Integrated Multidimensional Maturity Assessments Predicting the High-risk Occurrence of Peak Angle Velocity During Puberty in Progressive Female Idiopathic Scoliosis.

STUDY DESIGN: A consecutive and prospective longitudinal study.

OBJECTIVE: To propose an integrated multidimensional maturity assessment that was designated as forming a reliable system precisely predicting the high-risk occurrence of peak angle velocity (PAV) in a group of progressive braced female idiopathic scoliosis (IS).

SUMMARY OF BACKGROUND DATA: Scoliosis deterioration is believed to keep pace with the evolution of skeletal maturity during puberty. There is, however, a paucity of data in the literature regarding which unidimensional or multidimensional maturity assessment was most informational, and could be employed to predict the likelihood of significant curve progression.

MATERIALS AND METHODS: In this prospective study, braced IS girls with open triradiate cartilage were recruited and followed up at 6-month regular intervals. At each visit, the following data were collected: chronologic age, stage of menses, standing height, Cobb angle of the main curve, spine length, status of triradiate cartilage, Risser sign, and digital skeletal age (DSA) scores. The height velocity (HV) and spine length velocity (SLV), as well as the angle velocity (AV) of each visit were calculated. Finally, those with main curve progression of ≥5 degrees during brace treatment and with a minimum of 2-year follow-up covering the closure of the triradiate cartilage were recruited in this analysis, and their PAV was defined as the peak of AV curves during the whole follow-up period in puberty. Logistic regression analysis was used to evaluate the contribution of each measurement to the risk of PAV onset.

RESULTS: Thirty-six IS girls were finally recruited in the study, with an average age of 10.8 years at initial visit and 11.8 years at PAV. The average DSA score, spine length, standing height, and Cobb angle of main curve at PAV were 479.5, 326.7 mm, 150.8 cm, and 26.5 degrees, respectively. The average HV, AV, and SLV at PAV were 8.3 cm, 7.8 degrees, and 28.2 mm/y, respectively. The PAV occurred with Risser 0, 1, and 2 in 80.6%, 11.1%, and 8.3% of the IS girls and closed triradiate cartilages were found at PAV in all the girls. The logistic regression model revealed that the following variables contributed significantly to high-risk occurrence of PAV: chronologic age between 11 and 13 years [odds ratio (OR)=3.961; 95% confidence interval (CI), 1.023-15.342], Risser 0 (OR=14.261; 95% CI, 1.167-65.528), closed triradiate cartilage (OR=6.590; 95% CI, 1.612-26.943), DSA scores between 400 and 500 (OR=6.042; 95% CI, 1.282-28.482), HV>6 cm/y (OR=5.711; 95% CI, 1.105-29.526), Cobb angle of main curve >30 degrees (OR=5.492; 95% CI, 1.151-26.207) and SLV>20 mm/y (OR=5.973; 95% CI, 1.546-23.071).

CONCLUSIONS: Integrated multidimensional maturity assessments, defined as chronologic age between 11 and 13 years, modified Risser 0, DSA scores between 400 and 500, HV>6 cm/y, and SLV>20 mm/y, combined with preexisting scoliotic curve >30 degrees, were prone to increase the risk of entering the rapid curve acceleration phase in progressive IS girls.