bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing uncertainty in building material emissions using scenario-aware Monte Carlo simulation
Authors: Bin Thaneya Ahmad , Gursel Aysegul Petek , Kane Seth , Miller Sabbie A , Horvath Arpad
Published: April 2024

Global greenhouse gas emissions from the built environment remain high, driving innovative approaches to develop and adopt building materials that can mitigate some of those emissions. However, life-cycle assessment (LCA) practices still lack standardized quantitative uncertainty assessment frameworks, which are urgently needed to robustly assess mitigation efforts. Previous works emphasize the importance of accounting for the three types of uncertainties that may exist within any quantitative assessment: parameter, scenario, and model uncertainty. Herein, we develop a quantitative uncertainty assessment framework that distinguishes between different types of uncertainties and suggest how these uncertainties could be handled systematically through a scenario-aware Monte Carlo simulation (MCS). We demonstrate the framework’s decision-informing power through a case study of two multilevel ordinary Portland cement (OPC) manufacturing scenarios. The MCS utilizes a first-principles-based OPC life-cycle inventory, which mitigates some of the model uncertainty that may exist in other empirical-based cement models. Remaining uncertainties are handled by scenario specification or sampling from developed probability distribution functions. We also suggest a standardized method for fitting distributions to parameter data by enumerating through and implementing distributions based on the Kolmogorov–Smirnov test. The level of detail brought by the high-resolution parameter breakdown of the model allows for developing emission distributions for each process of OPC manufacturing. This approach highlights how specific parameters, along with scenario framing, can impact overall OPC emissions. Another key takeaway includes relating the uncertainty of each process to its contributions to total OPC emissions, which can guide LCA modelers in allocating data collection and refinement efforts to processes with the highest contribution to cumulative uncertainty. Ultimately, the aim of this work is to provide a standardized framework that can provide robust estimates of building material emissions and be readily integrated within any uncertainty assessment.
Convergence of the numerical approximations and well-posedness: Nonlocal conservation laws with rough flux
Authors: Aggarwal Aekta , Vaidya Ganesh
Published: April 2024

We study a class of nonlinear nonlocal conservation laws with discontinuous flux, modeling crowd dynamics and traffic flow. The discontinuous coefficient of the flux function is assumed to be of bounded variation (BV) and bounded away from zero, and hence the spatial discontinuities of the flux function can be infinitely many with possible accumulation points. Strong compactness of the Godunov and Lax-Friedrichs type approximations is proved, providing the existence of entropy solutions. A proof of the uniqueness of the adapted entropy solutions is provided, establishing the convergence of the entire sequence of finite volume approximations to the adapted entropy solution. As per the current literature, this is the first well-posedness result for the aforesaid class and connects the theory of nonlocal conservation laws (with discontinuous flux), with its local counterpart in a generic setup. Some numerical examples are presented to display the performance of the schemes and explore the limiting behavior of these nonlocal conservation laws to their local counterparts.
Surface counterexamples to the Eisenbud-Goto conjecture
Authors: Han Jong In , Kwak Sijong
Published: April 2024

It is well known that the Eisenbud-Goto regularity conjecture is true for arithmetically Cohen-Macaulay varieties, projective curves, smooth surfaces, smooth threefolds in

P

5

\mathbb {P}^5

, and toric varieties of codimension two. After J. McCullough and I. Peeva constructed counterexamples in 2018, it has been an interesting question to find the categories such that the Eisenbud-Goto conjecture holds. So far, surface counterexamples have not been found while counterexamples of any dimension greater or equal to 3 are known.

In this paper, we construct counterexamples to the Eisenbud-Goto conjecture for projective surfaces in

P

4

\mathbb {P}^4

and investigate projective invariants, cohomological properties, and geometric properties. The counterexamples are constructed via binomial rational maps between projective spaces.
Equivariant lattice bases
Authors: Le Dinh , Römer Tim
Published: April 2024

We study lattices in free abelian groups of infinite rank that are invariant under the action of the infinite symmetric group, with emphasis on finiteness of their equivariant bases. Our framework provides a new method for proving finiteness results in algebraic statistics. As an illustration, we show that every invariant lattice in

Z

(

N

×
[
c
]
)

\mathbb {Z}^{(\mathbb {N}\times [c])}

, where

c
∈

N

c\in \mathbb {N}

, has a finite equivariant Graver basis. This result generalizes and strengthens several finiteness results about Markov bases in the literature.
Projective dimensions of hyperplane arrangements
Authors: Abe Takuro
Published: April 2024

We establish a general theory for projective dimensions of the logarithmic derivation modules of hyperplane arrangements. This includes an addition-deletion and a restriction theorem, a Yoshinaga type result, and a division theorem for projective dimensions of hyperplane arrangements. These new theorems are all generalizations of classical results for free arrangements, which is the special case of projective dimension zero. To prove these results, we introduce several new methods to determine the surjectivity of the Euler and the Ziegler restriction maps, which is combinatorially determined when the projective dimension is not maximal for all localizations. Also, we introduce a new class of arrangements in which the projective dimension is combinatorially determined.
Cortical activations associated with spatial remapping of finger touch using EEG
Authors: Alouit Anaëlle , Gavaret Martine , Ramdani Céline , Lindberg Påvel G , Dupin Lucile
Published: April 2024

The spatial coding of tactile information is functionally essential for touch-based shape perception and motor control. However, the spatiotemporal dynamics of how tactile information is remapped from the somatotopic reference frame in the primary somatosensory cortex to the spatiotopic reference frame remains unclear. This study investigated how hand position in space or posture influences cortical somatosensory processing. Twenty-two healthy subjects received electrical stimulation to the right thumb (D1) or little finger (D5) in three position conditions: palm down on right side of the body (baseline), hand crossing the body midline (effect of position), and palm up (effect of posture). Somatosensory-evoked potentials (SEPs) were recorded using electroencephalography. One early-, two mid-, and two late-latency neurophysiological components were identified for both fingers: P50, P1, N125, P200, and N250. D1 and D5 showed different cortical activation patterns: compared with baseline, the crossing condition showed significant clustering at P1 for D1, and at P50 and N125 for D5; the change in posture showed a significant cluster at N125 for D5. Clusters predominated at centro-parietal electrodes. These results suggest that tactile remapping of fingers after electrical stimulation occurs around 100–125 ms in the parietal cortex.
Prediction of incident chronic kidney disease in community-based electronic health records: a systematic review and meta-analysis
Authors: Haris Mohammad , Raveendra Keerthenan , Travlos Christoforos K , Lewington Andrew , Wu Jianhua , Shuweidhi Farag , Nadarajah Ramesh , Gale Chris P
Published: April 2024

Background

Chronic kidney disease (CKD) is a major global health problem and its early identification would allow timely intervention to reduce complications. We performed a systematic review and meta-analysis of multivariable prediction models derived and/or validated in community-based electronic health records (EHRs) for the prediction of incident CKD in the community.

Methods

Ovid Medline and Ovid Embase were searched for records from 1947 to 31 January 2024. Measures of discrimination were extracted and pooled by Bayesian meta-analysis, with heterogeneity assessed through a 95% prediction interval (PI). Risk of bias was assessed using Prediction model Risk Of Bias ASsessment Tool (PROBAST) and certainty in effect estimates by Grading of Recommendations, Assessment, Development and Evaluation (GRADE).

Results

Seven studies met inclusion criteria, describing 12 prediction models, with two eligible for meta-analysis including 2 173 202 patients. The Chronic Kidney Disease Prognosis Consortium (CKD-PC) (summary c-statistic 0.847; 95% CI 0.827–0.867; 95% PI 0.780–0.905) and SCreening for Occult REnal Disease (SCORED) (summary c-statistic 0.811; 95% CI 0.691–0.926; 95% PI 0.514–0.992) models had good model discrimination performance. Risk of bias was high in 64% of models, and driven by the analysis domain. No model met eligibility for meta-analysis if studies at high risk of bias were excluded, and certainty of effect estimates was ‘low’. No clinical utility analyses or clinical impact studies were found for any of the models.

Conclusions

Models derived and/or externally validated for prediction of incident CKD in community-based EHRs demonstrate good prediction performance, but assessment of clinical usefulness is limited by high risk of bias, low certainty of evidence and a lack of impact studies.
Iterated Admissibility does not Refine Extensive-form Rationalizability
Authors: Catonini Emiliano
Published: April 2024

I show that, in an extensive-form game, the outcomes that are consistent with iterated admissibility (i.e., with the iterated elimination of weakly dominated strategies) need not be consistent with extensive-form rationalizability.
Diversity of fishing strategies and high spatial adaptivity in the Alaskan snow crab fishery
Authors: Wang Terrance , Szuwalski Cody S , Punt André E , Hilborn Ray
Published: April 2024

Fishing behavior is an important link between management decisions and bioeconomic outcomes. The diversity in fishers’ behavior, motivations, and abilities should inform incentive structures if management aims to consider heterogeneous impacts on and by communities. Modeling human behavior in resource management is important for successful fisheries, especially for fisheries undergoing rapid transformation, such as the Alaskan snow crab fishery. This study modeled how snow crabbers choose where to fish in the eastern Bering Sea and examined the diversity of strategies among individuals by fitting a random utility model to data on fishing locations using a variety of potential drivers of behavior as covariates. The overall fishing strategy of the snow crab fleet prioritizes revenue and shared information, while avoiding risk, poor weather, and cost. Diversity of fishing strategies was driven by differences in spatial footprint, vessel size, and ports of landing. Larger vessels ventured farther north, where weather conditions are more extreme. Despite differences in vessel size, crabbers were spatially adaptive and switched fishing regions depending on the abundance and distribution of crab. These findings on the patterns of fishing strategies can inform better management of the Alaskan snow crab fishery as it undergoes rebuilding.
The Extremal Number of Cycles with All Diagonals
Authors: Bradač Domagoj , Methuku Abhishek , Sudakov Benny
Published: April 2024

In 1975, Erd̋s asked the following question: What is the maximum number of edges that an $n$-vertex graph can have without containing a cycle with all diagonals? Erd̋s observed that the upper bound $O(n^{5/3})$ holds since the complete bipartite graph $K_{3,3}$ can be viewed as a cycle of length six with all diagonals. In this paper, we resolve this old problem. We prove that there exists a constant $C$ such that every $n$-vertex graph with at least $Cn^{3/2}$ edges contains a cycle with all diagonals. Since any cycle with all diagonals contains cycles of length four, this bound is best possible using well-known constructions of graphs without four-cycles based on finite geometry. Among other ideas, our proof involves a novel lemma about finding an almost-spanning robust expander, which might be of independent interest.
Combining compositional data sets introduces error in covariance network reconstruction
Authors: Brunner James D , Robinson Aaron J , Chain Patrick S G
Published: April 2024

Microbial communities are diverse biological systems that include taxa from across multiple kingdoms of life. Notably, interactions between bacteria and fungi play a significant role in determining community structure. However, these statistical associations across kingdoms are more difficult to infer than intra-kingdom associations due to the nature of the data involved using standard network inference techniques. We quantify the challenges of cross-kingdom network inference from both theoretical and practical points of view using synthetic and real-world microbiome data. We detail the theoretical issue presented by combining compositional data sets drawn from the same environment, e.g. 16S and ITS sequencing of a single set of samples, and we survey common network inference techniques for their ability to handle this error. We then test these techniques for the accuracy and usefulness of their intra- and inter-kingdom associations by inferring networks from a set of simulated samples for which a ground-truth set of associations is known. We show that while the two methods mitigate the error of cross-kingdom inference, there is little difference between techniques for key practical applications including identification of strong correlations and identification of possible keystone taxa (i.e. hub nodes in the network). Furthermore, we identify a signature of the error caused by transkingdom network inference and demonstrate that it appears in networks constructed using real-world environmental microbiome data.
Real-time automated deep learning based railroad trespassing violation detection and tracking at highway-rail grade crossing
Authors: Yang Xue , Li Joshua Qiang , Zhan You (Jason) , Yu Wenying
Published: April 2024

Trespassing is one of the utmost safety concerns at highway-rail grade crossings (HRGCs) but many trespassing incidents have not been recorded and deeply studied since no collision or otherwise injured or killed, which might possibly contribute to crashes if they repeatedly occur. Detection and prevention of such events are critical for railroad safety improvements, while this task is challenging due to the immense labor costs required for processing streamed video files. This study developed an advanced You Look Only Once (YOLO) deep learning architecture and the Deep Simple Online and Real-time Tracking (Deep SORT) algorithm with a low confidence tracking filter for real-time trespassing violation detection. Different types of trespassing violation were detected at a gated HRGC in Folkston, Georgia. 436 trespassing violations were identified in the selected 104-hour video data. The automated trespassing violation detection speed ranged from 43.2 to 654.5 frames per second (FPS), exceeding the field video data recording rate at 30 FPS. The developed methodology resulted in 32 false negatives and 20 false positive detections, with the precision, recall, and F1 values scoring above 92.0%. This work could assist railroad agencies in reducing trespassing violations based on real-time detection and tracking.
Lessons learned from Jordan’s response to the Syria refugee crisis
Authors: Popescu Christian , Abu-Siam Ibraheem , Khalifa Adam , Ababneh Huda , Al Raiby Jamela , Bartsch Dominik , Bellizzi S
Published: April 2024

The number of refugees across the world has jumped from 15.7 million to 34.6 million in the past 10 years, and their forced displacement situation has remain for an average period of 20 years. To ensure sustainable benefits, health system strengthening through development cooperation should be a priority in parallel to humanitarian aid early on in refugee crises.
Assessing the quality of data on international migration flows in Europe: The case of undercounting
Authors: Dańko Maciej J , Wiśniowski Arkadiusz , Jasilionis Domantas , Jdanov Dmitri A , Zagheni Emilio
Published: April 2024

Undercounting is a critical issue in migration statistics, resulting in bias. This typically arises from insufficient reporting requirements and problems with enforcing such requirements. The main sources of information on undercounting are the metadata accompanying official statistics and expert opinions. However, metadata and arbitrary expert opinions may be limited by overlooking important details in migration data shared by various countries. This includes potential oversight of changes in methodologies, definitions, or retrospective updates to the data following censuses. This work presents a methodological solution with three objectives to address undercounting in international migration data. First, we provide an overview of available metadata and expert opinions on undercounting in European migration flows. Secondly, we propose a novel data-driven approach that incorporates year-specific and duration-of-stay-adjusted classifications. The proposed methodological solution relies on comparisons of flows in the same direction reported by a given country with high-quality data reported by another set of countries. We use bilateral migration data provided by Eurostat, United Nations, and selected national statistical institutes. Duration-of-stay correction coefficients are derived through an optimization model or borrowed from the literature. Metadata and expert opinion scores can also be integrated to classify undercounting. Finally, we provide a dynamic classification of undercounting for thirty-two European countries (2002–21), accessible through an online Shiny application, offering flexibility and adaptability. The findings highlight significant undercounting in new European Union Member States, particularly Bulgaria, Latvia, and Romania. Interestingly, other European countries, including those presumed to maintain reliable population statistics, also exhibit notable periods of undercounting.
QTL Mapping of Adult Plant Resistance to Powdery Mildew in Chinese Wheat Landrace Baidatou
Authors: Zhou Yongchao , Gu Yudi , Zhang Xiaomei , Wang Wenli , Li Qiang , Wang Baotong
Published: April 2024

Wheat powdery mildew, caused by the biotrophic fungus Blumeria graminis f. sp. tritici (Bgt), is one of the most devastating diseases affecting wheat throughout the world. Breeding and growing resistant wheat cultivars is one of the most economic and effective methods to control the disease, and as such, identifying and mapping the new and effective resistance genes is critical. Baidatou, a Chinese wheat landrace, shows excellent field resistance to powdery mildew. To identify the resistance gene(s) in Baidatou, 170 F7:8 recombinant inbred lines (RILs) derived from the cross Mingxian 169/Baidatou were evaluated for powdery mildew response at the adult-plant stage in the experimental fields in Yangling (YL) of Shaanxi Province and Tianshui (TS) in Gansu Province in 2019, 2020, and 2021. The relative area under disease progress curve (rAUDPC) of Mingxian 169/Baidatou F7:8 RILs indicated that the resistance of Baidatou to powdery mildew was controlled by quantitative trait loci (QTLs). Based on bulk segregation analysis combined with the 660K single nucleotide polymorphism (SNP) array and genotyping by target sequencing (16K SNP) of the entire RIL population, two QTLs, QPmbdt.nwafu-2AS and QPmbdt.nwafu-3AS, were identified, and these accounted for up to 44.5% of the phenotypic variation. One of the QTLs was located on the 3.32 cM genetic interval on wheat chromosome 2AS between the kompetitive allele-specific PCR markers AX-111012288 and AX_174233809, and another was located on the 9.6 cM genetic interval on chromosome 3AS between the SNP markers 3A_684044820 and 3A_686681822. These markers could be useful for successful breeding of powdery mildew resistance in wheat.
What molecular allergy teaches us about genetics and epidemiology of allergies
Authors: Biagioni Benedetta , Scala Enrico , Cecchi Lorenzo
Published: April 2024

Purpose of review

To delineate pertinent information regarding the application of molecular allergology within the realm of both genetic and epidemiological facets of allergic diseases.

Recent findings

The emergence of molecular allergy has facilitated the comprehension of the biochemical characteristics of allergens originating from diverse sources. It has allowed for the exploration of sensitization trajectories and provided novel insights into the influence of genetics and environmental exposure on the initiation and development of allergic diseases. This review delves into the primary discoveries related to the genetics and epidemiology of allergies, facilitated by the application of molecular allergy. It also scrutinizes the impact of environmental exposure across varied geoclimatic, socioeconomic, and lifestyle contexts. Additionally, the review introduces specific models of molecular allergy within the realms of plants and animals.

The utilization of molecular allergy in clinical practice holds crucially acknowledged diagnostic and therapeutic implications. From a research standpoint, there is a growing need for the widespread adoption of molecular diagnostic tools to achieve a more profound understanding of the epidemiology and natural progression of allergic diseases.
Improving Osteoporosis Prediction Using Vertebral Bone Quality Score and Paravertebral Muscle Measurements From Lumbar MRI Scans
Authors: Özmen Emre , Biçer Ozancan , Bariş Alican , Circi Esra , Yüksel Serdar , Beytemür Ozan , Kesiktaş Fatma Nur
Published: April 2024

Study Design:

Retrospective cohort.

Objective:

This study aims to use a novel method of combining vertebral bone quality score with paravertebral cross-sectional area measurements to improve the accuracy of predicting individuals with total hip T-scores <−2.5.

Summary of Background Data:

Osteoporosis is a prevalent skeletal condition associated with decreased bone density and increased fracture risk. Dual-energy x-ray absorptiometry (DXA) is the conventional method for diagnosing osteoporosis, but it has limitations. Opportunistic osteoporosis screening techniques using lumbar magnetic resonance imaging (MRI), particularly the vertebral bone quality (VBQ) score, have shown promise. This study aims to improve the accuracy of predicting individuals with low total hip T-scores using a novel method that combines VBQ scores with paravertebral cross-sectional area (CSA) measurements.

Methods:

A retrospective cohort of 98 patients with DXA and lumbar MRI scans was analyzed. VBQ scores were calculated based on lumbar MRI images, and CSA measurements of paravertebral and psoas muscles were obtained. Threshold-based logistic regression was used to identify optimal thresholds for predicting total hip T-scores <−2.5.

Results:

The combined model incorporating the VBQ score and paravertebral muscle percent achieved an accuracy of 96.9% for predicting total hip T-scores <−2.5, compared to 81.6% when using the VBQ score alone. Incorporating paravertebral muscle measurements significantly improved the accuracy of identifying osteoporotic individuals.

Conclusions:

The combination of VBQ score and paravertebral muscle measurements enhances the accuracy of predicting individuals with low total hip T-scores. Lumbar MRI scans provide valuable information beyond opportunistic osteoporosis screening, and the inclusion of paravertebral muscle measurements could aid in identifying at-risk individuals more accurately.
Improvement of Postoperative Quality of Life in Patients Over 80 Years Old With Thoracic Spinal Stenosis
Authors: Chen Guozhao , Shi Jinhui
Published: April 2024

Study Design:

A retrospective comparative study was conducted to analyze the outcome of surgical and conservative treatment for patients over 80 years old with thoracic spinal stenosis (TSS).

Objective:

To evaluate the safety and efficiency of posterior spinal cord decompression surgery for over 80-year-old patients with TSS.

Summary of Background Data:

Concerned about the risk of surgery, over 80-year-old patients with TSS are usually treated conservatively, which often leads to a decline in quality of life. So far as we know, no study demonstrates the risk and benefit of spine surgery for these patients.

Methods:

Over 80 years of age who underwent dorsal decompression surgery or conservative treatment due to TSS between January 2010 and November 2020 were analyzed. Sixty-four patients who completed follow-up PROM (patient-reported outcome measure) data were collected, including the mJOA (modified Japanese Orthopedic Association score) scoring system, VAS (visual analogue scale), questionnaire-based assessment of the ODI (Oswestry disability index), BI (Barthel index), and SF-36v2 (Short Form-36v2) Health Survey. The clinical characteristics, preoperative and postoperative imaging findings, operative records, complications, and individual outcomes were analyzed.

Results:

Of the 64 patients, 38 underwent posterior decompression, pedicle screw fixation, and posterolateral fusion; another 26 chose conservative treatment. The baseline characteristics of the TSS patients in 2 groups show no significant differences. The clinical symptoms and imaging outcomes showed a significant improvement in the surgical group compared with the nonsurgical group, according to mJOA, VAS, ODI, BI, and SF-36v2. Cerebrospinal fluid leakage occurred in 6 patients, and transient neurological impairment occurred in 2 patients.

Conclusions:

Posterior decompression surgery for over 80-year-old patients with TSS is a safe and effective treatment, it has a good clinical outcome as well as an acceptable complication rate. However, there were no obvious improvements in quality of life or pain with conservative treatment.
Surgical Outcomes of Extensive Dome-Like Laminoplasty Using En Bloc Resection of C2 Inner Lamina for Patients With Severe Cord Compression Behind C2 Body
Authors: Kang Kyung-Chung , Lee Jung-Hee , Lee Ki Young , Jang Tae Su
Published: April 2024

Study Design:

A retrospective, single-center study.

Objective:

The aim of this study is to evaluate the efficacy and safety of a newly developed extensive dome-like laminoplasty using en bloc resection of the C2 inner lamina in patients with severe cord compression behind the C2 body.

Summary of Background Data:

A surgery for severe cord compression behind C2 body is challenging for spinal surgeons. To date, there has been no established solution for severe cord compression behind the C2 body.

Materials and Methods:

Patients with severe cord compression behind the C2 body who underwent posterior surgery consecutively were enrolled. Extensive dome-like laminoplasty that was newly developed was performed to remove en bloc removal of the C2 inner lamina were performed. Preoperative and postoperative canal diameters behind the C2 and mean removed area of the C2 inner lamina were measured using MRI and CT scan. Clinical and radiographic parameters were assessed preoperative and postoperative periods. In addition, perioperative complications were analyzed.

Results:

A total of 36 patients underwent extensive dome-like laminoplasty and their diagnoses were ossification of the posterior longitudinal ligament (OPLL, 66.7%) and congenital stenosis with spondylosis (33.3%). The mean canal diameter behind the C2 increased from 9.85 (2.28) mm preoperatively to 19.91 (3.93) mm at the last follow-up (P<0.001). Clinically, neck and arm visual analog scale, Japanese Orthopaedic Association score, and neck disability index significantly improved at postoperative 1 month (P<0.05), and the scores were maintained until the last follow-up. No meaningful radiographic changes occurred after the surgeries. During the procedures, there were no particular complications, but one patient showed deteriorated myelopathic symptoms and underwent additional C1–C2 decompressive surgery.

Conclusions:

After extensive dome-like laminoplasty, surgical outcomes are satisfactory, and complications are rare. This technique may be a viable option for patients with severe cord compression behind the C2 body.

Level of Evidence:

Level IV.
The Evolution of Enhanced Recovery After Surgery
Authors: Passias Peter G. , Tretiakov Peter S. , Onafowokan Oluwatobi O. , Galetta Matthew , Lorentz Nathan , Mir Jamshaid M. , Das Ankita , Dave Pooja , Lafage Renaud , Yee Timothy , Diebo Bassel , Vira Shaleen , Jankowski Pawel P. , Hockley Aaron , Daniels Alan , Schoenfeld Andrew J. , Mummaneni Praveen , Paulino Carl B. , Lafage Virginie
Published: April 2024

Study Design:

Retrospective cohort.

Objective:

To investigate the impact of evolving Enhanced Recovery After Surgery (ERAS) protocols on outcomes after cervical deformity (CD) surgery.

Background:

ERAS can help accelerate patient recovery and assist hospitals in maximizing the incentives of bundled payment models while maintaining high-quality patient care. However, there remains a paucity of literature assessing how developments have impacted outcomes after adult CD surgery.

Methods:

Patients with operative CD 18 years or older with pre-baseline and 2 years (2Y) postoperative data, who underwent ERAS protocols, were stratified by increasing implantation of ERAS components: (1) early (multimodal pain program), (2) intermediate (early protocol + paraspinal blocks, early ambulation), and (3) late (early/intermediate protocols + comprehensive prehabilitation). Differences in demographics, clinical outcomes, radiographic alignment targets, perioperative factors, and complication rates were assessed through Bonferroni-adjusted means comparison analysis.

Results:

A total of 131 patients were included (59.4 ± 11.7 y, 45% females, 28.8 ± 6.0 kg/m2). Of these patients, 38.9% were considered “early,” 36.6% were “intermediate,” and 24.4% were “late.” Perioperatively, rates of intraoperative complications were lower in the late group (P = 0.036). Postoperatively, discharge disposition differed significantly between cohorts, with late patients more likely to be discharged to home versus early or intermediate cohorts [χ2(2) = 37.973, P < 0.001]. In terms of postoperative disability recovery, intermediate and late patients demonstrated incrementally improved 6 W modified Japanese Orthopedic Association scores (P = 0.004), and late patients maintained significantly higher mean Euro-QOL 5-Dimension Questionnaire and modified Japanese Orthopedic Association scores by 1 year (P < 0.001, P = 0.026). By 2Y, cohorts demonstrated incrementally increasing SWAL-QOL scores (all domains P < 0.028) domain scores versus early or intermediate cohorts. By 2Y, incrementally decreasing reoperation was observed in early versus intermediate versus late cohorts (P = 0.034).

Conclusions:

The present study demonstrates that patients enrolled in an evolving ERAS program demonstrate incremental improvement in preoperative optimization and candidate selection, greater likelihood of discharge to home, decreased postoperative disability and dysphasia burden, and decreased likelihood of intraoperative complications and reoperation rates.
Factors Associated With Repeat Surgery in Cervical Ossification of the Posterior Longitudinal Ligaments
Authors: Jang Hyun Jun , Moon Bong Ju , Kim Kyung Hyun , Park Jeong Yoon , Chin Dong Kyu , Kim Keun Su , Cho Yong Eun
Published: April 2024

Study Design:

Single-center retrospective study.

Objective:

The objective of this study is to identify the factors leading to repeat surgery in patients with cervical ossification of the longitudinal ligament (OPLL) during a minimal 8-year follow-up after the initial surgery.

Summary of Background Data:

The long-term effects of cervical OPLL are well known, but it’s not always clear how many patients need to have surgery again because their neurological symptoms get worse.

Methods:

This study is included 117 patients who underwent surgery for cervical OPLL and had a follow-up of at least 8 years. OPLL type, surgical extent, surgical method, and sagittal radiological parameters were measured, and OPLL characteristics were analyzed.

Results:

The average age of patients at the time of surgery was 53.2 years, with a male-to-female ratio of 78:39. The median follow-up duration was 122 months (96–170 mo). Out of the total, 20 cases (17.1%) necessitated repeat surgery, among which 8 cases required surgery at the same site as the initial operation. The highest rate of repeat surgery was observed in patients who underwent total laminectomy without fusion (TL), where 6 out of 21 patients (29%) needed a second surgery, and 5 of these (23%) involved the same surgical site. Patients who underwent repeat surgery at the same site exhibited a greater range of motion (ROM) one year postsurgery (16.4 ± 8.5° vs. 23.1 ± 12.7°, P=0.041). In addition, the ROM at 1 year was higher in patients who underwent TL compared with those who had laminoplasty. Furthermore, the recurrence rate for hill-shape OPLL was higher at 30.8% compared to 10% for plateau-shape OPLL (P = 0.05).

Conclusion:

Larger cervical ROM 1 year after surgery is related to repeat surgery at the same level as previous surgery, especially in laminectomy without fusion surgery.
Comparison of Cervical Pedicle Screw Placement Accuracy With Robotic Guidance System Versus Image Guidance System Using Propensity Score Matching
Authors: Yamamoto Yuki , Fujishiro Takashi , Hirai Hiromichi , Hayama Sachio , Nakaya Yoshiharu , Usami Yoshitada , Neo Masashi
Published: April 2024

Study Design:

A retrospective study.

Objective:

To compare the accuracy of cervical pedicle screw (CPS) placement using a robotic guidance system (RGS) with that of using an image guidance system (IGS; navigation system) through propensity score matching.

Background:

The RGS may provide accurate CPS placement, which may outperform IGS. However, no study has directly compared the accuracy of CPS placement with the RGS to that with the IGS.

Patients and Methods:

We retrospectively reviewed the data of patients who had undergone cervical fusion surgery using CPS with the RGS or IGS. To adjust for potential confounders (patient demographic characteristics, disease etiology, and registration material), propensity score matching was performed, creating robotic guidance (RG) and matched image guidance (IG) groups. The accuracy of CPS placement from C2 to C6, where the vertebral artery runs, was evaluated on postoperative computed tomography images according to the Neo classification (grade 0 to grade 3). Furthermore, the intraoperative CPS revisions and related complications were examined.

Results:

Using propensity score matching, 22 patients were included in the RG and matched groups each, and a total of 95 and 105 CPSs, respectively, were included in the analysis. In both the axial and sagittal planes, the clinically acceptable rate (grades 0 + 1) of CPS placement did not differ between the RG and matched IG groups (97.9% vs 94.3% and 95.8% vs 96.2%, respectively). The incidence of CPS revision was similar between the groups (2.1% vs 2.9%), and no CPS-related complications were documented. Meanwhile, the incidence of lateral breach (grades 1 + 2 + 3) was significantly lower in the RG group than in the matched IG group (1.1% vs 7.7%, P = 0.037).

Conclusion:

The RGS and IGS can equally aid in accurate and safe CPS placement in clinical settings. Nonetheless, RGS can further reduce the lateral breach, compared with IGS.
Delayed Infection After Cervical Disc Arthroplasty
Authors: Federico Vincent P. , Zavras Athan G. , Vucicevic Rajko S. , Salazar Luis M. , An Howard S. , Colman Matthew W. , Phillips Frank M.
Published: April 2024

Study Design:

Case report and literature review.

Objective:

To report the relatively rare complication of delayed infection after cervical disc arthroplasty (CDA).

Background:

Delayed infection of the M6 device has been a rarely reported complication, with all cases described outside of the United States. The reliability of positive intraoperative cultures remains an ongoing debate.

Methods:

Cases were reviewed, and findings were summarized. A literature review was performed and discussed, with special consideration to current reports of delayed M6 infection, etiology, and utility of intraoperative cultures.

Results:

We present a case of delayed infection 6 years after primary 1-level CDA with the M6 device. At revision surgery, gross purulence was encountered. Intraoperative cultures finalized with Staphylococcus epidermidis and Cutibacterium acnes. The patient was revised with removal of the M6 and conversion to anterior cervical discectomy and fusion. A prolonged course of intravenous antibiotics was followed by an oral course for suppression. At the final follow-up, the patient’s preoperative symptoms had resolved.

Conclusion:

Delayed infection after CDA is a rare complication, with ongoing debate regarding the reliability of positive cultures. We describe an infected M6 and demonstrate the utility of implant removal, conversion to anterior cervical discectomy and fusion, and long-term antibiotics as definitive treatment.

Level of Evidence:

Level V—case report and literature review.
A Study on Interobserver and Intraobserver Reliability of the Huashan Radiologic Classification System for Cervical Spinal Cord Injury Without Fracture and Dislocation
Authors: Sun Chi , Xu Guangyu , Wang Hongwei , Nie Cong , Xu Guanhua , Liu Dayong , Yang Yong , Wang Xiandi , Xie Lin , Li Linli , Ma Xiaosheng , Lu Feizhou , Jiang Jianyuan , Wang Hongli
Published: April 2024

Study Design:

Observational study.

Objective:

To assess the reproducibility and reliability of the system.

Background:

The Huashan radiologic classification system for cervical spinal cord injury without fracture and dislocation (CSCIWFD) was recently proposed and found useful for clinical practice.

Patients and Methods:

Patients diagnosed with CSCIWFD between 2015 and 2021 were recruited. Six spine surgeons from different institutions, three experienced and other inexperienced respectively, were trained as observers of the system, and these surgeons classified the recruited patients using the system. Then, 8 weeks later, they repeated the classification on the same patients in a different order. The interobserver and intraobserver agreement between the results was analyzed using percentage agreement, weighted kappa, and Cohen kappa (κ) statistics.

Results:

A total of 60 patients were included in the analysis. Type I was the most frequent type (29 cases, 48.3%), followed by type II (13 cases, 21.7%), type III (12 cases, 20%), and type IV (6 cases, 10%). For all the observers, experienced observers, and inexperienced observers, the overall agreement percentages were 77.6% (κ = 0.78), 84.4% (κ = 0.84), and 72.8% (κ = 0.74), respectively, indicating substantial to nearly perfect interobserver reproducibility. A higher level of agreement was found for differentiating type I from other types, with the percentage agreement ranging from 87.8% to 94.4% (κ = 0.74–0.88). For distinguishing compression on the spinal cord (types I and II vs types III and IV) among the different groups of observers, the percentage agreement was 97.8% (κ = 0.94), indicating nearly perfect reproducibility. As for intraobserver agreement, the percentage agreement ranged from 86.7% to 96.7% (κ = 0.78–0.95), indicating at least substantial reliability.

Conclusions:

The Huashan radiologic classification system for CSCIWFD was easy to learn and apply in a clinical environment, showing excellent reproducibility and reliability. Therefore, it would be promising to apply and promote this system for the precise evaluation and personalized treatment strategy.
The Effect of C2 Muscular Exposure Technique on Radiographic and Clinical Outcomes After C2–T2 Posterior Cervical Fusion
Authors: Levy Hannah A. , Pinter Zachariah W. , Pumford Andrew , Salmons Harold I. , Townsley Sarah , Katsos Konstantinos , Reed Ryder , Chen Selby , Abode-Iyamah Kingsley , Deen H. Gordon , Clarke Michelle , Bydon Mohamad , Fogelson Jeremy L. , Elder Benjamin D. , Currier Bradford , Freedman Brett A. , Nassr Ahmad N. , Karamian Brian A. , Sebastian Arjun S.
Published: April 2024

Study Design:

Retrospective cohort analysis.

Objective:

To determine whether the C2 exposure technique was a predictor of change in cervical alignment and patient-reported outcomes measures (PROMs) after posterior cervical decompression and fusion (PCDF) for degenerative indications.

Background:

In PCDF handling of the C2 posterior paraspinal musculature during the operative approach varies by surgeon technique. To date, no studies have investigated whether maintenance of the upper cervical semispinalis cervicis attachments as compared with complete reflection of upper cervical paraspinal musculature from the posterior bony elements is associated with superior radiographic and clinical outcomes after PCDF.

Patients and Methods:

All adult patients who underwent C2–T2 PCDF for myelopathy or myeloradiculopathy at multi-institutional academic centers between 2013 and 2020 were retrospectively identified. Patients were dichotomized by the C2 exposure technique into semispinalis preservation or midline muscular reflection groups. Preoperative and short and long-term postoperative radiographic outcomes (upper cervical alignment, global alignment, and fusion status) and PROMs (Visual Analog Scale–Neck, Neck Disability Index, and Short Form-12) were collected. Univariate analysis compared patient factors, radiographic measures, and PROMs across C2 exposure groups.

Results:

A total of 129 patients met the inclusion/exclusion criteria (73 muscle preservation and 56 muscle reflection). Patients in the muscular preservation group were on average younger (P = 0.005) and more likely to have bone morphogenic protein (P < 0.001) and C2 pars screws (P = 0.006) used during surgery. Preoperative to postoperative changes in C2 slope, C2 tilt, C2–C3 segmental lordosis, C2–C3 listhesis, C0–C2 Cobb angle, proximal junctional kyphosis, ADI, C1 lamina-occiput distance, C2 sagittal vertical axis, C2–C7 lordosis, and PROMs at all follow-up intervals did not vary significantly by C2 exposure technique. Likewise, there were no significant differences in fusion status, C2–C3 pseudoarthrosis, C2 screw loosening, and complication and revision rates between C2 exposure groups.

Conclusions:

Preservation of C2 semispinalis attachments versus muscular reflection did not significantly impact cervical alignment, clinical outcomes, or proximal junction complications in long-segment PCDF.

Level of Evidence:

Level III.
Civilian Ballistic Injuries to the Atlantoaxial Spine
Authors: Johnson Christopher T. , Batbold Anudariya , Benson Dillon , Herman Martin , Lee Michael J. , Ramos Edwin , El Dafrawy Mostafa
Published: April 2024

Study Design:

Retrospective case series.

Objective:

Describe the injury characteristics of ballistic fractures involving the atlantoaxial spine.

Summary of Background Data:

Civilian gunshot wounds to the spine are an increasingly common injury in the United States. Civilian studies have focused on ballistic injuries to the entire spine as opposed to a region-specific fashion. Only a single 10-patient case series investigating ballistic fractures to the upper cervical spine (C1 and C2) exists, leaving a large gap in the understanding of this injury complex.

Methods:

A retrospective chart review was performed. Extracted data included patient demographics, neurological status on presentation, fracture morphology, assessment of stability, other associated injuries, and surgical procedures performed. Proportional analysis was performed to characterize the fractures and their associated neurological injuries.

Results:

Thirty-six patients were identified, with 86% being male with an average patient age of 30.0 ± 10.36 years (mean ± SD). Fracture morphology was characterized using proportional analysis. Initial neurological exams were either ASIA A or ASIA E, without any incomplete injuries noted. Patients who sustained a transcanal injury did not show any neurological improvement. The initial in-hospital mortality rate was 5.6%, with a 1-year mortality rate of 8.3%. There is a high incidence of associated vascular injury (66%) and mandible fracture (33%).

Conclusions:

Ballistic penetrating trauma to the atlantoaxial spine often results in complex injury patterns necessitating multidisciplinary care with high rates of morbidity and mortality. If neurological deficits are present initially, they are often complete. Two thirds of patients sustained an associated vascular injury, which should be screened for with CT angiography.
Do Busier Surgeons Have Lower Intraoperative Costs? An Analysis of Anterior Cervical Discectomy and Fusion Using Time-Driven Activity-Based Costing
Authors: Sarikonda Advith , Leibold Adam , Sami Ashmal , Mansoor Ali Daniyal , Tecce Eric , August Ari , O’Leary Matthew , Thalheimer Sara , Heller Joshua , Prasad Srinivas , Sharan Ashwini , Jallo Jack , Harrop James , Vaccaro Alexander R. , Sivaganesan Ahilan
Published: April 2024

Study Design:

The present study is a single-center, retrospective cohort study of patients undergoing neurosurgical anterior cervical discectomy and fusion (ACDF).

Objective

Our objective was to use time-driven activity-based costing (TDABC) methodology to determine whether surgeons’ case volume influenced the true intraoperative costs of ACDFs performed at our institution.

Summary of Background Data:

Successful participation in emerging reimbursement models, such as bundled payments, requires an understanding of true intraoperative costs, as well as the modifiable drivers of those costs. Certain surgeons may have cost profiles that are favorable for these “at-risk” reimbursement models, while other surgeons may not.

Methods:

Total cost was divided into direct and indirect costs. Individual costs were obtained by direct observation, electronic medical records, and through querying multiple departments (business operations, sterile processing, plant operations, and pharmacy). Timestamps for all involved personnel and material resources were documented. All surgeons performing ACDFs at our primary and affiliated hospital sites from 2017 to 2022 were divided into four volume-based cohorts: 1–9 cases (n=10 surgeons, 38 cases), 10–29 cases (n=7 surgeons, 126 cases), 30–100 cases (n=3 surgeons, 234 cases), and > 100 cases (n=2 surgeons, 561 cases).

Results:

The average total intraoperative cost per case was $7,116 +/− $2,945. The major cost contributors were supply cost ($4,444, 62.5%) and personnel cost ($2,417, 34.0%). A generalized linear mixed model utilizing Poisson distribution was performed with the surgeon as a random effect. Surgeons performing 1–9 total cases, 10–29 cases, and 30–100 cases had increased total cost of surgery (P < 0.001; P < 0.001; and P<0.001, respectively) compared to high-volume surgeons (> 100 cases). Among all volume cohorts, high-volume surgeons also had the lowest mean supply cost, personnel cost, and operative times, while the opposite was true for the lowest-volume surgeons (1–9 cases).

Conclusion:

It is becoming increasingly important for hospitals to identify modifiable sources of variation in cost. We demonstrate a novel use of TDABC for this purpose.

Level of Evidence:

Level—III.