Impact of kyphosis exceeding 30° on lumbar spine in patients with post-traumatic kyphosis

This study investigated the impact of post-traumatic kyphosis (PTK) on the lumbar spine using a local Cobb angle of 30° as the cutoff point. The measurements included the local Cobb angle, lumbar lordosis angle (L1-L5), intervertebral space angle (IVSA), lumbar disc degeneration, and posterior wall height loss (PWHL). Patient characteristics such as sex, age, disease duration, American Spinal Injury Association (ASIA) grade, fracture site, bone mineral density (BMD), Oswestry Disability Index (ODI), and visual analogue scale (VAS) score were also recorded. Patients were divided into two groups based on the thoracolumbar local Cobb angle: Group 1 (local Cobb angle > 30°, n = 48) and Group 2 (local Cobb angle ≤ 30°, n = 28). Comparative analysis revealed that Group 1 had a significantly longer disease duration, higher VAS and ODI scores, greater lumbar lordosis angle, increased L4/5 IVSA, and more severe lumbar disc degeneration (p < 0.05). Furthermore, across all patients, disease duration, lumbar lordosis angle, and L4/5 IVSA were positively correlated with the local Cobb angle (p < 0.05). These findings suggest that when the local Cobb angle exceeds 30°, PTK may aggravate lumbar degeneration.