Table 2. Comparison on relative spinal dimensions of vertebrae and discs in the thoracic spine (T4-T12) in AIS subgroups and normal controls.

	Primary thoracic curves (Lenke 1–4) T4-12 (n = 86)	Secondary thoracic curves (Lenke 5–6) T4-T12 (n = 19)	Normal controls T4-T12 (n = 11)	P ANOVA between all 3 groups	P Lenke 1–4 versus Lenke 5–6	P Lenke 1–4 versus controls	P Lenke 5–6 versus controls
Vertebra Rhw	0.67 ± 0.05	0.71 ± 0.06	0.65 ± 0.06	<0.01	<0.01	0.22	<0.01
Vertebra Rhd	0.82 ± 0.06	0.85 ± 0.11	0.78 ± 0.08	0.06	0.14	0.09	<0.05
Vertebra Rwd	1.23 ± 0.07	1.21 ± 0.10	1.20 ± 0.06	0.26	0.17	0.06	0.41
Disc Rhw	0.17 ± 0.02	0.16 ± 0.02	0.15 ± 0.04	<0.01	<0.05	0.06	0.28
Disc Rhd	0.21 ± 0.03	0.18 ± 0.02	0.17 ± 0.04	<0.01	<0.01	<0.05	0.26
Disc Rwd	1.22 ± 0.07	1.19 ± 0.10	1.19 ± 0.05	0.18	0.11	0.05	0.47

Statistically significant results, p < 0.05 are shown in bold.