Analysis of two plates versus four plates for fixation in expansive open-door cervical laminoplasty

English Keywords:Cervical spondylotic myelopathy  Expansive open door cervical laminoplasty  Micro-titanium plate  Spinal canal decompression  Complications

English Abstract:

  【Abstract】 Objectives: To compare the clinical effect of fixation with two plates versus four plates in expansive open-door cervical laminoplasty. Methods: A retrospective study was performed on 65 patients with multi-segmental cervical spondylotic myelopathy who underwent C3-C6 single-door titanium plate fixation for spinal canal enlargement from July 2010 to December 2017. According to the number of titanium plates used in the operation, the patients were placed into either a two-titanium-plate group(n=49) or a four-titanium-plate group(n=16). There were 47 males and 18 females with an average age of 58.3±10.2 years. The course of disease ranged from 3 days to 20 years. The preoperative JOA score was 11.3±2.9 points. The average follow-up time was 29.7±22.9 months. The operation time, intraoperative blood loss, postoperative hospital stay, consumables cost and JOA score were recorded in both groups. Surgical complications were recorded, including the development of axial symptoms, C5 nerve root paralysis, postoperative screw loosening, re-closing and cervical kyphosis. Imaging evaluation programs included cervical curvature(Giovanni D value), C2-C7 Cobb angle, C3-C6 spinal sagittal diameter and Pavlov ratio. Results: There were no significant differences in baseline data between the two groups(P>0.05). There were no significant differences between the two groups in terms of operation time, intraoperative blood loss, postoperative hospital stay, JOA improvement rate and the rate of surgical complications(P>0.05). The cost of consumables was significantly different(P<0.001). There was statistically significant difference in the ratio of C4 spinal sagittal diameter and C4 Pavlov between before surgery and 6 months after surgery(P<0.01). The JOA scores at the final follow-up, the anteroposterior diameter of C3-C6 and the C3-C6 Pavlov ratio were significantly improved at 6 months after surgery, and the difference was statistically significant(P<0.05). Cervical curvature and the C2-C7 Cobb angle had a decreasing trend at the 6-month follow-up compared with preoperative values. There was significant difference when two titanium plates were used(P<0.05), but no difference when four titanium plates were used(P>0.05). Conclusions: Both groups can achieve effective support to prevent re-closure, and the improvement rate at the final follow-up is greatly improved. The tendency for the cervical curvature to straighten or become kyphotic appeared in both groups. There is insufficient evidence to suggest that four titanium plates are superior in maintaining cervical curvature and reducing postoperative complications.