The value of spine length velocity in the prediction of curve progression in idiopathic scoliosis undergoing bracing treatment

English Keywords:Idiopathic scoliosis  Maturity indicator  Spine length velocity  Growth potential  Cobb velocity

English Abstract:

  【Abstract】 Objectives: To investigate the correlative factors of Cobb velocity(CV) in idiopathic scoliosis(IS) girls, and to evaluate the value of spine length velocity(SLV) in the prediction of curve progression. Methods: Twenty-three IS girls(average age of 10.8 years) undergoing bracing treatment were included in this study. All patients were initially recruited with Risser 0 and no neurologic abnormality, and were followed up untill brace weaning. The curve patterns were single thoracic curves in 19 patients and double-main curves in 4 patients. At each visit, the following data were collected and recorded: 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), SLV, and CV of each visit were calculated. Correlation analysis was performed by using the Spearman coefficients. Results: The average chronologic age, DSA score, spine length, height and Cobb angle at the first visit was 10.8±1.3 years, 384.6±51.9, 311.6±23.6mm, 145.5±7.8cm and 23.0°±6.9°, respectively. The average SLV, HV and CV during follow-up was 19.1±17.1mm/year, 5.4±4.1cm/year and 5.7°±8.1°/year, respectively. In addition, the peak of both SLV(>20mm/year) and CV(>5°/year) took place during 10 and 13 years. The correlation analysis showed that SLV was significantly correlated with age, Risser sign, DSA score, HV and CV(r=-0.337, -0.292, -0.199, 0.374 and 0.456, P<0.05). Significant correlations between CV and age, DSA score and HV were observed(r=-0.192, -0.188 and 0.281, P<0.05). Conclusions: CV is significantly correlated with age, DSA score and HV in IS girls. SLV is significantly correlated with age, Risser sign, DSA score, HV and CV, which is proved to be a good predictor of CV and growth potential in IS. SLV more than 20 mm/year indicates a high risk of curve progression.