Coronal and Sagittal Balance in Surgically Treated Adolescent Idiopathic Scoliosis

Background: Adolescent Idiopathic Scoliosis(AIS) is a three-dimensional deformity in coronal, sagittal & axial vertebral planes. Objectives: This study aimed to evaluate sagittal & coronal spine balance in adolescent idiopathic scoliosis patients treated surgically. Patients and methods: Patients were assessed clinically & radiologically preoperatively & postoperatively by standard standing long anteroposterior and sagittal spine X-ray. Measurements were done using Surgimap® software. Results: 25 AIS patients, 6 males & 19 females average 16 years. Preoperative & postoperative means respectively were as follows: 1ry Cobb was 72.88 & 26.76 (p > 0.001) and 2ry Cobb was 51.18 & 15.73 (p > 0.001). Coronal balance was 15.32 & 15.40. Cervical lordosis was 10.76 & 10.60. Thoracic kyphosis, lumbar lordosis & T1 slope were 46.24, 63.68 & 22.96 and 26.24, 50.72 & 18.04 respectively (p > 0.001, p > 0.001 & p = 0.021 respectively). PI, SS & PT were 50.88, 39.52 & 11.28 and 51.24, 39.12 & 12.16 respectively. SSA, SVA, SFD & GT were 132.9, -20.60, 36.68 & 7.04 and 130.9, -8.40, 37.96 & 9.56 respectively. The SVA/SFD ratio was -0.74 & 0.15 (p > 0.021). Implant density was 74.59 %. Intraoperative blood loss was 2618 cc. Operative time was 5.12 hours. There were many statistically significant correlations pre- & post-operatively. Conclusion: TK & LL has highly significant changes & correlations. T1 slope correlates to TK and CL. SVA/SFD ratio may be more important for assessing global sagittal balance. Correlation chain existed (PI to SS to LL to TK to CL). PI = SS + PT.