Application of modified micro titanium plate for extensor attachment point reconstruction in open-door laminoplasty

Abstract

Objective: To observe the effect of modified micro titanium plate for extensor attachment point reconstruction in open-door laminoplasty. Methods: From January 2016 to February 2017, 26 patients with cervical spondylotic myelopathy underwent open-door laminoplasty+modified micro-titanium plate fixation+extensor muscle attachment point reconstruction at Tianjin Hospital were enrolled in this study. There were 14 males and 12 females in this group, aged (59±18) years. The improvement of neurological function based on the Japanese Orthopedic Association (JOA) score and the changes cervical curvature based on the cervical curvature index (CCI), especially the atrophy of the back muscles and the occurrence axial symptoms were recorded and analyzed. Intra-group comparisons were performed by using repeated measures of variance analysis or paired t-test. Results: The operations were performed well without injury to spinal cord. The operation time was (116±32) min with a blood loss of (196±41) ml. The JOA scores was improved form 7.8±2.1 preoperatively to 13.5±3.4 three months after surgery, and 13.9±3.7 at the final follow up (F=30.619, P<0.05). The improvement rate of neurological function was 66%±13%. The CCI decreased from 14.3%±3.9% preoperatively to 13.7%±3.7% three months after surgery and 13.0%±3.3% at the last follow-up (F=0.829, P>0.05). The cross-sectional area of the posterior cervical muscle was (35.9±7.6) cm(2) before surgery, and it was (33.5±6.7) cm(2) at the last follow-up (t=1.208, P>0.05). The spinal cord drift distance was (2.6±0.5) mm. The axial symptoms occurred in three patients, the incidence rate was 11.5%. Conclusion: In the open-door laminectomy, modified micro titanium plate can maintain the stability of the cervical spine, it also can rebuild the extensor attachment points and reduce the atrophy of the posterior cervical muscles, which avoid the occurrence of kyphotic deformity and reduce the occurrence of axial symptoms.