Les lésions osseuses par mécanismes tranchants et tranchants contondants (apport du microscope électronique à balayage)

Ce travail expérimental a été conduit sur des fragments osseux humains où furent créées des lésions traumatiques de petite dimension. L'objectif principal était de définir des critères sémiologiques macroscopiques et microscopiques permettant de distinguer les lésions osseuses générées par un instrument tranchant (couteau) de celles générées par un instrument tranchant contondant (hachette). Les autres objectifs étaient d'une part d'orienter le sens de frappe de la pointe d'un couteau à " lame simple tranchant ", et d'autre part d'identifier formellement un instrument, en s'appuyant sur l'étude des stries osseuses. La comparaison macroscopique s'est révélée très difficile. La comparaison microscopique des lésions a montré une opposition sémiologique significative, permettant de distinguer le mécanisme tranchant du mécanisme tranchant contondant. La richesse sémiologique observée a également permis de comprendre qu'il existe un véritable continuum dans le mécanisme lésionnel (en partant du tranchant pur, pour aller jusqu'au contondant pur). Par ailleurs l'analyse des stries générées sur le support osseux permet d'identifier formellement l'instrument en cause. Le microscope électronique à balayage est donc d'un apport considérable dans l'étude des lésions anthropologiques traumatiques, aussi bien sur les populations du passé qu'en médecine légale, mettant en évidence une sémiologie lésionnelle riche, orientant vers le mécanisme lésionnel, et autorisant l'identification formelle d'un instrument unique, à l'origine de la lésionThis experimental work was carried out on human bone fragments, with small lesions. The aim of this study was to define criteria, macroscopically and microscopically in order to make distinctions between traumatic lesions due to a sharp instrument or a sharp-blunt instrument. Simultaneously we wanted to study the orientation of the blade when the blow was struck, and identify the instrument, by studying the marks produced by the blade. The macroscopical analysis was difficult. The microscopic analysis assessed that characteristics examined were useful in distinguishing sharp from sharp-blunt injury to the bone. The microscope facilitates analysis at a level not possible with macroscopic methods and demonstrates that there is a continuum between sharp force injury and blunt force injury. Futhermore, successful identification of the instrument by a study of the abrasion markings was achieved. Because of the high level of resolution and magnification of scanning electron microscopy (SEM), some three-dimensional characteristics not visible to the naked eye can be shown quite clearly with its use. Emphasis will be placed on the value of SEM as a tool of the anthropologist in bone lesion injuriesAIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Prise en charge au CHU de Nice des patientes se déclarant victimes d'agression sexuelle (état des lieux de 1998 à 2006 et évaluation du protocole institutionnel multidisciplinaire)

NICE-BU Médecine Odontologie (060882102) / SudocSudocFranceF

Sex determination from the distal part of the femur in a French contemporary population.

International audienceUntil now, determining the sex of a recently deceased individual using the measurement of the bicondylar breadth of the femur (also known as condylar width, epicondylar breadth and distal epiphyseal breadth) raised some concerns as to accuracy because no sample of contemporary French subjects was available. In this study, a sample of 88 female and male femurs taken from recently deceased elderly French people was studied. The bones were collected from subjects who had donated their bodies to the Medical School of Nice. The mean value of the male bicondylar breadth was found to be greater than that of females (84.3mm versus 74.8mm), confirming the sexual dimorphism of this parameter. Furthermore, the results showed a 95.4% accuracy rate for sexing individuals. To date, in the French population, as in some other samples, epicondylar breadth is the single most accurate measurement of sex determination, ahead even of head diameter. A discriminant function is presented to allow sex determination from remains of the distal femur. With regard to the data available in the literature, sexual dimorphism is probably the result of both genetic and environmental factors. The comparison of our results with those of other populations shows that there are inter-population variations of the bicondylar breadth, and also intra-population variations that account for the differences in the accuracy rate of this variable for the purposes of sex determination. These findings underscore the need to re-evaluate bone measurements within various contemporary populations

Reexamination of a measurement for sexual determination using the supero-inferior femoral neck diameter in a modern European population.

International audienceThe present study reexamines the accuracy of the supero-inferior femoral neck diameter for the determination of sex using a modern sample of French individuals. In 1998, Seidemann et al. used this univariate method for sex determination with the Hamann-Todd collection. Stojanowski and Seidemann in 1999 tested previous results on a modern sample taken from the University of New Mexico and concluded that the Caucasian male samples exhibited no significant differences between individuals born before and after 1900, but the Caucasian female subgroup did exhibit differences with an increase of the SID in the modern sample. The current study compares the previous results of the supero-inferior femoral neck diameter with a modern sample of elderly French individuals born after 1910. Both sides of the femur were measured. No statistical difference was found between the right and left side (p = 0.31). The results showed a significant difference between the pre-1900 and the modern sample, with an increase in femoral neck diameter in modern populations. The comparison of the SID values between the two modern samples (Mexico and Nice) showed no significant differences in the femoral neck diameter in the two male subgroups (p = 0.05), but the measurements of the SID in the female subgroup did exhibit significant differences with an increase of the neck femoral diameter (p < 0.01) in the modern French population. These results demonstrate an increase in the neck femoral morphology in the elderly European French females samples

Reexamination of a measurement for sexual determination using the supero-inferior femoral neck diameter in a modern European population.

International audienceThe present study reexamines the accuracy of the supero-inferior femoral neck diameter for the determination of sex using a modern sample of French individuals. In 1998, Seidemann et al. used this univariate method for sex determination with the Hamann-Todd collection. Stojanowski and Seidemann in 1999 tested previous results on a modern sample taken from the University of New Mexico and concluded that the Caucasian male samples exhibited no significant differences between individuals born before and after 1900, but the Caucasian female subgroup did exhibit differences with an increase of the SID in the modern sample. The current study compares the previous results of the supero-inferior femoral neck diameter with a modern sample of elderly French individuals born after 1910. Both sides of the femur were measured. No statistical difference was found between the right and left side (p = 0.31). The results showed a significant difference between the pre-1900 and the modern sample, with an increase in femoral neck diameter in modern populations. The comparison of the SID values between the two modern samples (Mexico and Nice) showed no significant differences in the femoral neck diameter in the two male subgroups (p = 0.05), but the measurements of the SID in the female subgroup did exhibit significant differences with an increase of the neck femoral diameter (p < 0.01) in the modern French population. These results demonstrate an increase in the neck femoral morphology in the elderly European French females samples

A comparison between neural network and other metric methods to determine sex from the upper femur in a modern French population.

International audienceForensic anthropologists are frequently asked to assess partial or badly damaged skeletal remains. One such request led us to compare the predictive accuracy of different mathematical methods using four non-standard measurements of the proximal femur (trochanter–diaphysis distance (TD), greater–lesser trochanter distance (TT), greater trochanter width (TW) and trochanter–head distance (TH)). These measurements were taken on 76 femurs (38 males and 38 females) of French individuals. Intra- and inter-observer trials did not reveal any significant statistical differences. The predictive accuracy of three models built using linear and non-linear modelling techniques was compared: discriminant analysis, logistic regression and neural network. The neural network outperformed discriminant analysis and, to a lesser extent, logistic regression. Indeed, the best results were obtained with a neural network that correctly classified 93.4% of femurs, with similar results in males (92.1%) and females (94.7%). Univariate functions were less accurate (68–88%). Discriminant analysis and logistic regression, both using all four variables, led to slightly better results (88.2% and 89.5%, respectively). In addition, all the models, save the neural network, led to unbalanced results between males and females. In conclusion, the artificial neural network is a powerful classification technique that may improve the accuracy rate of sex determination models for skeletal remains

Determination of heroin after embalmment.

International audienceA 30-year-old male died in Thailand after a scuffle. The corpse was embalmed and repatriated to France where an autopsy was performed. As usual in cases of embalmment, fluids such as blood and urine were unavailable and the toxicological analyses was performed on the bile and the liver. An overdose of heroin was determined as the cause of death. A review of the literature indicates that several drugs can be detected in fluids and tissues that contain formaldehyde. This case demonstrates that in embalmed corpses, toxicological assessment is still possible, e.g. after heroin fatalities

Évaluation du raisonnement clinique en médecine d’urgence : les tests de concordance des scripts décèlent mieux l’expérience clinique que les questions à choix multiples à contexte riche

Contexte : La médecine d’urgence est sur le point de devenir une spécialité en France, ce qui implique l’utilisation d’outils de certification adaptés. Buts : Comparer l’aptitude des tests de concordance des scripts (TCS) et des questions à choix multiples à contexte riche (QCM) à identifier le niveau d’expérience des cliniciens en matière de raisonnement clinique en médecine d’urgence. Méthode : 60 QCM et 30 TCS ont été rédigés selon les recommandations publiées et administrées à 20 résidents de première année, 16 étudiants de fin de sixième année, et à neuf médecins seniors en poste dans des services d’urgences. L’analyse d’item des QCM a inclus la détermination des indices de difficulté et de discrimination. La fidélité des QCM et des TCS a été mesurée par le coefficient alpha de Cronbach. Les scores obtenus aux deux épreuves par les trois groupes ont été comparés (ANOVA avec correction de Bonferoni-Dunn après vérification de l‘homogénéité des variances par un test de Levene). Ils ont été corrélés (test de Pearson) dans le groupe des résidents. Résultats : QCM et TCS ont obtenu des coefficients de fidélité corrects (respectivement 0,85 à 0,95 et 0,92 à 0,96 selon les groupes étudiés). Seuls, les TCS ont pu identifier le niveau d’expérience des différents cliniciens. Les scores des TCS et des QCM variaient dans le même sens, sans corrélation significative. Ce point suggère que QCM et TCS explorent deux aspects complémentaires de la compétence médicale. Conclusion : Le TCS paraît être un outil d’évaluation intéressant en médecine d’urgence, complémentaire d’autres tests d’évaluation

Scanning electron microscopy analysis of experimental bone hacking trauma of the mandible.

International audienceThe authors report on a macroscopic and microscopic study of human mandible bone lesions achieved by a single-blade knife and a hatchet. The aim of this work was to complete the previous data (scanning electron microscopy analysis of bone lesions made by a single-blade knife and a hatchet, on human femurs) and to compare the lesions of the femur with those of the mandible. The results indicate that the mandible is a more fragile bone, but the features observed on the mandible are quite similar to those previously observed on the femur. This work spells out the main scanning electron microscopy characteristics of sharp (bone cutting) and blunt (exerting a pressure on the bone) mechanisms on human bone. Weapon characteristics serve to explain all of these features

Scanning electron microscopy analysis of experimental bone hacking trauma.

International audienceThe authors report on their macro- and microscopy study of bone lesions made by a sharp force instrument (a single blade knife), and a sharp-blunt instrument classified as a chopping weapon (a hatchet). The aim of this work was to attempt to identify the instrument by analyzing the general class characteristics of the cuts. Each weapon was used on human bones. The results indicate that macroscopic analysis is more problematic. The microscopic analysis assessed that characteristics examined were effective in distinguishing sharp from sharp-blunt injury to the bone. The microscope facilitates analysis unachievable with macroscopic methods, some three-dimensional characteristics not visible to the naked eye being clearly defined with its use. Emphasis has been placed on the value of SEM as an anthropologist's tool in bone lesion injuries