Analysis Of The Effect Of Posterior Cervical Open-Door Laminoplasty In The Treatment Of Multilevel Cervical Spondylotic Myelopathy

Purpose: This study aims to explore the clinical efficacy and radiographic parameters changes of posterior cervical single open-door laminoplasty combined with micro-titanium plate internal fixation in the treatment of multilevel cervical spondylotic myelopathy.Methods: A retrospective study was conducted to select 30 patients with multilevel cervical spondylotic myelopathy who were treated with micro-titanium plate combined with posterior open-door cervical surgery in The Second Affiliated Hospital of Bengbu Medical College from June 2016 to December 2020 and met the inclusion criteria,including 27 males and 3 females.All 30 patients were followed up,JOA scores and imaging data of the patients were collected.The improvement of neurological function and the changes of cervical imaging parameters such as cervical 2-7Cobe angle,cervical curvature,sagittal diameter of spinal canal,and distance between vertebral body and posterior edge of spinal cord before and after operation were compared.The efficacy of posterior cervical single open-door laminoplasty combined with micro-titanium plate internal fixation in the treatment of multilevel cervical spondylotic myelopathy was comprehensively evaluated.Results: The operation was successfully completed in 30 patients.No spinal hematoma,spinal cord injury,cervical 5 nerve root paralysis or internal fixation failure occurred in all patients.One patient had cerebrospinal fluid leakage and three patients had axial symptoms.Preoperative JOA score of the patient was(10.23±3.56),one week after surgery was(13.00±3.63),and one year after surgery was(15.10±2.47).The improvement rate of neurological function one year after surgery was 71.94%.The JOA scores at one week and one year after operation were significantly higher than those before operation,and the differences were statistically significant(P<0.05).The preoperative cervical curvature was(19.84±5.66°),and the postoperative cervical curvature was(15.20±5.30°).The postoperative cervical curvature decreased by 4.64°compared with the preoperative,and the difference was statistically significant(P<0.05).The 2-7Cobe angle before surgery was(20.08±7.72°)and after surgery was(19.10±5.83°),and the difference was not statistically significant(P>0.05).Preoperative sagittal diameter of cervical canal was(11.01±1.71mm)and postoperative diameter of cervical canal was(17.49±1.60mm).The anterior and posterior diameter of cervical canal increased by 6.48 mm on average after surgery,and the difference was statistically significant(P<0.05).The distance between vertebrae and spinal cord posterior margin was(9.15±1.49mm)before surgery,(12.25±1.90mm)after surgery,and the average drift distance of cervical spinal cord was 3.10 mm after surgery.The difference of the distance between vertebrae and spinal cord posterior margin before and after surgery was statistically significant(P<0.05).The spinal cord retrogression distance in the simple lesion group was(3.21±0.80mm),and that in the complex lesion group was(2.50±0.56mm),the difference was statistically significant(P<0.05).Conclusion: 1.Posterior cervical single open-door laminoplasty combined with micro-titanium plate internal fixation in the treatment of multilevel cervical spondylotic myelopathy can increase the sagittal diameter of the spinal canal,make the spinal cord drift backward,promote the recovery of neurological function,and improve the clinical symptoms.2.The spinal cord is more likely to drift backward in simple cervical disc herniation than in multilevel cervical spondylotic myelopathy with ossification of the posterior longitudinal ligament and/or calcification of the ligamentum flavum.