Does thoracoscopic anterior release of rigid idiopathic scolioses associated with correction by posterior instrumentation result in better long-term frontal and sagittal balance?

Introduction: The aim of treatment of scolioses is to reduce deformities and restore balance in the spine.

Hypotheses: In rigid forms of scoliosis, associating anterior release could provide greater frontal and/or sagittal plane correction and improve balance in the spine.

Patients And Methods: This study compared correction and long-term balance on two planes between two homogeneous groups of idiopathic rigid scolioses treated with and without thoracoscopic release. The study included rigid scolioses with less than 35% reducibility and a Cobb angle of more than 60°, who all underwent posterior correction using a rod rotation technique. There were 29 patients, 14 who underwent a one-step procedure (group A) and 15 a two-step procedure (group B), with the subgroups of kyphoscolioses and lordoscolioses determined in each group. Frontal balance, Cobb angle, thoracic kyphosis and the Jackson plumbline were measured on pre- and postoperative X-rays and at the final follow-up.

Results: The mean long-term final follow-up was 144 months for group A and 54 months for group B. Frontal plane correction was identical in groups A and B. Frontal balance was preserved in all cases at the final follow-up. Sagittal balance was not modified with or without anterior release. The thoracoscopic release step resulted in an additional correction of 15.5° (23%) of thoracic hyperkyphosis in patients with kyphoscoliosis (P=0.003).

Discussion: Thoracoscopy did not improve short term results in the Cobb angle or frontal or saggital balance. Nevertheless, enhanced correction of thoracic hyperkyphosis was obtained with this procedure. In this study, the association of thoracoscopic anterior release with posterior correction by rod rotation to treat rigid scolioses did not appear to improve results, except for the correction of thoracic hyperkyphosis.