Zifang Huang, Wenyuan Sui, Han Huang, Yaolong Deng, Jianyi Li, Limin Liu, Jingfan Yang, Junlin Yang

November 2021, Volume 30, Issue 11, pp 3200 - 3208 Original Article Read Full Article 10.1007/s00586-021-06840-1

First Online: 18 May 2021


This study aimed to quantify osteotomy protocol for severe spinal deformity correction based on pre-operative demographic, clinical and radiologic parameters.


A total of 131 Yang’s A type severe spinal deformity patients were included. All patients received one of following osteotomies: Ponte/2 (Ponte osteotomy/Grade 2 osteotomy, n = 30), PSO/3 (pedicle subtraction osteotomy/Grade 3 osteotomy, n = 19), BDBO/4 (bone-disc-bone osteotomy/Grade 4 osteotomy, n = 26), SVCR/5 (single-level vertebral column resection/Grade 5 osteotomy, n = 38) and MVCR/6 (multilevel vertebral column resection/Grade 6 osteotomy, n = 18). Demographic, clinical and radiologic characteristics were compared among groups.


Tukey's test identified 6 significant variables between paired groups: age for MVCR/6 versus Ponte/2 + PSO/3 + BDBO/4 + SVCR/5 groups; bending Cobb angle for Ponte/2 versus MVCR/6; sagittal deformity angular ratio (S-DAR) for Ponte/2 + PSO/3 versus BDBO/3 + SVCR/5 versus MVCR/6; pre-operative scoliosis for Ponte/2 versus SVCR/5; total-DAR (T-DAR) and pre-operative kyphosis for Ponte/2 + PSO/3 versus BDBO/4 + SVCR/5 + MVCR/6. Receiver Operating Characteristic (ROC) analysis showed the Area under the Curve (AUC) for the 6 variables ranged from 0.69 to 0.839. Multivariate k-means clustering analysis showed that Ponte/2 + PSO/3, BDBO/4 + SVCR/5, and MVCR/6 were three comparatively significant clusters, which could be discriminated by pre-operative kyphosis, T-DAR, age and S-DAR.


This study showed that osteotomy plan of severe spinal deformity could be determined as follows: Firstly, Ponte/2 + PSO/3 and BDBO/4 + SVCR/5 + MVCR/6 groups can be divided by either T-DAR (cutoff = 28) or the Cobb angle of pre-operative maximum kyphosis (cutoff = 100). Secondly, Ponte/2 + PSO/3 group could be further dichotomized into Ponte/2 and PSO/3 by age (cutoff = 18). Finally, BDBO/4 + SVCR/5 + MVCR/6 group could be divided into BDBO/4 + SVCR/5 and MVCR/6 groups by S-DAR (cutoff = 20).

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