[Combining K-line to analyse the relationship between cervical range of motion of patients with ossification of cervical posterior longitudinal ligament and surgical prognosis].

Combining K-line (the connecting line of the midpoint of C₂ and C₇ spinal canal on the cervical lateral X-ray film) to analyze the relationship between cervical range of motion of patients with ossification of posterior longitudinal ligament (OPLL) and surgical prognosis.A total 42 patients with ossification of cervical posterior longitudinal ligament underwent cervical posterior single open-door laminoplasty between April 2014 and March 2017 were retrospectively ananyzed. The patients were dividing into K-line (+) group and K-line (-) group according to the position realationship of OPLL and K-line. The lesion of ossification of the posterior longitudinal ligament was not over than the K-line known as K-line (+). Conversely, the lesion of ossification of the posterior longitudinal ligament crossing the K-line was called K-line (-). Preoperative and postoperative 3 months JOA scores were observed, and postoperative 3 months JOA improvement rate were computed to assess patient's neurological function recovery. Preoperation and postoperative 3 months, OPLL occupation ratio (OOR), cervical lordotic angles (CLA) and cervical lordotic value (CLV) were measured respectively. The realationship between postoperative neurologic functional recovery in patients of CLV>0 group and CLV 0.05) respectively, postoperative at 3 months JOA scores were 14.2±1.8 and 12.6±2.2 (P 0 group at 3 months after operation, with improvement rate of (52.3±17.2)%, and 4 patients in CLV 0 group (P 0, their improvement rate was lower than that of the patients with postoperative at 3 months CLV<=0.