目的 探讨融合器高度和融合器位置等因素对OLIF手术间接减压效果的影响,同时分析OLIF术后间接减压失败的影响因素.方法 回顾性分析该科2019 年3 月~2022 年3 月开展OLIF手术的 103 例LSS患者资料,手术节段为L2-3 节段~L4-5 节段;其中单节段手术63 例,两节段手术26 例,三节段手术 14 例.测量以下影像学指标:硬膜囊直径,椎管直径,硬膜囊横截面积(cross sectional area,CSA),椎管CSA,左右侧关节下直径,左右侧黄韧带厚度和黄韧带面积,椎间盘突出物的直径,椎间盘高度,节段性前凸角,椎间孔高度和椎间孔面积等.所有患者均随访6 个月以上,观察间接减压失败的发生率,并分析其影响因素.结果 103 例患者均成功完成OLIF手术,与术前相比,患者术后 6 个月时的疼痛VAS评分均获得显著改善(P<0.001).高度为 14 mm的融合器(n =18)置入后,其硬膜囊直径、右侧黄韧带厚度和椎间盘突出物直径的收缩值等指标的改善程度,均显著大于高度为 10 mm(n =9)和 12 mm(n =76)的融合器(P<0.05).融合器前置(n =48)可获得更好的节段性前凸矫正效果(P=0.041);而融合器后置(n =109)可获得更高的椎间盘后缘高度矫正效果(P =0.018),同时可获得更好的左、右侧关节下直径改善效果(P=0.005,P=0.019),右侧黄韧带厚度的减少程度也更显著(P=0.023).多因素Logistic回归分析显示,术前硬膜囊CSA(OR=0.952)、融合器位置(OR =0.276),均是OLIF手术间接减压失败的独立影响因素.ROC曲线分析得出:①术前硬膜囊CSA的最佳截断值是 47.3 mm2,敏感度为 90.7%,特异度为 82.9%,AUC =0.869;②术前融合器位置的最佳截断值是4.8,敏感度为61.8%,特异度为 82.3%,AUC =0.757.结论 OLIF手术是治疗LSS有效的间接减压术式,术中将融合器后置可获得更理想的减压效果;但对于术前硬膜囊CSA<47.3 mm2 的节段,可能不适合间接减压术式.融合器高度与OLIF手术的减压效果有关,但并不是独立影响因素.
Objective To explore the influence of the height and position of the fusion cage on the indirect decompression effect of OLIF operation,and analyze the influencing factors for indirect decompression failure after OLIF operation.Methods The clinical da-ta of 103 patients with LSS who underwent OLIF from March 2019 to March 22 in our department were analyzed retrospectively.There were 157 surgical segments,including21 L2-3 segments,54 L3-4 segments,and 82 L4-5 segments;among them,63 cases underwent single-segment surgery,26 cases underwent two-stage surgery,and 14 cases underwent three-segment surgery.According to the X-ray film and MRI examination data before and after the operation,the following imaging indexes were measured:dural sac diameter,spinal canal diameter,cross sectional area of dural sac(CSA),spinal canal CSA,left and right subarticular diameter,left and right ligamen-tum flavum thickness and area,diameter of disc protrusion,disc height,segmental protrusion angle,intervertebral foramen height and intervertebral foramen area,etc.The influence of the height and placement position of the fuse on the above indicators was analyzed.All patients were followed up for more than six months to observe the incidence of indirect decompression failure within six months and analyze its influencing factors.Results Altogether 103 patients successfully completed OLIF surgery,and compared with preopera-tion,the pain VAS score of patients six months after surgery showed significant improvement(P<0.001).Afterthe placementofafu-sion cage with a height of 14 mm(n =18),the improvement in indicators such as dural sac diameter,right ligamentum flavum thick-ness,and intervertebral disc protrusion diameter was significantly greater than that of fusion cages with a height of 10 mm(n =9)and 12mm(n =76)(P<0.05).In terms of the position of fusion cage,the anterior position of fusion cage(n =48)could obtain better correction effect on segmental lordosis(P =0.041);however,the posterior placement of the fusion cage(n =109)could achieve a higher correction effect on the posterior edge height of the interverte-bral disc(P=0.018);at the same time,it could achieve a better effect on the left and right lower joint diameters(P=0.005,P= 0.019),and the thickness of the right ligamentum flavum was also significantly reduced(P=0.023).Multivariate logistic regression analysis showed that preoperative dural sac CSA(OR=0.952)and fusion cage position(OR =0.276)were independent influencing factors for indirect decompression failure in OLIF surgery.The ROC curve analysis showed that:① the best cutoff value of dural sac CSA before operation was 47.3 mm2,the sensitivity was 90.7%,the specificity was 82.9%,and AUC =0.869;② The best cutoff value of fusion cage position before operation was 4.8,sensitivity was 61.8%,specificity was 82.3%,and AUC =0.757.Conclusion OLIF operation is an effective indirect decompression operation for LSS,and the posterior placement of fusion cage can achieve better decompression effect.However,for the segment with dural sac CSA<47.3 mm2 before operation,indirect decompression may not be suitable.The fusor height is related to the decompression effect of olif surgery,but is not an independent influencing factor for decom-pression failure.