Evaluation of the medial clavicular epiphysis according to the Schmeling and Kellinghaus method in living individuals: A retrospective CT study

Forensic age estimation of adolescents using computed tomography of the clavicles

In forensic age estimation, CT imaging of the clavicles is used to determine an age over completed 21 years. If ossification of the medial clavicular epiphysis is complete, young men are assumed to be over 21 years of age. The aim of this study is to check the statistical parameters (specificity, predictive probability) for the characteristic "completed ossification of the medial clavicles". 285 male patients who, for various reasons, received a chest CT at the Medical Center of the University of Freiburg between 1st December 2019 and 6th December 2022 were screened for the study, of whom 203 patients were included in the study. The stage of clavicular ossification was classified as stage 1 - 5 according to Schmeling. While 70 out of 71 patients under 21 years of age were correctly estimated to be under 21 years of age, there was one patient whose ossification on one side was classified as stage 4 and who would therefore have been estimated to be over 21 years of age. If only subjects whose ossification stage was the same on both sides are included, the specificity of the test method is 100% and the positive predictive probability is 100%. If patients for whom only one side is stage 4 are also included, the specificity is 98.6%. Thus, only the complete and symmetrical ossification of both clavicles (stage 4 according to the Schmeling classification) in a standardised thin-layer CT can be classified as a reliable indicator of an age over 21 years in young men. In the case of asymmetric ossification of the medial clavicles (stage 4 is not reached on one side), false positive evaluations and the incorrect assumption of an age over 21 years can occur.

Evaluating Skeletal Maturity at Time of Surgical Correction of Pectus Excavatum Based on Medial Clavicle Epiphyseal Ossification

BACKGROUND

Surgical correction of pectus excavatum (SCOPE) is dependent upon chest wall pliability with optimal timing prior to complete skeletal maturation. Measures of skeletal maturity are not readily available for operative planning; therefore, surgeons use age as proxy despite patient-specific rates of skeletal maturation. We aimed to determine whether preoperative skeletal maturity is associated with postoperative pain as surrogate for chest wall pliability.

METHODS

Children ≤18 years who underwent SCOPE from 2020 to 2022 were retrospectively identified. Preoperative CT within 3 months of procedure was reviewed by 2 radiologists and 1 surgeon. Skeletal maturity was determined by Schmeling-Kellinghaus classification which stages secondary epiphyseal ossification of the medial clavicle. Inter-rater reliability was evaluated. Schmeling-Kellinghaus stage and postoperative pain were compared.

RESULTS

Of twenty-eight records reviewed, 57% were Schmeling-Kellinghaus stage 1. High inter-rater reliability was identified (inter-radiologist: kappa = .95, P < .001, all raters: kappa = .78, P < .001). Median age at operation was 15.5 years (interquartile range: 14.8-16.0) and increased with skeletal maturity (P < .001). When comparing stage 1 (n = 16) to >1 (n = 12), stage 1 had lower maximum pain scores (P < .001), total morphine equivalents (P < .001), and benzodiazepine use (P < .001) after surgery.

CONCLUSIONS

The Schmeling-Kellinghaus classification system is a valid proxy of skeletal maturity that can be applied with high inter-rater reliability. SCOPE during stage 1 was found to have less postoperative pain and narcotic use than more mature stages. This is proof of concept that skeletal maturity should be considered when determining optimal timing of surgical correction. Future research will evaluate the impact of skeletal maturity on postoperative outcomes.

Age estimation based on the metamorphosis of the clavicle end: A test of Falys and Prangle method in two contemporary samples

Upon finding skeletal unidentified remains, four are the questions that must be answered: age, sex, ancestry, and stature. Regarding age estimation, clavicle has received special attention because medial epiphysis is the last epiphysis, among long bones that ossifies. Falys and Prangle proposed a method of age estimation based on three degenerative characteristics-surface topography (TOP), Porosity (POR) and Osteophyte formation (OST)-evaluated on the sternal end of the clavicle according to the descriptions and the illustrations provided in the original article producing satisfactory results. The current study aims to test the applicability of the Falys' and Prangle's method on 174 individuals from two contemporary samples, one from Greece (Cretan osteological Collection and Athens Forensic Anthropology Lab collection) and one from Thailand (Osteological collection in Chiang Mai). Composite scores were calculated, inter and intra- observer error were estimated by kappa statistics and regression equations of the original study were tested in our sample and in subsamples divided by sex and population. The Greek sample gave more accurate estimates compared to the Thai sample. Regressions of known sex gave slightly better results in most cases. When individuals <40 years old were excluded, classification increased for both Thai and Greeks. The results of this pilot study indicate that there are morphological features on the clavicle that are highly correlated with age. Thus, there is a scope of expanding research on the morphological features of the collar bone.

Comparing a common clavicle maturation-based age estimation method to ordinary regression analyses with quadratic and sex-specific interaction terms in adolescents

Established methods of age estimation are based on correlating defined maturation stages of bony structures with tables representing the observed range of biological ages in the majority of cases. In this retrospective monocentric study in southwestern Germany, common age estimation methodology was assessed in n = 198 subjects at the age of 25 or younger by analyzing the influence of age, quadratic age, biological sex and age-sex interaction on the ossification stages of the medial epiphysis fugue. Three readers (ICC ≥ 0.81 for left/right side) evaluated routine care computed tomography images of the clavicle with a slice thickness of 1 mm. By using least square regression analyses, to determine the real biological age a quadratic function was determined corrected for the age estimated by established methods and sex (R2 = 0.6 each side), reducing the mean absolute error and root mean squared error in the age estimation of women (2.57 and 3.19) and men (2.57 and 3.47) to 1.54 and 1.82 for women, and 1.54 and 2.25 for men. In women, the medial clavicle epiphysis seem to fuse faster, which was particularly observable from approximately 18 years of age. Before that age, the estimation method was relatively close to the ideal correlation between assessed and real age. To conclude, the presented new method enables more precise age estimation in individuals and facilitates the determination and quantification of additional variables, quantifying their influence on the maturation of the medial clavicle epiphysis based on the established ossification stages.

Standards of practice in forensic age estimation with CT of the medial clavicular epiphysis-a systematic review

The AGFAD (Arbeitsgemeinschaft für Forensische Alterdiagnostik, Study Group on Forensic Age Diagnostics) has published several recommendations regarding both technical aspects of computed tomography (CT) of the medial clavicular epiphysis (MCE) and the process of reading and interpreting the CT images for forensic age estimations (FAE). There are, however, no published recommendations regarding CT scan protocols and no dose reference values for CT of the MCE. The objective of this analysis was to assess adherence to AGFAD recommendations among practitioners of FAE and analyse reported dose-relevant CT scan parameters with the objective of helping to establish evidence-based dose reference values for FAE. A systematic literature search was conducted in PubMed and in Google Scholar with specific MeSH terms to identify original research articles on FAE with CT of the MCE from 1997 to 2022. A total of 48 studies were included. Adherence to AGFAD recommendations among practitioners of FAE is high regarding the use of Schmeling main stages (93%), bone window (79%), ≤ 1 mm CT slices (67%), axial/coronal CT images (65%), and Kellinghaus sub-stages (59%). The reporting of CT technique and CT dose-relevant scan parameters is heterogeneous and often incomplete in the current literature. Considering the success achieved by the AGFAD in creating standards of practice of FAE in living subjects, there is potential for the AGFAD to establish standards for radiation protection in FAE as well.

Evaluation of distal femoral and proximal tibial epiphyseal plate in bone age estimation with 3.0T MRI: a comparison of current methods

OBJECTIVE

Dedouit et al, Kramer et al and Vieth et al defined different staging methods over different sequences in knee MRI for bone age determination. Our study aims to examine three different methods in which the maturation stages of the knee epiphyses are evaluated by MRI in the same population, to compare the methods and results and evaluate them for some age thresholds and to discuss their applicability in forensic age estimation.

METHODS

In this study, 597 knee images obtained using a 3.0T MR scanner were evaluated retrospectively. The T 1 weighted and proton density-weighted sequences were evaluated by two observers. Knee bone development was staged on the femur and tibia, and descriptive statistics were calculated for each stage according to age and sex. Descriptive statistics were presented according to the age and sex of the cases, and intra- and interobserver agreements were evaluated by the κ and κw statistics obtained by the Fleiss approach.

RESULTS

Significant changes were found in stages depending on age. The intra- and interobserver agreement levels were very good (κ > 0.80) for each method. The methods of Dedouit, Kramer and Vieth can be used as an additional criteria for forensic age estimation for 14, 15, 18 and 21 year thresholds.

CONCLUSION

Knee MRI stands out as an alternative modality for age estimation and it is necessary to prefer the method intended for the investigated age range with an individual-specific approach.

ADVANCES IN KNOWLEDGE

Our study stands out as the first study in which current classification methods were applied and compared in the same population for age estimation with knee MRI.

Age estimation in the living: A scoping review of population data for skeletal and dental methods

Age estimation of living individuals has become a crucial part of the forensic practice, especially due to the global increase in cross-border migration. The low rate of birth registration in many countries, hence of identification documents of migrants, especially in Africa and Asia, highlights the importance of reliable methods for age estimation of living individuals. Despite the fact that a number of skeletal and dental methods for age estimation have been developed, their main limitation is that they are based on specific reference samples and there is still no consensus among researchers on whether these methods can be applied to all populations. Though this issue remains still unsolved, population information at a glance could be useful for forensic practitioners dealing with such issues. This study aims at presenting a scoping review and mapping of the current situation concerning population data for skeletal (hand-wrist and clavicle) and dental methods (teeth eruption and third molar formation) for age estimation in the living. Two hundred studies on the rate of skeletal maturation and four hundred thirty-nine on the rate of dental maturation were found, covering the period from 1952 and 2020 for a total of ninety-eight countries. For most of the western and central African countries there are currently no data on the rate of skeletal and dental maturation. The same applies to the countries of the Middle East, as well as the eastern European countries, especially as regard the skeletal development.

The influence of motion artefacts on magnetic resonance imaging of the clavicles for age estimation

PURPOSE

To determine how motion affects stage allocation to the clavicle's sternal end on MRI.

MATERIALS AND METHODS

Eighteen volunteers (9 females, 9 males) between 14 and 30 years old were prospectively scanned with 3-T MRI. One resting-state scan was followed by five intentional motion scans. Additionally, a control group of 72 resting-state scans were selected from previous research. Firstly, six observers allocated developmental stages to the clavicles independently. Secondly, they re-assessed the images, allocating developmental statuses (immature, mature). Finally, the resting-state scans of the 18 volunteers were assessed in consensus to decide on the "correct" stage/status. Results were compared between groups (control, prospective resting state, prospective motion), and between staging techniques (stages/statuses).

RESULTS

Inter-observer agreement was low (Krippendorff α 0.23-0.67). The proportion of correctly allocated stages (64%) was lower than correctly allocated statuses (83%). Overall, intentional motion resulted in fewer assessable images and less images of sufficient evidential value. The proportion of correctly allocated stages did not differ between resting-state (64%) and motion scans (65%), while correctly allocated statuses were more prevalent in resting-state scans (83% versus 77%). Remarkably, motion scans did not render a systematically higher or lower stage/status, compared to the consensus.

CONCLUSION

Intentional motion impedes clavicle MRI for age estimation. Still, in case of obvious disturbances, the forensic expert will consider the MRI unsuitable as evidence. Thus, the development of the clavicle as such and the staging technique seem to play a more important role in allocating a faulty stage for age estimation.

Applicability of 3.0 T MRI images in the estimation of full age based on shoulder joint ossification: Single-centre study

Skeletal maturity is evaluated by many radiological methods for forensic age estimation. Direct radiography and computed tomography lead to a rise in ethical concerns due to radiation exposure. Therefore, magnetic resonance imaging (MRI) has currently been used in recent studies. In this study, the ossification stage of the shoulder joint was determined retrospectively in 178 male and 109 female individuals in the age group 12 to 30 years using 3.0 T MRI. All the images were evaluated with T1-weighted turbo spin echo (T1 TSE) sequence and T1 fast low angle shot two-dimensional sequence (T1 FL2D). The combined staging method, which was defined by Kellinghaus et al. and Schmeling et al., was used. The intra- and inter-observer agreement levels were very good (κ and κ_w). There were no significant age differences between males and females in all stages. In most of the stages, the ossification of the proximal humeral epiphyses occurred earlier in females than in males. Stage 4 did not occur in either of the sexes before the 18th birthday as the youngest patients in this stage was at 19 and 18 years of age in males and females, respectively. We concluded that evaluating the ossification of the proximal humeral epiphysis with MRI imaging for forensic age estimation may be beneficial. Evaluating the same anatomical structure with different MRI sequences may be useful for accurate staging diagnosis.

Dental age estimation based on the radiographic visibility of the periodontal ligament in the lower third molars: application of a new stage classification

The purpose of the present study was to test whether a new stage classification based on radiographic visibility of the periodontal ligament in lower third molars in a Chinese population can be used for the 18- and 21-year thresholds. A total of 1300 orthopantomograms, including equal numbers of northern Chinese males and females evenly distributed between the ages of 15 and 40 years, were analyzed. The stages were defined according to the visibility of periodontal ligament for the outer parts of lower third molar roots because the visibility status of the periodontal ligament between the roots of lower third molars is none valuable in many Chinese individuals. Stage 0 was first achieved at the age of 17.05 years in males and 17.46 years in females. The earliest appearance of stage 1 was 17.47 years in males and 17.86 years in females. Stage 2 was first observed in males at the age of 21.43 years and in females at the age of 21.96 years. The onset of stage 3 was first observed at the age of 25.83 years in males and 23.14 years in females. Compared with the stage classification of Olze et al., which also considers the mesial parts of the roots, the number of assessable cases could be significantly increased. Therefore, our novel approach is effective for age estimation in the Chinese population.

Anatomic shape variants of extremitas sternalis claviculae as collected from sternoclavicular thin-slice CT-studies of 2820 male borderline-adults

Within medical age assessment practice, the indicator "medial clavicular ossification" constitutes crucial evidence capable of excluding age minority "beyond reasonable doubt" concerning age-disputed individuals doubtfully claiming children's rights during legal procedures. Yet, one of its characteristics affects the morphological variability including a fair amount of downright peculiar appearances. As a result, inexperienced examiners are tempted to classify actually not-assessable formations according to the two established developmental typologies of Schmeling et al. and Kellinghaus et al. being at the same time the most frequent systemic error of age-related clavicular taxation. Since a respective overview appears missing, the study extracts not-assessable shape variants of the medial collar bone from a large sample of 2820 male borderline-adults as seen from thin-slice, sternoclavicular computed tomography. The two already highlighted configurations "more than one, medial, secondary ossification centres" and "medial metaphyseal concavity" are found as the most commonly encountered features impeding reliable delineation of staging criteria. In accordance with previous literature, it is emphasized that "qualified" rating of extremitas sternalis claviculae within age assessment practice presupposes "knowledge about the diversity of [its] anatomic shape variants."

Intraindividual incongruences of medially ossifying clavicles in borderline adults as seen from thin-slice CT studies of 2595 male persons

In the past, numerous studies have documented the possibility of intraindividual differing appearances of the paired age-marker "medial clavicular ossification" in borderline adults. However, the extent of the divergences is rarely mentioned. Against that the article describes this phenomenon from a large sample of 2595 male persons by means of thin-slice CT imaging of the sternoclavicular regions. For determining the ossification stage of the medial clavicles, the two accepted classifications by Schmeling et al. (five main stages) and Kellinghaus et al. (six substages) were applied and buildings deviating from that labelled as atypical "norm variants". The longstanding observation could be confirmed that intraindividual stage discrepancies of this age indicator are generally moderate and do not exceed one main stage or two substages of the respective classifications. It is concluded that stage determination should be scrutinized, if a dissimilarity seems to show larger differences.