RESUMO
In the recent 10 to 15 years, the most popular issue in the spine field is evaluation and treatment of the sagittal alignment and sagittal balance of the spine. Adult spine deformity (ASD) includes not only coronal deformity, such as degenerative scoliosis, but also sagittal deformity. Degenerative scoliosis is also associated with sagittal deformity of the spine. Even in degenerative scoliosis, accompanying sagittal deformity is more important to clinical symptoms than coronal deformity. Sagittal deformity of the spine is significantly correlated with health-related quality of life score, such as visual analogue scale and Oswestry disability index, short form-36 health survey. For the appropriate evaluation and treatment of ASD, understanding the normal and abnormal sagittal alignment and sagittal balance of the spine is very important. Various compensatory mechanisms should be applied in order to maintain the balanced upright posture. Assessment of the compensatory mechanism is also mandatory for proper surgical planning. Some spinopelvic parameters show particularly high correlation with clinical symptoms in case of sagittal imbalance. Therefore, assessment of these parameters is necessary for evaluation of surgical outcomes.