峡部裂性腰椎滑脱的影像学相关因素分析

Analysis of imaging factors related to isthmic spondylolisthesis

目的:探讨腰椎峡部裂及峡部裂性腰椎滑脱(isthmic spondylogisthesis,IS)的影像学相关因素,以了解IS的发生发展机制。方法:选取2018年7月~2020年8月在我院行全脊柱X线正侧位片检查的34例正常体检者作为正常组(A组),年龄26.8±5.6岁(18~35岁);另选取腰椎峡部裂组(B组)21例,腰椎峡部裂伴峡部退变组(C组)23例,IS组(D组)19例,B、C、D组峡部裂均位于L5。所有图像均由两位高年资放射科诊断医师判定。测量各组的脊柱-骨盆平衡参数和下腰椎解剖参数,脊柱平衡参数包括胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)、矢状面轴向垂直距离(sagittal vertical axis,SVA);骨盆平衡参数包括骨盆入射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS);下腰椎解剖参数包括椎板角、椎间隙角。通过单因素方差分析比较4组间各影像学参数差异,通过Logistic回归分析腰椎峡部裂及IS的相关因素,最后通过受试者工作特征曲线(receiver operating characteristics curve,ROCC)及约登指数确定临界值。结果:单因素方差分析结果显示,4组间TK、SVA、PI、PT、SS、L3椎板角、L4椎板角均有统计学差异(P<0.05)。Logistic回归分析结果显示SS、TK、L3/4椎间隙角和L5/S1椎间隙角(L5/S1 intervertebral space angle,LSA)与腰椎峡部裂的发生密切相关,SS和TK与腰椎峡部裂的发生呈正相关(P<0.05),L3/4椎间隙角、LSA与腰椎峡部裂的发生呈负相关(P<0.05);PI和SVA与IS的发生呈正相关(P<0.05)。ROCC及约登指数结果显示腰椎峡部裂的正相关因素SS、TK临界值分别为28.4°、25.8°;其负相关因素L3/4椎间隙角、LSA的临界值分别为10.8°、6.0°;IS的正相关因素PI、SVA的临界值分别为50.5°、10.9mm。结论:SS、TK、L3/4椎间隙角、LSA、PI、SVA与L5 IS的发生、发展密切相关,SS、TK增大易发生腰椎峡部裂,而L3/4椎间隙角、LSA是腰椎峡部裂的保护性因素;PI、SVA增大易发生IS。

Objectives:To explore the imaging relevant factors of lumbar spondylolysis and isthmic spondylolisthesis in order to understand the occurrence and development mechanism of isthmic spondylolisthesis.Methods:A retrospective analysis of 34 normal patients who underwent full spine X-ray radiographs in our hospital from July 2018 to August 2020 were regarded as the normal group(group A),and their age was 18-35(26.8±5.6)years old.In addition,21 patients were selected in the lumbar isthmus fissure group(group B),23 cases in the group with lumbar isthmic fissure with isthmic degeneration(group C),and 19 cases in the group with isthmic spondylolisthesis(group D),the isthmic fissures of group B,C,D are all located at L5.All images were determined by two senior radiologists.The spine-pelvic balance parameters and lower lumbar anatomical parameters of all images were observed.The spine balance parameters include thoracic kyphosis(TK),lumbar lordosis(LL),and sagittal axial vertical distance(sagittal vertical axis,SVA);pelvic balance pa-rameters include:pelvic incidence(PI),pelvic tilt(PT),sacral slope(SS);lower lumbar anatomical parameters include:lamina angle,intervertebral space angle were recorded and analyzed.One-way analysis of variance was used to compare the differences in imaging parameters between the 4 groups.The Logistic regression was used to analyze the revelant factors of lumbar spondylolysis and isthmic spondylolisthesie.The receiver operating characteristics curve(ROCC)and the Yorden index were used to determine the critical value.Results:The results of one-way analysis of variance showed that TK,SVA,PI,PT,SS,L3 lamina angle and L4 lamina angle were different among the four groups,and the differences was statistically significant(P<0.05).Logistic regression analysis results showed that SS,TK,L3/4 intervertebral space angle and L5/S1 intervertebral space angle(LSA)were closely related to the occurrence of lumbar spondylolysis.SS and TK were positively related to the occurrence of lumbar spondylolysis(P<0.05),L3/4 intervertebral space angle LSA was negatively correlated with the occurrence of lumbar spondylolysis(P<0.05);PI and SVA were positively correlated with the occurrence of isthmic spondylolisthesis(P<0.05).The results of ROCC and Yorden index showed that the critical values of the positive correlation factors SS and TK of lumbar spondylolysis were 28.4°and 25.8°,the critical values of the negative correlation factors L3/4 intervertebral space angle and LSA were 10.8°and6.0°;The critical values of PI and SVA,which were positively relevant factors of lumbar spondylolisthesis,were 50.5°and 10.9 mm.Conclusions:SS,TK,and L3/4 intervertebral space angle,LSA,PI,and SVA are closely related to the occurrence and development of isthmic spondylolisthesis.Increased SS and TK are prone to lumbar spondylolysis,while L3/4 intervertebral space angle and LSA are protective factors for lumbar spondylolysis;increased PI and SVA are prone to isthmic spondylolisthesis.