Diagnostic performance of coronary calcifications on CT to rule out acute coronary syndrome in the emergency department.

BACKGROUND: At present, the diagnosis of acute coronary syndrome (ACS) can be made by emergency physicians using the usual complementary tests, since the current troponin and electrocardiogram (ECG) protocols have been extensively tested for their safety. However, the detection of coronary calcifications on CT associated with coronary obstruction may be of interest for the diagnostic strategy in the emergency department (ED). The aim of this study was to evaluate a strategy combining a non-ischemic ECG with an initial normal troponin assay and the diagnostic accuracy of chest CT in detecting coronary calcifications to rule out the presence of an acute coronary event in patients presenting with chest pain in the ED. METHODS: This was a retrospective, single-center study carried out in an ED in France and included all patients over 18 years of age presenting with chest pain between 1 June 2021 and 31 December 2021 with a non-ischemic ECG and a negative first troponin assay. The primary endpoint was the diagnostic performance of the combing strategy in ruling out ACS. The secondary endpoints were the sensitivity and specificity of calcifications in acute coronary syndrome, comparison with the diagnostic performance of a second troponin assay and the rate of reconsultation, rehospitalisation and investigations within 2 months of the ED. RESULTS: Of the 280 patients included, 141 didn't have calcifications. A total of 14 events were found with a negative predictive value for the combining strategy of 99.8% [95%CI: 98.2 - 100]. Sensitivity and specificity were 98.4% [95%CI: 83.8 - 100] and 53% [95%CI: 47 - 58.9], respectively. Among patients with no calcification, 8.2% were admitted to hospital and none suffered an acute coronary event. A total of 36 patients (12.8%) consulted a doctor within 2 months, with 23 investigations, all of which were negative in the non-calcification group. CONCLUSIONS: A strategy combining the detection of coronary calcifications on chest CT in patients with a non-ischemic ECG and a single troponin assay is effective to rule out ACS in the ED, and may perform better then ECG and troponin alone.

Using machine learning or deep learning models in a hospital setting to detect inappropriate prescriptions: a systematic review.

OBJECTIVES: The emergence of artificial intelligence (AI) is catching the interest of hospital pharmacists. A massive collection of health data is now available to train AI models and hold the promise of disrupting codes and practices. The objective of this systematic review was to examine the state of the art of machine learning or deep learning models that detect inappropriate hospital medication orders. METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. MEDLINE and Embase databases were searched from inception to May 2023. Studies were included if they reported and described an AI model intended for use by clinical pharmacists in hospitals. Risk of bias was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). RESULTS: 13 articles were selected after review: 12 studies were judged to have high risk of bias; 11 studies were published between 2020 and 2023; 8 were conducted in North America and Asia; 6 analysed orders and detected inappropriate prescriptions according to patient profiles and medication orders; and 7 detected specific inappropriate prescriptions, such as detecting antibiotic resistance, dosage abnormality in prescriptions, high alert drugs errors from prescriptions or predicting the risk of adverse drug events. Various AI models were used, mainly supervised learning techniques. The training datasets used were very heterogeneous; the length of study varied from 2 weeks to 7 years and the number of prescription orders analysed went from 31 to 5 804 192. CONCLUSIONS: This systematic review points out that, to date, few original research studies report AI tools based on machine or deep learning in the field of hospital clinical pharmacy. However, these original articles, while preliminary, highlighted the potential value of integrating AI into clinical hospital pharmacy practice.

Micro-costing analysis of suspected lower respiratory tract infection care in a French emergency department.

Introduction: In the context of budgetary constraints faced by healthcare systems, the medical-economic evaluation of care strategies becomes essential. In particular, valuing consumed resources in the overcrowded emergency departments (EDs) has become a priority to adopt more efficient approaches in treating the growing number of patients. However, precisely measuring the cost of care is challenging. While bottom-up micro-costing is considered the gold standard, its practical application remains limited. Objective: The objective was to accurately estimate the ED care cost for patients consulting in a French ED for suspected lower respiratory tract infection. Methods: The authors conducted a cost analysis using a bottom-up micro-costing method. Patients were prospectively included between January 1, and March 31, 2023. The primary endpoint was the mean cost of ED care. Resources consumed were collected using direct observation method and cost data were obtained from information available at Strasbourg University Hospital. Results: The mean cost of ED care was €411.68 (SD = 174.49). The cost elements that made the greatest contribution to the total cost were laboratory tests, labor, latency time, imaging and consumables. Considering this cost and the current epidemiological data on respiratory infections in France, the absence of valuation for outpatient care represents an annual loss of over 17 million euros for healthcare facilities. Conclusion: Micro-costing is a key element in valuing healthcare costs. The importance of accurately measuring costs, along with measuring the health outcomes of a defined care pathway, is to enhance the relevance of health economic evaluations and thus ensure efficient care.

Organizational Benefits of Ultra-Low-Dose Chest CT Compared to Chest Radiography in the Emergency Department for the Diagnostic Workup of Community-Acquired Pneumonia: A Real-Life Retrospective Analysis.

Background and Objectives: Chest radiography remains the most frequently used examination in emergency departments (ED) for the diagnosis of community-acquired pneumonia (CAP), despite its poor diagnostic accuracy compared with ultra-low-dose (ULD) chest computed tomography (CT). However, although ULD CT appears to be an attractive alternative to radiography, its organizational impact in ED remains unknown. Our objective was to compare the relevant timepoints in ED management of CT and chest radiography. Materials and Methods: We conducted a retrospective study in two ED of a University Hospital including consecutive patients consulting for a CAP between 1 March 2019 and 29 February 2020 to assess the organizational benefits of ULD chest CT and chest radiography (length of stay (LOS) in the ED, time of clinical decision after imaging). Overlap weights (OW) were used to reduce covariate imbalance between groups. Results: Chest radiography was performed for 1476 patients (mean age: 76 years [63; 86]; 55% men) and ULD chest CT for 133 patients (mean age: 71 [57; 83]; 53% men). In the weighted population with OW, ULD chest CT did not significantly alter the ED LOS compared with chest radiography (11.7 to 12.2; MR 0.96 [0.85; 1.09]), although it did significantly reduce clinical decision time (6.9 and 9.5 h; MR 0.73 [0.59; 0.89]). Conclusion: There is real-life evidence that a strategy with ULD chest CT can be considered to be a relevant approach to replace chest radiography as part of the diagnostic workup for CAP in the ED without increasing ED LOS.

Variation of cervical sagittal alignment parameters according to age and pelvic incidence in degenerative spinal deformity patients.

INTRODUCTION: In asymptomatic subjects, variations of cervical sagittal alignment parameters according to age and spinopelvic organization have been reported. A large range of compensation phenomena has been observed in degenerative spinal deformity in order to maintain horizontal gaze, but it remains unclear how age and spinopelvic morphology could additionally influence cervical alignment. The aim of this observational retrospective study was to describe the distribution of cervical sagittal alignment parameters according to age and pelvic incidence in subjects with and without degenerative spinal deformity in order to precisely evaluate cervical compensation phenomena in adult spinal deformity (ASD). MATERIAL AND METHODS: Radiographs of 478 subjects (327 females and 151 males) were distributed into 235 asymptomatic and 243 deformed subjects. Occipito-cervical parameters were McGregor-C1, McGregor-C2, C1-C2 and occipito-C2 angles. The cervicothoracic inflection point (CTIP) was determined. Caudal cervical sagittal alignment parameters were: C2-C7 lordosis, C2-apex (superior arch), apex-CTIP (inferior arch), occipito-C3 and occipito-C4 angles, C7-slope and T1-slope. The distribution of parameters was analyzed using a Bayesian inference (significant when Pr > 0.975 or Pr < 0.025). Comparisons between asymptomatic and deformed subjects were done after matching on age (40-60 years; > 60 years) and on PI (< 45°; 45-60°; > 60°). RESULTS: Among occipito-cervical parameters, there was no significant change in McGregor-C1 angle. However, McGregor-C2 angle was significantly higher in the ASD group (Pr = 0.0029), with influence of age (Pr = 0.023), but PI influence. C1-C2 lordosis was significantly higher in the ASD group compared to the asymptomatic group (Pr < 0.0007), without influence of age or PI noticed. C2-C7 lordosis was also higher in the ASD group (Pr < 0.025) with a role of age and PI (Pr < 0.025). Cervical lordosis in the superior arch was significantly higher in the ASD group (Pr > 0.999), without influence of age or PI. In the inferior arch, the lordosis angle was not modified according to the group, but there was an influence of age (Pr < 0.0007). C7-slope and T1-slope were higher according the age group (Pr < 0.0012), without influence of the group or PI. CONCLUSION: This observational study highlights cervical sagittal alignment adaptations in degenerative spinal deformity, matched on age and pelvic incidence. The inferior cervical spine seemed to be modified with a higher lordosis, increasing with age responding to the age-related thoracic kyphosis increase. In addition to that, the superior cervical spine hyperextends more in adult degenerative deformity to maintain horizontal gaze. LEVEL OF EVIDENCE: III.

Evaluating the Portability of Rheumatoid Arthritis Phenotyping Algorithms: A Case Study on French EHRs.

Previous work has successfully used machine learning and natural language processing for the phenotyping of Rheumatoid Arthritis (RA) patients in hospitals within the United States and France. Our goal is to evaluate the adaptability of RA phenotyping algorithms to a new hospital, both at the patient and encounter levels. Two algorithms are adapted and evaluated with a newly developed RA gold standard corpus, including annotations at the encounter level. The adapted algorithms offer comparably good performance for patient-level phenotyping on the new corpus (F1 0.68 to 0.82), but lower performance for encounter-level (F1 0.54). Regarding adaptation feasibility and cost, the first algorithm incurred a heavier adaptation burden because it required manual feature engineering. However, it is less computationally intensive than the second, semi-supervised, algorithm.

Proximal and distal mechanical repercussions of instrumentation by double rods and interbody grafts in adult scoliosis.

INTRODUCTION: Correction of adult scoliosis by instrumentation with double rods and interbody grafts aims to reduce the risk of pseudarthrosis with rod fracture. An increase in instrumentation rigidity can lead to an increase in stresses at the proximal and distal ends of the construct. The aim of this study was to analyze the incidence and clinical repercussions of proximal junctional kyphosis (PJK), proximal junctional failure (PJF) and iliac screw loosening. MATERIEL AND METHODS: An analysis of patients operated on for adult scoliosis with instrumentation to the pelvis using 4 rods and interbody cages was carried out from a prospective register. The Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Scoliosis Research Society 22 (SRS-22) clinical scores and radiological parameters were collected preoperatively, postoperatively at 3 months, 1 year and 2 years. The appearance of PJK, PJF or distal screw loosening was sought; the clinical impact and the risk factors were analyzed by Bayesian inference. RESULTS: Fifty-one patients with a mean age of 64.5 years were included. The clinical scores improved significantly (Pr>0.95) at 2 years: VAS back 6.9 versus 2.6, VAS leg 4.9 versus 2.5, ODI 48.2 versus 25.4, SRS-22 2.4 versus 3.5. The radiological parameters were corrected (Pr>0.95): Cobb angle 63.9° versus 22.8°, spinosacral angle (SSA) 112.4° versus 118.8°, T1-pelvic angle (TPA) 24, 8° versus 20.8°, lumbar lordosis 43.8° versus 51.0°, thoracic kyphosis 45.2° versus 53.6°. Thirteen patients (25.5%) presented with PJK and 11 (21.6%) with PJF. Seven patients (13.7%) presented with iliac screw loosening. None of these complications was associated with a significant deterioration in clinical scores. Cranial migration of the lumbar apex increased the risk of distal screw loosening: Odds-Ratio 10.31 (Pr>0.999). Two patients were re-operated on for PJF and one patient for iliac screw loosening (5.9%). No rod fracture with pseudarthrosis was found. CONCLUSION: Instrumentation with double rods and interbody grafts was associated with a rate of 47.1% of mechanical repercussions at the extremity of the construct. However, these complications were not associated with a significant deterioration in clinical scores. LEVEL OF EVIDENCE: III.

Psychopathological profile and sagittal alignment in low-back pain.

INTRODUCTION: Low-back pain requires comprehensive care using a biopsychosocial model. The psychologic dimension plays an important role, but the link between sagittal alignment and a given psychopathological profile is little studied. The aim of this study was to analyze the psychopathological profiles and sagittal parameters of a population with low-back pain and to assess the link. MATERIAL AND METHODS: 205 patients, with a mean age of 49.6 years (range, 18-70 years), presenting chronic common low-back pain without radicular involvement, were included prospectively. Mood scores comprised: the self-administered "Hospital Anxiety and Depression Scale" (HAD), Hamilton Anxiety Scale (HAM-A), Hamilton Depression Scale (HAM-D) and Young Mania Rating Scale (YMRS). Radiological parameters, measured on lateral full-spine radiographs, included: L1-S1 lordosis, T1-T12 kyphosis, pelvic incidence, pelvic tilt, sacral slope, sagittal vertical axis (SVA), T1 slope, and Roussouly type. RESULTS: Mean HAM-A score was 16.1; 54% of patients had scores ≥14, indicating anxiety disorder. Mean HAM-D score was 10.8; 55% of patients had scores ≥10, indicating depressive disorder. Mean YMRS score was 2.6; only 1 patient had a score ≥20, indicating manic disorder. The 112 patients with HAM-A score >14 showed mean 51.6° L1-S1 lordosis (p=0.356), 48.3° T1-T12 kyphosis (p=0.590), -4.3mm C7 SVA (p=0.900), and 29.3° T1 slope (p=0.451). In case of HAM-A <14, there were no significant differences. The 113 patients with HAM-D score >10 showed significant differences in T1-T12 kyphosis (mean 49.0°; p<0.05) and T1 slope (30.2°; p<0.05); mean L1-S1 lordosis was 50.5° (p=0.861) and C7 SVA 1.6mm (p=0.462). In case of HAM-D <10, T1-T12 kyphosis was 45.5° (p<0.05) and T1 slope 26.2° (p<0.05); mean lordosis was 50.9° (p=0.861) and mean C7 SVA -7.1mm (p=0.259). Multivariate analysis found no significant link between Roussouly type and psychiatric scores: HAD (p=0.715), HAM-A (p=0.652), and HAM-D (p=0.902). CONCLUSION: More than 50% of patients with common low-back pain presented a mood disorder. Depressive disorder was associated with greater T1-T12 kyphosis and T1 slope. There was no relationship between psychiatric scores and overall sagittal alignment. LEVEL OF EVIDENCE: II.

Environmental Drivers of Monkeypox Transmission in the Democratic Republic of the Congo.

Monkeypox (MPX) is an emergent severe zoonotic disease resembling that of smallpox. To date, most cases of human MPX have been reported in the Democratic Republic of the Congo (DRC). While the number of cases has increased steadily in the DRC over the last 30 years, the environmental risk factors that drive the spatiotemporal dynamics of MPX transmission remain poorly understood. This study aimed to investigate the spatiotemporal associations between environmental risk factors and annual MPX incidence in the DRC. All MPX cases reported weekly at the health zone level over a 16-year period (2000-2015) were analyzed. A Bayesian hierarchical generalized linear mixed model was conducted to identify the spatiotemporal associations between annual MPX incidence and three types of environmental risk factors illustrating environment as a system resulting from physical, social and cultural interactions Primary forest (IRR 1.034 [1.029-1.040]), economic well-being (IRR 1.038 [1.031-1.047]), and temperature (IRR 1.143 [1.028-1.261]) were positively associated with annual MPX incidence. Our study shows that physical environmental risk factors alone cannot explain the emergence of MPX outbreaks in the DRC. Economic level and cultural practices participate from environment as a whole and thus, must be considered to understand exposure to MPX risk Future studies should examine the impact of these factors in greater detail.

COVID-19 Impact on Stroke Admissions during France's First Epidemic Peak: An Exhaustive, Nationwide, Observational Study.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic continues to have great impacts on the care of non-COVID-19 patients. This was especially true during the first epidemic peak in France, which coincided with the national lockdown. The aim of this study was to identify whether a decrease in stroke admissions occurred in spring 2020, by analyzing the evolution of all stroke admissions in France from January 2019 to June 2020. METHODS: We conducted a nationwide cohort study using the French national database of hospital admissions (Information Systems Medicalization Program) to extract exhaustive data on all hospitalizations in France with at least one stroke diagnosis between January 1, 2019, and June 30, 2020. The primary endpoint was the difference in the slope gradients of stroke hospitalizations between pre-epidemic, epidemic peak, and post-epidemic peak phases. Modeling was carried out using Bayesian techniques. RESULTS: Stroke hospitalizations dropped from March 10, 2020 (slope gradient: -11.70), and began to rise again from March 22 (slope gradient: 2.090) to May 7. In total, there were 23,873 stroke admissions during the period March-April 2020, compared to 29,263 at the same period in 2019, representing a decrease of 18.42%. The percentage change was -15.63%, -25.19%, -18.62% for ischemic strokes, transient ischemic attacks, and hemorrhagic strokes, respectively. DISCUSSION/CONCLUSION: Stroke hospitalizations in France experienced a decline during the first lockdown period, which cannot be explained by a sudden change in stroke incidence. This decline is therefore likely to be a direct, or indirect, result of the COVID-19 pandemic.

Activation of 20-HETE Synthase Triggers Oxidative Injury and Peripheral Nerve Damage in Type 2 Diabetic Mice.

Diabetic Peripheral Neuropathy (DPN), highly prevalent among patients with diabetes, is characterized by peripheral nerve dysfunction. Reactive Oxygen Species (ROS) overproduction has been suggested to orchestrate diabetic complications including DPN. Untargeted antioxidant therapy has exhibited limited efficacy, highlighting a critical need to explore ROS sources altered in a cell-specific manner in DPN. Cytochromes P450 (CYP) enzymes are prominent sources of ROS. Particularly, the 20-HETE synthase, CYP4A, is reported to mediate diabetes-induced renal, retinal, and cardiovascular injuries. This work investigates the role of CYP4A/20-HETE in DPN and their mechanisms of action. Non-obese type 2 Diabetic mice (MKR) were used and treated with a CYP4A-inhibitor (HET0016) or AMPK-activator (Metformin). Peripheral nerves of MKR mice reflect increased CYP4A and 20-HETE levels, concurrent with altered myelin proteins and sensorimotor deficits. This was associated with increased ROS production and altered Beclin-1 and LC3 protein levels, indicative of disrupted autophagic responses in tandem with AMPK inactivation. AMPK activation via Metformin restored nerve integrity, reduced ROS production, and regulated autophagy. Interestingly, similar outcomes were revealed upon HET0016 treatment whereby ROS production, autophagic responses, and AMPK signaling were normalized in diabetic mice. Altogether, the results highlight hyperglycemia-mediated oxidative injury in DPN through a novel CYP4A/20-HETE/AMPK pathological axis. PERSPECTIVE: To our knowledge, this is the first study to highlight the role of CYPs/20-HETE-induced oxidative injury in the pathogenesis of diabetic peripheral neuropathy. Targeting the identified pathological axis CYP4A/20-HETE/AMPK may be of clinical potential in predicting and alleviating peripheral nerve injury in patients with Type 2 Diabetes Mellitus.

Cognitive reserve as one of the determinants of the progression of Alzheimer disease.

To assess the validity of Yaakov Stern's theory, which postulates that the first cognitive deficits of Alzheimer disease are delayed in patients with high cognitive reserve, compared to those with low cognitive reserve, but this is subsequently associated with faster cognitive decline when cerebral lesions have reached a certain degree of severity. A retrospective study of 318 patients with Alzheimer disease without associated cerebral disorders, was performed at the Memory Clinic of the University Hospital of Strasbourg. The patients were divided into five groups according to their degree of cognitive reserve, as assessed by their level of education (primary, middle school, intermediate, high school and higher education). Cognitive status was assessed by scores on the Mini Mental Status Examination (MMSE) at the first examination and during follow-up lasting four years or longer. Slopes of cognitive decline were computed and compared between groups using ß linear regression. Patients in the higher education group had higher MMSE scores than those in the other groups at the first consultation, but a statistically significant steeper slope during the follow-up. Our results are consistent with Stern's theoretical model, which assumes that high cognitive reserve is accompanied by compensation mechanisms which hinder the onset of clinical cognitive decline in patients with Alzheimer disease, but that is then associated with a faster decline at a later stage when the reserve is exhausted.

Variation of cervical sagittal alignment parameters according to gender, pelvic incidence and age.

PURPOSE: The aim was to describe radiographic cervical sagittal alignment variations according to age, gender and pelvic incidence (PI) and to investigate relationships with thoracic alignment. METHODS: A total of 2599 individuals (5-93 years) without spinal deformity were studied. Cranial cervical parameters were: McGregor slope, occipita-C2 angle, McGregor-C2 lordosis and C1-C2 lordosis. Caudal cervical parameters were: C2-C7, cranial arch and caudal arch lordosis and C7- and T1-slope. A Bayesian inference compared parameter distributions. Correlations with spinopelvic and global alignment parameters were investigated. RESULTS: Among cranial cervical parameters, variations of McGregor slope were non-significant. McGregor-C2 lordosis and C1-C2 lordosis were smaller in males and increased significantly during growth, whereas the occipito-C2 angle decreased (Pr > 0.95). The occipito-C2 angle was larger and McGregor-C2 lordosis was smaller in low PI (Pr > 0.95). Among caudal cervical parameters, C2-C7 lordosis and C7- and T1-slope were larger in males and increased after 50 years (Pr > 0.95). Lordosis changes were non-significant in the cranial arch, whereas values increased in the caudal arch after 35 years (Pr > 0.95). Caudal parameter differences were non-significant between PI groups. Strong correlations existed between C2-C7, caudal arch lordosis, C7-slope, T1-slope and thoracic kyphosis. The sagittal vertical axis C2 correlated with caudal arch lordosis and T1-slope (ρ > 0.5; Pr > 0.95). CONCLUSION: Cervical alignment parameters vary according to age, gender and PI. In the cranial cervical spine, changes occur mainly during growth. In the caudal cervical spine, lordosis increases in the caudal arch, which is related to thoracic kyphosis increase with age. The caudal cervical arch acts as a compensatory segment by progressive extension, allowing horizontal gaze.

Effect of emergency start and central venous catheter on outcomes in incident hemodialysis patients: a prospective observational cohort.

BACKGROUND: Unfavorable conditions at hemodialysis inception reduce the survival rate. However, the relative contribution to outcomes of predialysis follow-up, symptoms, emergency start or central venous catheter (CVC) is unknown. METHODS: We analyzed the determinants of survival according to dialysis initiation conditions in the nationwide REIN registry, using two methods based either on clinical classification or data mining. We divided patients into four groups according to dialysis initiation (emergency vs planned, symptoms or not, previous follow-up). "Followed planned starters" began dialysis as outpatients and with an arteriovenous fistula (AVF). "Followed symptomatic non-urgent starters" were patients who started earlier because of any non-urgent symptomatic event. "Followed urgent starters" had seen a nephrologist before inception but started dialysis in an emergency condition. "Unknown urgent starters" were patients without any follow-up and who had a CVC at inception. RESULTS: "Followed urgent" starters had the lowest 2-year survival rate (66.8%) compared to "followed planned" (77.3%), "followed symptomatic non urgent" (79.2%), and "unknown urgent" (71.7%). Compared to other groups, the risk of mortality was lower in followed symptomatic non urgent (HR 0.86 95% CI 0.75-0.99) and higher in followed urgent starters (HR 1.05 (95% CI 0.94-1.18). In data mining Classification And Regression Tree regrouping in five categories, the lowest 2-year survival (52.3%) was in over 70-year-old starters with a CVC. The survival was 93.2% in under 57-year-old patients without active cancer, 82.5% in 57-70-year-old individuals without cancer, 72.4% in over 70-year-old patients without CVC and 61.4% in under 70-year-old subjects with cancer. The hazard ratio of data mining categories varied between 2.12 (95% CI 1.73-2.60) in 57-70-year-old subjects without cancer and 4.42 (95% CI 3.64-5.37) in over 70-year-old patients with CVC. Therefore, regrouping incident patients into five data mining categories, identified by age, cancer, and CVC use, could discriminate the 2-year survival in patients starting hemodialysis. CONCLUSIONS: Although each classification captured different prognosis information, both analyses showed that starting hemodialysis on a CVC has more dramatic outcomes than emergency start per se.

Simulation on synthetic bone: A tool for teaching thoracolumbar pedicle screw placement.

INTRODUCTION: Simulation workshops for surgical training of residents are becoming popular. The gold standard for teaching thoracolumbar pedicle screw placement are cadaver labs; however, the availability of human bodies is limited. The primary objective of this study was to determine if training on a synthetic bone model improves the apprenticeship of accurate pedicle screw placement. The secondary objective was to check the influence of residents' previous experience in spine surgery. HYPOTHESIS: The main hypothesis was that theoretical learning with practical application on synthetic bone was superior to theoretical learning alone. METHODS: Twenty-three orthopedic residents were taught about free-hand pedicle screw placement using a theoretical presentation. Six residents had previous experience with screwing techniques. After randomization in two groups, 11 residents (group 1) participated in a workshop on synthetic bone, whereas 12 residents received only theoretical instruction (group 2). Each resident was asked to place two thoracic screws (T7-T11) and two lumbar screws (L1-L5) on a cadaver. Screw placement accuracy was analyzed using the Gertzbein classification on computed tomography (grades 0 and 1=accurate positioning; grades 2 and 3=malposition>2mm). RESULTS: Rates of accurate screw positioning were 64.0% and 62.5% for thoracic levels, and 72.7% and 66.6% for lumbar levels in group 1 and 2, respectively. There was no significant difference in malposition rates on cadavers between the groups (p=0.1809). A resident who was first trained by simulation had a chance of decreasing the Gertzbein score with an odds-ratio of 1.7714 [0.7710-4.1515]. The odds ratio was 4.5188 [0.0456-0.8451] when comparing residents with previous experience in spinal surgery to novice residents. DISCUSSION: Theoretical teaching associated with a simulation model is relevant for learning a surgical technique. A single simulation workshop on synthetic bone seems insufficient to improve pedicle screw placement accuracy compared to theoretical teaching alone. Progressive experience and the repetition of technical gestures during hands-on supervised learning in spine surgery with a senior surgeon had an influence on the accuracy of pedicle screw placement. LEVEL OF EVIDENCE: II.

Analysis of factors associated with sagittal alignment deterioration after correction of degenerative scoliosis by in situ contouring.

INTRODUCTION: In situ contouring is one of the surgical techniques used for scoliosis reduction. The initial correction could change over time, with deterioration of the sagittal balance. The purpose of this study was to analyze the loss of correction after degenerative lumbar scoliosis surgery using in situ contouring. MATERIALS AND METHODS: Full spine radiographs of 73 patients (mean age 63.3 years, mean follow-up 27 months) were analyzed before surgery, after surgery, and at the final follow-up. The following radiographic parameters were measured: C2-C7 lordosis, T4-T12 kyphosis, L1-S1 lordosis, pelvic tilt, pelvic incidence, sacral slope, SVA C7, SVA C2, Cobb angle. Bayesian inference was used to compare the changes in these parameters. A probability>0.95 was considered as a significant change. RESULTS: After surgery, lumbar lordosis increased from -28.4° to -37.8° (probability 0.999), then decreased to -32.1° at the final follow-up (probability 0.953). Thoracic kyphosis increased from 29.6° to 37.4° after surgery (probability 1.00) and continued to increase to 41.6° at the final follow-up (probability 0.999). SVA C7 increased from 38.5mm to 62.3mm (probability 0.999) and pelvic tilt from 19.4° to 25.1° (probability 1.00) during the follow-up period. Ten patients had to be reoperated because of a surgical site infection. Infection (14%) was associated with an increase of SVA C7 (probability 0.989) and thoracic kyphosis (probability 0.987). Nonunion (16%) was associated with a decrease in lumbar lordosis (probability 0.756). CONCLUSION: Correction of degenerative lumbar scoliosis by in situ contouring resulted in sagittal balance correction; however, some of this correction was lost during the follow-up period. The main risk factors were deep wound infection and nonunion. LEVEL OF EVIDENCE: IV, Retrospective study.

[Cognitive reserve, one of the determinants of the progression of Alzheimer's disease]. / La réserve cognitive, un des déterminants de l'évolution de la maladie d'Alzheimer.

To appraise the validity of the Yaakov Stern's theory, which postulates that the first cognitive deficits of Alzheimer's disease are delayed in patients with high cognitive reserve, compared to those with low cognitive reserve, but is subsequently associated with faster cognitive decline when cerebral lesions have reached some degree of severity. A retrospective study of 318 patients with Alzheimer's disease without associated cerebral disorders, was performed in the Memory Clinic of the University Hospital of Strasbourg. The patients were divided into 5 groups according to the degree of cognitive reserve assessed by the level of education (primary, middle school, intermediary, high school and higher education). Cognitive status was assessed by the scores on the Mini Mental Status at the first examination and during a 4-year or more follow-up. Slopes of cognitive decline were computed and compared between groups by ß linear regression. Patients in the higher education group had higher MMSE scores than those in the other groups at the first consultation, but a statistically significant steeper slope during the follow-up. Our results are congruent with the Stern's theoretical model, assuming that high cognitive reserve brings into play compensation mechanisms which hinder the onset of clinical cognitive decline in patients with Alzheimer's disease, but then is associated with a faster decline at a later stage when the reserve is exhausted.

Fine-scale geographic variations of rates of renal replacement therapy in northeastern France: Association with the socioeconomic context and accessibility to care.

BACKGROUND: The strong geographic variations in the incidence rates of renal replacement therapy (RRT) for end-stage renal disease are not solely related to variations in the population's needs, such as the prevalence of diabetes or the deprivation level. Inequitable geographic access to health services has been involved in different countries but never in France, a country with a generous supply of health services and where the effect of the variability of medical practices was highlighted in an analysis conducted at the geographic scale of districts. Our ecological study, performed at the finer scale of townships in a French area of 8,370,616 inhabitants, investigated the association between RRT incidence rates, socioeconomic environment and geographic accessibility to healthcare while adjusting for morbidity level and medical practice patterns. METHODS: Using data from the Renal Epidemiology and Information Network registry, we estimated age-adjusted RRT incidence rates during 2010-2014 for the 282 townships of the area. A hierarchical Bayesian Poisson model was used to examine the association between incidence rates and 18 contextual variables describing population health status, socioeconomic level and health services characteristics. Relative risks (RRs) and 95% credible intervals (95% CrIs) for each variable were estimated for a 1-SD increase in incidence rate. RESULTS: During 2010-2014, 6,835 new patients ≥18 years old (4231 men, 2604 women) living in the study area started RRT; the RRT incidence rates by townships ranged from 21 to 499 per million inhabitants. In multivariate analysis, rates were related to the prevalence of diabetes [RR (95% CrI): 1.05 (1.04-1.11)], the median estimated glomerular filtration rate at dialysis initiation [1.14 (1.08-1.20)], and the proportion of incident patients ≥ 85 years old [1.08 (1.03-1.14)]. After adjusting for these factors, rates in townships increased with increasing French deprivation index [1.05 (1.01-1.08)] and decreased with increasing mean travel time to reach the closest nephrologist [0.92 (0.89-0.95]). CONCLUSION: These data confirm the influence of deprivation level, the prevalence of diabetes and medical practices on RRT incidence rates across a large French area. For the first time, an association was found with the distance to nephrology services. These data suggest possible inequitable geographic access to RRT within the French health system.

PoleSat's Modelling a Reorganization of Vascular Catheterization Provision at the Territorial Hospital Grouping Level.

Since a French organization (2016) has defined "the territorial hospital groupings", public hospitals must share medical-economic knowledge and decision-makers expect prospective analyses. PoleSat aims, quick hospital-catchment area modellings, completed by population analyses. Modellings are based on "diagnostic and interventional vascular catheterizations" acts and Nouvelle-Aquitaine, and they are carried out 3 times, through the graphical user interface's main-setting values, coupled with 3 activity-scenarios. Scenario results cannot confirm the NA02-Atlantique's H0. The experts have approved PoleSat's method as a robust help-tool; therefore they project to repeat its usages.