, 7.3±3.5 y). The NTDB identified 1565 patients with floating elbows, including 13 (0.8%, P≤0.0001) who developed compartment syndrome (average age, 6.47±2.71 y). The NTDB query also identified 530 patients with neurovascular injury (NVI), with 4.5% (n=24) that developed compartment syndrome. In the regression analysis, older age (OR, 1.1; 95% CI, 1.0-1.2; P<0.0092), male sex (OR, 2.7; 95% CI, 1.5-4.8; P=0.0005), floating elbow fracture pattern (OR, 3.2; 95% CI, 1.7-6.1; P=0.0003) and NVI (OR, 25.0; 95% CI, 14.6-42.8; P≤0.0001) were identified as risk factors for developing compartment syndrome. CONCLUSIONS: Data from our institution and NTDB reveal that acute traumatic compartment syndrome is rare, occurring in ∼2 to 3 fractures of 1000. However, there is a significantly increased risk with NVI, floating elbow fractures, males, and older patients. SIGNIFICANCE: Characterizing the incidence and associated risk factors of ACS with concomitant SCH and forearm fracture patterns can improve clinical understanding and management of pediatric patients.

A missing link in the estuarine nitrogen cycle?: Coupled nitrification-denitrification mediated by suspended particulate matter.

In estuarine and coastal ecosystems, the majority of previous studies have considered coupled nitrification-denitrification (CND) processes to be exclusively sediment based, with little focus on suspended particulate matter (SPM) in the water column. Here, we present evidence of CND processes in the water column of Hangzhou Bay, one of the largest macrotidal embayments in the world. Spearman's correlation analysis showed that SPM was negatively correlated with nitrate (rho = -0.372, P = 0.018) and marker genes for nitrification and denitrification in the water column were detected by quantitative PCR analysis. The results showed that amoA and nir gene abundances strongly correlated with SPM (all P < 0.01) and the ratio of amoA/nir strongly correlated with nitrate (rho = -0.454, P = 0.003). Furthermore, aggregates consisting of nitrifiers and denitrifiers on SPM were also detected by fluorescence in situ hybridization. Illumina MiSeq sequencing further showed that ammonia oxidizers mainly belonged to the genus Nitrosomonas, while the potential denitrifying genera Bradyrhizobium, Comamonas, Thauera, Stenotrophomonas, Acinetobacter, Anaeromyxobacter, Sulfurimonas, Paenibacillus and Sphingobacterium showed significant correlations with SPM (all P < 0.01). This study suggests that SPM may provide a niche for CND processes to occur, which has largely been missing from our understanding of nitrogen cycling in estuarine waters.

Estimating δ15N fractionation and adjusting the lipid correction equation using Southern African freshwater fishes.

Stable isotope analysis is an important tool for characterising food web structure; however, interpretation of isotope data can often be flawed. For instance, lipid normalisation and trophic fractionation values are often assumed to be constant, but can vary considerably between ecosystems, species and tissues. Here, previously determined lipid normalisation equations and trophic fractionation values were re-evaluated using freshwater fish species from three rivers in the Upper Zambezian floodplain ecoregion in southern Africa. The parameters commonly used in lipid normalisation equations were not correct for the 18 model species (new D and I parameters were estimated as D = 4.46‰ [95% CI: 2.62, 4.85] and constant I = 0 [95% CI: 0, 0.17]). We suggest that future isotopic analyses on freshwater fishes use our new values if the species under consideration do not have a high lipid content in their white muscle tissue. Nitrogen fractionation values varied between species and river basin; however, the average value closely matched that calculated in previous studies on other species (δ15N fractionation factor of 3.37 ± 1.30 ‰). Here we have highlighted the need to treat stable isotope data correctly in food web studies to avoid misinterpretation of the data.

Lisfranc injuries in children and adolescents.

In this descriptive analysis of pediatric Lisfranc injuries, records of 56 children treated for bony or ligamentous Lisfranc injuries over a 12-year period were reviewed. Overall, 51% of fractures and 82% of sprains were sports-related (P=0.03). A total of 34% of the cohort underwent open reduction internal fixation, which was more common among patients with closed physes (67%). Full weight bearing was allowed in open reduction internal fixation patients at a mean of 14.5 weeks, compared to 6.5 weeks in the nonoperative group. Complications were rare (4%) and included physeal arrest in one patient and a broken, retained implant in one patient.

¹³C pulse-chase labeling comparative assessment of the active methanogenic archaeal community composition in the transgenic and nontransgenic parental rice rhizospheres.

More and more investigations indicate that genetic modification has no significant or persistent effects on microbial community composition in the rice rhizosphere. Very few studies, however, have focused on its impact on functional microorganisms. This study completed a ¹³C-CO2 pulse-chase labeling experiment comparing the potential effects of cry1Ab gene transformation on ¹³C tissue distribution and rhizosphere methanogenic archaeal community composition with its parental rice variety (Ck) and a distant parental rice variety (Dp). Results showed that ¹³C partitioning in aboveground biomass (mainly in stems) and roots of Dp was significantly lower than that of Ck. However, there were no significant differences in ¹³C partitioning between the Bt transgenic rice line (Bt) and Ck. RNA-stable isotope probing combined with clone library analyses inferred that the group Methanosaetaceae was the predominant methanogenic Archaea in all three rice rhizospheres. The active methanogenic archaeal community in the Bt rhizosphere was dominated by Methanosarcinaceae, Methanosaetaceae, and Methanomicrobiaceae, while there were only two main methanogenic clusters (Methanosaetaceae and Methanomicrobiaceae) in the Ck and Dp rhizospheres. These results indicate that the insertion of cry1Ab gene into the rice genome has the potential to result in the modification of methanogenic community composition in its rhizosphere.

Residents' perceptions of sex diversity in orthopaedic surgery.

BACKGROUND: Sex diversity in orthopaedic surgery lags behind other surgical specialties. Women comprise 13.2% of orthopaedic residents and 15% of full-time faculty, despite 47.8% of graduating medical students being women. The purposes of this study were to demonstrate how orthopaedic surgery has been less successful in recruiting women compared with general surgery and to identify the sex-specific factors that influenced orthopaedic surgery residents to choose their specialty. METHODS: A search of graduate medical data was performed to compare the recruitment of women into orthopaedic and general surgery. Next, a seven-question survey was e-mailed to 2629 orthopaedic residents by the American Academy of Orthopaedic Surgeons. Questions were formulated to detect why orthopaedic surgery residents chose their specialty. Data were collected over six weeks and responses were analyzed with use of one-tailed t tests to make comparisons of responses on the basis of sex. RESULTS: The historical data search showed that the percentage of female representation in both orthopaedic and general surgery has increased since 1968, but it has increased significantly faster in general surgery than in orthopaedic surgery (p < 0.0001). Five hundred and twenty-nine (20%) of the 2629 orthopaedic surgery residents who were contacted responded to the survey. Of the respondents, 114 (22%) were female and 415 (78%) were male. Several significant differences were found in the responses between the sexes. These include the timing of the decision to enter orthopaedic surgery and positive influences in choosing orthopaedic surgery as a specialty. Additionally, women, significantly more than men, believed that more of their peers entered general surgery because of greater acceptance by senior faculty in that field (p < 0.0001). CONCLUSIONS: To our knowledge, this study is the first to survey residents on their perceptions of orthopaedic surgery and to identify factors that may hinder the recruitment of women into orthopaedic surgery. Our data show that increased exposure to orthopaedic content during medical school and increased female mentorship may help recruit more women into the orthopaedic surgery workforce.