C7 sacral tilt (C7ST): a novel spinopelvic parameter reveals the relationship between pelvic parameters and global spinal sagittal balance and converts pelvic parameters into spinal parameters

European spine journal

article

Wen Zhang¹  Tao Li¹  Mengmeng Xu²  Xiaoyang Liu¹  Guodong Wang¹  Bingxiang Wang¹  Jianmin Sun¹  Xingang Cui¹  Zhensong Jiang¹ 

[1] Department of Spine Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Provincial Hospital Affiliated to Shandong University;Department of Pediatrics, Qilu Hospital of Shandong University

关键词: C7 sacral tilt;    Global tilt;    Pelvic incidence;    Pelvic tilt;    Sacral slope;   

DOI  :  10.1007/s00586-020-06548-8

来源: Springer

【 摘 要 】

The aim is to propose a novel spinopelvic parameter C7 sacral tilt (C7ST), of which its sum with global tilt (GT) is equal to pelvic incidence (PI), from a geometrical point of view. A cohort of 198 patients was recruited and the whole lateral spine and pelvic radiographs were performed. The following sagittal parameters were measured: sagittal vertical axis (SVA), C7 vertical tilt (C7VT), sacral slope (SS), pelvic tilt (PT), PI, GT and C7ST. The correlations between them were analyzed using the Pearson or Spearman correlation coefficient, and simple linear regressions were simultaneously conducted. P < 0.05 was set as the level of significance. Geometric construction by complementary angles revealed that PI = C7ST + GT, GT = PT + C7VT, and C7ST = SS − C7VT. Both C7ST and GT were moderately correlated with PI (R = 0.52 and 0.596, respectively), strongly correlated with SS and PT, respectively (SS = 0.9 * C7ST + 1.15, R = 0.955; PT = 0.87 * GT + 3.86, R = 0.96). The correlation coefficients of the SVA and C7VT, SVA and SS − C7ST, and SVA and GT − PT were 0.935, 0.925 and 0.863, respectively. The novel proposed spinopelvic parameter C7ST has the advantages of convenient measurement, reduced error, and extrapolation of other parameters. The greatest significance of proposing C7ST is that pelvic parameters (PI, PT and SS) are converted into spinal parameters (C7ST and GT), which is very helpful for a more intuitive understanding of the progression of spinal sagittal imbalance.

【 授权许可】

Unknown