Computed Tomographic Assessment of Sagittal Plane Alignment of the Thoracolumbar Junction in a Young Adult Korean Population

Objective: The purpose of this study was to determine reference values for the sagittal plane alignment of the thoracolumbar junction (TLJ) in a young adult Korean population. Methods: Thoracolumbar computed tomography (CT) scans of 1000 individuals (age range, 20–39 years; 500 men and 500 women) from Hanyang University Health Care Center were reviewed. All subjects had no spinal pathology or a history of previous spinal surgery. The segmental (each level from T11 to L2) and global (T11-L1 and T11-L2) Cobb angles of the TLJ of the spine were measured in midsagittal CT scans. Moreover, comparisons between the 2 age groups (20s and 30s) and sexes were performed. Results: The segmental Cobb angles of T11, T12, L1, and L2 were 6.5° ± 3.9°, 5.5° ± 4.1°, 2.2° ± 4.7°, and −3.3° ± 5.3°, respectively. The global Cobb angles of T11-L1 and T11-L2 were 6.5° ± 5.2° and 0.5° ± 6.1°, respectively. There were no differences in the sagittal alignment between the 2 age groups. Women presented less kyphotic and more lordotic alignment in the lumbar spine (L1 and L2) than men; however, the thoracic spine (T11 and T12) alignment was not different between the 2 groups. Conclusions: This study provides reference values with a wide physiologic range for the sagittal alignment of the TLJ of the spine in a young adult Korean population.