To analyze the correlation of spinopelvic parameters and the change mechanism of pelvic incidence angle by measuring the spinopelvic sagittal parameters of asymptomatic elderly Han people, and to establish the linear relationship between lumbar lordosis (LL) and pelvic incidence (PI).

The spinopelvic parameters of 80 volunteers were measured by global spine X-rays using the picture archiving and communication systems at Shougang Hospital of Peking University. The parameters included PI, pelvic tilt (PT), sacral slope (SS), LL, thoracic kyphosis (TK), spinosacral angle (SSA), T₉ sagittal offset (T₉SO), and sagittal vertical axis (SVA). Pearson correlation analysis of spinopelvic parameters was performed and the linear regression between LL and PI was assessed with SPSS 20.0 statistical software.

PI, PT, SS, LL, TK, SSA, T₉SO, and SVA were (51.72±9.53)°, (14.52±7.27)°, (37.20±7.84)°, (52.13±10.46)°, (37.57±9.15)°, (126.72±8.21)°, (9.96±3.09)°, and (18.62±28.15) mm, respectively. PI was significantly positively correlated with SS (r=0.665, P<0.001), PT (r=0.593, P<0.001), LL (r=0.502, P<0.001), SSA (r=0.513, P<0.001), and SVA (r=0.290, P=0.009). LL was significantly correlated with SS (r=0.840, P<0.001), PT (r=-0.248, P=0.026), TK (r=0.371, P=0.001), SSA (r=0.878, P<0.001), and SVA (r=-0.258, P=0.021). The linear regression equation between LL and PI was LL=0.55×PI+ 24 (R²=0.252).

There are significant correlations between spinopelvic parameters in asymptomatic elderly Han people. PI is (51.72±9.53)°. The linear regression equation between LL and PI in the Chinese elderly Han population is LL=0.55×PI+ 24, which can provide a strategic reference for spinal deformity in Chinese elderly patients.