Abstract

Background: In football there are established age-related tournaments for males and females to guarantee equal chances within the game for all the different age groups. To prevent participation in the incorrect age group, and owing to the fact that in some Asian and African countries registration at birth is not compulsory, other methods of age determination need to be available. Standard radiographs of the left wrist have been used for assessment of skeletal age for many years. This is, however, not ethical in the sporting environment.

Aim: To study the possible use of magnetic resonance imaging (MRI), which has no radiation risk, in estimating the age of healthy adolescent football players.

Methods: The examination protocol was applied in four countries using, their respective MRI equipment using a 1-T or 1.5-T magnet and a wrist coil. 496 healthy male adolescent football players between the ages of 14 and 19 years from Switzerland, Malaysia, Algeria and Argentina were selected for the study. The degree of fusion of the left distal radial physis was determined by three independent raters by a newly developed grading system which can be used in future MRI epiphysial fusion grading studies.

Results: The inter-rater reliability for grading was high (r = 0.91 and 0.92); all correlations were highly significant (p<0.001). The average age increased with a higher grading of fusion, and the correlation between age and grade of fusion was highly significant (r = 0.69, p<0.001). Only one player (0.8%) in the 16-year-old age group was graded as completely fused.

Conclusion: MRI of the wrist offers an alternative as a non-invasive method of age determination in 14–19-year-old male adolescents. The grading system presented here clearly identifies the skeletal maturity by complete fusion in all MRI slices, which eliminates any risk associated with standard radiographic rating as determined by the International Atomic Energy Agency.