Radiological assessment of age from epiphyseal fusion at the knee joint

Objectives: Age determination is needed in administration of justice, employment, marriage, forensic investigation and identification. This cross-sectional study aimed to investigate the relationship between stages of epiphyseal union at the knee joint and chronological age. Methods: Anterior posterior and lateral knee radiographs of 100 males and 110 females aged 9–19 years were examined. Epiphyseal union was divided into five specific stages in the femur, tibia and fibula. Fusion was scored as stage 0: non-union,stage 1: beginning union, stage 2: active union, stage 3: recent union, and stage 4: complete union. Results: Mean age gradually increased with each stage of union and varied between males and females. A statistically significant difference in mean age was recorded between stages for the three epiphyses. Epiphyseal union occurred earlier in females than in males. A statistically significant difference was observed between the mean age of union for males and females for stages 1 and 2 for the femur, and stages 0, 1, 2 and 3 for the tibia and fibula. Conclusion: The results of this study indicate that radiographic analysis of the knee is a valuable alternative for estimation of chronological age. Keywords: age estimation; epiphysis; fusion; knee joint; radiograph; skeletal maturation