Objective To analyze the correlation between the position of spacer (PS) and the surgical results and to select appropriate spacer by the calculation of spinal canal area in the double-door laminoplasty of the cervical stenosis.

Objective To evaluate the retaining spinal posterior structure to bilateral open-door expansive laminoplasty.

Modified unilateral open-door cervical laminoplasty using miniscrew-plates fixation;

Clinical Preliminary Report of Modified Open-door Laminoplasty;