Possible application of CT morphometry of the calcaneus and talus in forensic anthropological identification

Central nervous system stimulants promote nerve cell death under continuous hypoxia

Intake of central nervous system (CNS) stimulants causes hypoxia and brain edema, which results in nerve cell death. However, no study has yet investigated the direct and continuous effects on nerve cells of CNS stimulants under hypoxia. Thus, based on autopsy cases, the effects of CNS stimulant drugs on the CNS were examined. The pathological changes in cultured nerve cells when various CNS stimulants were added under a hypoxic condition were also investigated. Five groups (Group A, stimulants; Group B, stimulants with psychiatric drugs; Group C, caffeine; Group D, psychiatric drugs; and Group E, no drugs) according to the detected drugs in autopsy cases were compared, and brain edema was evaluated using morphological findings. Furthermore, the number of dead cultured nerve cells was counted after the addition of drugs (4-aminopyridine (4-AP), caffeine, and ephedrine) under hypoxia (3% O2). Staining with anti-receptor-interacting protein 3 (RIP3) and other associated stains was also performed to investigate the neuronal changes in the brain. Group A showed significantly more brain edema than the other groups. In the culture experiments, the ratio of nerve cell death after the addition of 4-AP was the highest in the hypoxic condition. Groups with stimulants detected were stained more strongly by RIP3 immunostaining than by other staining. Addition of stimulants to cultured nerve cells in a persistent hypoxic condition led to severe cytotoxicity and nerve cell death. These findings suggest that necroptosis is involved in nerve cell death due to the addition of CNS stimulants in the hypoxic condition.

Morphometric variations of the lateral surface of calcaneus: Can standard plate sizes fit all?

PURPOSE

Displaced intraarticular fractures of the calcaneum often require plate fixation. The complex fractures are usually fixed with standard lateral plates and are approached via the extensile lateral approach which is fraught with the risk of wound complications. Oversized calcaneal plates produce tension on the wound closure site and can, thus result in wound healing problems. The current study analyses the morphometry of the lateral surface of the calcaneus for the ideal configuration of the calcaneal plates for Indian patients using a CT based analysis of intact calcanei.

METHODS

Fifty CT based studies of normal calcanei were retrospectively analyzed using Horos® software version 3.3.5. The cross-section of the lateral third of calcaneum was assessed for the morphometric measurements relevant to the dimensions of the standard plating devices for calcaneum. We measured the overall plating length of calcaneum, the vertical heights at the anterior process and calcaneal tuberosity, the height of the posterior facet, the lengths of the anterior process, and the posterior facet. The inclination angles of the posterior facet, cuboid facet were also measured. The findings were compared between male and female cases.

RESULTS

The mean plating length of the calcaneus was 60.06 ± 4.05 mm. The mean vertical height of the anterior process and the calcaneal tuberosity were 24.3 ± 2.71 mm and 39.48 ± 4.73, respectively. The length of the anterior process and the posterior facet were 21.36 ± 1.72 and 25.02 ± 4.17, respectively. The mean Gissane angle and the angle of inclination of posterior facet in relation to the plating length were 118.04 ± 5.99° and 47.3 ± 5.20°. The mean anterior slant angle of the cuboid facet was 96.64 ± 4.39°. Significant differences were observed in the measurements among male and female groups except for the angular parameters.

CONCLUSION

The current analysis suggests the individual morphometric variations of the lateral plating surface of the calcaneus. Although female calcanei have smaller dimensions compared to male calcanei, the angular parameters are comparable among the two groups. Considering the wide variations in the majority of the morphometric parameters, it is difficult to standardize the plate dimensions. However, a few serial increments in the plate dimensions can help in providing the best fit rather than an ideal fit. Also, the plates should be available with multiple inclination angles of the facet limbs according to the local population variations.

Morphological variations of the human talus investigated using three-dimensional geometric morphometrics

INTRODUCTION

The shape of the talus determines the positional and kinematic features of the subtalar, talonavicular, and talocrural joints during walking. Thus, detailed knowledge of the pattern of sexual dimorphism of the human talus may be useful for revealing the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. The aim of this study was to characterize and visualize the three-dimensional shape variations of the talus in relation to sex and age using geometric morphometrics.

MATERIALS AND METHODS

Computed tomography images of 56 feet without talar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on a bone model of the talus to calculate principal components (PCs) of shape variations among specimens. PC scores were compared between sexes, and their correlations with age were also investigated.

RESULTS

The female talus had a longer neck and narrower head width than the male talus. The superior trochlea was tilted more laterally in the frontal plane in females. Furthermore, the female talar head was more twisted and was more elongated in the dorsoplantar direction.

CONCLUSIONS

Morphological features of the talus in females could alter the subtalar and talonavicular joint kinematics during walking and could be a structural factor in the pathogenetic mechanism underlying foot and knee disorders. This study contributes to the comprehensive understanding of shape variations in the human talus.

Sex determination from talus in Chinese population by three-dimensional measurement approach

OBJECTIVE

The determination of sex is an essential part of building the biological profile for unknown human remains. Sex determination from talus in Chinese population has been rarely reported. The aim of this study was to determine sex by discriminant function analysis through talus measurement in Chinese population.

METHODS

48 male and 47 female Chinese northeast subjects were taken in this research. The ankle joints of these subjects were scanned by CT. In total, thirteen indexes were measured through Mimics and Magics software. Length and breadth indexes of total talus, trochlea, talar head, medial and lateral malleolus articular surface were mainly selected. Nine of them were measured through Mimics software. The other four indexes were measured through Magics software. All data were analyzed by independent-samples t-test in SPSS and Stata software. Discriminant function equations were generated for sex determination.

RESULTS

All the indexes were normally distributed. No significant difference between left and right talus in either males or females was identified (P > 0.05). All results showed significant sexual difference (P < 0.05) except posterior breadth of trochlea. The average accuracy of sex determination ranged from 95.85% to 98.45% in the direct method and 98.95% in the stepwise method.

CONCLUSIONS

Length indexes showed higher accuracy rate than breadth ones. Length of lateral malleolus articular surface was the best discriminator of sexual dimorphism. Talus was proved effective for sex determination in Chinese population. This study provided a remarkable reference for sex determination in forensic science.

Sex estimation of the sternum by automatic image processing of multi-slice computed tomography images in a Croatian population sample: a retrospective study

AIM

To determine the sexual dimorphism of the sternum with standard measurements in a contemporary Croatian population sample using multi-slice computed tomography (MSCT) and to compare the data obtained by an automatic with those obtained by a manual approach.

METHODS

Five sternal measurements were obtained from MSCT images of 73 men and 55 women and three sternal indices were calculated. Custom image analysis software was developed for automatic segmentation and calculation of sternal measurements. Measurements of sexual dimorphism were automatically calculated and compared with manual measurements.

RESULTS

All of the sternal measurements exhibited significant differences between men and women. The discrepancies between manual and automatic measurements ranged from 2.8% to 3.6% of the mean average values obtained with the automatic approach. The most accurate single-variable discriminant function was sternal body length (82.8%), the most accurate index was sternal area (89.1%), and the discriminant function using three variables was manubrium width, sternal body length, and sternal body width (90.6%).

CONCLUSION

Sternal measurements are a reliable sex indicator and can be used in forensic casework. Computer-aided measurement methods can accelerate sex estimation and improve its precision and accuracy.

Virtual computed tomography morphometry of the patella for estimation of sex using postmortem Japanese adult data in forensic identification

In forensic anthropological identification of human remains and single bones, computed tomography (CT) data analysis facilitates volumetric and radiographic density analyses, and a recently developed automated analysis system markedly improved the performance, accuracy, and reproducibility of three-dimensional (3-D) reconstruction. The present study aimed to investigate virtual CT morphometry of the patella for the estimation of sex using postmortem CT data of forensic autopsy cases of Japanese individuals aged ≥18 years (total n=220; 110 males and 110 females; estimated postmortem interval <88h), especially with regard to the efficacy of 3-D bone volumetry. Sex-related differences were detected for all parameters (males>females; p<0.0001), but the differences were the most notable for bone mass volume; the estimated cut-off values (cm³) for discriminating males and females were 20.35 with a sensitivity and specificity of 0.85 and 0.91 for the left side and 19.96 with a sensitivity and specificity of 0.83 and 0.92 for the right side, respectively. The mean CT value showed an age-dependent decrease and was particularly low in females aged >60years. These findings indicate the efficacy of virtual CT morphometry of the patella using an automated analyzer for sex estimation.

Sexual dimorphism of the calcaneus in contemporary Cretans

During the past decade, several studies have been carried out using the calcaneus bone for sex estimation. This paper collected data using ten variables for metric characteristics of the calcaneus of 144 modern Cretans and examined their correlation with known sex. Secondly, the formulae developed by Peckmann et al. (2015) for modern Athenians was put to the test in order to investigate if it could be applied to this modern Cretan sample as well. Results showed a high correlation between the calcaneus metrics and the known sex of the individuals, however the formulae for Athenians do not seem to be suitable for the Cretans due to the high sex bias reported in this study. Thus, new standards were created for sex estimation from the calacanei in our sample. Bilateral asymmetry was noted in the majority of cases, thus formulae were developed for left, right and mean values. Maximum width (MAXW) was the variable that performed the best in the Cretan sample. Overall, the cross-validated accuracies for univariate and multivariate equations reached 84.2% with males most often correctly identified. The calcaneus was proved to be useful for sex estimation in this modern Cretan population. Further work will explore the suitability of the produced standards for other regions of mainland Greece and islands.