Editorial Commentary: Gracilis-Sparing Anterior Cruciate Ligament Hamstring Graft Reconstruction Is Less Invasive Than Semitendinosus-Gracilis Graft Harvest, and Shows No Clinical Difference in Outcomes With Grafts Greater Than 8 mm in Diameter.

Although patellar tendon grafts are most commonly used for anterior cruciate ligament reconstruction in the United States, hamstring autograft is most commonly used worldwide. Hamstring advantages include easy, quick harvest; low morbidity; ease of rehabilitation (compared with patellar tendon grafts); and relatively less pain. Historically, both the semitendinosus (ST) and gracilis are harvested, but by doubling, tripling, or quadrupling the ST to achieve an 8-mm graft, the gracilis can be spared, resulting in less knee flexion weakness. However, recent research has shown no clinically important difference between ST and ST-gracilis patient outcomes.

Surgeons lack of agreement on determining preoperative radiographic and clinical shoulder balance in adolescent and adult idiopathic scoliosis patients.

PURPOSE: Preoperative shoulder balance is an important factor in determining the upper instrumented vertebrae (UIV). In adolescent and adult idiopathic scoliosis (AIS/AdIS) patients, we studied the intraobserver and interobserver reliability of spinal surgeons' assessment of preoperative shoulder balance using X-rays (XR) and anterior/posterior photographs. METHODS: An observational review of a prospective multicenter database (AIS Lenke Type 1/5/6) and prospective single-institution database (AdIS) was conducted. Ten spine surgeons reviewed AIS cases; 12 spine surgeons reviewed AdIS cases. Surgeons rated the higher shoulder: left/right/same/unsure. Reliability was calculated using Fleiss' kappa coefficient. RESULTS: Among 145 Type 1 AIS cases, intraobserver reliability was moderate-to-substantial: XR (κ = 0.59), anterior photographs (κ = 0.68), posterior photographs (k = 0.65). Interobserver reliability was fair to moderate for XR (κ = 0.31), anterior photographs (κ = 0.20), and posterior photographs (κ = 0.30). Among 52 Type 5/6 AIS cases, intraobserver reliability was substantial: XR (κ = 0.70), anterior photographs (κ = 0.76), posterior photographs (κ = 0.71). Interobserver reliability was fair to moderate for XR (κ = 0.49), anterior photographs (κ = 0.47), and posterior photographs (κ = 0.36). Among 66 AdIS cases, intraobserver reliability was substantial: XR (κ = 0.68), anterior photographs (κ = 0.67), posterior photographs (κ = 0.69). Interobserver reliability was moderate for XR (κ = 0.45), anterior photographs (κ = 0.43), posterior photographs (κ = 0.49). Within Type 1 AIS patients, attendings had better intraobserver reliabilities compared to fellows using X-rays (κ = 0.61 vs. 0.53), yet no effect of surgeon experience was seen with clinical photographs. CONCLUSION: Though surgeons' ability to agree with themselves was moderate to substantial, surgeons' ability to agree with each other was fair to moderate. Combined measures to assess preoperative shoulder balance are needed for UIV selection.

Current and emerging therapies for hand eczema.

Although hand eczema (HE) and chronic hand eczema (CHE) are common conditions with significant disease burden, they traditionally have had limited treatment options beyond topical and short-term systemic corticosteroids. We reviewed published and preliminary evidence on the current and emerging topical and systemic therapeutic agents for HE and CHE. The etiologies of various HE subtypes are discussed, and remaining knowledge and practice gaps are highlighted to encourage further investigations. A comprehensive search of ClinicalTrials.gov and PubMed was completed for clinical trials that utilized known and emerging treatment options for HE and CHE. Several agents that target IL-4 and IL-13 signaling, keratinocyte proliferation, inflammatory cytokine production, bacterial protein synthesis, and inflammatory mediator (TNF-α, JAK1, JAK2, and JAK3) proliferation are shown to be involved in the pathogenesis of CHE. Systemic agents include dupilumab, alitretinoin, acitretin, cyclosporine, azathioprine, and probiotics. Topical agents include delgocitinib, retapamulin, halometasone/triclosan, calcipotriol/betamethasone, tacrolimus, and pimecrolimus. These modalities have demonstrated varying degrees of clinical efficacy, evaluated by subjective assessments and scoring indexes. Targeted therapies are emerging for HE, but options are still limited, partially due to our narrow understanding of this heterogeneous condition. Additional and targeted therapeutic options are needed to match the rising prevalence and burden of HE. KEYPOINTS: Hand eczema (HE) is a heterogenous dermatosis with limited therapeutic options due to a lack of international guidelines regarding classification of HE subtypes and treatment. This review discusses current and emerging topical and systemic agents and their efficacies in the treatment of different types of hand eczema.

Topical probiotics: the unknowns behind their rising popularity.

OBJECTIVE: Topical probiotics have been used for skin care and treatment since the early 20th century. Over the past decade, there has been a dramatic surge of commercially-available topical probiotic products. We conducted a systematic search of clinical data relating to the use of topical probiotics and identified relevant clinical and regulatory gaps. METHODS: PubMed and Google Scholar searches were conducted for trials and reviews of probiotics. FDA definitions of cosmetics, drugs, and regulation of topical probiotics were reviewed. RESULTS: Topical probiotics have shown efficacy in a number of limited trials, particularly those involving the treatment of acne, atopic dermatitis, and rosacea. However, there is a paucity of literature on the safety profiles, mechanistic action, and therapeutic potential of topical probiotic products. Several regulatory gaps exist, including approval and classification of topical probiotic products by the FDA; currently there are no topical probiotic products the FDA has approved as drugs. CONCLUSION: With increasing popularity among the general public, but insufficient clinical data to demonstrate large-scale effectiveness and a thorough understanding of side effects, there is a need for further mechanistic and clinical investigation, as well as improved regulation and standardization of topical probiotic products.

Nitisinone arrests ochronosis and decreases rate of progression of Alkaptonuria: Evaluation of the effect of nitisinone in the United Kingdom National Alkaptonuria Centre.

QUESTION: Does Nitisinone prevent the clinical progression of the Alkaptonuria? FINDINGS: In this observational study on 39 patients, 2 mg of daily nitisinone inhibited ochronosis and significantly slowed the progression of AKU over a three-year period. MEANING: Nitisinone is a beneficial therapy in Alkaptonuria. BACKGROUND: Nitisinone decreases homogentisic acid (HGA), but has not been shown to modify progression of Alkaptonuria (AKU). METHODS: Thirty-nine AKU patients attended the National AKU Centre (NAC) in Liverpool for assessments and treatment. Nitisinone was commenced at V1 or baseline. Thirty nine, 34 and 22 AKU patients completed 1, 2 and 3 years of monitoring respectively (V2, V3 and V4) in the VAR group. Seventeen patients also attended a pre-baseline visit (V0) in the VAR group. Within the 39 patients, a subgroup of the same ten patients attended V0, V1, V2, V3 and V4 visits constituting the SAME Group. Severity of AKU was assessed by calculation of the AKU Severity Score Index (AKUSSI) allowing comparison between the pre-nitisinone and the nitisinone treatment phases. RESULTS: The ALL (sum of clinical, joint and spine AKUSSI features) AKUSSI rate of change of scores/patient/month, in the SAME group, was significantly lower at two (0.32 ±â€¯0.19) and three (0.15 ±â€¯0.13) years post-nitisinone when compared to pre-nitisinone (0.65 ±â€¯0.15) (p < .01 for both comparisons). Similarly, the ALL AKUSSI rate of change of scores/patient/month, in the VAR group, was significantly lower at one (0.16 ±â€¯0.08) and three (0.19 ±â€¯0.06) years post-nitisinone when compared to pre-nitisinone (0.59 ±â€¯0.13) (p < .01 for both comparisons). Combined ear and ocular ochronosis rate of change of scores/patient/month was significantly lower at one, two and three year's post-nitisinone in both VAR and SAME groups compared with pre-nitisinone (p < .05). CONCLUSION: This is the first indication that a 2 mg dose of nitisinone slows down the clinical progression of AKU. Combined ocular and ear ochronosis progression was arrested by nitisinone.

Constrained evolution of the sex comb in Drosophila simulans.

Male fitness is dependent on sexual traits that influence mate acquisition (precopulatory sexual selection) and paternity (post-copulatory sexual selection), and although many studies have documented the form of selection in one or the other of these arenas, fewer have done it for both. Nonetheless, it appears that the dominant form of sexual selection is directional, although theoretically, populations should converge on peaks in the fitness surface, where selection is stabilizing. Many factors, however, can prevent populations from reaching adaptive peaks. Genetic constraints can be important if they prevent the development of highest fitness phenotypes, as can the direction of selection if it reverses across episodes of selection. In this study, we examine the evidence that these processes influence the evolution of the multivariate sex comb morphology of male Drosophila simulans. To do this, we conduct a quantitative genetic study together with a multivariate selection analysis to infer how the genetic architecture and selection interact. We find abundant genetic variance and covariance in elements of the sex comb. However, there was little evidence for directional selection in either arena. Significant nonlinear selection was detected prior to copulation when males were mated to nonvirgin females, and post-copulation during sperm offence (again with males mated to nonvirgins). Thus, contrary to our predictions, the evolution of the D. simulans sex comb is limited neither by genetic constraints nor by antagonistic selection between pre- and post-copulatory arenas, but nonlinear selection on the multivariate phenotype may prevent sex combs from evolving to reach some fitness maximizing optima.

Ramped-amplitude NOVEL.

We present a pulsed dynamic nuclear polarization (DNP) study using a ramped-amplitude nuclear orientation via electron spin locking (RA-NOVEL) sequence that utilizes a fast arbitrary waveform generator (AWG) to modulate the microwave pulses together with samples doped with narrow-line radicals such as 1,3-bisdiphenylene-2-phenylallyl (BDPA), sulfonated-BDPA (SA-BDPA), and trityl-OX063. Similar to ramped-amplitude cross polarization in solid-state nuclear magnetic resonance, RA-NOVEL improves the DNP efficiency by a factor of up to 1.6 compared to constant-amplitude NOVEL (CA-NOVEL) but requires a longer mixing time. For example, at τmix = 8 µs, the DNP efficiency reaches a plateau at a ramp amplitude of ∼20 MHz for both SA-BDPA and trityl-OX063, regardless of the ramp profile (linear vs. tangent). At shorter mixing times (τmix = 0.8 µs), we found that the tangent ramp is superior to its linear counterpart and in both cases there exists an optimum ramp size and therefore ramp rate. Our results suggest that RA-NOVEL should be used instead of CA-NOVEL as long as the electronic spin lattice relaxation T1e is sufficiently long and/or the duty cycle of the microwave amplifier is not exceeded. To the best of our knowledge, this is the first example of a time domain DNP experiment that utilizes modulated microwave pulses. Our results also suggest that a precise modulation of the microwave pulses can play an important role in optimizing the efficiency of pulsed DNP experiments and an AWG is an elegant instrumental solution for this purpose.

Mosquitoes of field and forest: the scale of habitat segregation in a diverse mosquito assemblage.

Knowledge of the distribution of arthropod vectors across a landscape is important in determining the risk for vector-borne disease. This has been well explored for ticks, but not for mosquitoes, despite their importance in the transmission of a variety of pathogens. This study examined the importance of habitat, habitat edges, and the scale at which mosquito abundance and diversity vary in a rural landscape by trapping along transects from grassland areas into forest patches. Significant patterns of vector diversity and distinct mosquito assemblages across habitats were found. The scale of individual species' responses to habitat edges was often dramatic, with several species rarely straying even 10 m from the edge. The present results suggest blood-seeking mosquito species are faithful to certain habitats, which has consequences for patterns of vector diversity and risk for pathogen transmission. This implies that analysts of risk for pathogen transmission and foci of control, and developers of land management strategies should assess habitat at a finer scale than previously considered.

Localization of Cl-35 nuclei in biological solids using rotational-echo double-resonance experiments.

Chloride ions play important roles in many chemical and biological processes. This paper investigates the possibility of localizing 35Cl nuclei using solid-state NMR. It demonstrates that distances shorter than 3.8Å, between 13C atoms and 35Cl atoms in 10% uniformly labeled 13C L-tyrosine·HCl and natural abundance Glycine·HCl can be measured using rotational-echo (adiabatic passage) double-resonance (RE(AP)DOR). Furthermore the effect of quadrupolar interaction on the REDOR/REAPDOR experiment is quantified. The dephasing curve is plotted in a three dimensional chart as a function of the dephasing time and of the strength of quadrupolar interaction felt by each orientation. During spinning each orientation feels a quadrupolar interaction that varies in time, and therefore at each moment in time we reorder the crystallite orientations as a function of their contribution to the dephasing curve. In this way the effect of quadrupolar interaction on the dipolar dephasing curve can be fitted with a polynomial function. The numerical investigation performed allows us to generate REDOR/REAPDOR curves which are then used to simulate the experimental data.

Reprint of: Localization of Cl-35 Nuclei in Biological Solids using Rotational-Echo Double-Resonance Experiments.

Chloride ions play important roles in many chemical and biological processes. This paper investigates the possibility of localizing 35Cl nuclei using solid-state NMR. It demonstrates that distances shorter than 3.8Å, between 13C atoms and 35Cl atoms in 10% uniformly labeled 13C L-tyrosine·HCl and natural abundance Glycine·HCl can be measured using rotational-echo (adiabatic passage) double-resonance (RE(AP)DOR). Furthermore the effect of quadrupolar interaction on the REDOR/REAPDOR experiment is quantified. The dephasing curve is plotted in a three dimensional chart as a function of the dephasing time and of the strength of quadrupolar interaction felt by each orientation. During spinning each orientation feels a quadrupolar interaction that varies in time, and therefore at each moment in time we reorder the crystallite orientations as a function of their contribution to the dephasing curve. In this way the effect of quadrupolar interaction on the dipolar dephasing curve can be fitted with a polynomial function. The numerical investigation performed allows us to generate REDOR/REAPDOR curves which are then used to simulate the experimental data.

The role of diffusion tensor imaging in spinal pathology: A review.

Diffusion tensor imaging (DTI) allows for noninvasive, in vivo visualization of white matter fiber tracts in the central nervous system by measuring the diffusion of water molecules. It provides both quantitative and qualitative (i.e., tractography) means to describe a region-of-interest. While protocols for the use of DTI are better established in the brain, the efficacy and potential applications of DTI in spinal cord pathology are less understood. In this review, we examine the current literature regarding the use of DTI in the spinal cord pathology, and in particular its diagnostic and prognostic value in traumatic injury, spinal tumors, cervical myelopathies, amyotrophic lateral sclerosis, and multiple sclerosis. Although structural magnetic resonance imaging (MRI) has long been the gold standard for noninvasive imaging of soft tissues, DTI provides additional tissue characteristics not found in the conventional MRI. We place emphasis on the unique characteristics of DTI, its potential value as an adjunct imaging modality, and its impact on clinical practice.

Rapid and accurate identification of Xanthomonas citri subspecies citri by fluorescence in situ hybridization.

Citrus canker is an economically important disease caused by the bacterial pathogen Xanthomonas citri subsp. citri (Xcc). This organism targets a wide range of citrus plants, including sweet orange, grapefruit, lemon and lime. As Xcc is spread by environmental factors such as wind and rain, it is difficult to control its movement once the disease has established. In order to facilitate monitoring of citrus canker we sought to design a novel diagnostic protocol based on fluorescence in situ hybridization (FISH) for identification of bacterial cells directly from canker pustules without cultivation or DNA extraction. This method was validated for specificity against a range of Xanthomonas species and strains. We show that our assay is extremely rapid (typically requiring between 2 and 3 h), and possesses a similar specificity to existing PCR diagnostic tools. The sensitivity of the assay is comparable to that of an existing PCR-based technique and sufficient for identifying Xcc in symptomatic plant material. The method is easily transferable to diagnosticians without prior experience using FISH. SIGNIFICANCE AND IMPACT OF THE STUDY: Xanthomonas citri subsp. citri (Xcc) is an aggressive and hardy pathogen of citrus plants worldwide. Outbreaks are difficult and costly to contain and the establishment of citrus canker results in restricted trade. In order to extend the existing toolkit for identification of Xcc we developed a novel diagnostic approach based on fluorescence in situ hybridization. Our approach is of comparable specificity and sensitivity to existing methods but can be performed directly on infected tissue making it significantly faster than existing PCRs, and requiring fewer laboratory resources.

Within-population Y-linked genetic variation for lifespan in Drosophila melanogaster.

The view that the Y chromosome is of little importance for phenotypic evolution stems from early studies of Drosophila melanogaster. This species' Y chromosome contains only 13 protein-coding genes, is almost entirely heterochromatic and is not necessary for male viability. Population genetic theory further suggests that non-neutral variation can only be maintained at the Y chromosome under special circumstances. Yet, recent studies suggest that the D. melanogaster Y chromosome trans-regulates hundreds to thousands of X and autosomal genes. This finding suggests that the Y chromosome may play a far more active role in adaptive evolution than has previously been assumed. To evaluate the potential for the Y chromosome to contribute to phenotypic evolution from standing genetic variation, we test for Y-linked variation in lifespan within a population of D. melanogaster. Assessing variation for lifespan provides a powerful test because lifespan (i) shows sexual dimorphism, which the Y is primarily predicted to contribute to, (ii) is influenced by many genes, which provides the Y with many potential regulatory targets and (iii) is sensitive to heterochromatin remodelling, a mechanism through which the Y chromosome is believed to regulate gene expression. Our results show a small but significant effect of the Y chromosome and thus suggest that the Y chromosome has the potential to respond to selection from standing genetic variation. Despite its small effect size, Y-linked variation may still be important, in particular when evolution of sexual dimorphism is genetically constrained elsewhere in the genome.

Confined crystallization of fenofibrate in nanoporous silica.

Producing stable nanocrystals confined to porous excipient media is a desirable way to increase the dissolution rate and improve the bioavailability of poorly water soluble pharmaceuticals. The poorly soluble pharmaceutical fenofibrate was crystallized in controlled pore glass (CPG) of 10 different pore sizes between 12 nm and 300 nm. High drug loadings of greater than 20 wt% were achieved across all pore sizes greater than 20 nm. Nanocrystalline fenofibrate was formed in pore sizes greater than 20 nm and showed characteristic melting point depressions following a Gibbs-Thomson relationship as well as enhanced dissolution rates. Solid-state Nuclear Magnetic Resonance (NMR) was employed to characterize the crystallinity of the confined molecules. These results help to advance the fundamental understanding of nanocrystallization in confined pores.

Time domain DNP with the NOVEL sequence.

We present results of a pulsed dynamic nuclear polarization (DNP) study at 0.35 T (9.7 GHz/14.7 MHz for electron/(1)H Larmor frequency) using a lab frame-rotating frame cross polarization experiment that employs electron spin locking fields that match the (1)H nuclear Larmor frequency, the so called NOVEL (nuclear orientation via electron spin locking) condition. We apply the method to a series of DNP samples including a single crystal of diphenyl nitroxide (DPNO) doped benzophenone (BzP), 1,3-bisdiphenylene-2-phenylallyl (BDPA) doped polystyrene (PS), and sulfonated-BDPA (SA-BDPA) doped glycerol/water glassy matrices. The optimal Hartman-Hahn matching condition is achieved when the nutation frequency of the electron matches the Larmor frequency of the proton, ω(1S) = ω(0I), together with possible higher order matching conditions at lower efficiencies. The magnetization transfer from electron to protons occurs on the time scale of ∼100 ns, consistent with the electron-proton couplings on the order of 1-10 MHz in these samples. In a fully protonated single crystal DPNO/BzP, at 270 K, we obtained a maximum signal enhancement of ε = 165 and the corresponding gain in sensitivity of ε(T1/T(B))(1/2)=230 due to the reduction in the buildup time under DNP. In a sample of partially deuterated PS doped with BDPA, we obtained an enhancement of 323 which is a factor of ∼3.2 higher compared to the protonated version of the same sample and accounts for 49% of the theoretical limit. For the SA-BDPA doped glycerol/water glassy matrix at 80 K, the sample condition used in most applications of DNP in nuclear magnetic resonance, we also observed a significant enhancement. Our findings demonstrate that pulsed DNP via the NOVEL sequence is highly efficient and can potentially surpass continuous wave DNP mechanisms such as the solid effect and cross effect which scale unfavorably with increasing magnetic field. Furthermore, pulsed DNP is also a promising avenue for DNP at high temperature.

Formation of Organic Molecular Nanocrystals under Rigid Confinement with Analysis by Solid State NMR.

Crystallization in rigid confinement is a promising method to obtain organic molecular nanocrystals. However, the crystallization behavior and the related characterization methods are not well studied. Here we present a systematic study of the nucleation of organic molecular nanocrystals in rigid pores. Four different compounds were studied, ibuprofen, fenofibrate, griseofulvin, and indomethacin, which range from simple to complex molecules. Solid-state Nuclear Magnetic Resonance (NMR) was employed to analyse the structure of these compounds inside pores which are difficult to characterize by other analytical methods. We successfully demonstrated the production of nano-crystalline ibuprofen, fenofibrate and griseofulvin in porous silica particles with ~ 40 nm pores. These nanocrystals showed significant enhancement in dissolution rates. These results help advance the fundamental understanding of nucleation under rigid confinement and may lead to potential applications in developing new formulations in the pharmaceutical industry.

Overhauser effects in insulating solids.

We report magic angle spinning, dynamic nuclear polarization (DNP) experiments at magnetic fields of 9.4 T, 14.1 T, and 18.8 T using the narrow line polarizing agents 1,3-bisdiphenylene-2-phenylallyl (BDPA) dispersed in polystyrene, and sulfonated-BDPA (SA-BDPA) and trityl OX063 in glassy glycerol/water matrices. The (1)H DNP enhancement field profiles of the BDPA radicals exhibit a significant DNP Overhauser effect (OE) as well as a solid effect (SE) despite the fact that these samples are insulating solids. In contrast, trityl exhibits only a SE enhancement. Data suggest that the appearance of the OE is due to rather strong electron-nuclear hyperfine couplings present in BDPA and SA-BDPA, which are absent in trityl and perdeuterated BDPA (d21-BDPA). In addition, and in contrast to other DNP mechanisms such as the solid effect or cross effect, the experimental data suggest that the OE in non-conducting solids scales favorably with magnetic field, increasing in magnitude in going from 5 T, to 9.4 T, to 14.1 T, and to 18.8 T. Simulations using a model two spin system consisting of an electron hyperfine coupled to a (1)H reproduce the essential features of the field profiles and indicate that the OE in these samples originates from the zero and double quantum cross relaxation induced by fluctuating hyperfine interactions between the intramolecular delocalized unpaired electrons and their neighboring nuclei, and that the size of these hyperfine couplings is crucial to the magnitude of the enhancements. Microwave power dependent studies show that the OE saturates at considerably lower power levels than the solid effect in the same samples. Our results provide new insights into the mechanism of the Overhauser effect, and also provide a new approach to perform DNP experiments in chemical, biophysical, and physical systems at high magnetic fields.

The Effect of Radial Inclination on the Stage of Kienbock Disease at the Time of Initial Diagnosis.

BACKGROUND: Negative ulnar variance is a widely accepted risk factor for the development of Kienbock disease (KD). Variation in radial inclination has been proposed as a risk factor, but evidence thus far has been inconclusive. We aim to clarify the relationship between radial inclination and KD. METHODS: A retrospective analysis of all KD patients from a single institution from 2007 to 2021 was conducted. Radiographs were reviewed to measure anatomic parameters and stage of disease. An exploratory multinomial regression model was created to examine the association of patient age, radial height, ulnar variance, radial inclination, volar tilt, scapholunate angle, duration of symptoms prior to evaluation, history of wrist trauma, and diagnosis of diabetes with stage of disease. RESULTS: Fifty-seven cases of KD were identified, with a mean duration of disease of 33.3 months. A history of trauma to the wrist was common (53%) and significantly associated with stage of disease at initial presentation. Twenty-seven cases (47%) were stage IIIB or greater. The average initial radial inclination, radial height, and ulnar variance was 21.9°, 10.7 mm, and -1.23 mm, respectively. A multinominal logistic regression model revealed decreased initial radial inclination is associated with Lichtman stage IIIB or greater at the time of initial patient presentation. CONCLUSIONS: A correlation exists between decreased radial inclination and more advanced KD at presentation, suggesting this may be a risk factor for disease progression. This correlation is strengthened by our finding of decreased ulnar variance being associated with later stage at presentation, which is one of the most widely accepted proposed risk factors for development and progression of disease. LEVEL OF EVIDENCE: IV.

A Quantitative Assessment of ChatGPT as a Neurosurgical Triaging Tool.

BACKGROUND AND OBJECTIVES: ChatGPT is a natural language processing chatbot with increasing applicability to the medical workflow. Although ChatGPT has been shown to be capable of passing the American Board of Neurological Surgery board examination, there has never been an evaluation of the chatbot in triaging and diagnosing novel neurosurgical scenarios without defined answer choices. In this study, we assess ChatGPT's capability to determine the emergent nature of neurosurgical scenarios and make diagnoses based on information one would find in a neurosurgical consult. METHODS: Thirty clinical scenarios were given to 3 attendings, 4 residents, 2 physician assistants, and 2 subinterns. Participants were asked to determine if the scenario constituted an urgent neurosurgical consultation and what the most likely diagnosis was. Attending responses provided a consensus to use as the answer key. Generative pretraining transformer (GPT) 3.5 and GPT 4 were given the same questions, and their responses were compared with the other participants. RESULTS: GPT 4 was 100% accurate in both diagnosis and triage of the scenarios. GPT 3.5 had an accuracy of 92.59%, slightly below that of a PGY1 (96.3%), an 88.24% sensitivity, 100% specificity, 100% positive predictive value, and 83.3% negative predicative value in triaging each situation. When making a diagnosis, GPT 3.5 had an accuracy of 92.59%, which was higher than the subinterns and similar to resident responders. CONCLUSION: GPT 4 is able to diagnose and triage neurosurgical scenarios at the level of a senior neurosurgical resident. There has been a clear improvement between GPT 3.5 and 4. It is likely that the recent updates in internet access and directing the functionality of ChatGPT will further improve its utility in neurosurgical triage.

Femoral Neck Fractures With Associated Ipsilateral Femoral Shaft Fractures in Young Adults <50 Years Old: A Multicenter Comparison of 80 Cases Versus Isolated Femoral Neck Fractures.

OBJECTIVES: To analyze patients, injury patterns, and treatment of femoral neck fractures (FNFs) in young patients with FNFs associated with shaft fractures (assocFNFs) to improve clinical outcomes. The secondary goal was to compare this injury pattern to that of young patients with isolated FNFs (isolFNFs). DESIGN: Retrospective multicenter cohort series. SETTING: Twenty-six North American level-1 trauma centers. PATIENT SELECTION CRITERIA: Skeletally mature patients, <50 years old, treated with operative fixation of an FNF with or without an associated femoral shaft fracture. OUTCOME MEASURES AND COMPARISONS: The main outcome measurement was treatment failure defined as nonunion, malunion, avascular necrosis, or subsequent major revision surgery. Odds ratios for these modes of treatment were also calculated. RESULTS: Eighty assocFNFs and 412 isolFNFs evaluated in this study were different in terms of patients, injury patterns, and treatment strategy. Patients with assocFNFs were younger (33.3 ± 8.6 vs. 37.5 ± 8.7 years old, P < 0.001), greater in mean body mass index [BMI] (29.7 vs. 26.6, P < 0.001), and more frequently displaced (95% vs. 73%, P < 0.001), "vertically oriented" Pauwels type 3, P < 0.001 (84% vs. 43%) than for isolFNFs, with all P values < 0.001. AssocFNFs were more commonly repaired with an open reduction (74% vs. 46%, P < 0.001) and fixed-angle implants (59% vs. 39%) (P < 0.001). Importantly, treatment failures were less common for assocFNFs compared with isolFNFs (20% vs. 49%, P < 0.001) with lower rates of failed fixation/nonunion and malunion (P < 0.001 and P = 0.002, respectively). Odds of treatment failure [odds ratio (OR) = 0.270, 95% confidence interval (CI), 0.15-0.48, P < 0.001], nonunion (OR = 0.240, 95% CI, 0.10-0.57, P < 0.001), and malunion (OR = 0.920, 95% CI, 0.01-0.68, P = 0.002) were also lower for assocFNFs. Excellent or good reduction was achieved in 84.2% of assocFNFs reductions and 77.1% in isolFNFs (P = 0.052). AssocFNFs treated with fixed-angle devices performed very well, with only 13.0% failing treatment compared with 51.9% in isolFNFs treated with fixed-angle constructs (P = <0.001) and 33.3% in assocFNFs treated with multiple cannulated screws (P = 0.034). This study also identified the so-called "shelf sign," a transverse ≥6-mm medial-caudal segment of the neck fracture (forming an acute angle with the vertical fracture line) in 54% of assocFNFs and only 9% of isolFNFs (P < 0.001). AssocFNFs with a shelf sign failed in only 5 of 41 (12%) cases. CONCLUSIONS: AssocFNFs in young patients are characterized by different patient factors, injury patterns, and treatments, than for isolFNFs, and have a relatively better prognosis despite the need for confounding treatment for the associated femoral shaft injury. Treatment failures among assocFNFs repaired with a fixed-angle device occurred at a lower rate compared with isolFNFs treated with any construct type and assocFNFs treated with multiple cannulated screws. The radiographic "shelf sign" was found as a positive prognostic sign in more than half of assocFNFs and predicted a high rate of successful treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.