Clinical Application of a Novel Open-door Laminoplasty with Internal Fixation of Lateral Mass Screw Combine with Process and Lamina Screw

Objective Laminoplasty is well described as a surgical option for treating ossification of the posterior longitudinal ligament(OPLL) and cervical stenotic myelopathy.An obstacle to the open door technique widespread use is the lack of a suitable fixation systems to adequately secure the fractured lamina to the lateral mass.Our objective was to analyse the feasibility of a novel open-door laminoplasty with internal fixation of lateral mass screw combine with process and lamina screw,and report the initial clinical effect.Methods 12 consecutive patients with cervical spondylosis between May 2008 and December 2010 were involved in this study.All cases were performed a novel open-door laminoplasty with internal fixation of lateral mass screw combine with process and lamina screw.Three cases were multiple segments cervical spondylotic myelopathy,Three cases were ossification of posterior longitudina ligament of cervical spine,Four cases were acute traumatic central cervical spinal cord syndrome,Two cases were cervical development stenosis combined with spinal cord injury.The scope of operation decompression:C3～7 3 cases,C3～6 8 cases,C3～5 1 case.5 cases were opened door in left side,7 cases were opened door in right side.After the vertebral lamina was lift up,lateral mass screw combine with spinal process and vertebral lamina screw were fixed on the same segment of the same lateral side with polyaxial screw of the Vertex System,then there was no need to bite off the spinous process and the supraspinallig.Results All patients were followed up for about 15.2 months(6 to 28 months).All patients,clinical symptom were improved.The average operation time prolonged 120 minutes(90 to 150 minutes),the average blood losing volume was 1 400 mL(800～4 300 mL).There are no nerve and blood vessel injury during the operation.During the follow-up period,we found 1 case have the pivotal symptom,1 case has brief nerve root paralysis of C5,all these syndromes were relieved after 6 weeks.The mean JOA score of 12 patients significantly increased from 9.2(range 7～12) points before operation to12.9(range 9～15) points post operation one month,The mean improving rate of JOA was 44.2%(range 20.0%～60.0%),the scores enhanced 14.3 points post operation in three months,The mean improving rate of JOA enhanced 61.8%(range 44.0%～80.0%).The results of the improving rate of JOA were 3 cases of excellent persons(≥75%),accounting for 25%,8 cases of good persons(50%～74%),accounting for 66.7%,1 case of fair persons(25%～49%),accounting for 8.3%,It improve little after 6 mouths.The CT shows the vertebral canal was enlarged appropriately,the rate of the door-oriented bone combination was 100%.There were no phenomenon of close door.During the follow-up period,we found no the deformity of goose neck.Conclusion Opendoor side with internal fixation of lateral mass screw combine with process and lamina screw can effectively preserves postoperative sagittal diameter after cervical laminoplasty.The screw-rod system is easy to use and provides a rigid construct that may be more able to prevent postoperative cervical kyphosis and decrease axiality symptom.On account of keeping the posterior spinous process,ligament compound and physiological functions of zygapophyseal articulation,the postopetative physiological radian and stability proves good.