Chang SY, Kim Y, Kim J, et al. - A retrospective case-control study was conducted to present and compare the sagittal spinal alignment between patients with and without the ossification of the ligamentum flavum in the thoracic spine (TOLF). Between January 2014 and December 2019, researchers evaluated the preoperative sagittal alignment parameters in consecutive patients who underwent posterior decompression for TOLF in a single institution. They compared sagittal parameters of the patients with TOLF, with those of the age- and gender-matched control group with lumbar spondylosis. The TOLF group (n = 43 [23 men, 20 women]), with a mean age of 69.5 (range: 41–86) years was compared with the control group (n = 86). This is the first research to report the sagittal alignment in patients with TOLF. The TOLF group exhibited a hypolordotic spine with a larger pelvic incidence minus lumbar lordosis mismatch in comparison with the age- and gender-matched control group with lumbar spondylosis.