Insight into how to use multiple skeletal maturity indices for growth assessment: correlation between olecranon, Sanders and DRU classification systems

Abstract

Summary: This was a radiographic analysis of 114 pediatric patients with hand and wrist, and elbow radiographs to study the relationships between olecranon, digital and wrist maturity indices. Olecranon stage 1 coincided with R3, R4, U3, SS1 and olecranon stage 5 occurring as early as R7, U6, SS4. All three indices used together can provide the best prediction for the peak height velocity (PHV) while the hand and wrist classifications provides better assessment of the post-PHV period until skeletal maturity. Hypothesis: Combination of multiple maturity parameters provide better prediction of key maturity milestones. Design: Cross-sectional radiographic study. Introduction: No single maturity index provides perfect prediction of pubertal growth. Very often multiple parameters are used and their interaction can aid in more precise maturity assessment. Methods: Left hand and wrist (Sanders staging; SS and Distal Radius and Ulna classification; DRU), and lateral elbow (olecranon staging) radiographs of paediatric patients were assessed by nine raters of different levels of experience. Their reproducibility and reliability were assessed using intra-class correlation and Goodman and Kruskal’s gamma with Bonferroni correction. Inter-index associations, central tendency and dispersion of each maturity parameter were studied. Mapping of individual grades of each classification based on chronological age was performed. Results: A total of 114 patients (63.2% girls) were studied. The reproducibility and reliability of the three maturity parameters were satisfactory, with significant correlations and associations (p<0.001) between them. All three indices overlapped across 10.2-15.1 years for girls and 12.6-16.1 years for boys. DRU grades depicted the highest and the lowest mean age for both genders. Mapping reveals uneven spans and coverage of different period by each maturity parameter, with olecranon stage 1 coincided with R3, R4,U3, SS1 and olecranon stage 5 occurring as early as R7, U6, SS4. Conclusion: The simplified olecranon method and DRU classification can be used in conjunction at pre-pubertal and growth acceleration phases of pubertal growth spurt. All three parameters can provide precise PHV prediction, whereas only DRU and Sanders staging provides assessment of the post-PHV period until skeletal maturity.