Lateral access techniques for degenerative conditions of the spine

Operative approaches for degenerative conditions of the spine include traditional posterior approaches and a newer generation of lateral approaches. These operative corridors have their roots in anterior lumbar fusion and modifications have evolved to include lateral and oblique lumbar interbody fusion. The principal advantages of lateral approaches are that they are minimally invasive, less disruptive, and provide greater access to the disc space, thus allowing for larger cage placement and theoretically greater indirect foraminal decompression with lower rates of subsidence. We describe the anterior, lateral, and oblique lumbar interbody fusion approaches, with particular emphasis on surgical techniques and complications.     

Minimally invasive lumbar spinal fusion

Minimally invasive techniques for lumbar spine fusion have been developed in an attempt to decrease the complications related to traditional open exposures (eg, infection, wound healing problems). Anterior minimally invasive procedures include laparoscopic and mini-open anterior lumbar interbody fusion as well as the lateral transpsoas and percutaneous presacral approaches. Posterior techniques typically use a tubular retractor system that avoids the muscle stripping associated with open procedures. These techniques can be applied to both posterior and transforaminal lumbar interbody fusion procedures. Many initial reports have shown similar clinical results in terms of spinal fusion rates for both traditional open and minimally invasive posterior approaches. However, the anterior minimally invasive procedures are often associated with significantly greater incidence of complications and technical difficulty than their associated open approaches. There is a steep learning curve associated with minimally invasive techniques, and surgeons should not expect to master them in the first several cases.     

The ALIF concept

The terms ‘minimally invasive’ or ‘less invasive surgery’ have been used recently to describe surgical approaches or operations that are performed with less trauma to anatomical structures on the way to or surrounding the surgical ‘target area’. These types of surgical procedures are usually performed with the help of ‘high-tech’ instruments such as surgical endoscopes or surgical microscopes, modern video techniques and automated instruments. Within the last 10 years, such techniques have been developed in the field of spinal surgery. The application of minimally or less invasive procedures has concentrated predominantly on anterior approaches to the thoracic and lumbar spine. This article describes two anterior approach techniques for performing anterior lumbar interbody fusion (ALIF) through a minimally invasive retroperitoneal or transperitoneal approach. The technical principles are microsurgical modifications of traditional anterior approaches to the lumbar spine. Through small (4-cm) skin incisions, the target area can be exposed. Preliminary results suggest decreased peri - and postoperative morbidity, less blood loss, earlier rehabilitation and acceptable complication rates. The technique is currently used by the author for all patients requiring anterior lumbar interbody fusion.     

Comparison of open and minimally invasive techniques for posterior lumbar instrumentation and fusion after open anterior lumbar interbody fusion

Background contextMinimally invasive techniques for spinal fusion have theoretical advantages for the reduction of iatrogenic injury. Although this topic has been investigated previously for posterior-only interbody surgery, such as transforaminal lumbar interbody fusion, similar studies have not evaluated these techniques after anteroposterior spinal fusion, a study design that can more accurately determine the effect of pedicle screw placement and decompression via a minimally invasive technique without the confounding effect of simultaneous interbody cage placement.PurposeTo compare process measures that provide insight into the morbidity of surgery, such as surgical time and the length of postoperative hospital stay between open and minimally invasive anteroposterior lumbar fusion; and to compare the complications during the intraoperative and early postoperative period between open and minimally invasive anteroposterior lumbar fusion.Study designRetrospective case-control study.Patient sampleOne hundred sixty-two patients.Outcome measuresEstimated blood loss, length of surgery, intraoperative fluoroscopy time, length of postoperative hospital stay, malpositioned instrumentation on postoperative imaging, and postoperative complications, including pulmonary embolus and surgical site infection.MethodsPatients who underwent open anterior lumbar interbody fusion followed by either traditional open posterior fusion (Open group) or minimally invasive posterior fusion (minimally invasive surgery [MIS] group) were matched by the number of surgical levels. A chart review was performed to document the intraoperative and postoperative process measures and associated complications in the two groups. Secondary analyses were performed to compare the subgroups of patients, who did and did not undergo a posterior decompression at the time of posterior instrumentation to determine the effect of decompression.ResultsBaseline characteristics were similar between the Open and MIS groups. Estimated blood loss and postoperative transfusion rate were significantly higher in the Open group, differences that the subanalyses suggested were largely because of those patients who underwent concomitant decompression. Length of stay was not significantly different between the groups but was significantly shorter for MIS patients treated without decompression than for Open patients treated without decompression. Intraoperative fluoroscopy time was significantly longer in the MIS group. There was no difference in the infection or complication rates between the groups.ConclusionsOur case-control study comparing patients who underwent anterior lumbar interbody fusion followed by open posterior instrumentation with those who underwent anterior lumbar interbody fusion followed by minimally invasive posterior instrumentation demonstrated that patients undergoing MIS fusion without decompression had less blood loss, less need for transfusion in the perioperative period, and a shorter hospital stay. In contrast, most outcome measures were similar between MIS and Open groups for patients who underwent decompression.     

The ALIF concept

The terms 'minimally invasive' or 'less invasive surgery' have been used recently to describe surgical approaches or operations that are performed with less trauma to anatomical structures on the way to or surrounding the surgical 'target area'. These types of surgical procedures are usually performed with the help of 'high-tech' instruments such as surgical endoscopes or surgical microscopes, modern video techniques and automated instruments. Within the last 10 years, such techniques have been developed in the field of spinal surgery. The application of minimally or less invasive procedures has concentrated predominantly on anterior approaches to the thoracic and lumbar spine. This article describes two anterior approach techniques for performing anterior lumbar interbody fusion (ALIF) through a minimally invasive retroperitoneal or transperitoneal approach. The technical principles are microsurgical modifications of traditional anterior approaches to the lumbar spine. Through small (4-cm) skin incisions, the target area can be exposed. Preliminary results suggest decreased peri - and postoperative morbidity, less blood loss, earlier rehabilitation and acceptable complication rates. The technique is currently used by the author for all patients requiring anterior lumbar interbody fusion.     

后路微创化技术治疗下腰椎退变性疾病

目的介绍两种微创手术,通过减压和椎体间融合治疗部分下腰椎退变性疾病,总结该技术相对于传统开放术的利弊。方法 (1)经皮椎弓根螺钉植入+小切口椎板开窗或椎间盘镜下开窗减压,椎间植骨融合术,共9例;(2)小切口棘旁两侧分次有限暴露固定并减压椎间植骨融合术,共38例。所有病例分别于术后3、6、12个月得到随访。结果本组与传统术式相比,手术时间、出血量及骨性融合率都无显著性差异,但融合病发生率显著降低,术后开始训练时间显著提早。结论微创化术式可减少局部创伤,提早康复锻炼,降低融合病发生率。     

L’arthrodèse mini-invasive dans le traitement chirurgical des pathologies rachidiennes dégénératives

Background and purpose

As in many other surgical fields, new minimally invasive techniques have been developed over the past 20 years, with reducing the muscular trauma associated with the traditional surgical approach and reducing related morbidity as the main goals. Initially limited to the laparoscopic or video-assisted approaches of the anterior spine, these techniques have been extended to the posterior transmuscular access of the lumbar spine. This article reviews the value of these approaches in the treatment of degenerative lumbar spine disorders.

Methods

We describe the main techniques used in minimally invasive lumbar spine surgery, including posterior pedicle screwing as well as anterior (ALIF), posterior (PLIF), transforaminal (TLIF), extreme lateral (XLIf), and presacral (AxiaLIF) interbody fusion. The results of recently published series are reported.

Results

Percutaneous pedicle screwing is reported to be an effective technique of lumbar spine arthrodesis associated with a low rate of screw misplacement. Minimally invasive PLIF, TLIF, and ALIF have been associated with shorter mean operative time, less postoperative pain, reduction of the estimated blood loss, a shorter hospital stay, and quicker functional recovery. Despite these encouraging early clinical results, no prospective, randomized published scientific study has proved that minimally invasive techniques are better than standard techniques. Larger clinical series with a longer follow-up could fill this gap.     

Minimally invasive transforaminal lumbar interbody fusion — A narrative review on the present status

Minimally invasive lumbar transforaminal interbody fusion (MIS TLIF) has become the most commonly performed lumbar fusion procedure. There are multiple variables such as bone graft properties, use of rhBMP (recombinant human bone morphogenic protein), interbody cage properties, image guidance techniques, etc., that may impact the outcomes and fusion rates. Radiation exposure to the patient as well as to the operating team is an important concern. The minimally invasive anterior approaches for lumbar fusion with ability to insert larger cages and achieve better sagittal correction have added another option in management of lumbar degenerative deformities. A literature review of recent studies and systematic reviews on different aspects impacting the outcomes of MIS TLIF has been done to define the present status of the procedure in this narrative review. Iliac crest bone graft can help achieve very good fusion rate without significantly increasing the morbidity. RhBMP is most potent enhancer of fusion and the adverse effects can be avoided by surgical technique and using lower dose. The use of navigation techniques has reduced the radiation exposure to patient and the surgeons but the benefit seems to be significant only in long segment fusions.     

Lateral lumbar interbody fusion via a unilateral true percutaneous approach associated with minimally invasive pedicle screw fixation for degenerative disc disease and lumbar instability. A technical note

In recent years, minimally invasive surgical techniques for lumbar fusion and fixation procedures gained worldwide popularity. Herein we describe a personal technique for percutaneous lumbar interbody fusion associated with minimally invasive posterior fixation for patients affected by degenerative disc disease and lumbar instability. The procedure is described in a step-by-step way and early results are presented. Although the present data reflect only an early experience, we believe that this is a straightforward procedure which may be more advantageous in terms of surgical invasiveness, potentially saving operative and recovery time and reducing risks compared to posterior or anterior approaches for lumbar interbody fusion.     

退变性腰椎管狭窄症的微创治疗策略顾广飞贺石生张海龙顾昕张立国丁悦

 目的 探讨退变性腰椎管狭窄症的微创治疗策略。方法 回顾性分析 2008年 3月至 2010年 8月采用微创手术治疗的 73例腰椎管狭窄症患者, 根据患者的临床、影像学表现及是否合并其它脊柱疾病进行分类, 对不同类型病变采取不同的微创手术方式, 分别统计手术时间、出血量、手术并发症及术前、术后 6个月和末次随访时日本矫形外科学会(Japanese Orthopaedic Association, JOA)评分及 Oswestry功能障碍指数(Oswestry disability index, ODI), 根据 JOA评价标准对手术疗效进行评价。结果 73例微创手术均顺利完成。 25例患者采用双侧减压方法, 48例患者采用单侧入路潜行双侧减压; 23例患者在减压的同时进行椎间融合加经皮内固定手术。手术时间、术中出血量与减压方式及是否行椎间融合内固定相关。术中硬膜囊撕裂 1例;1例骨质疏松患者行椎间融合时融合器打入上位椎体中, 取出融合器, 予椎体间植骨融合;术后出现切口愈合不良 3例, 考虑与术中微创可扩张通道撑开过紧有关, 予抗炎及换药后切口愈合。术后随访 10~35个月, 平均 13个月。患者术前及术后 6个月的 JOA评分和 ODI明显改善, 差异有统计学意义(P< 0.01)。 23例行椎间融合及内固定患者, 22例患者获得满意融合, 无螺钉断裂及松动发生。结论 微创手术治疗腰椎管狭窄症疗效肯定, 但应根据腰椎管狭窄症患者的临床、影像学表现、合并疾患及术者的临床经验和医院的具体条件来选择合适的手术方式。     

Emerging directions in motion preservation spinal surgery

In this review, we focus on novel surgical techniques and spinal arthroplasty systems inactive development. First, we discuss systems that allow for minimally invasive approaches to the lumbar disc space: (1) lateral approaches, (2) posterior approaches,and (3) oblique approaches. These techniques offer the potential for a minimally invasive lumbar arthroplasty system. Second, we discuss novel facet replacement technology. The facet joints, with the intervertebral disc, comprise the three-joint complex of the spinal unit. Facet joint health is thus crucial to proper disc biomechanics and function. Finally,we discuss dynamic neutralization of the lumbar spine with an artificial posterior tension band device. This allows for a certain degree of immobilization without fusion. Minimally invasive surgical approaches, facet arthroplasty, and posterior tension band devices may be the future of motion preservation spinal surgery.     

微创通道结合经皮椎弓根螺钉固定治疗腰椎退变的个体化方案选择

目的探讨应用微创通道减压融合结合经皮椎弓根螺钉固定治疗腰椎退行性疾病的初步临床效果及手术方案选择。方法收集2009年8月至2011年7月第四军医大学唐都医院运用微创通道减压融合结合经皮椎弓根螺钉固定治疗并获得随访的64例腰椎退变患者的临床资料。采用Quadrant、Pipeline或Luxor通道系统,经椎间孔腰椎间融合（TLIF）或后路TLIF（PTLIF）入路,行髓核摘除或椎间处理并植入椎间融合器,通道内行椎弓根螺钉固定并安装连接棒。于对侧相应椎体处行椎弓根经皮植入Sextant、vipor或Mantis螺钉固定。微创策略的选择：（1）单侧通道下减压椎间植骨融合,常规椎弓螺钉内固定;（2）一侧通道下减压植骨融合通用螺钉固定 ＋ 对侧通道下通用螺钉固定;（3）一侧通道下减压植骨融合通用螺钉固定 ＋ 对侧经皮螺钉固定;（4）一侧通道下减压椎间植骨融合＋双侧经皮螺钉固定。融合方式包括单节段融合、双节段融合和跨节段融合。观察患者术中出血量、手术时间、术后下床活动时间、住院天数、内固定位置以及术后症状改善情况。结果随访3～22 个月（平均 16 个月）。术中出血量 70～230 mL（平均 90 mL）、手术时间 70～210 min（平均 100 min）、下床活动时间为术后3～10 d（平均5 d）、住院天数5～15 d（平均7 d）。腰痛视觉模拟评分（VAS）和腿痛VAS分别由术前的（9.2 ± 1.4）分和（7.4 ± 1.2）分减少到末次随访的（2.6 ± 0.5）分和（2.2 ± 0.6）分,Oswestry功能障碍指数（ODI）由术前的（57.4 ± 6.4）%降至末次随访的（25.8 ± 4.3）%,差异均有统计学意义（P 〈0.05）。术中、术后X线片和/或 CT 检查显示内固定及融合器位置良好。结论一侧采用微创通道 TLIF 或 PTLIF 入路行单节段或双节段椎间处理融合,或在此基础上行对侧通道下通用螺钉/经皮椎弓根螺钉固定或双侧经皮螺钉固定等个体化方案治疗腰椎退行性疾病,术中出血少,手术时间短,术后可早期下床进行功能锻炼,初步临床效果优良。     

Minimally invasive 360° instrumented lumbar fusion

A retrospective preliminary study was undertaken of combined minimally invasive instrumented lumbar fusion utilizing the BERG (balloon-assisted endoscopic retroperitoneal gasless) approach ¶anteriorly, and a posterior small-incision approach with translaminar screw fixation and posterolateral ¶fusion. The study aimed to quantify the clinical and radiological results using this combined technique. The traditional minimally invasive approach to the anterior lumbar spine involves gas insufflation and provides reliable access only to L5-S1 and in some cases L4-5. A gas-mediated approach yields many technical drawbacks to performing spinal surgery. A minimally invasive posterior approach involving suprafascial pedicle screw instrumentation has been developed, but without widespread use. Translaminar facet fixation may be a viable alternative to transpedicular fixation in a 360° instrumented fusion model. Past studies have shown open 360° instrumented lumbar fusion yields high arthrodesis rates. The study examined the cases of 46 patients who underwent successful 360° instrumented lumbar fusion using a combined minimally invasive approach. Anterior lumbar interbody fusion (ALIF) at one or two levels was performed through the BERG approach; a gasless retroperitoneal approach to the lumbar spine allowing the use ¶of standard anterior instrumentation. Posteriorly, all patients underwent successful decompression, translaminar fixation, and posterolateral fusion at one or two levels through ¶one small (2.5-5.0 cm) incision. Results showed mean hospital stay of 2.02 days; mean combined blood loss was 255 cc; and mean pain relief was 56%, with 75.5% of patients reporting good, excellent, or total pain relief. Forty-two of 46 patients (93.2%) achieved a solid fusion ¶24 months after surgery. A total of 47% of all patients working prior to surgery returned to work following surgery. The study showed that minimally invasive 360° instrumented lumbar fusion, when performed utilizing these approaches, yields a high rate of solid arthrodesis (93.3%), good pain relief, short hospital stays, low blood losses, accelerated rehabilitation, and a quick return to the workforce. The BERG approach offers technical advantages over the traditional gas-mediated laparoscopic approach to the anterior lumbar spine.     

Minimally invasive 360° instrumented lumbar fusion

A retrospective preliminary study was undertaken of combined minimally invasive instrumented lumbar fusion utilizing the BERG (balloon-assisted endoscopic retroperitoneal gasless) approach ¶anteriorly, and a posterior small-incision approach with translaminar screw fixation and posterolateral ¶fusion. The study aimed to quantify the clinical and radiological results using this combined technique. The traditional minimally invasive approach to the anterior lumbar spine involves gas insufflation and provides reliable access only to L5-S1 and in some cases L4-5. A gas-mediated approach yields many technical drawbacks to performing spinal surgery. A minimally invasive posterior approach involving suprafascial pedicle screw instrumentation has been developed, but without widespread use. Translaminar facet fixation may be a viable alternative to transpedicular fixation in a 360° instrumented fusion model. Past studies have shown open 360° instrumented lumbar fusion yields high arthrodesis rates. The study examined the cases of 46 patients who underwent successful 360° instrumented lumbar fusion using a combined minimally invasive approach. Anterior lumbar interbody fusion (ALIF) at one or two levels was performed through the BERG approach; a gasless retroperitoneal approach to the lumbar spine allowing the use ¶of standard anterior instrumentation. Posteriorly, all patients underwent successful decompression, translaminar fixation, and posterolateral fusion at one or two levels through ¶one small (2.5–5.0 cm) incision. Results showed mean hospital stay of 2.02 days; mean combined blood loss was 255 cc; and mean pain relief was 56%, with 75.5% of patients reporting good, excellent, or total pain relief. Forty-two of 46 patients (93.2%) achieved a solid fusion ¶24 months after surgery. A total of 47% of all patients working prior to surgery returned to work following surgery. The study showed that minimally invasive 360° instrumented lumbar fusion, when performed utilizing these approaches, yields a high rate of solid arthrodesis (93.3%), good pain relief, short hospital stays, low blood losses, accelerated rehabilitation, and a quick return to the workforce. The BERG approach offers technical advantages over the traditional gas-mediated laparoscopic approach to the anterior lumbar spine.     

椎间融合器在椎管狭窄治疗中的应用及生物力学评价

目的：报道应用椎间融合器经后路减压椎间融合术（Posterior Lumbar Interbody Fusion,PLIF)治疗腰椎管狭窄症的临床效果，并对该术进行生物力学评价。方法：采用后路扩大减压，单椎间盘摘除，椎间融合器植入，治疗严重腰椎管狭窄症37例。实验研究中，取6具新鲜尸体标本的L2－S1节段制作脊柱功能单位（Functional Spinal Unit,FSU)进行生物力学稳定性测试。结果：术后对其中33例患者进行平均1年的随访，优良率90．8％，X线评价椎体间骨融合率达94．8％，无严重并发症出现，生物力学结果表明，全椎板扩大减压导致椎节失稳，椎间融合器或椎弓根钉的使用可恢复节段稳定性。结论：临床实践和生物力学实验均表明，椎间融合器在严重椎管狭窄症手术治疗中的应用是一种安全有效的方法，具有重建脊柱稳定性，恢复椎间隙和神经根管高度和增加椎间融合率等优势。     

Thorakolumbale Frakturen

The article outlines the current knowledge about minimally invasive anterior surgery for stabilization of thoracolumbar fractures. With the use of minimally invasive or endoscopic techniques, all areas of the thoracolumbar spine can be addressed surgically with outcomes comparable to those with standard open procedures. Thoracoscopic and thoracoscopic-assisted surgery are well-proven methods for treating the spine from T4 to L2. Typically, an incision of the diaphragm is necessary to reach the spine below T12. Additionally, the lumbar spine can be reached using minimally invasive retroperitoneal approaches. Laparoscopic and retroperitoneoscopic approaches have shown no advantages. Minimally invasive surgery reduces postoperative pain and improves cosmetic results compared with open procedures; however, the total complication rate has not been significantly reduced so far. Minimally invasive anterior stabilization of thoracolumbar fractures is safe and effective. Full endoscopic techniques have no advantages compared with endoscopic-assisted approaches.     

显微内镜辅助经皮微创椎间孑L入路腰椎椎体间融合术治疗腰椎退行性疾病

背景：传统开放椎间孔入路腰椎椎体间融合术（transforaminal lumbar interbody fusion,TLIF）由于剥离肌肉广泛及长时间牵拉,可导致部分患者持续性腰背痛。随着脊柱微创技术的发展,采用微创手段实施TLIF技术取得了良好的临床效果,但小切口经扩张通道系统的微创TLIF仍不可避免存在肌肉剥离,需探索更加微创的手术方式。 目的：探讨显微内镜辅助经皮微创TLIF治疗腰椎退行性疾病的近期疗效及安全性。 方法：2010年9月至2011年7月,72例腰椎退行性疾病患者接受了单节段TLIF手术,腰椎失稳症36例,腰椎管狭窄症25例,复发型腰椎间盘突出症11例。采用VIPER经皮椎弓根螺钉系统结合椎间盘镜下TLIF手术32例（微创组）,传统开放TLIF手术40例（开放组）,对两组患者近期临床疗效、并发症、术中射线暴露指标等进行比较。 结果：所有患者均获随访,随访时间6-15个月,平均9个月。两组手术时间无明显统计学差异（P〉0．05）,微创组术中出血量、伤口引流量、住院天数、术后应用镇痛药剂量均明显低于开放组（P〈0．01）;微创组术中射线暴露时间及剂量高于开放组（P〈0．01）;微创组术后疼痛（VAS评分）及ODI功能指数较开放组明显降低（P〈0．01）。微创组出现术中减压错误1例,置钉位置错误1例,导针穿透椎体前壁1例,硬膜撕裂1例;开放组出现术中硬膜撕裂3例,术后伤口浅表感染1例。两组患者均未出现神经损伤并发症。 结论：显微内镜辅助经皮微创TLIF较传统开放手术具有创伤小、出血少、恢复快、住院时间短等优点,具有良好的近期疗效,是治疗腰椎失稳症值得推荐的微创手术方式。     

Intervertebral Fusion with Mobile Microendoscopic Discectomy for Lumbar Degenerative Disc Disease

The aim of this article is to introduce a technique for lumbar intervertebral fusion that incorporates mobile microendoscopic discectomy (MMED) for lumbar degenerative disc disease. Minimally invasive transforaminal lumbar interbody fusion is frequently performed to treat degenerative diseases of the lumbar spine; however, the scope of such surgery and vision is limited by what the naked eye can see through the expanding channel system. To expand the visual scope and reduce trauma, we perform lumbar intervertebral fusion with the aid of a MMED system that provides a wide field through freely tilting the surgical instrument and canals. We believe that this technique is a good option for treating lumbar degenerative disc disease that requires lumbar intervertebral fusion.