1.首都医科大学 生物医学工程学院;2.民航总医院 神经外科;3.首都医科大学宣武医院 神经外科
目的 研究半椎板切除、全椎板切除及椎板回植成形对颈椎稳定性的影响。方法 将14例新鲜成年绵羊颈椎标本（C2-C7）分为两组，每组7例。每例标本均被施加前屈后伸、左右侧弯和左右轴向旋转等6个方向3.0Nm的载荷，测量C3-C6运动节段在不同载荷下的运动范围及中性区。对第一组进行完整状态、C5半椎板切除和C4-C6半椎板切除3种状态下标本的运动范围和中性区的测量。对第二组进行完整状态、C4-C6全椎板切除和C4-C6椎板回植成形3种状态下标本的运动范围和中性区的测量。结果 与完整状态比较，C5半椎板切除和C4-C6半椎板切除状态下标本的运动范围和中性区没有明显差异，且C5半椎板切除和C4-C6半椎板切除两种状态之间标本的运动范围和中性区也没有显著性差异。与完整状态比较，C4-C6全椎板切除与C4-C6椎板回植成形状态下在前屈后伸载荷下的运动范围有显著性增大（P <0.05）。C4-C6椎板回植成形与C4-C6全椎板切除状态比较，标本在后伸载荷下的运动范围明显减小（P<0.05），而其余载荷下的运动范围，椎板回植成形和全椎板切除之间没有显著性差异。结论 半椎板切除后，颈椎标本的活动范围和中性区无明显增加，并不影响颈椎的稳定性。全椎板切除后，颈椎标本在前屈后伸载荷下的活动范围和中性区明显增加，颈椎稳定性受影响。椎板回植成形术并没有明显改善椎板切除术后颈椎的稳定性。
Objective To study the effect of hemilaminectomy, total laminectomyand recapping laminoplasty on the stability of the cervical spine. Methods 14 fresh adult sheep cervical spine specimens were divided into two groups. There were 7 cases in each group. Each specimen was applied a pure moment load of 3Nm in 6 different directions, including flexion/extension, left/right lateral bending, and left/right axial rotation. And the range of motion (ROM) and neutral zone (NZ) of specimen was 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-C6 hemilaminectomy state respectively. In the second group, the ROMs and NZs of specimens under the intact state, C4-C6 total laminectomy state and C4-C6 recapping laminoplasty state were measured and compared. Results There was no significant difference in the ROMs and NZs between C5 hemilaminectomy state and C4-C6 hemilaminectomy state compared with the intact state (P < 0.05). Compared with the intact state, the ROMs of the specimens were significantly increased in the direction of flexion and extension under the condition of C4-C6 laminectomy state and C4-C6 recapping laminoplasty state（P<0.05）. In addition, Compared with the C4-C6 laminectomy state, the ROMs of the specimen were significant decreased only in the direction of extension under the condition of C4-C6 recapping laminoplasty state（P<0.05）. There was no significant difference for the ROMs between total laminectomy and laminoplasty under other loads. Conclusions After hemilaminectomy, the ROMs and NZs of the cervical spine did not increase significantly, which did not affect the stability of the cervical spine. After C4-C6 total laminectomy, the ROMs and NZs in the direction of flexion and extension increased significantly, and the stability of cervical spine was affected. Recapping laminoplasty does not significantly improve the stability of cervical spine after total laminectomy.