Progressive coronal caudal curve after corrective osteotomies for congenital cervicothoracic scoliosis: incidence and predictors.

Objective: Postoperative progressive coronal caudal curve (PCC) was characterized by a postoperative de novo caudal S-curve ≥ 20° following congenital cervicothoracic scoliosis (CTS) corrective osteotomies, and at least 20° greater than the preoperative measurement, while the incidence was uncertain and the pathogenesis was equivocal. The objective of this study was to investigate the morbidity and potential factors contributing to PCC following CTS surgery.

Methods: This study reviewed 72 CTS patients between 2005 and 2021. Patients were categorized into two groups according to the absence or presence of PCC at last follow-up, namely the nonprogressive curve group (NPC-group) and the progressive curve group (PC-group). Demographics, radiographic data and the Scoliosis Research Society-22 (SRS-22) questionnaire results were reviewed. Multivariate linear regression analyses were utilized to determine possible predictors for PCC.

Results: PCC was observed in 11 (15%) of the total 72 patients. Compared with the NPC-group, the PC-group exhibited greater postoperative residual local curve (24.0 ± 9.7° vs. 9.1 ± 4.4°, P < 0.001), upper instrumented vertebra (UIV) tilt (16.9 ± 7.4° vs. 6.2 ± 3.7°, P < 0.001), T1 tilt (14.3 ± 9.4° vs. 6.6 ± 3.9°, P = 0.022) and neck tilt (10.1 ± 6.7° vs. 3.7 ± 2.5, P = 0.009). The multivariable linear regression demonstrated that the larger postoperative UIV tilt, residual local curve and neck tilt were associated with PCC. In addition, patients with PCC showed lower SRS-22 scores in terms of pain, mental health, self-image and satisfaction (P < 0.05).

Conclusions: The morbidity of PCC was 15% in CTS patients who underwent corrective osteotomies. Greater residual local curve, postoperative UIV tilt and neck tilt were identified as predictors for PCC.