Trunk Growth in Early-Onset Idiopathic Scoliosis Measured With Biplanar Radiography.

STUDY DESIGN: Cross-sectional and longitudinal retrospective study. OBJECTIVES: To measure thoracic dimensions and volume during growth in early-onset idiopathic scoliosis (EOIS) patients and to compare them to a population of asymptomatic adults and to the previous literature. SUMMARY OF BACKGROUND DATA: Data on trunk growth for scoliotic children between 6 and 14 years of age is sparse in the literature. METHODS: Thirty-six patients (29 girls and 7 boys, between 3 and 14 years old, average Cobb angle 33°±15°) were included, all with a minimum two-year follow-up. Sixty-one asymptomatic girls and 54 asymptomatic adults were included as control groups. All subjects underwent biplanar radiography and 3D reconstruction of the spine, pelvis, and rib cage. EOIS patients repeated their radiologic examination every six months. Cobb angle, rib cage volume, anteroposterior and transverse diameters, thoracic index, thoracic perimeter, pelvic incidence, and T1-T12 and T1-S1 distance were calculated. Reproducibility of measurement was assessed. RESULTS: Measurement reliability in such young patients was comparable to previous studies in adolescents and adults. Geometrical parameters of EOIS patients increased linearly with age. For instance, rib cage volume in girls with EOIS increased from 2200 cm3 at six to seven years of age to 4100 cm3 at 13-14 years (65% of adult values, 294 cm3/y). Comparison with asymptomatic girls showed that EOIS could affect growth spurt. Longitudinal analysis on a cohort of six girls who had a follow-up of six years confirmed the cross-sectional data. CONCLUSIONS: In this longitudinal and cross-sectional study, trunk growth between 3 and 14 years of age was characterized, for the first time, with biplanar radiography and 3D reconstruction. The results can be useful to estimate patient growth and thus have potential application in the surgical planning of EOIS patients. LEVEL OF EVIDENCE: Level II, retrospective study.

Thoracic cage volume and dimension assessment by optoelectronic molding in normal children and adolescents during growth.

PURPOSE: The thoracic spine, the chondral and osseous ribs, and the sternum together make up the thoracic cage. These elements are strictly correlated, although their growth is not synchronous. The purpose of this study is to provide a comprehensive data set of thoracic dimensions and non-invasive volumetric assessment in a large cohort of males and females from early childhood to young adult age. METHODS: In all, 622 healthy individuals (406 girls, 216 boys) aged 6-18 years were consecutively enrolled between 2006 and 2016. All had to be healthy with no history of spinal deformity, or any lung, cardiovascular, systemic or neuromuscular disease. The optical ORTEN system for trunk surface data acquisition was used to calculate thoracic cage volume (V) and perimeter (Pe), anterior-posterior depth (AP) and transverse diameter (TD), AP/TD ratio, sternal length (St), and T1-T12 distance (Tle) in all patients. RESULTS: The overall average age was 11.1 ± 2.5 years (4-18) for girls and 11.0 ± 3.1 years (4-18) for boys. Average growth parameters were: standing height 146.2 ± 14.6 cm (103-172) for girls and 146.4 ± 20.0 cm (94-192) for boys, sitting height 75.4 ± 8.6 cm (61-91) for girls and 75.5 ± 10.3 cm (60-99) for boys, weight 37.6 ± 10.4 kg (16-65) for girls and 38.3 ± 14.3 kg (13.7-104) for boys, BMI 16.7 ± 3.7 (18.5-26) for girls and 17.0 ± 3.3 (18.7-34.3) for boys. At age 6-8 years: V was 52.5% of its final size in girls and 44.9% in boys; Pe was 80.2% its final length in girls and 76.8% in boys; St reached 68% of its final size in girls and 66.9% in boys; Tle reached 73.3% of its final length in girls and 71.2% in boys. At skeletal maturity, thoracic cage volume in boys was 19.4% greater than in girls (p < 0.05). AP/TD ratio remained < 1 in all age groups and did not differ between genders (p > 0.05). CONCLUSION: Growth of the thoracic cage is shown to be a gradual process that is more linear than previously reported. Only small increases in annual growth rates were observed during the pubertal growth spurt. The most important events characterizing thoracic cage development occurred during the first few years of postnatal growth. The circular cross-section of the very young child's thorax reached adult-like proportions together with its ovoid shape before age 6 years.