The effect of the expansive open-door laminoplasty on the three-dimensional motion and stiffness of the cervical spine
- VernacularTitle:颈椎后路单开门手术对颈椎三维运动及刚性的影响
- Author:
Weishan CHEN
;
Qixin CHEN
;
Xingli WANG
- Publication Type:Journal Article
- From:
Chinese Journal of Orthopaedics
2001;21(4):213-217
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the effect of the expansive open-door laminoplasty on the three-dimensional motion and stiffness of the cervical spine. Methods 55 cases after open-door laminoplasty of cervical spine due to myelopathy were follow-up for an average of 35.9 months. Cervical axial symptoms, neural functionality (JOA scoring system) and pre- and post-surgery dynamic cervical spine lateral X-ray films were evaluated. The Three-dimensional Motion and Stiffness of the Cervical Spine of Human Body Measuring Equipment was used in 12 post-operative open door laminoplasty cases and 10 pre-operative cases to measure the active and passive range of motion(ROM), load-displacement relationship, stiffness of cervical spine and torque caused by the isometric contraction of the extensors and flexors of the cervical spine. Results The average rate of improvement was 66. 2%. The excellent and good rate was 78.2%. The number of cases with distinct or severe cervical axial symptoms increased after the surgery ( P ＜ 0. O1 ) . The patients who have severe axial symptoms tend to have less curved cervical spine (P ＜ 0. 01 ) . There was no significant statistic difference between the severity of post-surgery cervical axial symptoms and JOA improvement level (P ＞ 0. 05). The active and passive ROM of extension, rotation and lateral bending of cervical spine were decreased after the surgery ( P ＜ 0. 05), and the main affection was on the middle and lower part of the cervical spine. The load-displacement figure of cervical spine can fit into an exponential equation T= b0eb1θ. In each direction, the lateral bending had the strongest stiffness, then the extension and flexion. The stiffness of rotation was the weakest. The stiffness of cervical spine of the post-surgery group was stronger than that of the contrast group. Conclusion The open-door laminoplasty of cervical spine damages the static mechanic balance on the sagittal plane and decreases the ROM and the flexibility of cervical spine. The curvature of the cervical spine is related to the severity of the axial symptoms and seems not to be related to the JOA score improvement.
