Factors associated with postoperative coronal imbalance in adult patients with severe and rigid scoliosis: a retrospective study

Extensive studies examined coronal imbalance (CIB) in adolescent and adult degenerative scoliosis; however, few studies addresses on CIB in adult with severe rigid scoliosis (SRS). Therefore, we analyzed postoperative SRS patients to identify factors associated with postoperative CIB.

In this retrospective study, we investigated SRS patients undergoing one-stage posterior column osteotomy (PCO) and fusion at our hospital between August 2012 and January 2019. The preoperative, postoperative and follow-up whole-spine anteroposterior (AP) radiographs were evaluated. Potential risk factors for postoperative CIB were analyzed using the LASSO regression, and independent risk factors were identified using binary logistic regression. A nomogram prediction model was constructed and validated.

Ninety eligible SRS patients were included. Postoperative radiographs showed a main curve correction rate of 54.17 ± 14.02%; however, follow-up CIB persisted in 26.67% of patients. Three independent variables affecting follow-up CIB were identified by LASSO regression, including preoperative CIB+ [OR = 12.414 (95% CI: 2.228, 69.162), P = 0.004], major curve flexibility index < 10% [OR = 14.300 (95% CI: 2.200, 92.957), P = 0.005], and immediate postoperative CIB [OR = 5.169 (95% CI: 1.387, 19.263), P = 0.014]. ROC and DCA analysis demonstrated that the nomogram had good predictive performance.

Preoperative CIB+, major curve flexibility index < 10%, and immediate postoperative CIB were significantly associated with postoperative CIB. These findings offer valuable guidance to improve surgical outcomes and reduce complications.