European Spine Journal
ORIGINAL ARTICLE
Age‑based normal sagittal alignment in Chinese asymptomatic adults:
establishment of the relationships between pelvic incidence and other
parameters
Siyu Zhou1,2 · Fei Xu1,2 · Wei Wang1,2 · Da Zou1,2 · Zhuoran Sun1 · Weishi Li1
Received: 28 May 2019 / Revised: 11 August 2019 / Accepted: 5 October 2019
© Springer-Verlag GmbH Germany, part of Springer Nature 2019
Abstract
Purpose To investigate the age-based normal values of sagittal parameters and establish the relationships between them in
Chinese population.
Method Two hundred eighteen asymptomatic adult volunteers were included in this cross-sectional study. The whole spine
standing radiograph was taken from them, and the parameters including sagittal vertical axis (SVA), T1 pelvic angle (TPA),
global tilt (GT), spino-sacral angle, lumbar lordosis (LL), thoracic kyphosis (TK), T1 slope (T1S), cervical lordosis (CL),
C2–C7SVA, pelvic tilt (PT), sacral slop (SS) and pelvic incidence (PI) were measured. The gender diferences in sagittal
alignment were compared. Pearson correlation was calculated, and a linear regression analysis was used to establish the
relation between PI and other parameters.
Results The average values of PI, LL, TPA and GT were 46.2°, 48.2°, 7.8° and 10.6°, respectively, in this cohort. SVA, GT,
TPA, TK, T1S, CL and PT signifcantly increased with age (p<0.05). The females presented smaller T1S, C2–C7SVA and
larger PI, PT than the males. The relationships between PI and TPA, GT, SS, LL could be presented as TPA=0.411*PI−11.2
(R2 = 0.328, p < 0.001), GT = 0.483 * PI − 11.7 (R2 = 0.297, p < 0.001), SS = 0.354 * PI + 16.1 (R2 = 0.203, p < 0.001),
LL=0.588*PI+21.0 (R2 =0.267, p<0.001), respectively.
Conclusion The normal values of sagittal parameters were presented and changed with age in Chinese asymptomatic popula-
tion. The gender diferences existed in sagittal parameters. The relationships between PI and other parameters were estab-
lished which could be used for further research.
Graphic abstract
These slides can be retrieved under Electronic Supplementary Material.
Table: The normal values of parameters
in different age groups
Figure: The relationships between
PI and other parameters
Key points
Take Home Messages
Parameters
SVA (mm)
Age 20-30 Age 30-40 Age 40-50 Age 50-60 Age 60-70
-17.1 23.1 -12.2 35.6 -13.0 28.0 -8.5 26.2
Age>70
7.5 29.1
-8.3 29.4
TPA (°)
GT (°)
SSA (°)
5.7 5.5
7.7 6.7
5.6 5.7
8.0 6.7
6.6 6.7
10.2 8.1
9.3 5.3
12.1 6.8
9.6 7.2
12.2 9.1
10.6 5.5
14.8 7.1
1. Normal values
2. T1 pelvic angle
3. Sagittal alignment
4. Adult deformity
5. Pelvic incidence
1. The normal values of sagittal parameters were presented in this
study and changed with age in Chinese asymptomatic population.
126.8 6.2 126.0 7.0 125.6 8.1 124.4 6.4 123.8 7.8 122.6 10.
9
C2-7SVA (mm)
CL (°)
TK (°)
T1S (°)
LL (°)
L4-S1 (°)
PI (°)
PT (°)
SS (°)
PI-LL (°)
LL-TK (°)
T1S-CL (°)
10.9 7.1
7.4 5.6
13.5 9.1
10.5 6.5
26.5 9.8
21.7 6.9
48.9 9.0
35.4 6.7
45.3 5.9
10.4 5.5
35.0 6.0
-3.6 9.4
18.9 9.8
11.8 6.6
32.4 9.3
20.9 7.8
50.2 11.1
36.5 7.8
47.0 9.3
13.1 6.7
32.6 10
11.0 10.5 17.6 13.1 14.6 13.2
12.3 8.6
33.5 10.8
21.9 5.6
49.1 8.6
31.6 8.6
46.8 9.5
14.9 7.1
31.4 5.8
-2.4 7.4
15.6 9.4
9.5 7.0
13.6 9.2
33.4 9.2
23.3 7.4
22.0 6.8
40.4 10.1
27.8 6.3
21.6 9.3
17.8 5.9
45.5 8.0
31.9 5.3
45.5 9.8
12.6 6.4
32.7 5.6
0.1 7.2
2. The gender differences did exist in sagittal parameters.
47.6 11.4 47.5 12.0
32.6 8.7
46.5 8.3
14.2 7.7
31.8 5.3
-1.2 11.1
14.3 10.9
9.7 8.6
34.1 8.1
45.4 9.3
14.6 4.9
30.8 7.9
-2.1 9.8
7.1 12.6
5.8 8.9
3. The relationships between PI and TPA, GT, SS, LL could be
presented as TPA=0.411*PI-11.2 (R2=0.328, P<0.001),
GT=0.483*PI-11.7 (R2=0.297, P<0.001), SS=0.354*PI+16.1
(R2=0.203, P<0.001), LL=0.588*PI+21.0 (R2=0.267, P<0.001),
respectively.
-3.2 10.7
23.9 9.1
10.4 8.0
22.4 10.3 17.9 13.2
11.2 5.4 9.1 8.0
Zhou S, Xu F, Wang W, Zou D, Sun Z, Li W (2019) Age-based Normal Sagittal Alignment
in Chinese Asymptomatic Adults: Establishment of the Relationships between Pelvic
Incidence and Other Parameters. Eur Spine J;
Zhou S, Xu F, Wang W, Zou D, Sun Z, Li
in Chinese Asymptomatic Adults: Establishment of the Relationships between Pelvic
Incidence and Other Parameters. Eur Spine J;
W
(2019) Age-based Normal Sagittal Alignment
Zhou S, Xu F, Wang W, Zou D, Sun Z, Li W (2019) Age-based Normal Sagittal Alignment
in Chinese Asymptomatic Adults: Establishment of the Relationships between Pelvic
Incidence and Other Parameters. Eur Spine J;
Keywords Normal values · T1 pelvic angle · Sagittal alignment · Adult deformity · Pelvic incidence
Siyu Zhou and Fei Xu contributed equally to this work.
Extended author information available on the last page of the article
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