Establishing case volume benchmarks for ACGME-accredited orthopedic surgery of the spine fellowship training.

BACKGROUND CONTEXT: There has been increasing scrutiny on the standardization of surgical training in the US. PURPOSE: This study provides case volume benchmarks for Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopedic spine surgery fellowship training. STUDY DESIGN/SETTING: This was a retrospective cross-sectional study of fellows at ACGME-accredited orthopedic spine surgery fellowships (2017-2022). PATIENT SAMPLE: N/A. OUTCOME MEASURES: Reported case volume during fellowship training. METHODS: Case volume percentiles were calculated across ACGME-defined case categories and temporal changes assessed via linear regression. Variability between the highest and lowest deciles by case volume was calculated as fold-differences (90th percentile/10th percentile). Sensitivity analyses were performed to identify potential targets for case minimum requirements. RESULTS: A total of 163 spine surgery fellows were included in this study. Total mean reported spine surgery case volume increased from 313.2±122 in 2017 to 382.0±164 in 2022 (p=.19). Most cases were classified as adult (range, 97.2%-98.0%) over pediatric cases (range, 2.0%-2.8%). An average of 322.0 cases were reported and most were classified as laminectomy (32%), posterior arthrodesis (29%), and anterior arthrodesis (20%). Overall variability in total case volume was 2.4 and the greatest variability existed for posterior instrumentation (38.1), application of cage (34.6), anterior instrumentation (20.8), and fractures and dislocations (17.3). If case minimum requirements for total reported cases was assumed at 200 cases, then all spine fellows included in this study would achieve this requirement. However, if case minimum requirements were assumed at 250 total cases, then approximately thirty percent of fellows (n=49) would not achieve this requirement for graduation. CONCLUSIONS: Increasingly, national societies and accrediting bodies for surgical education recognize the need for standardized training. This study provides benchmarks to inform potential case minimum requirements and help reduce variability during spine fellowship training. Future studies are needed to establish case minimum requirements for spine surgery fellowship training across comprehensive and granular case categories that cover the full gamut of orthopedic spine surgery.

Patient Resiliency and Caregiver Burden After Traumatic Spinal Cord Injury Resulting in Quadriplegia.

Traumatic spinal cord injury (tSCI) resulting in quadriplegia is a life-altering injury for patients and caregivers. We conducted a retrospective review of patients treated for tSCI and quadriplegia at a level 1 trauma center to assess quality of life (QOL), socioeconomic factors, and mortality. Patients and caregivers were surveyed. Of the 65 patients included, 33 contacts were made. Seventeen surveys were completed (12 caregivers and 5 patients). Six unreachable patients were confirmed alive via medical record. Mortality rate among these 39 accessible patients was 23% (n = 9). Medicaid and uninsured patients experienced longer hospital length of stay (P < .0001) and discharged to home or nursing facilities (P < .0001) more often than those with private insurance or Medicare. Patients reported overall "good" QOL (80%) while caregivers reported overall decreased QOL markers. Our results reflect the resilience among this patient population, but also highlight the impact of this life-altering injury on the caregiver.

Energy Consumption and Substrate Utilization During Spinal Surgery.

INTRODUCTION: This study aims to measure surgeon physiologic stress and energy expenditure during adult spine surgery. Energy expenditures were assessed based on patient BMI, lead use, instrumentation/intraoperative navigation, primary/revision surgeries, tranexamic acid (TXA) use, and anatomic region involved. METHODS: The senior author wore a heart rate (HR) monitor and triaxial accelerometer during spinal surgeries, providing assessments of mean HR, maximum HR, calories consumed/minute, and calories as measured by a Polar device (P calories) and Fitbit device (F calories). RESULTS: One hundred sixty-two surgeries were included. Median patient age was 62 years. Median BMI was 29.02. Significant differences existed for BMI and estimated blood loss (P < 0.05). TXA use had a significant effect on case time, estimated blood loss, P calories, F calories, and Kcal/min (P < 0.05). Instrumentation use was significant for all variables (P < 0.05), except for mean HR and Kcal/min (P > 0.05). Lead use did not have a significant effect on max HR, P calories, F calories, and Kcal/min (P > 0.05). Navigation use was associated with significant differences for every variable tested (P ≤ 0.05). Differences were observed between primary and revision surgeries for case time, estimated blood loss, and F calories (P < 0.05). CONCLUSIONS: In spinal surgery, the use of navigation, instrumentation use, TXA use, and performing revision surgeries were associated with increased energy expenditure and can potentially increase surgeon fatigue.

The effect of water on gold supported chiral graphene nanoribbons: rupture of conjugation by an alternating hydrogenation pattern.

In the last few years we have observed a breakpoint in the development of graphene-derived technologies, such as liquid phase filtering and their application to electronics. In most of these cases, they imply exposure of the material to solvents and ambient moisture, either in the fabrication of the material or the final device. The present study demonstrates the sensitivity of graphene nanoribbon (GNR) zigzag edges to water, even in extremely low concentrations. We have addressed the unique reactivity of (3,1)-chiral GNR with moisture on Au(111). Water shows a reductive behaviour, hydrogenating the central carbon of the zigzag segments. By combining scanning tunnelling microscopy (STM) with simulations, we demonstrate how their reactivity reaches a thermodynamic limit when half of the unit cells are reduced, resulting in an alternating pattern of hydrogenated and pristine unit cells starting from the terminal segments. Once a quasi-perfect alternation is reached, the reaction stops regardless of the water concentration. The hydrogenated segments limit the electronic conjugation of the GNR, but the reduction can be reversed both by tip manipulation and annealing. Selective tip-induced dehydrogenation allowed the stabilization of radical states at the edges of the ribbons, while the annealing of the sample completely recovered the original, pristine GNR.

Applications of SPECT/CT in the Evaluation of Spinal Pathology: A Review.

BACKGROUND: Accurate identification of pain generators in the context of low back and spine-related pain is crucial for effective treatment. This review aims to evaluate the potential usefulness of single photon emission computed tomography with computed tomography (SPECT/CT) as an imaging modality in guiding clinical decision-making. METHODS: A broad scoping literature review was conducted to identify relevant studies evaluating the use of SPECT/CT in patients with spine-related pain. Studies were reviewed for their methodology and results. RESULTS: SPECT/CT appears to have advantages over traditional modalities, such as magnetic resonance imaging and CT, in certain clinical scenarios. It may offer additional information to clinicians and improve the specificity of diagnosis. However, further studies are needed to fully assess its diagnostic accuracy and clinical utility. CONCLUSIONS: SPECT/CT is a promising imaging modality in the evaluation of low back pain, particularly in cases where magnetic resonance imaging and CT are inconclusive or equivocal. However, the current level of evidence is limited, and additional research is needed to determine its overall clinical relevance. CLINICAL RELEVANCE: SPECT/CT may have a significant impact on clinical decision-making, particularly in cases in which traditional imaging modalities fail to provide a clear diagnosis. Its ability to improve specificity could lead to more targeted and effective treatment for patients with spinal pathology.

Topological Design and Synthesis of High-Spin Aza-triangulenes without Jahn-Teller Distortions.

The atomic doping of open-shell nanographenes enables precise tuning of their electronic and magnetic states, which is crucial for their promising potential applications in optoelectronics and spintronics. Among this intriguing class of molecules, triangulenes stand out with their size-dependent electronic properties and spin states, which can also be influenced by the presence of dopant atoms and functional groups. However, the occurrence of Jahn-Teller distortions in such systems can have a crucial impact on their total spin and requires further theoretical and experimental investigation. In this study, we examine the nitrogen-doped aza-triangulene series via a combination of density functional theory and on-surface synthesis. We identify a general trend in the calculated spin states of aza-[n]triangulenes of various sizes, separating them into two symmetry classes, one of which features molecules that are predicted to undergo Jahn-Teller distortions that reduce their symmetry and thus their total spin. We link this behavior to the location of the central nitrogen atom relative to the two underlying carbon sublattices of the molecules. Consequently, our findings reveal that neutral centrally doped aza-triangulenes have one less radical than their undoped counterparts, irrespective of their predicted symmetry. We follow this by demonstrating the on-surface synthesis of π-extended aza-[5]triangulene, a large member of the higher symmetry class without Jahn-Teller distortions, via a simple one-step annealing process on Cu(111) and Au(111). Using scanning probe microscopy and spectroscopy combined with theoretical calculations, we prove that the molecule is positively charged on the Au(111) substrate, with a high-spin quintet state of S = 2, the same total spin as undoped neutral [5]triangulene. Our study uncovers the correlation between the dopant position and the radical nature of high-spin nanographenes, providing a strategy for the design and development of these nanographenes for various applications.

Allergic contact dermatitis to Dermabond Prineo after abdominal wound closure for anterior lumbar interbody fusion: case report.

Background: Dermabond Prineo is popular for wound closure due to its anti-microbial attribute, ease of application, and patient comfort. Reports of allergic contact dermatitis have increased, likely due to increased usage, mostly in breast augmentations and joint replacements. To the authors' knowledge, this is the first report of allergic contact dermatitis following spine surgery. Case Description: This case involved a 47-year-old male with a history of two posterior L5-S1 lumbar microdiscectomies. Dermabond Prineo was used in the revision microdiscectomy with no skin complications noted. Six weeks after revision microdiscectomy, the patient underwent discectomy and anterior lumbar interbody fusion of L5-S1, again closed with Dermabond Prineo. One week later, the patient presented with allergic contact dermatitis around his incision, which was treated with topical hydrocortisone and diphenhydramine. Around the same time, he was diagnosed with post-operative pneumonia. Conclusions: Previous studies have suggested that repeated usage and duplicate coverage with 2-octyl cyanoacrylate (Dermabond Prineo) correlate with an increased risk of allergic reaction. Type IV hypersensitivity reactions require an initial sensitization to the allergen and subsequent re-exposure for reaction. In this case, the revision microdiscectomy closed with Dermabond Prineo functioned as the sensitization and repeated usage in a subsequent discectomy caused an allergic reaction. Providers should be aware of the increased risk of allergic reaction when using Dermabond Prineo for repeat surgeries.

Circumventing the stability problems of graphene nanoribbon zigzag edges.

Carbon nanostructures with zigzag edges exhibit unique properties-such as localized electronic states and spins-with exciting potential applications. Such nanostructures however are generally synthesized under vacuum because their zigzag edges are unstable under ambient conditions: a barrier that must be surmounted to achieve their scalable integration into devices for practical purposes. Here we show two chemical protection/deprotection strategies, demonstrated on labile, air-sensitive chiral graphene nanoribbons. Upon hydrogenation, the chiral graphene nanoribbons survive exposure to air, after which they are easily converted back to their original structure by annealing. We also approach the problem from another angle by synthesizing a form of the chiral graphene nanoribbons that is functionalized with ketone side groups. This oxidized form is chemically stable and can be converted to the pristine hydrocarbon form by hydrogenation and annealing. In both cases, the deprotected chiral graphene nanoribbons regain electronic properties similar to those of the pristine nanoribbons. We believe both approaches may be extended to other graphene nanoribbons and carbon-based nanostructures.

Biomarker context-of-use: how organizational design can impact the implementation of the appropriate biomarker assay strategy.

Since 2011, the European Bioanalysis Forum has been discussing the topic of context-of-use for biomarker assays, in support of a cross-industry implementation of its principles. The discussions have led to the acknowledgement of the challenges that we face as an industry in implementing these principles. In addition to scientific recommendations, the European Bioanalysis Forum has addressed these challenges by providing recommendations on organizational design, and what works in both sponsor and contract research organizations, to support and enable context-of-use across biomarker strategies. Here, we highlight the key considerations for organizational design to help ensure that biomarker assays are characterized and validated according to the right context-of-use, to ensure that the right decisions based on the biomarker data can be made during drug development.

Direct Experimental Evidence for Substrate Adatom Incorporation into a Molecular Overlayer.

While the phenomenon of metal substrate adatom incorporation into molecular overlayers is generally believed to occur in several systems, the experimental evidence for this relies on the interpretation of scanning tunneling microscopy (STM) images, which can be ambiguous and provides no quantitative structural information. We show that surface X-ray diffraction (SXRD) uniquely provides unambiguous identification of these metal adatoms. We present the results of a detailed structural study of the Au(111)-F4TCNQ system, combining surface characterization by STM, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy with quantitative experimental structural information from normal incidence X-ray standing wave (NIXSW) and SXRD, together with dispersion-corrected density functional theory (DFT) calculations. Excellent agreement is found between the NIXSW data and the DFT calculations regarding the height and conformation of the adsorbed molecule, which has a twisted geometry rather than the previously supposed inverted bowl shape. SXRD measurements provide unequivocal evidence for the presence and location of Au adatoms, while the DFT calculations show this reconstruction to be strongly energetically favored.

Clinical Performance of Triage Strategies for Hr-HPV-Positive Women; A Longitudinal Evaluation of Cytology, p16/K-67 Dual Stain Cytology, and HPV16/18 Genotyping.

BACKGROUND: We evaluated the longitudinal performance of three options: HPV16/18 genotyping (HPV16/18), cytology (LBC), and p16/Ki-67 dual stain cytology (DS) for the triage of high-risk Human Papillomavirus-positive (Hr-HPV+) women within the cervical screening program in Scotland. METHODS: Data were derived from a cohort of Hr-HPV+ women (n = 385) who participated in PaVDaG (Papillomavirus Dumfries and Galloway) study. Performance of triage strategies for detecting high-grade disease was assessed at 3 (in women <50 years) or 5 years (in women >50 years). Sensitivity, specificity, PPV, and cNPV of each triage test were calculated for CIN2+ and CIN3+ when used singly or sequentially. RESULTS: The sensitivity of LBC (≥ borderline), DS, and HPV 16/18 genotyping for the detection of CIN2+ was 62.7% (50.7-73.3), 77.7% (63.1-83.7), and 62.7% (50.7-73.3) with corresponding cNPVs of 10.9%, 8.4%, and 11.9%. The option with the highest sensitivity and lowest cNPV was HPV 16/18 genotyping followed by LBC of Hr-HPV other+ and then DS of the LBC negatives. This yielded sensitivity of 94.7% (86.2-98.3) and cNPV 2.7% for CIN2+. Triage performance was similar if women had tested Hr-HPV+ positive by vaginal self-sampling. CONCLUSIONS: Two-step triage with HPV 16/18 genotyping before LBC (or DS) for Hr-HPV other+ women was associated with a lower risk of significant disease at follow-up compared with single triage approaches. IMPACT: This study provides longitudinal performance data on triage strategies in Hr-HPV+ women and will be informative for the evolution of cervical screening programs that increasingly rely on molecular technologies.

Self-sampling as the principal modality for population based cervical screening: Five-year follow-up of the PaVDaG study.

Self-sampling provides a powerful means to engage women in cervical screening. In the original Papillomavirus Dumfries and Galloway study (PaVDaG), we demonstrated cross-sectional similarity of high-risk human papillomavirus (Hr-HPV) testing on self-taken vaginal vs clinician-taken samples for the detection of cervical intraepithelial neoplasia 2 or worse (CIN2+). Few data exist on the longitudinal performance of self-sampling; we present longitudinal outcomes of PaVDaG. Routinely screened women provided a self-taken and a clinician-collected sample. Ninety-one percent of 5136 women from the original cohort completed a further screening round. Sensitivity, specificity, positive predictive value and complement of the negative predictive value of the Hr-HPV test on self-samples for detection of CIN2+ and CIN3+ up-to 5 years after testing were determined. Additionally, clinical accuracy of Hr-HPV testing on vaginal and clinician-collected samples was assessed. A total of 183 CIN2+ and 102 CIN3+ lesions were diagnosed during follow-up. Risk of CIN2+ and CIN3+ following an Hr-HPV negative self-sample was 0.6% and 0.2%, respectively, for up to 5 years after testing. The relative sensitivity for CIN3+ and specificity for ≤CIN1 of Hr-HPV testing on self-taken specimens was slightly lower vs clinician-collected samples: 0.95 (95% CI: 0.90-0.99; PMcN = .0625) and 0.98 (95% CI: 0.95-1.00; PMcN = <.0000), respectively. The low risk of CIN2+ in women with Hr-HPV-self-sample(s) suggests, that the 3 to 5-year recall interval implemented in several cervical screening settings, based on clinician-taken samples, may be safe for self-samples. Future assessment will show if "universal" 5-year screening is appropriate for programs based on self-sampling.

Magnetic Interactions Between Radical Pairs in Chiral Graphene Nanoribbons.

Open-shell graphene nanoribbons have become promising candidates for future applications, including quantum technologies. Here, we characterize magnetic states hosted by chiral graphene nanoribbons (chGNRs). The substitution of a hydrogen atom at the chGNR edge by a ketone effectively adds one pz electron to the π-electron network, producing an unpaired π-radical. A similar scenario occurs for regular ketone-functionalized chGNRs in which one ketone is missing. Two such radical states can interact via exchange coupling, and we study those interactions as a function of their relative position, which includes a remarkable dependence on the chirality, as well as on the nature of the surrounding ribbon, that is, with or without ketone functionalization. Besides, we determine the parameters whereby this type of system with oxygen heteroatoms can be adequately described within the widely used mean-field Hubbard model. Altogether, we provide insight to both theoretically model and devise GNR-based nanostructures with tunable magnetic properties.

Order from a Mess: The Growth of 5-Armchair Graphene Nanoribbons.

The advent of on-surface chemistry under vacuum has vastly increased our capabilities to synthesize carbon nanomaterials with atomic precision. Among the types of target structures that have been synthesized by these means, graphene nanoribbons (GNRs) have probably attracted the most attention. In this context, the vast majority of GNRs have been synthesized from the same chemical reaction: Ullmann coupling followed by cyclodehydrogenation. Here, we provide a detailed study of the growth process of five-atom-wide armchair GNRs starting from dibromoperylene. Combining scanning probe microscopy with temperature-dependent XPS measurements and theoretical calculations, we show that the GNR growth departs from the conventional reaction scenario. Instead, precursor molecules couple by means of a concerted mechanism whereby two covalent bonds are formed simultaneously, along with a concomitant dehydrogenation. Indeed, this alternative reaction path is responsible for the straight GNR growth in spite of the initial mixture of reactant isomers with irregular metal-organic intermediates that we find. The provided insight will not only help understanding the reaction mechanisms of other reactants but also serve as a guide for the design of other precursor molecules.

Atomically-Precise Texturing of Hexagonal Boron Nitride Nanostripes.

Monolayer hexagonal boron nitride (hBN) is attracting considerable attention because of its potential applications in areas such as nano- and opto-electronics, quantum optics and nanomagnetism. However, the implementation of such functional hBN demands precise lateral nanostructuration and integration with other two-dimensional materials, and hence, novel routes of synthesis beyond exfoliation. Here, a disruptive approach is demonstrated, namely, imprinting the lateral pattern of an atomically stepped one-dimensional template into a hBN monolayer. Specifically, hBN is epitaxially grown on vicinal Rhodium (Rh) surfaces using a Rh curved crystal for a systematic exploration, which produces a periodically textured, nanostriped hBN carpet that coats Rh(111)-oriented terraces and lattice-matched Rh(337) facets with tunable width. The electronic structure reveals a nanoscale periodic modulation of the hBN atomic potential that leads to an effective lateral semiconductor multi-stripe. The potential of such atomically thin hBN heterostructure for future applications is discussed.

Challenges in the synthesis of corannulene-based non-planar nanographenes on Au(111) surfaces.

The on-surface synthesis of non-planar nanographenes is a challenging task. Herein, with the aid of bond-resolving scanning tunneling microscopy (BRSTM) and density functional theory (DFT) calculations, we present a systematic study aiming at the fabrication of corannulene-based nanographenes via intramolecular cyclodehydrogenation on a Au(111) surface. The formation of non-planar targeted products is confirmed to be energetically unfavorable compared to the formation of planar/quasi-planar undesired competing monomer products. In addition, the activation of intermolecular coupling further inhibits the formation of the final targeted product. Although it was not possible to access the corannulene moiety by means of on-surface synthesis, partial cyclodehydrogenation of the molecular precursors was demonstrated.

Chemical Stability of (3,1)-Chiral Graphene Nanoribbons.

Nanostructured graphene has been widely studied in recent years due to the tunability of its electronic properties and its associated interest for a variety of fields, such as nanoelectronics and spintronics. However, many of the graphene nanostructures of technological interest are synthesized under ultrahigh vacuum, and their limited stability as they are brought out of such an inert environment may compromise their applicability. In this study, a combination of bond-resolving scanning probe microscopy (BR-SPM), along with theoretical calculations, has been employed to study (3,1)-chiral graphene nanoribbons [(3,1)-chGNRs] that were synthesized on a Au(111) surface and then exposed to oxidizing environments. Exposure to the ambient atmosphere, along with the required annealing treatment to desorb a sufficiently large fraction of contaminants to allow for its postexposure analysis by BR-SPM, revealed a significant oxidation of the ribbons, with a dramatically disruptive effect on their electronic properties. More controlled experiments avoiding high temperatures and exposing the ribbons only to low pressures of pure oxygen show that also under these more gentle conditions the ribbons are oxidized. From these results, we obtain additional insights into the preferential reaction sites and the nature of the main defects that are caused by oxygen. We conclude that graphene nanoribbons with zigzag edge segments require forms of protection before they can be used in or transferred through ambient conditions.

Reassessing Alkyne Coupling Reactions While Studying the Electronic Properties of Diverse Pyrene Linkages at Surfaces.

The combination of alkyne and halogen functional groups in the same molecule allows for the possibility of many different reactions when utilized in on-surface synthesis. Here, we use a pyrene-based precursor with both functionalities to examine the preferential reaction pathway when it is heated on an Au(111) surface. Using high-resolution bond-resolving scanning tunneling microscopy, we identify multiple stable intermediates along the prevailing reaction pathway that initiate with a clearly dominant Glaser coupling, together with a multitude of other side products. Importantly, control experiments with reactants lacking the halogen functionalization reveal the Glaser coupling to be absent and instead show the prevalence of non-dehydrogenative head-to-head alkyne coupling. We perform scanning tunneling spectroscopy on a rich variety of the product structures obtained in these experiments, providing key insights into the strong dependence of their HOMO-LUMO gaps on the nature of the intramolecular coupling. A clear trend is found of a decreasing gap that is correlated with the conversion of triple bonds to double bonds via hydrogenation and to higher levels of cyclization, particularly with nonbenzenoid product structures. We rationalize each of the studied cases.