Gragnaniello Cristian, Seex Kevin
Department of Neurosurgery, George Washington University, Washington, DC, USA.
Neurosurgery Department, Macquarie University, Sydney, Australia.
J Spine Surg. 2016 Dec;2(4):256-265. doi: 10.21037/jss.2016.11.02.
Lateral interbody cages have been proven useful in spinal fusions. Spanning both lateral cortical rims while sparing the Anterior Longitudinal Ligament, the lateral interbody cages restore and maintain disc height while adding stability prior to supplemental fixation. The standard approach for their insertion is by a 90-degree lateral transpsoas method. This is relatively bloodless compared to other techniques although has its limitations, requiring neuro-monitoring and being, at times, very difficult at L4/5 due to iliac crest obstruction or an anterior plexus position. An oblique approach, with the patient in lateral decubitus, passes anterior to the iliac crest, retroperitoneal, and being anterior to psoas, eliminates the need for neuro-monitoring.
Twenty-one consecutive patients underwent surgery for a total of 32 levels instrumented with the ATP technique. Mean age at the time of surgery was 62.4±7.4 years. There was a 6 months minimum clinical follow up, with imaging to assess fusion, at 6 and 12 months. Indications included symptomatic degenerative lumbar spondylosis +/- spondylolisthesis, leg and back pain. All patients were assessed with the Oswestry Disability Index (ODI), Visual Analog Scale 100 mm for back pain (VASb) and for leg pain (VASl) preoperatively, at 3, 6 and 12 months. Last follow-up was at 12 months for 9 patients and the rest had 6 months follow up.
Statistical analysis showed significance for the results in ODI, VASb and VASl with improvement in all components except for one patient with worsening VASl. Eight patients had complications related to surgery which were still present at last follow-up including moderate weakness of hip flexion and EHL weakness. Lateral cutaneous nerve (LCN) palsy on the side of the approach was also seen as well as sympathectomy effect related to the mobilization of the sympathetic trunk. One patient, who also suffered from multiple sclerosis, experienced psoas abscess 3 months post op that required drainage.
The left sided anterior to psoas approach offers the most natural corridor to the disc space. The novel instruments and method described here allows insertion of large lateral cages between L2 to L5, without the problems associated with the transpsoas approach, particularly at L4/5.
外侧椎间融合器已被证明在脊柱融合手术中很有用。外侧椎间融合器跨越两侧皮质骨边缘，同时保留前纵韧带，可恢复并维持椎间盘高度，在补充固定之前增加稳定性。其标准植入方法是经腰大肌90度外侧入路。与其他技术相比，这种方法出血相对较少，尽管有其局限性，需要神经监测，并且在L4/5节段有时因髂嵴阻挡或前丛位置而非常困难。一种斜行入路，患者取侧卧位，经髂嵴前方、腹膜后且在腰大肌前方，无需神经监测。
21例连续患者接受了手术，共32个节段采用ATP技术进行器械植入。手术时的平均年龄为62.4±7.4岁。至少有6个月的临床随访，并在6个月和12个月时进行影像学检查以评估融合情况。手术指征包括有症状的退行性腰椎滑脱症+/-椎体滑脱、腿痛和背痛。所有患者术前、术后3个月、6个月和12个月均采用Oswestry功能障碍指数（ODI）、100mm视觉模拟量表评估背痛（VASb）和腿痛（VASl）。9例患者的末次随访时间为12个月，其余患者随访6个月。
统计分析显示ODI、VASb和VASl结果有显著意义，除1例患者VASl恶化外，所有指标均有改善。8例患者有与手术相关的并发症，在末次随访时仍然存在，包括中度髋关节屈曲无力和拇长伸肌无力。还可见手术侧的外侧皮神经（LCN）麻痹以及与交感干松解相关的交感神经切除效应。1例同时患有多发性硬化症的患者术后3个月出现腰大肌脓肿，需要引流。
腰大肌前方左侧入路为椎间盘间隙提供了最自然的通道。本文所述的新型器械和方法允许在L2至L5之间植入大型外侧融合器，而没有经腰大肌入路相关的问题，尤其是在L4/5节段。
