Preserving the C7 spinous process with its muscles attached: effect on axial symptoms after cervical laminoplasty

Many efforts to reduce axial symptoms after cervical laminoplasty have been tried and reported; nevertheless, avoiding the axial symptoms has not yet been solved. There have been some reports that preserving the muscles attached to the C7 spinous process could reduce axial symptoms. The purpose of this study was to investigate whether axial symptoms can be reduced by preserving the C7 spinous process with its muscles attached during cervical laminoplasty. A series of 21 patients (group A) with C4-6 laminoplasty, preserving the C7 spinous process and its attached muscles, were compared with 22 patients (group B) with C4-7 laminoplasty. The axial symptoms (incidence, intensity, severity), cervical mobility, cervical curvature morphology, cross-sectional area of posterior cervical muscles, and Japanese Orthopaedic Association (JOA) score were evaluated. There were no significant differences in incidence, intensity, or severity of axial symptoms 1 year after operation. In addition, there were no significant differences in the cervical mobility or curvature morphology, the cross-sectional area of the posterior cervical muscles, or the JOA score. These results suggest that both preserving and not preserving the C7 spinous process with its muscles attached during cervical laminoplasty are acceptable in the long term.