Intra-observer reproducibility and inter-observer agreement of Fels skeletal age assessments among male tennis players 8-16 years

• Main Authors: Paulo Sousa- (Author), Manuel J. Coelho- (Author), Jorge M. Celis-Moreno (Author), Daniela C. Costa (Author), Diogo V. Martinho (Author), Luís P. Ribeiro (Author), Tomas Oliveira (Author), João Gonçalves-Santos (Author), Oscar M. Tavares (Author), Joaquim M. Castanheira (Author), Telmo Pereira (Author), Jorge Conde (Author), Ricardo R. Cayolla (Author), Pedro Duarte-Mendes (Author), Gillian K. Myburgh (Author), Sean P. Cumming (Author), Robert M. Malina (Author)
• Format: Book
• Published: BMC, 2023-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.1186/s12887-023-03965-8; 1471-2431
• Keywords: Youth sports; Biological maturation; Bone age; Skeletal maturation; Maturity status; Pediatrics; RJ1-570
• Source: BMC Pediatrics, Vol 23, Iss 1, Pp 1-8 (2023)

Abstract Background Skeletal age (SA) is an estimate of biological maturity status that is commonly used in sport-related medical examinations. This study considered intra-observer reproducibility and inter-observer agreement of SA assessments among male tennis players. Methods SA was assessed with the Fels method in 97 male tennis players with chronological ages (CA) spanning 8.7-16.8 years. Radiographs were evaluated by two independent trained observers. Based on the difference between SA and CA, players were classified as late, average or early maturing; if a player was skeletally mature, he was noted as such as an SA is not assigned. Results The magnitude of intra-individual differences between repeated SA assessments were d = 0.008 year (observer A) and d = 0.001 year (observer B); the respective coefficients of variation were 1.11% and 1.75%. Inter-observer mean differences were negligible (t = 1.252, p = 0.210) and the intra-class correlation coefficient was nearly perfect (ICC = 0.995). Concordance of classifications of players by maturity status between observers was 90%. Conclusion Fels SA assessments were highly reproducible and showed an acceptable level of inter-observer agreement between trained examiners. Classifications of players by skeletal maturity status based on assessments of the two observers were highly concordant, though not 100%. The results highlight the importance of experienced observers in skeletal maturity assessments.