The course of sagittal plane abnormality in the patients with congenital scoliosis managed with convex growth arrest

of Background Data. Patient age; localization, length, and magnitude of the curve; and sagittal plane alignment are reported to be the major determinants in the selection of patients for convex growth arrest. Although the existence of sagittal plane abnormality (kyphosis or lordosis) is accepted as a contraindication for convex growth arrest, this issue has not been discussed in detail. Objectives. The purposes of this study are to investigate the effect of sagittal plane abnormality on the control of coronal plane deformity and to evaluate the course of sagittal plane abnormality of the patients with congenital scoliosis who were satisfactorily managed with convex growth arrest. Study Design. Retrospective analysis. Methods. Inclusion criteria are: 1) a diagnosis of congenital scoliosis in a patient younger than 6 years of age, 2) treatment with convex growth arrest, 3) follow up for more than 2 years, 4) stabilized or improved coronal plane deformity, and 5) abnormal sagittal plane alignment within the scoliotic segment before surgery. The patients were evaluated with anteroposterior and lateral radiographs, and segmental measurements were compared according to the normal of their corresponding age. Results. A total of 38 patients with congenital scoliosis treated with convex growth arrest were reviewed. Among 13 patients with segmental sagittal plane deformity, 2 were excluded because of insufficient control of the scoliosis. Eleven patients (8 girls, 3 boys) with a mean age of 35 months (range 6-72 months) and mean follow-up of 40 months (range 24-76 months) fulfilled these criteria. The coronal plane deformities were 58degrees (range 36degrees-105degrees) before surgery and 52degrees (13degrees-107degrees) at the final follow-up. While six of the curves improved, the remaining ones stabilized. Sagittal segmental alignments within the scoliotic segments were hyperkyphotic in 9 patients and hypokyphotic in 1 and lordotic in 1. At the end of the follow-up, sagittal Cobb angle of the abnormal segments remained stable in 7 patients and deteriorated in 4. None of the 4 patients required any reconstructive spine procedure for kyphosis during follow-up. Conclusion. Sagittal segmental abnormality does not have a negative effect on the control of scoliosis in the majority of the patients (11 of 13). If the coronal curvestabilizes or improves, then sagittal segmental abnormality could also be stabilized (in 7 of 11 patients).