Saito J, Koda M, Furuya T, et al. - In this study, the independent preoperative factors that have a significant impact on poor surgical outcome after laminoplasty for K-line (+) ossification of the posterior longitudinal ligament (OPLL) were explored. Researchers conducted this study recruiting a total of 72 patients (50 male and 22 female) who had undergone laminoplasty for K-line (+) cervical OPLL and were followed-up for at least 1 year. It was shown that after laminoplasty, large preoperative segmental ROM at the peak of the OPLL is an independent factor that has a significant effect on the poor surgical outcomes for K-line (+) OPLL.