Forensic age estimation using knee MRI: application of the Vieth staging system in a French population

Forensic age assessment is a critical process in determining an individual's legal status, particularly in the evaluation of the 18-year threshold, where reliable methods are essential. In this study, epiphyseal maturation of the knee was analyzed in a French population using magnetic resonance imaging (MRI) based on the Vieth staging system. A total of 512 knee MRI examinations (280 males, 232 females; age range 9-30 years) were retrospectively evaluated. The distal femoral and proximal tibial epiphyses were assessed using the six-stage Vieth classification on T1-weighted and fat-suppressed proton density (PD-FSE) sequences. A strong association between chronological age and ossification stage was observed (r ≈ 0.88; p < 0.001). Intraobserver agreement was almost perfect (κ = 0.99), and interobserver agreement was very good (κ = 0.81-0.87). No significant sex-related differences were identified across stages. The minimum age for complete fusion (stage 6) was 21.13 years in males and 20.74 years in females for the distal femur, and 19.92 and 17.69 years for the proximal tibia, respectively. These findings demonstrate that knee MRI using the Vieth system represents a reliable and reproducible method across different populations and observers. Further validation through studies involving diverse populations and varied MRI protocols is expected to enhance its standardization and strengthen its role in forensic decision-making.