Comparison of the Biomechanical Effects of Cervical Localized and Nonlocalized Rotation Manipulations on Cervical Spondylotic Radiculopathy: A Finite Element Study.

OBJECTIVE

The aim of this study was to compare the biomechanical effects between localized and nonlocalized rotation manipulations on cervical spondylotic radiculopathy and to investigate the influence of cervical disc degeneration on the manipulations using finite element models.

METHODS

In this study, 4 progressively degenerative finite element models of C3 to C7 segments were created to simulate cervical localized and nonlocalized rotation manipulations. In each model, disc degeneration was simulated at the C5 to C6 segment, a disc protrusion was assumed to be in the left posterolateral region of the C5 to C6 disc, and 2 rotation manipulations were performed on the right. Thirty nodes on the left posterolateral region of the C5 to C6 disc were selected, and the displacement and stress of the nodes, as well as the facet joint stress at the C5 to C6 level, were calculated and compared.

RESULTS

The displacement and stress in the left posterolateral region of the disc, as well as the facet joint stress at the C5 to C6 level, were higher in localized rotation manipulation than those in nonlocalized rotation manipulation (P < .05). The displacement and stress in the left posterolateral region of the disc decreased with the severity of disc degeneration (P < .05).

CONCLUSION

Using finite element models, this study demonstrated that cervical spine degeneration can adversely affect the biomechanical effects of rotation manipulations, in that more severe disc degeneration may be associated with poorer biomechanical effect. However, for the same level of degeneration severity, localized rotation manipulation may be more specific than nonlocalized rotation manipulation.