Positive effects of public breeding on US rice yields under future climate scenarios.

In this study, we model and predict rice yields by integrating molecular marker variation, varietal productivity, and climate, focusing on the Southern U.S. rice-growing region. This region spans the states of Arkansas, Louisiana, Texas, Mississippi, and Missouri and accounts for 85% of total U.S. rice production. By digitizing and combining four decades of county-level variety acreage data (1970 to 2015) with varietal information from genotyping-by-sequencing data, we estimate annual historical county-level allele frequencies. These allele frequencies are used together with county-level weather and yield data to develop ten machine learning models for yield prediction. A two-layer meta-learner ensemble model that combines all ten methods is externally evaluated against observations from historical Uniform Regional Rice Nursery trials (1980 to 2018) conducted in the same states. Finally, the ensemble model is used with forecasted weather from the Coupled Model Intercomparison Project across the 110 rice-growing counties to predict production in the coming decades for Composite Variety Groups assembled based on year of release, breeding program, and several breeding trends. Results indicate positive effects over time of public breeding on rice resilience to future climates, and potential reasons are discussed.

Gene disruption by structural mutations drives selection in US rice breeding over the last century.

The genetic basis of general plant vigor is of major interest to food producers, yet the trait is recalcitrant to genetic mapping because of the number of loci involved, their small effects, and linkage. Observations of heterosis in many crops suggests that recessive, malfunctioning versions of genes are a major cause of poor performance, yet we have little information on the mutational spectrum underlying these disruptions. To address this question, we generated a long-read assembly of a tropical japonica rice (Oryza sativa) variety, Carolina Gold, which allowed us to identify structural mutations (>50 bp) and orient them with respect to their ancestral state using the outgroup, Oryza glaberrima. Supporting prior work, we find substantial genome expansion in the sativa branch. While transposable elements (TEs) account for the largest share of size variation, the majority of events are not directly TE-mediated. Tandem duplications are the most common source of insertions and are highly enriched among 50-200bp mutations. To explore the relative impact of various mutational classes on crop fitness, we then track these structural events over the last century of US rice improvement using 101 resequenced varieties. Within this material, a pattern of temporary hybridization between medium and long-grain varieties was followed by recent divergence. During this long-term selection, structural mutations that impact gene exons have been removed at a greater rate than intronic indels and single-nucleotide mutations. These results support the use of ab initio estimates of mutational burden, based on structural data, as an orthogonal predictor in genomic selection.

First report of rice bacterial leaf blight disease caused by Pantoea ananatis in the United States.

In August 2021, bacterial leaf blight-like symptoms were observed on 14 out of 570 rice genotypes (Oryza sativa) in research field plots of global rice germplasm grown in Arkansas (eXtra Figure S1. A & B). The disease was characterized by spreading lesions on leaves, panicle sterility and reduced yield in highly susceptible, mature rice germplasm. No spread of disease to nearby plants was observed. Isolations were performed at Colorado State University, where soakates from symptomatic leaves were spread onto nutrient agar. After 72 h at 28°C, uniform, distinct, yellow-colored bacterial colonies were observed. To screen for the presence of common rice bacterial pathogens, PCR amplification directly from colonies or from DNA isolated from symptomatic field-collected leaves was performed. Primers specific for Xanthomonas oryzae pvs. oryzae and oryzicola (Lang et al., 2010), Burkholderia glumae (Echeverri-Rico et al., 2021), and Pseudomonas fuscovaginae (Ash et al., 2014) did not amplify indicating these organisms were not present. Sequencing of 16S rRNA gene (Weisburg et al., 1991) amplicons suggested the bacteria belonged to the genera Pantoea and Sphingomonas (NCBI accession no. OP683332 and OP683333, respectively). Amplicons resulting from primers specific to the gyrB gene region of P. ananatis (Kini et al., 2021) were sequenced and the fragment was compared to the P. ananatis PA13 reference genome using a BLAST analysis. One candidate (AR358) showed 100% identity with the P. ananatis gyrB region. Primers specific for Sphingomonas sp. (Bangratz et al., 2020) confirmed the second candidate (AR359) as a Sphingomonas sp. The identity of P. ananatis was confirmed by the Plant Pathogen Confirmatory Diagnostics Laboratory (Beltsville, MD, USA). To determine pathogenicity, leaves from 7-day-old seedlings of rice (Oryza sativa) cultivar Kitaake were scissor-clip inoculated (Kauffman et al., 1973) with four different treatments and compared to control leaves inoculated with sterile water. Treatments for the experiment consisted of bacterial suspensions (108 CFU/ml) of the two candidate organisms, P. ananatis (strain AR358) or Sphingomonas sp. (strain AR359), individually or in a 1:1 ratio of P. ananatis:Sphingomonas sp., or soakate from infected field tissue. Lesions similar to those observed in the field were only detected on leaves inoculated with P. ananatis or infected field tissue soakate at 7-days post-inoculation (eXtra Figure S1. C). Bacteria were recovered from the leaves of the artificially inoculated seedlings from three treatments (P. ananatis, P. ananatis:Sphingomonas sp. and soakate from the infected field tissue) and were determined to be P. ananatis based on colony morphology, amplification of 16s rRNA, and gyrB sequence data. Our results confirm the pathogenicity of P. ananatis to rice and fulfill Koch's postulates. P. ananatis was also recovered from several similarly diseased rice breeding lines at the University of Arkansas System Division of Agriculture Rice Research and Extension Center. We conclude that P. ananatis is the causal pathogen for leaf blight-like symptoms observed in the global rice cultivars grown in Arkansas. P. ananatis was previously reported as a pathogen on rice in several rice growing regions, including China (Yu et al., 2021), India (Reshma et al., 2022), and Africa (Kini et al., 2017), however, this is the first report of P. ananatis as a pathogen of rice in the United States.

Do Children With Medicaid Insurance Have Increased Revision Rates 5 Years After Posterior Spinal Fusions?

BACKGROUND: Socioeconomic disparities in musculoskeletal care are increasingly recognized, however, no studies to date have investigated the role of the insurance carrier on outcomes after posterior spinal fusion (PSF) with segmental spinal instrumentation for adolescent idiopathic scoliosis (AIS). METHODS: A US insurance dataset was queried using the PearlDiver Mariner software for all patients aged 10 to 18 undergoing PSF for a primary diagnosis of AIS between 2010 and 2020. Age, sex, geographic region, number of levels fused, and baseline medical comorbidities were queried. Complications occurring within 90 days of the index surgery were queried using the International Classification of Diseases, Ninth Revision (ICD-9) and International Classification of Diseases, 10th Revision (ICD-10) codes. Revision surgery was also queried up to 5 years after the index PSF. Categorical variables were compared using the Fisher χ 2 tests and continuous variables were compared using independent t tests. All-cause revision within 5 years was compared using the Kaplan-Meier analysis and a log-rank test. Significance was set at P -value <0.05. RESULTS: A total of 10,794 patients were identified with 9006 (83.4%) patients with private insurance and 1788 (16.6%) patients insured by Medicaid. The mean follow-up in the database was 5.36±3 years for patients with private insurance and 4.78±2.9 years for patients with Medicaid insurance ( P <0.001). Children with AIS and Medicaid insurance had a significantly higher prevalence of asthma, hypertension, and obesity. A larger percentage of children with Medicaid insurance (41.3%) underwent a ≥13-level PSF compared with privately insured children (34.5%) ( P <0.001). Medicaid patients did not experience higher odds of postoperative complications; in addition, revision surgeries occurred in 1.1% and 1.8% of patients with private insurance and Medicaid insurance, respectively at 5 years postoperatively ( P =0.223). CONCLUSION: Despite worse baseline comorbidities and longer fusion constructs, AIS patients insured with Medicaid did not have higher rates of complications or revisions at 5-year follow-up versus privately insured patients. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Effects of alternate wetting and drying on oxyanion-forming and cationic trace elements in rice paddy soils: impacts on arsenic, cadmium, and micronutrients in rice.

Rice is a global dietary staple and its traditional cultivation under flooded soil conditions leads to accumulation of arsenic (As) in rice grains. Alternate wetting and drying (AWD) is a widely advocated water management practice to achieve lower As concentrations in rice, water savings, and decreased methane emissions. It is not yet clear whether AWD leads to tradeoffs between concentrations of As and micronutrient elements (e.g., zinc, manganese, molybdenum) in rice grain. We analyzed pore water chemistry and rice grain composition data from a field experiment conducted in Arkansas, USA, in 2017 and 2018 to test the hypothesis that AWD will have diverging effects on oxyanion-forming (arsenic, molybdenum) vs. cationic (cadmium, zinc, manganese, copper) trace elements. This was hypothesized to occur via decreases in soil pH and/or precipitation of iron oxide minerals during oxidizing conditions under AWD. Solubility of all trace elements, except zinc, increased in more reducing conditions. Consistent with our hypothesis, AWD tended to increase grain concentrations of cationic elements while decreasing grain concentrations of oxyanionic elements. Decreases in total As in rice grains under AWD were mainly driven by changes in dimethylarsinic concentrations, with negligible changes in inorganic As. Linear mixed-effects modeling showed that effects of AWD on grain composition were more significant in 2017 compared to 2018. These differences may be related to the timing of dry-downs in the developmental stage of rice plants, with dry-downs during the heading stage of rice development leading to larger impacts on grain composition of certain elements. We also observed significant interannual variability in grain elemental composition from continuously-flooded fields and postulate the warmer temperatures in 2018 may have played a role in these differences.

The Effect of Proximal Anchor Choice During Distraction-based Surgeries for Patients With Nonidiopathic Early-onset Scoliosis: A Retrospective Multicenter Study.

BACKGROUND: It is unclear whether the type of proximal anchor affects the spine length achieved with distraction-based surgeries in patients with nonidiopathic early-onset scoliosis (EOS). Since distraction may produce kyphosis, spine length should be assessed in the sagittal plane using the sagittal spine length (SSL-curved arc length of the spine in the sagittal plane). Our purpose was to determine if the type of proximal anchor in distraction-based surgeries will affect final spine length. METHODS: Patients with nonidiopathic EOS treated with distraction-based systems (minimum 5 y follow-up, 5 lengthenings) were identified from 2 EOS registries. Radiographic analysis preoperative, postimplant (L1), and after each lengthening (L2-L5, L6-L10, L11-L15) was performed with the primary outcome of T1-S1 SSL. RESULTS: We identified 126 patients-70 had rib-based implants (52 congenital, 9 syndromic, 9 neuromuscular) and 56 had spine-based implants (15 congenital, 29 syndromic, 12 neuromuscular) with preoperative age 4.6 years, scoliosis 75 degrees, and kyphosis 48 degrees. After initial correction (P<0.05), scoliosis remained constant [58 degrees (13 to 104 degrees) at L11-L15] and kyphosis increased over time [38 degrees (9 to 108 degrees) at L1 to 60 degrees (17 to 134 degrees) at L11-L15] (P<0.05). Preoperative SSL was higher in the spine-based group (29.6 cm) when compared with the rib-based group (25.2 cm) (P<0.05). This difference was maintained after initial implantation (spine-based: 32.2 cm vs. rib-based: 26.7 cm, P<0.05) and at final follow-up (spine-based: 37.0 cm vs. rib-based: 34.4 cm, P<0.05). As preoperative SSL differed between groups, maximum SSL gains per interval were also normalized to preoperative SSL. There was no statistically significant difference between groups at L1, L2-L5, and L6-L10. However, at L11-L15, the rib-based group achieved a more relative increase in spine length compared with the spine-based group (45% vs. 31%, P<0.05). CONCLUSION: At minimum 5 year follow-up, distraction-based surgeries increased spine length for patients with nonidiopathic EOS; regardless of proximal anchor type.

Spinal Deformity in Sotos Syndrome: First Results of Growth-friendly Spine Surgery.

BACKGROUND: Sotos syndrome (SS), or cerebral gigantism, describes children with macrocephaly, craniofacial abnormalities, general overgrowth, ligamentous laxity, developmental delay, and neurological disabilities. Fewer than 500 cases have been reported since Sotos and colleagues described the condition in 1964 and no literature exists on the management of spinal deformity in children under 10 years old.The aims of this study were: (1) to characterize the presentation of spinal deformities in patients with SS; and (2) to provide preliminary results of growth-friendly instrumentation (GFI) in these children. METHODS: Thirteen children (9 boys) with SS and minimum of 2-year follow-up were identified from 2 multicenter early-onset scoliosis (EOS) databases (1997-2017). Mean age at index surgery and follow-up duration were 5.0 years (range, 1.8 to 10 y) and 7.2 years (range, 2.1 to 14.9 y), respectively. Patients underwent GFI for a mean of 5.7 years (range, 2 to 10.2 y), with an average of 9 lengthenings (range, 2 to 18). Definitive spinal fusion was performed in 4 patients (31%). Major curve magnitude, T1-T12 and T1-S1 lengths, thoracic kyphosis, and lumbar lordosis were evaluated preindex, postindex, latest GFI, and postfusion, when possible. RESULTS: Five thoracolumbar (38%), 4 double major (31%), 2 main thoracic (15%), and 2 double thoracic curves (15%) were seen that spanned a mean of 6.8 levels (5 to 9). Major curves improved 36% (range, 5% to 71%), from a mean of 71 degrees (range, 48 to 90 degrees) to 46 degrees (range, 20 to 73 degrees) postindex surgery (P<0.001). Major curves remained stable at a mean of 52 degrees (range, 20 to 87 degrees) at latest GFI (P=0.36). True T1-T12 and T1-S1 growth velocities during GFI were 0.5 mm/mo (range, 0.4 to 0.8 mm/mo) and 0.8 mm/mo (range, 0.1 to 2.1 mm/mo), respectively. Twenty-six complications occurred in 9 patients (69%) averaging 2 complications per patient (range, 0 to 7). CONCLUSIONS: This is the first study to evaluate the outcomes of GFI in children with SS and EOS. Compared with published data for outcomes of GFI in EOS, children with SS may have less major curve correction. Growth-friendly surgery remains an effective treatment method for EOS in patients with SS. LEVELS OF EVIDENCE: Level IV-retrospective case-series.

Idiopathic Early-onset Scoliosis: Growing Rods Versus Vertically Expandable Prosthetic Titanium Ribs at 5-year Follow-up.

BACKGROUND: Distraction-based techniques allow spinal growth until skeletal maturity while preventing curve progression. METHODS: Two multicenter early-onset scoliosis databases were used to identify patients with idiopathic spine abnormalities treated with traditional growing rods (TGR) or vertically expandable titanium ribs (VEPTR). Patients underwent at least 4 lengthenings and had at least 5-year follow-up. Significance was set at P<0.05. RESULTS: In total, 50 patients treated with TGR and 22 treated with VEPTR were included. Mean (±SD) age at surgery was 5.5 (±2.0) years for the TGR group versus 4.3 (±1.9) years for the VEPTR group (P=0.044); other demographic parameters were similar. VEPTR patients had more procedures (mean 15±4.2) than TGR patients (mean 10±4.0) (P=0.001). Unilateral constructs were present in 18% (4 of 22) of VEPTR and 16% (8 of 50) of TGR patients. Bilateral constructs spanned a mean 2.1 additional surgical levels and exposed patients to 1.6 fewer procedures than unilateral constructs. Curve correction was similar between bilateral and unilateral constructs. TGR patients experienced greater curve correction (50%) than VEPTR patients (27%) (P<0.001) and achieved a greater percentage of thoracic height gain (24%) than VEPTR patients (12%) (P=0.024). At latest follow-up, TGR patients had better maintenance of curve correction, less kyphosis, and 15% greater absolute gain in thoracic height versus VEPTR patients. TGR patients had a lower rate of wound complications (14%) than VEPTR patients (41%) (P=0.011). CONCLUSIONS: In patients with idiopathic early-onset scoliosis, TGRs produced greater initial curve correction, greater thoracic height gains, less kyphosis, and lower incidence of wound complications compared with VEPTR. LEVEL OF EVIDENCE: Level III.

Physiological and Metabolic Responses of Rice to Reduced Soil Moisture: Relationship of Water Stress Tolerance and Grain Production.

Access to adequate irrigation resources is critical for sustained agricultural production, and rice, a staple cereal grain for half of the world population, is one of the biggest users of irrigation. To reduce water use, several water saving irrigation systems have been developed for rice production, but a reliable system to evaluate cultivars for water stress tolerance is still lacking. Here, seven rice cultivars that have diverse yield potential under water stress were evaluated in a field study using four continuous irrigation regimes varying from saturation to wilting point. To understand the relationship between water stress and yield potential, the physiological and leaf metabolic responses were investigated at the critical transition between vegetative and reproductive growth stages. Twenty-nine metabolite markers including carbohydrates, amino acids and organic acids were found to significantly differ among the seven cultivars in response to increasing water stress levels with amino acids increasing but organic acids and carbohydrates showing mixed responses. Overall, our data suggest that, in response to increasing water stress, rice cultivars that do not show a significant yield loss accumulate carbohydrates (fructose, glucose, and myo-inositol), and this is associated with a moderate reduction in stomatal conductance (gs), particularly under milder stress conditions. In contrast, cultivars that had significant yield loss due to water stress had the greatest reduction in gs, relatively lower accumulation of carbohydrates, and relatively high increases in relative chlorophyll content (SPAD) and leaf temperature (Tm). These data demonstrate the existence of genetic variation in yield under different water stress levels which results from a suite of physiological and biochemical responses to water stress. Our study, therefore, suggests that in rice there are different physiological and metabolic strategies that result in tolerance to water stress that should be considered in developing new cultivars for deficit irrigation production systems that use less water.

Evidence for divergence of response in Indica, Japonica, and wild rice to high CO2 × temperature interaction.

High CO2 and high temperature have an antagonistic interaction effect on rice yield potential and present a unique challenge to adapting rice to projected future climates. Understanding how the differences in response to these two abiotic variables are partitioned across rice germplasm accessions may be key to identifying potentially useful sources of resilient alleles for adapting rice to climate change. In this study, we evaluated eleven globally diverse rice accessions under controlled conditions at two carbon dioxide concentrations (400 and 600 ppm) and four temperature environments (29 °C day/21 °C night; 29 °C day/21 °C night with additional heat stress at anthesis; 34 °C day/26 °C night; and 34 °C day/26 °C night with additional heat stress at anthesis) for a suite of traits including five yield components, five growth characteristics, one phenological trait, and four photosynthesis-related measurements. Multivariate analyses of mean trait data from these eight treatments divide our rice panel into two primary groups consistent with the genetic classification of INDICA/INDICA-like and JAPONICA populations. Overall, we find that the productivity of plants grown under elevated [CO2 ] was more sensitive (negative response) to high temperature stress compared with that of plants grown under ambient [CO2 ] across this diversity panel. We report differential response to CO2 × temperature interaction for INDICA/INDICA-like and JAPONICA rice accessions and find preliminary evidence for the beneficial introduction of exotic alleles into cultivated rice genomic background. Overall, these results support the idea of using wild or currently unadapted gene pools in rice to enhance breeding efforts to secure future climate change adaptation.

Parameters leading to a successful radiographic outcome following surgical treatment for Lenke 2 curves.

INTRODUCTION: In Lenke 2 curves, there are conflicting data when to include the PTC into the fusion. Studies focusing on Lenke 2 curves are scant. The number of patients with significant postoperative shoulder height difference (SHD) or trunk shift (TS) is as high as 30 % indicating further research. Therefore, the purpose of the current study was to improve understanding of curve resolution and shoulder balance following surgical correction of Lenke 2 curves as well as the identification of radiographic parameters predicting postoperative curve resolution, shoulder and trunk balance in perspective of inclusion/exclusion of the proximal thoracic curve (PTC). METHODS: This is a retrospective study of a 158 Lenke 2 curves. Serial radiographs were analyzed for the main thoracic curve (MTC), PTC, and lumbar curve (LC), SHD, clavicle angle (CA), T-1 tilt, deviation of the central sacral vertical line (CSVL) off the C7 plumb line.Patients were stratified whether the PTC was included in the fusion (+PTC group, n = 60) or not (-PTC group, n = 98). Intergroup results were studied. Compensatory mechanisms for SHD were studied in detail. Adding-on distally was defined as an increase of the lowest instrumented vertebra adjacent disc angle (LIVDA) >3°. Stepwise regression analyses were performed to establish predictive radiographic parameters. RESULTS: At follow-up averaging 24 months significant differences between the +PTC and -PTC group existed for the PTC (24° vs 28°, p < .01), PTC correction (42 vs 29 %, p < .01), rate of MTC-loss >5° (27 vs 53 %, p < .01), and spontaneous LC correction in patients with a selective thoracic fusion (STF) (80/93 %, p = .04). The number of patients with a new trunk shift (CSVL > 2 cm) was 9 (6 %): 7 in the -PTC vs 2 in the +PTC group (p = .03). Utilization of compensatory mechanisms (99 vs 83 %, p < .01) and adding-on (35 vs 20 %, p < .05) occurred more often in the +PTC vs the -PTC groups. Statistics showed postoperative SHD improvement in both the +PTC and -PTC groups. There were no significant differences regarding SHD, CA and T1-Tilt between groups. However, only in the -PTC group, a significant change between postoperative and follow-up SHD existed (p = .02). Statistics identified a preoperative 'left shoulder up' (p < .01) and CSVL (p = .03) predictive for follow-up SHD ≥1.5 cm. A statistical model only for the -PTC group showed 9 parameters highly predictive for a follow-up SHD ≥1.5 cm with highest prediction strength for a PTC >40° (p = .01), a preoperative 'left shoulder up' (p < .01) and anterior fusion (p = .02). To account for baseline differences between the +PTC and -PTC groups, 49 matched-pairs were studied. Postoperative differences remained significant between the +PTC and -PTC groups for the PTC (p < .01), MTC (p = .03) and the rate of loss of MTC >5° (p < .01). CONCLUSION: Prediction of a successful surgical outcome for Lenke 2 curves depends on multiple variables, in particular a preoperative left shoulder up, preoperative PTC >40°, MTC correction, and surgical approach. Shoulder balance is not significantly different whether the PTC is included in the fusion or not. But, powerful compensation mechanisms utilized to balance shoulder in the -PTC group can impose changes of trunk alignment, main and compensatory lumbar curves.

Seasonal methane and nitrous oxide emissions of several rice cultivars in direct-seeded systems.

An understanding of cultivar effects on field greenhouse gas (GHG) emissions in rice ( L.) systems is needed to improve the accuracy of predictive models used for estimating GHG emissions and to evaluate the GHG mitigation potential of different cultivars. We compared CH and NO emissions, global warming potential (GWP = NO + CH), yield-scaled GWP (GWP = GWP Mg grain), and plant growth characteristics of eight cultivars within four study sites in California and Arkansas. Nitrous oxide emissions were negligible (<10% of GWP) and were not different among cultivars. Seasonal CH emissions differed between cultivars by a factor of 2.1 and 1.4 at one California and one Arkansas site, respectively. Plant growth characteristics were generally not correlated with seasonal CH emissions; however, the strongest correlations were observed for shoot and total plant (root + shoot) biomass at heading ( = 0.60) at one California site and for grain at maturity ( = -0.95) at one Arkansas site. Although differences in GWP and GWP were observed, there were inconsistencies across sites, indicating the importance of the genotype × environment interaction. Overall, the cultivars with the lowest CH emissions, GWP, and GWP at the California and Arkansas sites were the lowest and highest yielding, respectively. These findings highlight the potential for breeding high-yielding cultivars with low GWP, the ideal scenario to achieve low GWP, but environmental conditions must also be considered.

Health-related quality of life and clinical outcomes for magnetically controlled growing rod patients after treatment termination.

PURPOSE: To determine the health-related quality of life (HRQoL) and clinical outcomes of children with early onset scoliosis (EOS) treated with magnetically controlled growing rods (MCGR) followed to definitive fusion (DF). METHODS: A retrospective review of EOS patients treated with MCGR and followed to DF was performed. Outcomes included HRQoL scores, radiographic, clinical, and unplanned returns to the operating room (UPROR) data collected at pre-MCGR implantation, immediately post-MCGR implantation, pre-DF, and post-DF. HRQoL scores were collected at least 6 months post-DF. RESULTS: Twenty-eight patients (57.1% females, mean age at MCGR insertion 7.19 ± 1.5 years, mean pre-MCGR Cobb 64.7° ± 17.6) met inclusion criteria. MCGR treatment resulted in an overall 30.2% improvement in coronal plane deformity following DF. The mean growth rates between MCGR implantation and pre-DF for T1-T12 height and T1-S1 length were 0.33 ± 0.23 mm/month and 0.49 ± 0.28 mm/month, respectively. Of the 28 included patients, 26 (92.9%) experienced at least one UPROR, with a total of 52 surgical complications occurring in the total cohort, representing 1.9 UPROR/patient. Interestingly, there was a decline in scores reported between post-MCGR implantation and the pre-DF time-point (N = 16, 78.2 ± 14.9 vs 69.7 ± 17.8, p = 0.02). These scores recovered post-DF, resulting in an overall unchanged HRQoL when comparing pre-MCGR to post-DF (N = 11, 79.9 ± 15.1 vs 76.7 ± 17.9, p = 0.44). CONCLUSION: While MCGR treatment achieves coronal plane deformity control and facilitates spinal growth, only 7.1% of children experienced a complication-free treatment course when followed to definitive fusion. Patients achieved modest curve correction and spinal growth, while maintaining stable HRQoL outcomes between pre-MCGR and post-DF.

Optimal fertilizer nitrogen rates and yield-scaled global warming potential in drill seeded rice.

Drill seeded rice ( L.) is the dominant rice cultivation practice in the United States. Although drill seeded systems can lead to significant CH and NO emissions due to anaerobic and aerobic soil conditions, the relationship between high-yielding management practices, particularly fertilizer N management, and total global warming potential (GWP) remains unclear. We conducted three field experiments in California and Arkansas to test the hypothesis that by optimizing grain yield through N management, the lowest yield-scaled global warming potential (GWP = GWP Mg grain) is achieved. Each growing season, urea was applied at rates ranging from 0 to 224 kg N ha before the permanent flood. Emissions of CH and NO were measured daily to weekly during growing seasons and fallow periods. Annual CH emissions ranged from 9.3 to 193 kg CH-C ha yr across sites, and annual NO emissions averaged 1.3 kg NO-N ha yr. Relative to NO emissions, CH dominated growing season (82%) and annual (68%) GWP. The impacts of fertilizer N rates on GHG fluxes were confined to the growing season, with increasing N rate having little effect on CH emissions but contributing to greater NO emissions during nonflooded periods. The fallow period contributed between 7 and 39% of annual GWP across sites years. This finding illustrates the need to include fallow period measurements in annual emissions estimates. Growing season GWP ranged from 130 to 686 kg CO eq Mg season across sites and years. Fertilizer N rate had no significant effect on GWP; therefore, achieving the highest productivity is not at the cost of higher GWP.

Challenges of spine surgery in patients with chondrodysplasia punctata.

BACKGROUND: Chondrodysplasia punctata (CDP) is a common manifestation of an etiologically heterogenous group of disorders. There is very little data regarding the development and management of spinal deformity in patients with CDP. The purpose of this study was to present a multicenter series of CDP, to describe the surgical outcomes of spinal deformities in CDP patients and to emphasize important considerations that may influence choice of surgical treatment of spinal deformity in this patient population. METHODS: The medical records and spinal radiographs of patients with the diagnosis of CDP followed in 2 centers between 1975 and 2011 were retrospectively reviewed. Epiphyseal stippling was present on radiographs in all patients who fulfilled the clinical criteria. RESULTS: Among the 17 patients who were diagnosed with CDP, 13 had spinal deformities. The mean age at diagnosis of spinal deformity was 14.6 months (range, 1 wk to 9 y). Males and females were close to equally represented (10 males and 7 females). Twelve patients (92%) required surgery to correct spinal deformity. Patients were followed for a median of 8.4 years (range, 2.8 to 19.5 y). The total number of surgical procedures performed was 17 averaging 1.5 per patient. Four patients required >1 procedure. Eighty percent of the patients who required >1 surgical procedure were females with probable diagnosis of X-linked dominant CDP. Revision surgery was indicated in 50% of the patients treated with combined anterior and posterior fusion and 20% of the patients treated with posterior fusion alone. CONCLUSIONS: Spinal deformity in CPD patients may range from significant kyphoscoliosis to minimal deformity that does not require any treatment. For those patients in whom spine surgery was indicated, a high incidence of revision surgery and curve progression after fusion was recorded. Female patients with probable diagnosis of X-linked dominant CDP were more likely to require a second surgical procedure. Isolated posterior fusion showed less favorable results compared with combined anteroposterior fusion in terms of revision surgery. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Increasing soft tissue depth is associated with stalling of magnetically controlled growing rods.

Background: Magnetically controlled growing rods (MCGR) represent the most used implant for the treatment of early onset scoliosis (EOS). These implants lengthen through the application of a remote magnetic field but distraction force generation has been negatively correlated with increasing soft tissue depth. Given the high rate of MCGR stalling, we proposed to investigate the impact of preoperative soft tissue depth on the rate of MCGR stalling at a minimum of 2 years following implantation. Methods: A single-center, retrospective review of prospectively enrolled children with EOS treated with MCGR was performed. Children were included if they had a minimum of 2-years follow-up after implantation and underwent advanced spinal imaging (MRI or CT) preoperatively within a year of implantation. The primary outcome was the development of MCGR stall. Additional measures included radiographic deformity parameters and gain in MCGR actuator length. Results: About 55 patients were identified with 18 having preoperative advanced imaging allowing tissue depth measurement (Mean 5.99 ± 1.9 years, 83.3% female, mean Cobb 68.6 ± 13.8°). At a mean follow-up of 46.1 ± 11.9 months, 7 patients (38.9%) experienced stalling. MCGR stalling was associated with increased preoperative soft tissue depth (21.5 ± 4.4 mm vs. 16.5 ± 4.1 mm; p = .025) and increased BMI (16.3 ± 1.6 vs. 14.5 ± 0.9; p = .007). Conclusions: Greater preoperative soft tissue depth and BMI were associated with the development of MCGR stalling. This data supports previous studies showing that the distraction capacity of MCGR diminishes with increased soft tissue depth. Further research is needed to validate these findings and their implications on the indications for MCGR implantation.

A thoracoscopic anterior approach to the spine for adolescent idiopathic scoliosis does not have a detrimental effect on pulmonary function at 2 years compared to posterior-only surgery.

PURPOSE: This study aims to examine pulmonary function outcomes in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with an anterior thoracoscopic release compared to those undergoing PSF alone. METHODS: A retrospective review of patients with AIS over a 9-year period at a single institution compared 2 groups: PSF with video-assisted thoracoscopic surgery (PSF/VATS) and patients undergoing a posterior spinal fusion (PSF) alone. Standard radiographs and Forced Expiratory Volume (FEV1) and Forced Vital Capacity (FVC) were obtained preoperatively and at regular follow up periods up to 2-year post-operatively. Within group and between-group comparisons were performed. RESULTS: There were 110 patients in the study: 12 in the PSF/VATS cohort and 98 in the PSF only cohort. The PSF/VATS group were younger (12.6 vs. 14.6, p = 0.003) and had larger coronal curves (80.8° vs. 60.7°, p = 0.001), and worse preoperative FVC (64.7% vs. 79.6%, p = 0.018) and FEV1 (62.3% vs. 77.6%, p = 0.003). At 2 years, the percent coronal Cobb correction was greater in the PSF/VATS group (67.9% vs. 48.4%, p < 0.001) with greater improvement in thoracic height (32.8 mm vs. 20.7 mm, p = 0.028). While the 2-year PFTs were the same for FEV1% (75.8% vs. 81.8%, p = 0.368) and FVC% (77.3% vs. 83.7%, p = 0.562), there was greater percent improvement over the 2 years in the PSF/VATS cohort: FEV1% (13.5% vs. 4.2%, p = 0.082) and FVC% (12.7% vs. 4.1%, p = 0.112). CONCLUSION: AIS patients who have a VATS approach in addition to PSF have greater coronal plane correction and improved pulmonary function compared to PSF alone despite more severe spinal deformity and worse baseline pulmonary function.

The evolving stall rate of magnetically controlled growing rods beyond 2 years follow-up.

PURPOSE: Magnetically controlled growing rods (MCGR) have become the dominant distraction-based implant for the treatment of early onset scoliosis (EOS). Recent studies, however, have demonstrated rising rates of implant failure beyond short-term follow-up. We sought to evaluate a single-center experience with MCGR for the treatment of EOS to define the rate of MCGR failure to lengthen, termed implant stall, over time. METHODS: A single-center, retrospective review was conducted identifying children with EOS undergoing primary MCGR implantation. The primary endpoint was the occurrence of implant stalling, defined as a failure of the MCGR to lengthen on three consecutive attempted lengthening sessions with minimum of 2 years follow-up. Clinical and radiographic variables were collected and compared between lengthening and stalled MCGRs. A Kaplan-Meier survival analysis was conducted to assess implant stalling over time. RESULTS: A total of 48 children met inclusion criteria (mean age 6.3 ± 1.8 years, 64.6% female). After a mean 56.9 months (range of 27 to 90 months) follow-up, 25 (48%) of children experienced implant stalling at a mean of 26.0 ± 14.1 months post-implantation. Kaplan-Meier survival analysis demonstrated that only 50% of MCGR continue to successfully lengthen at 2 years post-implantation, decreasing to < 20% at 4 years post-implantation. CONCLUSION: Only 50% of MCGR continue to successfully lengthen 2 years post-implantation, dropping dramatically to < 20% at 4 years, adding to the available knowledge regarding the long-term viability and cost-effectiveness of MCGR in the management of EOS. Further research is needed to validate these findings.

Impact of surgical treatment on parent-reported health related quality of life measures in early-onset scoliosis: stable but no improvement at 2 years.

PURPOSE: The etiology of early-onset scoliosis (EOS) has been shown to significantly influence baseline parent-reported health-related quality of life (HRQoL) measures as assessed by the Early Onset Scoliosis Questionnaire (EOSQ). We sought to assess the influence of distraction-based surgery and scoliosis etiology on EOSQ 2 years following surgical intervention remains unclear. METHODS: A retrospective review of a multi-center prospective EOS database was performed. Children untreated with distraction-based, growth friendly instrumentation for EOS with completed baseline and 2-year post-surgical EOSQ were included. Children were subdivided by curve etiology individually and in combined cohorts (congenital/idiopathic [C/I], neuromuscular/syndromic [NMS]). EOSQ domains and compositive HRQoL score at presentation and 2-year follow-up were compared across C-EOS etiologies. Minimal clinically important difference (MCID) was defined as ≥ 20% change in domain score and compared across etiologies. RESULTS: 150 children with EOS met inclusion criteria (mean 7.09 ± 2.6 years, 58.9% female). There were no differences in EOSQ domains between Congenital vs. Idiopathic nor NM vs. Syndromic etiologies at any timepoint. Combined C/I children demonstrated significantly higher EOSQ scores than combined NMS at initial and 2-years post-treatment. Etiology remained the only independent predictor of 2-year EOSQ composite HRQoL score. Overall, the vast majority of children demonstrated stable HRQoL composite scores, with a trend toward more positive MCID in NMS etiologies. CONCLUSION: EOS etiology remains the most significant influence on EOSQ scores 2 years following surgical intervention. However, the majority of patients, regardless of etiology, maintain stable HRQoL scores suggesting that surgery may only serve to stabilize HRQoL at 2 years.

Serial casting as a delay tactic in the treatment of moderate-to-severe early-onset scoliosis.

BACKGROUND: Serial casting can cure mild infantile idiopathic scoliosis. Its use in delaying surgery in older children and those with larger curves or syndromes is poorly defined. METHODS: A review of a single center's experience with casting was performed. Patients were included if they had a syndromic, neuromuscular, or congenital scoliosis or were older than 2.5 years with an idiopathic scoliosis measuring >50 degrees. RESULTS: A retrospective review was performed on 29 patients meeting all inclusion criteria. Of these, 12 were idiopathic and 17 were nonidiopathic curves. Average age at first cast was 4.4 ± 2.1 years, and 3.0 ± 1.8 cast changes were performed over 1.4 ± 1.1 years. Patients were transitioned to a brace and followed up for 5.5 years (range, 2.2 to 11.4 y). The main thoracic Cobb angle before casting was 68.8 ± 12.3 degrees, which corrected to 39.1 ± 16.4 degrees in a cast. Cobb angle after cast removal was 60.9 ± 18.4 degrees, which increased to 76.3 ± 24.0 degrees at final follow-up. T1-T12 height increased to 1.1 ± 2.6 cm during the treatment period (P=0.05). There were 5 minor complications. Fifteen patients (51.7%) required surgical treatment for their scoliosis at most recent follow-up and an additional 7 patients (24.1%) were delayed until a definitive anterior/posterior spinal fusion could be performed. Surgery was delayed 39 ± 25 months from the first cast. Growing rods were required in 8 patients (27.6%). The patients who ultimately underwent surgical intervention (SG) were more likely to have a larger postcasting residual main thoracic Cobb angle than those who did not require surgery [NS; 69.5 ± 14.6 degrees (SG) vs. 51.6 ± 17.9 degrees (NS), P=0.007] and had a greater progression of their curves after cast removal [20.9 ± 13.5 degrees (SG) vs. 9.4 ± 11.0 degrees (NS), P=0.02]. CONCLUSIONS: Serial casting is a viable alternative to surgical growth sparing techniques in moderate-to-severe early-onset scoliosis and may help delay eventual surgical intervention. Although a cure cannot be expected, an average of 39 months of delay was achieved in this patient cohort and 72.4% have avoided growing spine surgery. LEVEL OF EVIDENCE: Level IV, case series.