Bilateral symmetry of the subtalar joint facets and the relationship between the morphology and osteoarthritic changes.

There is a paucity in the literature regarding bilateral symmetry between the facets of the subtalar joint. Often surgeons use the contralateral side as a reference when dealing with a fracture or other joint pathology. Moreover, the presence of osteoarthritic (OA) changes in the subtalar joint is suggested to have a relation with its morphology. In this study, we addressed both these issues. Forty pairs of cadaveric tali and calcanei were analyzed by dissection and measurement. Twenty pairs of asymptomatic calcanei were morphologically analyzed by computer tomography imaging. In the cadaveric feet, the length and width of the facets, the number and interfacet connections, the intersection angle, and the presence of OA changes were registered. In the healthy feet, the orientation and curvature of the posterior facet were analyzed based on cylinder fittings. Bilateral symmetry was tested with paired Student's t tests. Significant associations between morphometric parameters and the presence of OA changes were tested with generalized estimating equation logistic regression models. The morphometric data demonstrated a high degree of bilateral symmetry. The types of tali and calcanei between left and right differed in about one-fifth of the individuals. No significant interactions were found between morphological parameters and the presence of OA changes. Only age had a significant association. There was a high degree of symmetry in the subtalar joints facets. No significant associations were found between OA changes and morphological features, whereas other studies did. Further research is needed to explore this relationship in further detail. Clin. Anat., 33:997-1006, 2020. © 2019 Wiley Periodicals, Inc.

The accuracy of 3D virtual bone models of the pelvis for morphological sex estimation.

It is currently unknown whether morphological sex estimation traits are accurately portrayed on virtual bone models, and this hampers the use of virtual bone models as an alternative source of contemporary skeletal reference data. This study determines whether commonly used morphological sex estimation traits can be accurately scored on virtual 3D pelvic bone elements. Twenty-seven intact cadavers from the body donation program of the Amsterdam UMC, University of Amsterdam, were CT scanned; this data was used to produce virtual bone models. Thereafter, the dry bones were obtained. Three traits by Klales (2012) and five traits from the Workshop of European Anthropologists (WEA) (1980) were scored on the virtual bone models and their dry skeletal counterparts. Intra- and inter-observer agreement and the agreement between the scores for each virtual bone model-dry bone pair were calculated using weighted Cohen's kappa (K). For all Klales (2012) traits, intra- and inter-observer agreement was substantial to almost perfect for the virtual- and dry bones (K = 0.62-0.90). The agreement in scores in the virtual-dry bone pairs ranged from moderate to almost perfect (K = 0.58-0.82). For the WEA (1980) traits, intra-observer agreement was substantial to almost perfect (K = 0.64-0.91), but results were less unambiguous for inter-observer agreement (K = 0.24-0.88). Comparison of the scores between the virtual bone models and the dry bones yielded kappa values of 0.42-0.87. On one hand, clinical CT data is a promising source for contemporary forensic anthropological reference data, but the interchangeability of forensic anthropological methods between virtual bone models and dry skeletal elements needs to be tested further.

Classification criteria for diffuse idiopathic skeletal hyperostosis: a lack of consensus.

Objectives: DISH is a condition characterized by flowing ossifications of the spine with or without ossifications of entheses elsewhere in the body. Studies on the prevalence and pathogenesis of DISH use a variety of partly overlapping combinations of classification criteria, making meaningful comparisons across the literature difficult. The aim of this study was to systematically summarize the available criteria to support the development of a more uniform set of diagnostic/classification criteria. Methods: A search was performed in Pubmed, Embase, Cochrane Library and Web of Science using the term DISH and its synonyms. Articles were included when two independent observers agreed that the articles proposed a new set of classification criteria for DISH. All retrieved articles were evaluated for methodological quality, and the presented criteria were extracted. Results: A total of 24 articles met the inclusion criteria. In all articles, spinal hyperostosis was required for the diagnosis of DISH. Peripheral, extraspinal manifestations were included as a (co-)requirement for the diagnosis DISH in five articles. Most discrepancies revolved around the threshold for the number of vertebral bodies affected and to defining different developmental phases of DISH. More than half of the retrieved articles described a dichotomous set of criteria and did not consider the progressive character of DISH. Conclusion: This systematic review summarizes the available different classification criteria for DISH, which highlights the lack of consensus on the diagnosis of (early) DISH. Consensus criteria, including consecutive phases of new bone formation that characterize DISH, can be developed based upon established diagnostic/classification criteria.

The geometrical precision of virtual bone models derived from clinical computed tomography data for forensic anthropology.

Almost all European countries lack contemporary skeletal collections for the development and validation of forensic anthropological methods. Furthermore, legal, ethical and practical considerations hinder the development of skeletal collections. A virtual skeletal database derived from clinical computed tomography (CT) scans provides a potential solution. However, clinical CT scans are typically generated with varying settings. This study investigates the effects of image segmentation and varying imaging conditions on the precision of virtual modelled pelves. An adult human cadaver was scanned using varying imaging conditions, such as scanner type and standard patient scanning protocol, slice thickness and exposure level. The pelvis was segmented from the various CT images resulting in virtually modelled pelves. The precision of the virtual modelling was determined per polygon mesh point. The fraction of mesh points resulting in point-to-point distance variations of 2 mm or less (95% confidence interval (CI)) was reported. Colour mapping was used to visualise modelling variability. At almost all (>97%) locations across the pelvis, the point-to-point distance variation is less than 2 mm (CI = 95%). In >91% of the locations, the point-to-point distance variation was less than 1 mm (CI = 95%). This indicates that the geometric variability of the virtual pelvis as a result of segmentation and imaging conditions rarely exceeds the generally accepted linear error of 2 mm. Colour mapping shows that areas with large variability are predominantly joint surfaces. Therefore, results indicate that segmented bone elements from patient-derived CT scans are a sufficiently precise source for creating a virtual skeletal database.

Paleodysmorphology and paleoteratology: Diagnosing and interpreting congenital conditions of the skeleton in anthropological contexts.

Most congenital conditions have low prevalence, but collectively they occur in a few percent of all live births. Congenital conditions are rarely encountered in anthropological studies, not least because many of them have no obvious effect on the skeleton. Here, we discuss two groups of congenital conditions that specifically affect the skeleton, either qualitatively or quantitatively. Skeletal dysplasias (osteochondrodysplasias) interfere with the histological formation, growth and maturation of skeletal tissues leading to diminished postural length, but the building plan of the body is unaffected. Well- known skeletal dysplasias represented in the archeological record include osteogenesis imperfecta and achondroplasia. Dysostoses, in contrast, interfere with the building plan of the body, leading to e.g. missing or extraskeletal elements, but the histology of the skeletal tissues is unaffected. Dysostoses can concern the extremities (e.g., oligodactyly and polydactyly), the vertebral column (e.g., homeotic and meristic anomalies), or the craniofacial region. Conditions pertaining to the cranial sutures, i.e., craniosynostoses, can be either skeletal dysplasias or dysostoses. Congenital conditions that are not harmful to the individual are known as anatomical variations, several of which have a high and population-specific prevalence that could potentially make them useful for determining ethnic origins. In individual cases, specific congenital conditions could be determinative in establishing identity, provided that ante-mortem registration of those conditions was ensured. Clin. Anat. 29:878-891, 2016. © 2016 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Virtual forensic anthropology: The accuracy of osteometric analysis of 3D bone models derived from clinical computed tomography (CT) scans.

Clinical radiology is increasingly used as a source of data to test or develop forensic anthropological methods, especially in countries where contemporary skeletal collections are not available. Naturally, this requires analysis of the error that is a result of low accuracy of the modality (i.e. accuracy of the segmentation) and the error that arises due to difficulties in landmark recognition in virtual models. The cumulative effect of these errors ultimately determines whether virtual and dry bone measurements can be used interchangeably. To test the interchangeability of virtual and dry bone measurements, 13 male and 14 female intact cadavers from the body donation program of the Amsterdam UMC were CT scanned using a standard patient scanning protocol and processed to obtain the dry os coxae. These were again CT scanned using the same scanning protocol. All CT scans were segmented to create 3D virtual bone models of the os coxae ('dry' CT models and 'clinical' CT models). An Artec Spider 3D optical scanner was used to produce gold standard 'optical 3D models' of ten dry os coxae. The deviation of the surfaces of the 3D virtual bone models compared to the gold standard was used to calculate the accuracy of the CT models, both for the overall os coxae and for selected landmarks. Landmark recognition was studied by comparing the TEM and %TEM of nine traditional inter-landmark distances (ILDs). The percentage difference for the various ILDs between modalities was used to gauge the practical implications of both errors combined. Results showed that 'dry' CT models were 0.36-0.45mm larger than the 'optical 3D models' (deviations -0.27mm to 2.86mm). 'Clinical' CT models were 0.64-0.88mm larger than the 'optical 3D models' (deviations -4.99mm to 5.00mm). The accuracies of the ROIs were variable and larger for 'clinical' CT models than for 'dry' CT models. TEM and %TEM were generally in the acceptable ranges for all ILDs whilst no single modality was obviously more or less reliable than the others. For almost all ILDs, the average percentage difference between modalities was substantially larger than the average percentage difference between observers in 'dry bone' measurements only. Our results show that the combined error of segmentation- and landmark recognition error can be substantial, which may preclude the usage of 'clinical' CT scans as an alternative source for forensic anthropological reference data.

Gender-related vitamin D deficiency in a Dutch 19th century farming community.

The most common cause of vitamin D deficiency is inadequate dermal exposure to sunlight. Residual rickets is nonadult vitamin D deficiency still evident in an adult individual, whereas osteomalacia occurs in adulthood. Previous research on the Beemster population, a 19th century rural community in the Netherlands, identified rickets in 30.4% of the nonadults between the ages of two and four years (n=7/23). Because the sex of these nonadults was not known it was not possible to determine if there were differences between boys and girls. To overcome this gap in our knowledge, the aim of this paper is to determine if there are gender related differences in vitamin D deficiency in the Beemster skeletal collection, based on adults with residual rickets and osteomalacia. Out of 200 adults (100 females; 100 males) no cases of osteomalacia were detected. However, there were 29 cases of residual rickets (14.5%), with 21 of those cases in females (21.0%; 21/100). A complex interplay of multiple factors is proposed to have affected vitamin D levels in nonadults, including sociocultural variables such as gender-based labour norms. This research highlights the importance of continuing to explore gender-based health differences in past populations.