Influence of the examiner’s qualification and sources of error during stage determination of the medial clavicular epiphysis by means of computed tomography

Abstract

Computed tomography (CT) of the medial clavicular epiphysis has been well established in forensic age estimations of living individuals undergoing criminal proceedings. The present study examines the influence of the examiner's qualification on the determination of the clavicular ossification stage. Additionally, the most frequent sources of error made during the stage assessment process should be uncovered. To this end, thin-slice CT scans of 1,420 clavicles were evaluated by one inexperienced and two experienced examiners. The latter did the evaluations in consensus. Two classification systems, a five-stage system and a substaging system for the main stages 2 and 3, were used. Prior to three of his six assessment sessions, the inexperienced examiner was specifically taught staging of clavicles. Comparison of the examiners' results revealed increasing inter- and intraobserver agreements with increasing state of qualification of the inexperienced examiner (from κ= 0.494 to 0.674 and from κ= 0.634 to 0.783, respectively). The attribution of a not-assessable anatomic shape variant to an ossification stage was identified as the most frequent error during stage determination (n= 349), followed by the overlooking of the epiphyseal scar defining stage 4 (n= 144). As to the clavicular substages, classifying substage 3a instead of 3b was found to be the most frequent error (n= 69). The data of this study indicate that κ values must not be considered as objective measures for inter- and intraobserver agreements. Furthermore, a high degree of specific qualification, particularly the knowledge about the diversity of anatomic shape variants, appears to be mandatory and indispensable for reliable evaluation of the medial clavicular epiphysis.

Magnetic resonance imaging of distal tibia and calcaneus for forensic age estimation in living individuals

“…We had no access to ethnicity data, but it has been reported that the degree of ossification might differ among ethnicities [34,35]. Observer experiences are known to have a bias effect on data [11,36]; however, our intraobserver and interobserver data were accurate. Another main limitation of our study could be the lack of experience of the observers in evaluating MR images of the distal tibial and calcaneal epiphysis.…”

CT evaluation of medial clavicular epiphysis as a method of bone age determination in adolescents and young adults

“…Mühler et al (1) reported that a CT slice thickness less than 5 mm reduces the risk of misdiagnosis in the ossification phase. Wittschieber et al (19) reported that the most common mistake was the incorrect interpretation of the variations of the anatomical picture, followed by the overlooking of a scar in the ossified epiphysis leading to mislabeling of stage IV as stage V. We think that the slice thickness mostly influences the differentiation of stage I and stage, II since thicker slices may obscure the thin epiphyseal line at stage II and lead to misinterpratation of it as stage I. Our results showed no significant differences between left/right clavicular epiphyseal stages.…”

Estimation of forensic age using substages of ossification of the medial clavicle in living individuals

“…Work on age-staging ossification of the medial clavicular bone has attracted particular intention; assessments may be made by X-ray [3,4], CT [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], ultrasonography [18,21,22], or magnetic resonance imaging [23][24][25]. During the last few years, CT has mainly been performed for research purposes in the forensic sciences; thus, it is recognized that the study of thin sections at high resolution may help eliminate mistakes by allowing more detailed assessments [6,8,10,12].…”

“…Kellinghaus et al [6] proposed the use of subclassifications as a supportive method for the Schmeling staging technique. However, few studies have focused on this subject [6,8,15,17].…”

“…The Schmeling five-stage method is the most frequently preferred method for staging of ossification of the medial clavicle [7,8,[10][11][12][15][16][17][18]. Kellinghaus et al [6] proposed the use of subclassifications as a supportive method for the Schmeling staging technique.…”