腰椎椎管与硬膜囊横截面积及其动态变化的实验研究

Dynamec changls in dimension of cross-sectional areasof lumbar canal and dural sac:an experimental study

作者采用ＣＴＭ和计算机图形测算技术对１０具尸体腰椎椎管和硬膜囊在伸屈体位下做了不同层面的扫描和横截面积测算。结果显示上述二者横截面积在不同层面和相同层面不同体位下大小均不相同，屈曲位增大，伸展位缩小。椎管以Ｌ＿（４，５），Ｌ＿５～Ｓ＿１椎间层面变化最具有显著性（Ｐ＜０．０１）；硬膜囊除Ｌ＿５～Ｓ＿１层面外，余各层面均值变化均具显著性（Ｐ＜０．０５～０．０１）。作者认为，椎间层面椎管横截面积动态变化的大小，取决于各椎间伸屈运动的程度，而硬膜囊横截面积的动态变化除受椎管变化影响外，亦与管内软性组织及囊自身长度变化等多种生物力学因素作用有关，故观测硬膜囊变化的实际临床意义大于前者。

AbstractThe variation in the cross-sectional areas (CSA)of lumbar canal and dural sac under extension and flex-ion was studied by using CT scans in ten humancadaver lumbar spine specimens. CSA at different lev-els or same level in varying positions were distinctive.CSA in flexion position was increased , while in exten-sion position reduced. Dynamic changes of CSA ofcanal(CSAC) at L_(4,5),L_5～S_1 were very significant(P<0.01), and those of CSA of dural a(CSADS)at alllevels but L_5～S_1 were significant(P<0.05). It wasconsidered that dynamic changes of CSAC at interver-tebral levels were determined by the range of lumbarrnotions, but those of CSADS were influenced bychanges of canal and biomechanical factors of intra-canal soft-tissue and changes of dural sac length. Mea-surement of CSAIDS was more significant than that ofCSAC.