后路椎体间融合术后融合器脱出的原因及其翻修术

The revision of the failed posterior lumbar interbody fusion

目的:探讨后路椎体间融合术后融合器脱出的原因及其翻修方法。方法:10例后路椎体间融合术后融合器脱出行翻修术的病例,其中腰椎滑脱症5例,腰椎管狭窄症3例,腰椎间盘突出症2例。手术节段为L4/54例,L5/S13例,L4/5+L5/S13例;融合器应用BAK(旋入型)7例,聚醚醚酮矩形融合器(PEEK)2例,钛金属矩形融合器1例。于首次术后1～90d内行翻修术。就其脱出原因、再次手术方法及疗效进行分析。结果:融合器脱出的原因:矩形融合器中2例型号太小,1例放置位置偏后;旋入型融合器1例定位错误,其余大都因两枚融合器之间发生碰撞挤压所致。翻修术后获得完整随访资料者8例,随访时间10～36个月,平均17个月,均得到融合,无融合器再次移位或脱出以及内固定的断裂,1例伴有足下垂者遗留患足背伸肌力减弱,其余病例神经症状消除。结论:后路腰椎椎体间融合术后融合器脱出的可能原因有融合器型号偏小导致椎间隙撑开不够,放置位置偏后,两枚融合器不对称或距离太近发生碰撞等。早期、积极的手术翻修能取得较好的疗效。

Objective：To analyse the reasons that contribute to the migration of intertbody cages after posterior lumbar interbody fusion and study the revision strategies.Method：10 patients who experienced the failure of posterior lumbar interbody fusion and underwent surgical correction were reviewed.2 males and 8 females with an average age of 51.5 years were included.The primal diagnoses were disc herniation in 2,lumbar spinal stenosis in 3,and spondylolisthesis in 5,the fused segments were L4/5 in 4,L5/S1 in 3 and L4/5 plus L5/S1 in 3.Three kinds of fusion cages including BAK, PEEK and titanium rectangular cage were used.The average length of time before revision surgery was 39 days （range from 1 to 90 days）Result：The reasons of migration were inadequate size or insufficient depth of insertion in anatomic cage and the collision of two cages in threaded cage.Among those patients,8 cases were followed up from 10 to 36 months with an average of 17 months,they all gained the solid fusion.No cage displacement or the failure of the internal fixation was observed.All the neurological deficits were recovered except 1 case suffered from mild dropping foot.Conclusion：The factors associated with failure of the original insertion procedure may fail to achieve adequate distraction of the interbody space by using undersized cages,be insufficient depth of the cage insertion into the disc space and inadequate placement of 2 cages.Early and positive revision procedure can lead to satisfactory clinical outcome.