PMC

Reduction of thoracic kyphosis and pelvis back tilt to maintain sagittal balance in (a) a NTLJDK patient and (b) a TLJDK patient. LL: Lumbar lordosis; TK: Thoracic kyphosis; SS: Sacral slope; TLK: Thoracolumbar kyphosis; NTLJDK: Non-thoracolumbar junctional degenerative kyphosis; TLJDK: Thoracolumbar junctional degenerative kyphosis.

Vertical fracture of the vertebral body could be an influencing factor for the progression of local kyphosis. a Comparison of the local cervical kyphosis between the two groups of patients with (n = 7) and without (n = 6) vertical fracture of the vertebral body, as measured by the posterior tangent method at the time of injury. b Comparison of the local cervical kyphosis between the two groups of patients with and without vertical fracture of the vertebral body as measured by the posterior tangent method at the time of final follow-up. c Comparison of the progression of local cervical kyphosis between the two groups of patients with and without vertical fracture of the vertebral body as measured by the posterior tangent method. d Comparison of the local cervical kyphosis between the two groups of patients with and without vertical fracture of the vertebral body as measured by the endplate method at the time of injury. e Comparison of the local cervical kyphosis between the two groups of patients with and without vertical fracture of the vertebral body as measured by the endplate method at the time of final follow-up. f Comparison of the progression of local cervical kyphosis between the two groups of patients with and without vertical fracture of the vertebral body as measured by the endplate method

Visual classification of kyphosis levels.
Our visual classification of kyphosis was performed by observing patient’s normal walking ability in the clinic. The kyphosis levels are no kyphosis (Level 0), very slight kyphosis without forward-bent posture (Level 1), moderate kyphosis with forward-bent posture (approximately 10°–40° of the lumbar spine) (Level 2), severe kyphosis with forward-bent posture (more than (≥) approximately 45° of the lumbar spine) (Level 3), and very severe kyphosis with forward-bent posture (more than (≥) approximately 90° of the lumbar spine) (Level 4). The forward-bent posture in Levels 2, 3, and 4 were measured by eyes, based on the angle between the line connecting the part of 7th cervical and 5th lumbar spinous processes, and the vertical line through 5th lumbar process. The forward-bent posture in Levels 2, 3, and 4 were measured by eyes, based on the angle between the line connecting the part of 7th cervical and 5th lumbar spinous processes, and the vertical line through 5th lumbar process.

a Junctional kyphosis with reduced thoracic kyphosis; b Long armonic kyphosis; c Long thoracic hyperkyphosis; d Thoraco-lumbar scoliosis with Junctional Kyphosis