Skeletal Maturation is Associated with Injury-Risk in Youth Elite 1 Soccer Players: A 4-Season Prospective Study with Survival 2 Analysis

Background: Injury epidemiology research in relation to skeletal maturation in youth elite soccer players remains sparse and inconclusive. Associations between injury-risk and skeletal maturity in youth elite soccer have received little attention. Hypothesis/Purpose: To prospectively investigate injury incidence and patterns, according to skeletal maturity in youth elite academy soccer players, and to determine the overall and lower limb apophyseal injury-risk associated with skeletal maturation status. Study Design: Descriptive epidemiology study. Methods: All medical attention and time-loss injuries were recorded prospectively during 4 consecutive seasons in 283 unique soccer players from U-13 (under 13 years) to U-19. The skeletal age (SA) was assessed in 454 player/seasons using the Fels method, to classify the maturity status (SA minus chronological age): Late > -1yr; Normal = +/-1yr; Early > +1yr and SA < 18yr; Mature: SA = 18yr. An adjusted Cox-regression was used to analyze the injury-risk. Results: 1565 injuries were recorded of which 60% were time-loss, resulting in 17,772 days lost. Adjusted injury-free survival analysis showed a significantly greater hazard ratio for different skeletal maturity status: Early > Normal (HR: 1.26, 95% CI, 1.11–1.42; p<0.001) and > Mature (HR: 1.35, 95% CI, 1.17–1.56; p<0.001). Players who were skeletally mature at the wrist had a substantially decreased risk of lower extremity apophyseal injures compared with late- (p<0.05), normal- (p<0.05), and early- (p<0.001) maturers, ranging from 45% to 61%. Conclusion: Musculoskeletal injury patterns and injury-risks varied depending on the players skeletal maturity status. Early-maturers had the greatest overall adjusted injury-risk. Players who were already skeletally mature at the wrist had the lowest risk of lower extremity apophyseal injuries but were still vulnerable for hip and pelvis apophyseal injuries.Clinical Relevance: The finding highlights that considering the individual skeletal maturation can benefit players with differing maturity status. This has important clinical implications in injury prevention and clinical management. Such outcomes provide valuable clinical insight to practitioners working in youth elite sports environments.