RESUMO
STUDY DESIGN: Prospective study OBJECTIVES: To analyze and compare the cervical and thoracic sagittal curves between normal adolescents and patients with thoracic adolescent idiopathic scoliosis (AIS). SUMMARY OF THE LITERATURE REVIEW: There are no reports on cervical sagittal curves and its correlation with thoracic sagittal curves in AIS. MATERIALS AND METHODS: The sagittal curves were analyzed in normal adolescents (N-adol group, n=23) and patients with thoracic AIS (AIS group, n=26) who had thoracic curves > or = 45degrees. Lateral standing radiographs of the cervical spine with a elbow straight and the whole spine with the hands on the clavicles were taken. The sagittal curves and balance were measured in the following segments; C2-C7, T2-T5, T5-12, T2-12, T12-S1. Cervical lordosis (C2-C7) was measured in both cervical spine radiographs and whole spine radiographs. RESULTS: In the N-adol group, the cervical lordosis was 9.2+/-14.6degrees in the cervical spine radiographs and -0.6+/-12.9degrees ('-' means kyphosis) in whole spine radiographs. In the AIS group, cervical lordosis was -5.0+/-12.9degrees in the cervical radiographs and -8.1+/-12.7degrees in the whole radiographs. The AIS group had significantly less cervical lordosis than the N-adol group. Thoracic kyphosis of T5-12 and T2-12 was 24.1+/-10.6degrees and 38.9+/-13.1degrees in the N-adol group, respectively, and 17.8+/-9.4degrees and 30.1+/-11.8degrees in the AIS group, respectively. There was a significant difference between the two groups (Ps0.05). In the AIS group, the cervical lordosis measured in the cervical spine radiograph showed a positive correlation with thoracic kyphosis of T2-5 (r=0.50, P=0.009) and T2-12 (r=0.57, P=0.003). CONCLUSIONS: AIS patients had significantly less cervical lordosis and thoracic kyphosis than normal adolescents. Decreased cervical lordosis in AIS had a significant correlation with their relative thoracic hypokyphosis.