下腰椎小关节的方向性与椎间盘突出和侧隐窝狭窄的关系

目的探讨下腰椎小关节的方向性在椎间盘突出的发生和侧隐窝狭窄的形成中的作用和影响。方法通过腰椎ＣＴ片对下腰椎小关节角度进行测量,并分析、研究小关节的对称性、方向性与椎间盘突出和侧隐窝狭窄的关系。共观察１３６例患者３８６个下腰椎间隙的ＣＴ影像,采用横切关节面角度（ＴＩＦＡ）测量法,测量了７７２个下腰椎小关节角度。结果（１）下腰椎椎间盘突出与小关节对称性无关;（２）在Ｌ４～Ｓ１小关节不对称的间隙中,椎间盘易突向矢状小关节侧;（３）小关节角度小于２０度易发生退行性侧隐窝狭窄症;（４）该组测量的国人下腰椎小关节角度明显小于西方学者测量的欧洲人的角度。结论（１）下腰椎高发椎间盘突出症为特殊体位导致的应力集中所致,与椎间小关节方向性无关;（２）在Ｌ４～Ｓ１椎间隙中,如果椎小关节角度不对称将影响椎间盘突出的方向;（３）下腰椎小关节角度太小易导致退行性侧隐窝狭窄的发生。

The relationship of facet orientation to intervertebral disc protrusion and lateral recess stenosis in lower lumbar spine

OBJECTIVE: To investigate the relationship of facet orientation to intervertebral disc protrusion and lateral recess stenosis in lower lumbar spine. METHOD: The relationship between facet geometry (joint angle and tropism) and disc protrusion, lateral recess stenosis was investigated with computer tomography (CT) at the vertebral levels L(3 - 4), L(4 - 5), and L(5) - S(1). 772 facet joint angles (386 lower lumbar levels of 136 patients) were measured on coronal CT scans by transverse interfacet-joint angle (TIFA). RESULT: There was no statistically significant relationship between facet joint asymmetry and disc protrusion (P > 0.05). Disc protrusion occurred more frequently on side of sagittally oriented facet joint than coronal side (P < 0.01). The patients whose lumbar transverse interfacet-joint angle less than 20 degrees easily suffered from degenerative lumbar lateral recess stenosis in the elderly. The TIFA in Asian less evident than in European may be the important cause for high incidence of lumbar lateral recess syndrome in Asia. CONCLUSION: Stress on the lower lumbar spine leads to disc protrusion. No association is found between facet joint asymmetry and lumbar disc protrusion. The asymmetry of facet joint will influence the direction of intervertebral disc protrusion at level from L(4) - S(1). The patient whose lower lumbar spine interfacet-joint angle may unlikely suffer from degenerative lumbar lateral recess stenosis.