Mid-term clinical efficacy of unilateral open-door cervical expansive laminoplasty plus centerpiece titanium plate fixation for cervical spondylotic myelopathy

English Keywords:Cervical spondylotic myelopathy  Unilateral open-door cervical expansive laminoplasty  Centerpiece titanium plate  Internal fixation  Efficacy

English Abstract:

  【Abstract】 Objectives: To evaluate the mid-term clinical efficacy of unilateral open-door cervical expansive laminoplasty plus centerpiece titanium plate fixation for cervical spondylotic myelopathy. Methods: From January 2009 to June 2011, 59 cases suffering from cervical spondylotic myelopathy underwent unilateral open-door expansive laminoplasty plus centerpiece fixation, among these, 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 neurological function was evaluated by Japanese Orthopaedic Association(JOA) score. The VAS(visual analogue score) and NDI(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 sagittal CT, cervical range of motion(ROM) and the C2－C7 Cobb angle on lateral X-ray were measured before opera?鄄tion and the final follow-up after operation respectively, and the expansion rate of spinal canal was counted [as(postoperative sagittal diameter-preoperative sagittal diameter)/(preoperative sagittal diameter)×100%]. Results: 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 was 7.2±0.7 days. Axial neck pain after surgery was observed in 15 patients. According to VAS score, 13 cases got slight pain and 2 cases with moderate pain. Axial neck pain was relieved at one year postoperatively in all 15 patients. C5 palsy was noted in 1 case at 3 day 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 48-79 months(mean 60.5±2.7 months). The average JOA score at 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 at preoperation was 3.9±0.4 and 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 enlarged 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 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 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 the hinge side at 6 months after operation without recurrence of cervical stenosis and neurofunction deterioration. Conclusions: Unilateral open-door expansive laminoplasty plus centerpiece titanium plate fixation for cervical spondylotic myelopathy is simple and reliable, and the mid-term clinical efficacy is satisfactory.