Clinical Efficacy Of Unilateral Open-door Cervical Expansive Laminoplasty With Centerpiece Titanium Plate Fixation For Cervical Spondylotic Myelopathy

Background: More and more people pay attention to cervical spondylotic myelopathy,for its severe clinical symptoms.Multi-segment cervical disc herniation,developmental cervical spinal stenosis and cervical ossification of the posterior longitudinal ligament which cause spinal cord severe compression often need surgery.In 1977,Hirabayashi and his colleagues firstly proposed unilateral open-door cervical expansive laminoplasty.Because it can effectively improve the patient's neurological symptoms,retain the posterior cervical structure and cervical motion segment,and reduce postoperative complications,therefore it has been widely used in clinical treatment for cervical spinal stenosis,with good short-term results.But the complication of axial neck pain and C5 palsy are also commonly reported.Centerpiece titanium plate is a new type of lamina internal fixation system in recent years used in the posterior operation and is reported as a simple and safe method for the treatment for cervical spondylosis.However,most of the study's follow-up times were too short to account for the mid-term clinical effects of the Centerpiece titanium.The aim of this study was to to evaluate the mid-term clinical efficacy of unilateral open-door cervical expansive laminoplasty with centerpiece titanium plate fixation for cervical spondylotic myelopathy.Objective: To evaluate the mid-term clinical efficacy of unilateral open-door cervical expansive laminoplasty with centerpiece titanium plate fixation for cervical spondylotic myelopathy.Method: 59 cases suffering from cervical spondylotic myelopathy underwent unilateral open-door expansive laminoplasty with centerpiece fixation,of these,from January 2009 to June 2011,there were 42 males and 17 females,with a mean age of 56.2±9.8 years(range,21~68 years).Preoperative MRI showed stenosis at three levels in 12 cases,four levels in 29 and five levels in 18.The neurofunction was evaluated by Japan Orthopaedic Association(JOA)score;The VAS(Visual Analogue Score)and NDI(The Neck Disability Index)were used to evaluate the pain severity and function.X-ray,CT and MRI were used to evaluate postoperative spinal canal enlargement and bone fusion at the hinge side.The mean sagittal diameter of spinal canal on the sagittal CT of cervical spine,ROM(cervical range of motion)and the C2~C7 cobb angle on the lateral X-ray were measured before operation and 3 days,3 months,6 months,1 year,2 years,3 years and the final follow-up after operation respectively,and the expansion rate of spinal canal was termed [as(postoperative sagittal diameter-preoperative sagittal diameter)/(preoperative sagittal diameter)×100%].Result: The average operation time was 142.2±18.1min;the average intraoperative blood loss was 264.5±50.5ml;the drainage volume was 252.3±28.6ml;the discharge time was7.2±0.7days.Axial neck pain after surgery was observed in 15 patients.According to VAS score,13 cases were slight pain,and 2 cases were moderate pain.Axial neck pain was relieved one year post-operatively in all 15 patients.C5 palsy was noted in 1 case 3day after operation,which was relieved significantly after 2 weeks of correspondent intervention and resolved completely 12 weeks after operation.All patients were followed up for 60.5±2.7 months(range,48~79 months).The average JOA score for preoperation was 8.5±0.5 and 15.4±1.3 at final follow-up after operation,with the improvement rate of(77.1±5.2)%.The average VAS score for preoperation was 3.9±0.4and 1.3±0.6 at final follow-up after operation.The average NDI score for preoperation was 20.3±5.4 and 6.5±1.8 at final follow-up after operation.Radiographic findings showed spinal canal en-larged perfectly at follow-up period after operation,and Spinal cord compression was completely lifted.The mean sagittal diameter of C2~C7 spinal canal was 9.7±0.9mm before operation and 16.8±1.2mm at final follow-up after operation,with the expansion rate of(67.6±13.9)%.The mean the cross-sectional area was 128.1±13.5mm2 before operation and 318.3±34.3mm2 at final follow-up after operation.ROM decreased by 9.6±2.4° at the final follow-up and the C2~C7 cobb angle decreased slightly in all patients without statistic difference(P>0.05).CT scan showed bony fusion at hinge side at 6 months after operation without recurrence of cervical stenosis and neurofunction deterioration.Conclusion: Unilateral open-door expansive laminoplasty with centerpiece titanium plate fixation for cervical spondylotic myelopathy is simple and reliable,and the mid-term clinical efficacy is satisfactory.This surgical approach is worth promoting.