椎板切除对颈脊髓前部受压减压效果的生物力学探讨

Biomechanical Study of the Effect of the Laminectomy on Anterior Compression of the Cervical Spinal Cord

目的:观察椎板切除对颈脊髓前部受压的减压效果。方法:采用新鲜成年尸体的完整脊柱7具,将小型压力传感器置入椎管,对颈脊膜脊髓由前向后致压,致压深度分别为椎管矢状径的20%、30%和40%,记录颈椎椎板切除前后不同致压深度下脊膜脊髓受压压力的变化以及硬膜囊的位移。结果:传感器致压深度达颈椎管矢状径的40%,脊膜脊髓前部受压压力3.86kPa,硬膜后壁上测得的压力为0.38kPa;椎板切除后颈脊膜脊髓受压压力下降6.06%～14.38%,相应水平之硬膜囊向后移位0.44mm。结论:颈脊膜脊髓受压压力主要被脊膜脊髓前部吸收,椎板切除对来自颈脊髓前方的压迫无明显减压作用。

Objective: To observe the decompressive effect of laminectomy on the spinal cord compressed anteriorly in the cervical spine. Methods : The compression of the cervical spinal cord-meningeal complex was simulated using a small transducer pushed into the spinal canal in 7 whole cadaver spines. The depth of canal occlusion was controlled depending on 20%, 30% and 40% of the saggital diameter of the canal. The distribution and the change of the stress on the spinal cord-meningeal complex and the displacement of dural sac were recorded before and after laminectomy. Results: When the anterior transducer was pushed into the spinal canal with 40% occlusion, the force was 3.86 kPa on the anterior wall and 0.38 kPa on the posterior wall of the spinal cord-meningeal complex respectively. After extensive laminectomy, the anterior compressive force decreased 6.06% - 14.38% and the displacement of the posterior dura wall was 0.44 mm. Conclusions: The anterior compressive force was mainly absorbed by the anterior part of the spinal cord-meningeal complex. Extensive laminectomy had no significant decompressive effect on the spinal cord compressed anteriorly inthecervical spine.