2023, Vol. 27 ›› Issue (9): 1346-1351

Dynamic analysis of structural changes in the lower cervical intervertebral foramen during rotation-traction manipulation by virtual reality technology

Liu Guangwei1, Feng Minshan1, 2, Zhu Liguo1, 2, Yin Xunlu2, Chen Zhuoxian2   

Abstract: BACKGROUND: Cervical spondylotic radiculopathy is a common clinical disease. Rotation-traction manipulation is an effective means to treat cervical spondylotic radiculopathy. The measurement of intervertebral foramen is an important reference standard in clinic.  
OBJECTIVE: To analyze the effects of different states of rotation-traction manipulation on the structural changes of lower cervical intervertebral foramen, and to explore the biomechanical mechanism of rotation-traction manipulation.
METHODS:   Cervical spine specimens were implanted with screws to facilitate positioning during CT imaging. Firstly, MTS material machine was used to simulate the rotation manipulation with different positioning angles on fresh cervical specimens. The motion trajectory of Marker points was obtained by motion capture technology. Then, the cervical specimens were scanned by thin-layer spiral CT. The three-dimensional cervical solid reconstruction was carried out by using Mimics software. According to the motion trajectory of cervical vertebra under the process of rotation-traction manipulation, the multi-mode medical image three-dimensional registration was carried out by Autodesk Maya software to realize dynamic virtual reality simulation, and then the dynamic image processing was carried out. Finally, ImageJ software and Adobe Photoshop software were used to measure the longitudinal diameter and area of lower cervical intervertebral foramen before and after rotation-traction manipulation.  
RESULTS AND CONCLUSION: (1) Positioning traction was helpful to open the lower cervical intervertebral foramen in advance. The traction effect was slightly worse than neutral traction, but positioning traction had better safety. (2) When the pulling force was within 150 N, the smaller the pulling force of rotation-traction manipulation, the smaller the increase of the longitudinal diameter and area of the lower cervical intervertebral foramen. After the pulling force exceeded 150 N, the increase of longitudinal diameter and area of cervical intervertebral foramen had little effect. (3) Rotation-traction manipulation may help to loosen the adhesion around the intervertebral foramen by increasing the lower cervical intervertebral foramen, so as to alleviate the symptoms of nerve root stimulation.
Key words: cervical spondylotic radiculopathy, rotation-traction manipulation, cervical intervertebral foramen, virtual reality, dynamic, positioning traction, neutral traction