Using B-mode ultrasound to evaluate Risser grading for the determination of skeletal maturity in adolescents

Introduction

Rapid adolescent growth is associated with an increased risk of disease and disease progression. This study assesses the reliability and validity of non-ionising B-mode ultrasound for the assessment of skeletal maturity (Risser Grade) and offers procedural guidelines for its use.

Methods

Twenty-three female adolescents with primary-right-thoracic scoliosis (age: 13.8 (1.6) years) and twenty age-matched female control participants without scoliosis (age: 13.1 (1.8) years) were recruited.

Skeletal maturity was determined from (i) a series of nine B-mode ultrasound images collected at sites equally spaced between the anterior and posterior superior iliac spines of the pelvis and (ii) clinical spine radiographs obtained as part of standard scoliosis care. Inter-rater reliability was assessed between a novice researcher and an experienced medical doctor. Concurrent-validity was assessed by comparing the location and degree of apophysis growth and fusion obtained via ultrasound with that obtained using radiograph Risser grading for scoliosis participants only.

Results

The inter-rater reliability of ultrasound Risser grading was strong [ICC(2,1): 0.99, p < 0.001]. High concurrent-validity was determined, with no difference in Risser grading identified between the radiograph and ultrasound grading methods (Wilcoxon signed-rank: Z = −1.93, p = 0.053).

Conclusion

Ultrasound provides a reliable non-ionising alternative to the gold standard of Risser grading from radiographs to determine and monitor skeletal maturity. This study provides a detailed methodology for using ultrasound to assess skeletal maturity.

Implications for practice

Rapid adolescent growth is associated with an increased risk of disease and disease progression. Therefore, accurately determining and monitoring skeletal maturity in these adolescents is crucial. This study assesses the reliability and validity of non-ionising B-mode ultrasound for the assessment of skeletal maturity and offers procedural guidelines for its use.