Comparison of biomechanical differences between cervical rotation and rotation-traction manipulations using finite element analysis

Weng Rui; Huang Xuecheng; Lin Dongxin; Xie Siyuan; Yu Yaoshuai; Chen Cairui; Tan Peng; Zhao Zilin; Xie Pusheng; Li Yikai

doi:10.12307/2026.205

Abstract：BACKGROUND:Currently,the biomechanical differences between cervical rotation manipulation and cervical rotation-traction manipulation for the treatment of cervical radiculopathy have not been systematically elucidated. OBJECTIVE:To compare the biomechanical differences between cervical rotation manipulation and cervical rotation-traction manipulation in the treatment of cervical spondylotic radiculopathy caused by cervical disc herniation,and to provide a basis for the rational selection of manipulation in clinical practice. METHODS:A 27-year-old Asian male patient with cervical spondylotic radiculopathy caused by left posterior cervical disc herniation compressing the nerve root was recruited.The CT scan data of the skull and cervical spine were extracted to construct a finite element model of the skull and the whole cervical spine.After the model was verified,the key parameters of cervical rotation manipulation and cervical rotation-traction manipulation were loaded into the model,and the effects of these two manipulations on the stress of the intervertebral disc,facet joint,spinal cord and nerve root,disc displacement,as well as the volume of the cervical intervertebral foramen and other indexes were compared and analyzed. RESULTS AND CONCLUSION:(1)In terms of Von-Mise stress,the maximum stresses of cervical rotation manipulation on the annulus fibrosus of the intervertebral disc,nucleus pulposus and facet joint were 0.903,0.139,and 2.186 MPa,respectively,which were increased by 18%,13%,and 30%compared with those of cervical rotation-traction manipulation(0.765,0.123,and 1.682 MPa).The maximum stress of the spinal cord and nerve root was 2.547 Mpa,which was 7%lower than that of cervical rotation-traction manipulation(2.738 MPa).(2)In terms of displacement,the maximum forward displacement of the side with intervertebral disc herniation under cervical rotation manipulation was 1.067 mm,which was 11.1%more than that under cervical rotation-traction manipulation(0.960 mm).(3)In terms of the change in the volume of the intervertebral foramen,both manipulations led to an increase compared with before the manipulation.The volume increased by 15.5%under rotation manipulation and 19.8%under rotation-traction manipulation,and the latter had a more significant effect on expanding the volume of the intervertebral foramen.(4)It is concluded that cervical rotation manipulation has an advantage in promoting the forward displacement of the herniated intervertebral disc,but it generates higher stress on the intervertebral disc and facet joint,and is likely to cause intervertebral disc injury.Cervical rotation-traction manipulation makes the spinal cord and nerve root bear slightly higher stress,but it can more effectively expand the volume of the intervertebral foramen and reduce the risk of intervertebral disc structural injury.In clinical treatment,the advantages and disadvantages of these two manipulations should be carefully weighed according to the specific condition of the patient,and the application should be rationally selected.