下腰椎关节突对TFC后路置入的阻抑作用

Restriction of the Lower Lumbar Facet against Posterior Placement of TFC

目的 :通过对下腰椎TFC融合架置入时必须切除的上关节突的定量分析 ,提出后路TFC腰椎界面固定时是否附加经椎弓根内固定必须考虑关节突切除的因素。方法 :选择无腰椎病变的受测者 78例进行L3 ～S1的CT断层横扫 ,在CT片上测量椎间隙水平和椎弓根水平的上关节突前缘间距、后缘间距。结果 :在L3 ～L4、L4～L5和L5～S1椎间隙置入理想直径TFC时最少需要切除的上关节突部分分别达 65 %、5 1%和 2 6%。结论 :下腰椎关节突对TFC融合架后路置入时有明显的阻止作用 ,节段越上 ,阻止作用越明显。因此关节突切除的范围必须作为是否需要附加经椎弓根短节段内固定的指标之一。

Objective: To investigate quantitatively the degree of superior facetectomy when the lower lumbar TFCs are placed.Method:78 lumbar spines without lumbar disease were scaned transversely by CT from L 3 to S 1,then anterior and posterior inter facet distances at the disc level?anterior and posterior inter facet distances at the pedicle level were measured from the CT scans.Result:At the levels of L 3～L 4?L 4～L 5 and L 5～S 1,the least percentages of superior facetectomy are 65%?51% and 26% respectively if TFCs with ideal diameters are used.Conclusion:Lower lumbar facet has obvious restriction against TFC placing,the lower the lumbar segment,the more obvious the restriction.So the degree of facetectomy must be considered as to decide whether or not using the transpedicular short segmental fixation.