Differences between the hand-wrist and the knee in assigned skeletal ages

Area of Science:

• Pediatric Radiology
• Skeletal Development Assessment
• Growth Monitoring

Background:

• Accurate skeletal age assessment is crucial for evaluating growth and development in children.
• Standard methods like the Greulich and Pyle (GP) and Tanner-Whitehouse (TW) methods are widely used.
• Previous studies suggest potential variations between different skeletal assessment areas.

Purpose of the Study:

• To compare skeletal ages derived from hand-wrist and knee radiographs in children aged 2-17 years.
• To determine the interchangeability of skeletal age assessments from these two anatomical areas.
• To quantify the discrepancies and their implications for clinical and research evaluations.

Main Methods:

• Utilized 4,902 pairs of hand-wrist and knee radiographs from children aged 2-17 years.
• Assessed skeletal age using the FELS method for hand-wrist and the Rochester-Whitehouse (RWT) method for knee radiographs.
• Analyzed mean absolute differences, standard deviations, and maximum differences within age- and sex-specific groups.

Main Results:

• Mean absolute differences in skeletal age ranged from 0.34 to 0.87 years, with standard deviations from 0.31 to 0.68 years.
• Maximum absolute differences ranged from 1.45 to 2.99 years, indicating substantial discrepancies.
• The 95th percentiles of absolute differences showed that in at least 5% of children, the choice of skeletal area markedly influenced individual evaluation.

Conclusions:

• Skeletal ages derived from hand-wrist and knee radiographs are not interchangeable.
• Significant differences exist between skeletal age assessments from these two areas, impacting individual assessments.
• Findings suggest that population-based descriptions using skeletal age from a single skeletal area may be misleading.