Forensic age estimation of the knee and clavicle using post-mortem CT

• This study provides reference material for the knee and clavicle for age estimation of deceased individuals. • PMCT provides a tool for creating reference materials. • With a few exceptions, the distribution of the stages for the clavicle follows chronological age. • Decision trees are presented for the combination of the bones to achieve a final age estimate. Age is crucial for constructing a biological profile to match data from missing persons in Disaster Victim Identification (DVI). For adolescents and young adults, methods often rely on bone end closures. Post-mortem computed tomography (PMCT) is a reliable tool for forensic age estimation in DVI cases. This study aimed to develop reference material for estimating the age of deceased adolescents and young adults using PMCT of the knee and clavicle in a Danish population. Results from the knee and clavicle were compared, and decision trees were created for final age estimates based on various bone combinations. The study included 221 individuals (57 females, 164 males) aged 10-25 years who underwent PMCT before medico-legal autopsy. Using the staging method by Schmeling et al. and Kellinghaus et al. ossification in the distal femoral, proximal tibial, proximal fibular, and medial clavicular epiphyses were evaluated. Large age intervals were observed for all bone stages, except for the earliest and latest clavicle stages. The clavicle stage distribution correlated well with chronological age, and reference values were consistent with previous studies. Individuals of younger age exhibited higher knee-bone stages than clavicle stages. Decision trees indicated that age intervals could be narrowed by combining clavicle stages with femur and fibula stages, though caution is required when intervals are too narrow. This study provides reference material for forensic age estimation in adolescents and young adults using PMCT of the knee and clavicle, relevant in DVI cases where limited body parts are available for analysis.