Applicability of Shoulder, Olecranon, and Wrist-based Skeletal Maturity Estimation Systems to the Modern Pediatric Population

Automated Distal Radius and Ulna Skeletal Maturity Grading from Hand Radiographs with an Attention Multi-Task Learning Method

Background: Assessment of skeletal maturity is a common clinical practice to investigate adolescent growth and endocrine disorders. The distal radius and ulna (DRU) maturity classification is a practical and easy-to-use scheme that was designed for adolescent idiopathic scoliosis clinical management and presents high sensitivity in predicting the growth peak and cessation among adolescents. However, time-consuming and error-prone manual assessment limits DRU in clinical application. Methods: In this study, we propose a multi-task learning framework with an attention mechanism for the joint segmentation and classification of the distal radius and ulna in hand X-ray images. The proposed framework consists of two sub-networks: an encoder-decoder structure with attention gates for segmentation and a slight convolutional network for classification. Results: With a transfer learning strategy, the proposed framework improved DRU segmentation and classification over the single task learning counterparts and previously reported methods, achieving an accuracy of 94.3% and 90.8% for radius and ulna maturity grading. Findings: Our automatic DRU assessment platform covers the whole process of growth acceleration and cessation during puberty. Upon incorporation into advanced scoliosis progression prognostic tools, clinical decision making will be potentially improved in the conservative and operative management of scoliosis patients.

Proposed complementary osteological indicators: Advancing the estimation of puberty stages in Bioarcheology

OBJECTIVES

The study of puberty is a well-established area of bioarcheological research, which greatly enhances our understanding of adolescence and growth in the past. Since the publications of Shapland and Lewis' works, which have become "standards" for estimating puberty in skeletal material, no additional osteological indicators of puberty have been proposed. Nevertheless, clinical practice constantly develops skeletal maturation markers that could be useful in bioarcheology. This study aims to assess the applicability and reliability of novel puberty indicators as a complementary tool to estimate puberty in skeletal remains.

MATERIALS AND METHODS

Four new maturation markers including spheno-occipital synchondrosis, humeral head ossification, calcaneal apophysis ossification, and mandibular premolar mineralization were selected and applied to a sample of 85 adolescents from pre-Roman southern Italy (Pontecagnano, 7th-4th BCE).

RESULTS

Despite some limits in adapting the original clinical methods to osteoarcheological material, the use of these novel skeletal indicators had moderate to excellent scoring repeatability and an overall high agreement with the puberty and menarche status previously estimated with standard methods. These results encourage us to apply these markers in bioarcheology. In some cases, minor adaptations of the original scoring systems are suggested to enhance reliability.

DISCUSSION

Including the proposed indicators in routine puberty data collection allows us to refine puberty estimation and improve the ability to identify key growth milestones in poorly preserved skeletons. Further application to osteological collections with diverse chronology and geographical differences is needed to assess how and to what extent the newly proposed maturation markers perform.

The Addition of Hand-specific Skeletal Maturity Parameters Does Not Improve Skeletal Maturity Estimation Accuracy of the Modified Fels Wrist System

BACKGROUND

The Modified Fels Wrist system is potentially the most accurate clinically accessible skeletal maturity system utilizing hand or wrist radiographs. During development, parameters distal to the metacarpals were excluded. We attempted to further optimize the Modified Fels wrist system through the inclusion of hand parameters distal to the metacarpals.

METHODS

Forty-three new anteroposterior (AP) hand radiographic parameters were identified from the Fels and Greulich and Pyle (GP) skeletal maturity systems. Twelve parameters were eliminated from further evaluation for poor correlation with skeletal maturity, poor reliability, and lack of relevance in the peripubertal years. In addition to the 8 previously described Modified Fels Wrist parameters, 31 hand radiographic parameters were evaluated on serial peripubertal AP hand radiographs to identify the ones most important for accurately estimating skeletal age. This process produced a "Modified Fels hand-wrist" model; its performance was compared with (1) GP only; (2) Sanders Hand (SH) only; (3) age, sex, and GP; (4) age, sex, and SH; and (5) Modified Fels Wrist system.

RESULTS

Three hundred seventy-two radiographs from 42 girls and 38 boys were included. Of the 39 radiographic parameters that underwent full evaluation, 9 remained in the combined Modified Fels Hand-Wrist system in addition to chronological age and sex. Four parameters are wrist specific, and the remaining 5 are hand specific. The Hand-Wrist system outperformed both GP and SH in estimating skeletal maturity ( P <0.001). When compared with the Modified Fels Wrist system, the Modified Fels Hand-Wrist system performed similarly regarding skeletal maturity estimation (0.36±0.32 vs. 0.34±0.26, P =0.59) but had an increased (worse) rate of outlier predictions >1 year discrepant from true skeletal maturity (4.9% vs. 1.9%, P =0.01).

CONCLUSIONS

The addition of hand parameters to the existing Modified Fels Wrist system did not improve skeletal maturity estimation accuracy and worsened the rate of outlier estimations. When an AP hand-wrist radiograph is available, the existing Modified Fels wrist system is best for skeletal maturity estimation.

LEVEL OF EVIDENCE

Level III.