Experimental Study of Hemilaminectomy, Total Laminectomy and Recapping laminoplasty of Cervical Spine in Sheep / 医用生物力学

ABSTRACT

Objective To study the effect of hemilaminectomy, total laminectomyand recapping laminoplasty on stability of the cervical spine. Methods Fourteen fresh adult sheep cervical spine specimens were divided into two groups, with 7 cases in each group. Each specimen was applied with a pure moment load of 3.0 N·m under flexion/extension, left/right lateral bending, and left/right axial rotation. The range of motion (ROM) and neutral zone (NZ) of specimens were measured. In the first group, the ROMs and NZs of the specimens were measured and compared under the intact state, C5 hemilaminectomy state and C4-6 hemilaminectomy state respectively. In the second group, the ROMs and NZs of specimens under the intact state, C4-6 total laminectomy state and C4-6 recapping laminoplasty state were measured and compared. Results There were no significant differences in ROMs and NZs between C5 hemilaminectomy state and C4-6 hemilaminectomy state compared with the intact state (P<0.05). Compared with the intact state, ROMs of the specimens were significantly increased during flexion and extension under C4-6 laminectomy state and C4-6 recapping laminoplasty state (P<0.05). In addition, compared with the C4-6 laminectomy state, ROMs of the specimen were significantly decreased only during extension unde C4-6 recapping laminoplasty state (P<0.05), while no significant differences were found in ROMs between total laminectomy and laminoplasty under other loads. Conclusions With hemilaminectomy, ROMs and NZs of the cervical spine did not increase significantly, and stability of the cervical spine was not affected. With C4-6 total laminectomy, ROMs and NZs during flexion and extension increased significantly, and stability of the cervical spine was affected. Recapping laminoplasty did not significantly improve stability of the cervical spine with total laminectomy.