New criteria of radiological assessment of treatment outcomes in idiopathic scoliosis.

Introduction: The aim of surgical treatment in idiopathic scoliosis is correction, solid fusion and restoration of normal sagittal alignment of the spinal curves. The goal of this paper is to formulate a new uniform approach to evaluation of treatment outcomes in idiopathic scoliosis patients, considering not only the degree of correction but also coronal and sagittal balance.

Material And Methods: A retrospective analysis was performed of radiographs of 150 patients with idiopathic scoliosis (136 females and 14 males). The mean thoracic curve was 56.1 degree and mean lumbar curve was 51.2 degree. All patients underwent posterior fusion with derotational instrumentation. The follow-up period was 3.7 years. The authors used their own radiological criteria for assessing surgical treatment outcomes separately for the coronal and sagittal planes and in both planes collectively.

Results: The degree of correction achieved was 61.8% in the thoracic spine and 66.6% in the lumbar spine. Good coronal plane outcomes were achieved in 97 patients (65%), and poor outcomes were seen in 53 (35%) cases. Good sagittal plane outcomes were achieved in 112 cases (75%), with poor outcomes in 38 (25%) patients. Good composite outcomes were noted in 76 cases (51%), and poor composite outcomes were achieved in 24 patients (16%) with ambiguous outcomes in 50 (33%). Apical vertebral translation in lumbar spine >or=35 mm, L4 angle >10 degree and lower fusion end at the L3 level are risk factors for a poor outcome.

Conclusions: The proposed system for evaluation of radiological outcomes provides unequivocal results, not only accounting for the degree of correction, but also enabling quantitative evaluation of spinal balance in the coronal and sagittal planes.