Invasive Lateral Lumbar Interbody Fusion Research Articles

Minimally Invasive Lateral Lumbar Interbody Fusion for Adult Spinal Deformity: Clinical and Radiological Efficacy With Minimum Two Years Follow-up.

A retrospective cohort study. To evaluate the clinical and radiological efficacies of supplementing minimally invasive lateral lumbar interbody fusion (LLIF) with open posterior spinal fusion (PSF) in adult spinal deformity (ASD). Minimally invasive techniques have been increasingly applied for surgery of ASD. Few reports have been published that directly compare LLIF combined with PSF to conventional PSF for ASD. To evaluate the advantages of minimally invasive LLIF for ASD, patients who underwent minimally invasive LLIF followed by open PSF (combined group) were compared with patients who only underwent PSF (only PSF group). The clinical and radiological outcomes for deformity correction and indirect decompression were assessed. The occurrence of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) were also evaluated. No significant differences were observed in the clinical outcomes of the Oswestry Disability Index (ODI), visual analog scale, and major complications including reoperations between the groups. No additional advantage was found for coronal deformity correction, but the restoration of lumbar lordosis in the combined group was significantly higher postoperatively (15.3° vs. 8.87°, P = 0.003) and last follow-up (6.69° vs. 1.02°, P = 0.029) compared to that of the only PSF group. In the subgroup analysis for indirect decompression for the combined group, a significant increase of canal area (104 vs. 122 mm) and foraminal height (16.2 vs. 18.5 mm) was noted. The occurrence of PJK or PJF was significantly higher in the combined group than in the only PSF group (P = 0.039). LLIF has advantages of indirect decompression and greater improvements of sagittal correction compared to only posterior surgery. LLIF should be conducted considering the above-mentioned benefits and complications including PJK or PJF in ASD. 4.

Does the Access Angle Change the Risk of Approach-Related Complications in Minimally Invasive Lateral Lumbar Interbody Fusion? An MRI Study.

ObjectiveTo investigate the potential risk of approach-related complications at different access angles in minimally invasive lateral lumbar interbody fusion. MethodsEighty-six axial magnetic resonance images were obtained to analyze the risk of approach-related complications. The access corridor were simulated at different access angles and the potential risk of neurovascular structure injury was evaluated when the access corridor touching or overlapping the corresponding structures at each angle. Furthermore, the safe corridor length was measured when the corridor width was 18 and 22 mm. ResultsWhen access angle was 0°, the potential risk of ipsilateral nerve roots injury was 54.7% at L4–L5. When access angle was 45°, the potential risk of abdominal aorta, contralateral nerve roots or central canal injury at L4–L5 was 79.1%, 74.4%, and 30.2%, respectively. The length of the 18 mm-wide access corridor was largest at 0° and it could reach 44.5 mm at L3–L4 and 46.4 mm at L4–L5. While the length of the 22 mm-wide access corridor was 42.3 mm at L3–L4 and 44.1 mm at L4–L5 at 0°. ConclusionChanges in the access angle would not only affect the ipsilateral neurovascular structures, but also might adversely influence the contralateral neural elements. It should be also noted to surgeons that alteration of the access angle changed the corridor length.

Analysis of Intraoperative Cone-Beam Computed Tomography Combined With Image Guidance for Lateral Lumbar Interbody Fusion.

Minimally invasive lateral lumbar interbody fusion (LLIF) is traditionally performed with biplanar fluoroscopy. Recent literature demonstrates that intraoperative cone-beam computed tomography combined with spinal navigation can be safely utilized for localization and cage placement in LLIF. To evaluate the accuracy and safety of cage placement using spinal navigation in LLIF, as well as to evaluate the radiation exposure to surgeon and staff during the procedure. The authors performed a retrospective analysis of a prospectively acquired database of patients undergoing LLIF with image-based navigation performed from April 2014 to July 2016 at a single institution. The medical records were reviewed, and data on clinical outcomes, cage accuracy, complications, and radiation exposure were recorded. All patients underwent a minimum 30-d clinical follow-up to assess intraoperative and short-term complications associated with their LLIF. Sixty-three patients comprising 117 spinal levels were included in the study. There were 36 (57.1%) female and 27 (42.9%) male patients. Mean age was 62.7 yr (range 24-79 yr). A mean 1.9 (range 1-4) levels per patient were treated. Cages were placed in the anterior or middle of 115 (98.3%) disc spaces. Image-guided cage trajectory was accurate in 116/117 levels (99.1%). In a subgroup analysis of 18 patients, mean fluoroscopy time was 11.7 ± 9.7 s per level. Sixteen (25.4%) patients experienced a complication related to approach. Use of intraoperative cone-beam computed tomography combined with spinal navigation for LLIF results in accurate and safe cage placement as well as significantly decreased surgeon and staff radiation exposure.

Clinical and radiographic analysis of expandable versus static lateral lumbar interbody fusion devices with two-year follow-up.

Utilization of static and expandable interbody spacers for minimally invasive lateral lumbar interbody fusion (LLIF) offers favorable clinical results. However, complications such as implant migration and/or subsidence may occur with a static implant. Expandable devices allow for in situ expansion to optimize fit and mitigate iatrogenic endplate damage during trialing and impaction. This study sought to compare clinical and radiographic outcomes of static and expandable spacers following LLIF and report device-related complications. This study included 29 patients who underwent LLIF with a static spacer and 27 with an expandable spacer; all procedures were combined with supplemental transpedicular posterior fixation. Patient self-assessment forms and radiographic records were used to assess clinical and radiologic outcomes. Mean patient age was 62.3±10.3 years (64% female). One-level surgery was performed in 87.5% of patients, and 12.5% underwent two-level surgery. Results showed no significant differences in blood loss or length of hospital stay (P>0.05). However, operative times differed statistically between static (63.3±37.8 min) and expandable (120.2±59.6 min) groups (P=0.000). Mean visual analog scale (VAS) and Oswestry Disability Index (ODI) scores improved significantly from preoperative to 24-month follow-up in both groups (P<0.05). Preoperative intervertebral and neuroforaminal height increased significantly in both groups (P<0.01). Fusion was observed in all operative levels in the static and expandable spacer groups by 24-month follow-up. Implant subsidence was reported in 16.1% of static levels and none of the expandable levels (P<0.01). Postoperative radiographs showed no evidence of implant migration, and no cases required surgical revision at the index or adjacent levels. LLIF using expandable spacers resulted in similar clinical and radiographic outcomes when compared with using static spacers, and led to a lower subsidence rate.

Clinical and radiographic analysis of expandable versus static lateral lumbar interbody fusion devices with two-year follow-up

Background: Utilization of static and expandable interbody spacers for minimally invasive lateral lumbar interbody fusion (LLIF) offers favorable clinical results. However, complications such as implant migration and/or subsidence may occur with a static implant. Expandable devices allow for in situ expansion to optimize fit and mitigate iatrogenic endplate damage during trialing and impaction. This study sought to compare clinical and radiographic outcomes of static and expandable spacers following LLIF and report device-related complications. Methods: This study included 29 patients who underwent LLIF with a static spacer and 27 with an expandable spacer; all procedures were combined with supplemental transpedicular posterior fixation. Patient self-assessment forms and radiographic records were used to assess clinical and radiologic outcomes. Results: Mean patient age was 62.3±10.3 years (64% female). One-level surgery was performed in 87.5% of patients, and 12.5% underwent two-level surgery. Results showed no significant differences in blood loss or length of hospital stay (P>0.05). However, operative times differed statistically between static (63.3±37.8 min) and expandable (120.2±59.6 min) groups (P=0.000). Mean visual analog scale (VAS) and Oswestry Disability Index scores improved significantly from preoperative to 24-month follow-up in both groups (P Conclusions: LLIF using expandable spacers resulted in similar clinical and radiographic outcomes when compared with using static spacers, and led to a lower subsidence rate.

Minimally invasive anterior and lateral transpsoas approaches for closed reduction of grade II spondylolisthesis: initial clinical and radiographic experience.

OBJECTIVE Minimally invasive anterior and lateral approaches to the lumbar spine are increasingly used to treat and reduce grade I spondylolisthesis, but concerns still exist for their usage in the management of higher-grade lesions. The authors report their experience with this strategy for grade II spondylolisthesis in a single-surgeon case series and provide early clinical and radiographic outcomes. METHODS A retrospective review of a single surgeon's cases between 2012 and 2016 identified all patients with a Meyerding grade II lumbar spondylolisthesis who underwent minimally invasive lateral lumbar interbody fusion (LLIF) or anterior lumbar interbody fusion (ALIF) targeting the slipped level. Demographic, clinical, and radiographic data were collected and analyzed. Changes in radiographic measurements, Oswestry Disability Index (ODI), and visual analog scale (VAS) scores were compared using the paired t-test and Wilcoxon signed rank test for continuous and ordinal variables, respectively. RESULTS The average operative time was 199.1 minutes (with 60.6 ml of estimated blood loss) for LLIFs and 282.1 minutes (with 106.3 ml of estimated blood loss), for ALIFs. Three LLIF patients had transient unilateral anterior thigh numbness during the 1st week after surgery, and 1 ALIF patient had transient dorsiflexion weakness, which was resolved at postoperative week 1. The mean follow-up time was 17.6 months (SD 12.5 months) for LLIF patients and 10 months (SD 3.1 months) for ALIF patients. Complete reduction of the spondylolisthesis was achieved in 12 LLIF patients (75.0%) and 7 ALIF patients (87.5%). Across both procedures, there was an increase in both the segmental lordosis (LLIF 5.6°, p = 0.002; ALIF 15.0°, p = 0.002) and overall lumbar lordosis (LLIF 2.9°, p = 0.151; ALIF 5.1°, p = 0.006) after surgery. Statistically significant decreases in the mean VAS and the mean ODI measurements were seen in both treatment groups. The VAS and ODI scores fell by a mean value of 3.9 (p = 0.002) and 19.8 (p = 0.001), respectively, for LLIF patients and 3.8 (p = 0.02) and 21.0 (p = 0.03), respectively, for ALIF patients at last follow-up. CONCLUSIONS Early clinical and radiographic results from using minimally invasive LLIF and ALIF approaches to treat grade II spondylolisthesis appear to be good, with low operative blood loss and no neurological deficits. Complete reduction of the spondylolisthesis is frequently possible with a statistically significant reduction in pain scores.

Adult spinal deformity: effectiveness of interbody lordotic cages to restore disc angle and spino-pelvic parameters through completely mini-invasive trans-psoas and hybrid approach.

The aim of the study is to assess and quantify the effectiveness of interbody lordotic cages applied by trans-psoas approach to improve radiographic parameters, showing the differences between completely mini-invasive and hybrid approach. We collected data of 65 patients affected by degenerative lumbar deformity/diseases and underwent mini-invasive lateral interbody fusion followed by percutaneous (group A, completely mini-invasive) or open (group B, hybrid) posterior instrumentation. A subgroup underwent anterior column realignment (ACR). We assessed statistical differences in preoperative and postoperative (at least 6-month) coronal and sagittal parameters, and disc angle (DA) at each level of cage application. 107 lordotic cages were implanted. Group B had the most significant mean changes, especially in coronal Cobb angle, sagittal vertical axis, lumbar lordosis (LL), pelvic incidence-LL mismatch and DA. Concerning DA, at each level of lordotic cage application, in group A changed from -2.9° preop to -6.5° postop (p=0.01); in group B, DA changed from -2.6° to -9.5° (p=0.002) and from +1° to -13.2° in patients underwent ACR. Minimally invasive lateral lumbar interbody fusion is an effective technique in improving sagittal parameters. When combined with posterior open approach and/or application of ACR procedure greater corrections are possible.

The effect of anterior longitudinal ligament resection on lordosis correction during minimally invasive lateral lumbar interbody fusion: Biomechanical and radiographic feasibility of an integrated spacer/plate interbody reconstruction device

BackgroundLateral lumbar interbody fusion is powerful for correcting degenerative conditions, yet sagittal correction remains limited by anterior longitudinal ligament tethering. Although lordosis has been restored via ligament release, biomechanical consequences remain unknown. Investigators examined radiographic and biomechanical of ligament release for restoration of lumbar lordosis. MethodsSix fresh-frozen human cadaveric spines (L3–S1) were tested: (Miller et al., 1988) intact; (Battie et al., 1995) 8mm spacer with intact anterior longitudinal ligament; (Cho et al., 2013) 8mm spacer without intact ligament following ligament resection; (Galbusera et al., 2013) 13mm lateral lumbar interbody fusion; (Goldstein et al., 2001) integrated 13mm spacer. Focal lordosis and range of motion were assessed by applying pure moments in flexion-extension, lateral bending, and axial rotation. FindingsCadaveric radiographs showed significant improvement in lordosis correction following ligament resection (P<0.05). The 8mm spacer with ligament construct provided greatest stability relative to intact (P>0.05) but did little to restore lordosis. Ligament release significantly destabilized the spine relative to intact in all modes and 8mm with ligament in lateral bending and axial rotation (P<0.05). Integrated lateral lumbar interbody fusion following ligament resection did not significantly differ from intact or from 8mm with ligament in all testing modes (P>0.05). InterpretationLordosis corrected by lateral lumbar interbody fusion can be improved by anterior longitudinal ligament resection, but significant construct instability and potential implant migration/dislodgment may result. This study shows that an added integrated lateral fixation system can significantly improve construct stability. Long-term multicenter studies are needed.

Preoperative assessment of the ureter with dual-phase contrast-enhanced computed tomography for lateral lumbar interbody fusion procedures.

Performing the minimally invasive lateral lumbar interbody fusion (LIF), such as the extreme lateral interbody fusion (XLIF) and oblique lateral interbody fusion (OLIF), through a retroperitoneal approach has become increasingly popular. Although urological injury is a major complication of LIF, the anatomical location of the ureter and its risk of injury have not been assessed. The purpose of this study was to evaluate the efficacy of dual-phase contrast-enhanced computed tomography for assessing the location of the ureter and risk of its injury in consecutive LIF cases. 27 cases (12 men and 15 women) were enrolled in the study. Dual-phase contrast-enhanced CT was performed preoperatively, and the risk of ureteral injury was assessed. The location of the ureter was classified using the psoas muscle and vertebral body as reference structures for OLIF and XLIF procedures, respectively. During the OLIF procedures, the location of the ureter was additionally assessed with direct vision and manual palpation in all cases. Simultaneously, potential vascular anomalies were assessed with both 3D and axial images of CT. A total of 125 among 162 ureters, excluding 13 with insufficient enhancement and 24 (44.4%) within the kidney at the L2-L3 level, were assessed preoperatively; 113 ureters (90.4%) were classified as anatomically close to the surgical corridor for OLIF, and 20 ureters (16.0%) as having a potential risk of injury during XLIF. In one case, OLIF was converted to a conventional posterior procedure because of a vascular anomaly. Intraoperative findings showed that ureters moved anteriorly with the peritoneum in all cases, as assessed by manual palpation under direct vision. Dual-phase contrast-enhanced CT is useful in assessing the location of the ureter, kidney, and vascular structures simultaneously. Both OLIF and XLIF have a potential risk of urological injury.

Effect of Sagittal Balance on Risk of Falling after Lateral Lumbar Interbody Fusion Surgery Combined with Posterior Surgery.

PurposeTo demonstrate the impact of correcting sagittal balance (SB) on functional outcomes of surgical treatment for degenerative spinal disease and actual falls via utilization of new minimally invasive lumbar fusion techniques via a lateral approach.Materials and MethodsFrom November 2011 to March 2015, we enrolled 56 patients who underwent minimally invasive lateral lumbar interbody fusion (LLIF) and matched 112 patients receiving decompression/postero-lateral fusion (PLF) surgery for lumbar spinal stenosis. According to SB status using C7-plumb line-distance (C7PL) and surgery type, patients were divided into three groups: SB PLF, sagittal imbalance (SI) PLF, and LLIF groups. We then compared their outcomes.ResultsThe mean C7PL was 6.2±13.6 mm in the SB PLF group, 72.9±33.8 mm in the SI PLF group, and 74.8±38.2 mm in the LLIF group preoperatively. Postoperatively, C7PL in only the LLIF group improved significantly (p=0.000). Patients in the LLIF group showed greater improvement in fall-related functional test scores than the SI PLF group (p=0.007 for Alternate-Step test, p=0.032 for Sit-to-Stand test). The average number of postoperative falls was 0.4±0.7 in the SB PLF group, 1.1±1.4 in the SI PLF group, and 0.8±1.0 in the LLIF group (p=0.041). Oswestry Disability Index and the Euro-QoL 5 dimension visual analogue scale scores also showed greater improvements in the LLIF group than in the SI PLF group at postoperative 1 year (p=0.003, 0.016).ConclusionSurgical correction of SI in patients with lumbar spinal stenosis using a combination of minimal invasive LLIF and posterior surgery achieved better surgical outcomes and a lower incidence of actual falls than PLF surgery.

Clinical outcomes after minimally invasive transforaminal lumbar interbody fusion and lateral lumbar interbody fusion for treatment of degenerative lumbar disease: a systematic review and meta-analysis.

The surgical procedures used for arthrodesis in the lumbar spine for degenerative lumbar diseases remain controversial. This systematic review aims to assess and compare clinical outcomes along with the complications and fusion of each technique (minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) or minimally invasive lateral lumbar interbody fusion (MIS LLIF)) for treatment of degenerative lumbar diseases. Relevant studies were identified from Medline and Scopus from inception to July 19, 2016 that reported Oswestry Disability Index (ODI), back and leg pain visual analog score (VAS), postoperative complications, and fusion of either technique. Fifty-eight studies were included for the analysis of MIS-TLIF; 40 studies were included for analysis of LLIF, and 1 randomized controlled trial (RCT) study was included for comparison of MIS-TLIF to LLIF. Overall, there were 9506 patients (5728 in the MIS-TLIF group and 3778 in the LLIF group). Indirect meta-analysis, MIS-TLIF provided better postoperative back and leg pain (VAS), disabilities (ODI), and risk of having complications when compared to LLIF technique, but the fusion rate was not significantly different between the two techniques. However, direct meta-analysis between RCT study and pooled indirect meta-analysis of MIS-TLIF have better pain, disabilities, and complication but no statistically significant difference when compared to LLIF. In LLIF, the pooled mean ODI and VAS back pain were 2.91 (95% CI 2.49, 3.33) and 23.24 (95% CI 18.96, 27.51) in MIS approach whereas 3.14 (95% CI 2.29, 4.04) and 28.29 (95% CI 21.92, 34.67) in traditional approach. In terms of complications and fusion rate, there was no difference in both groups. In lumbar interbody fusion, MIS-TLIF had better ODI, VAS pain, and complication rate when compared to LLIF with direct and indirect meta-analysis methods. However, in terms of fusion rates, there were no differences between the two techniques.

Novel Transabdominal Motor Action Potential (TaMAP) Neuromonitoring System for Spinal Surgery.

IntroductionMinimally invasive lateral lumbar interbody fusion (LLIF) approaches to the lumbar spine reduce patient morbidity compared to anterior or posterior alternatives. This approach, however, decreases direct anatomical visualization, creating the need for highly sensitive and specific neurophysiological monitoring. We seek to determine feasibility in 'transabdominal motor action potential (TaMAP)' monitoring as an assessment for the integrity of the neural elements during lateral-approach surgeries to the lumbar spine. MethodsCathode and anode leads were placed on the posterior and anterior surfaces of two porcine subjects. Currents of varying degrees were transmitted across, from front to back. Motor responses were monitored and recorded by needle electrodes in specific distal muscle groups of the lower extremity. Lastly, the cathode and anode were placed anterior and posterior to the chest wall and stimulated to the maximum of 1500 mA to determine any effect on cardiac rhythm.ResultsResponses were seen by measuring vertical height differences between peaks of corresponding evoked potentials. Recruitment began at 200 mA in the lower extremities. Stimulation at 450 mA recruited a reliable and distinguishable electrographic response from most muscle groups. Responses were recorded and reliably measured and increased in proportion to the graduation of transabdominal stimulation current; no responses were seen in the arms or face. 1500 mA across the chest wall failed to stimulate or induce cardiac arrhythmia on repeated stimulation, indicating safety of stimulation.ConclusionTaMAPs seen in the animal model provide a potential alternative to standard transcranial motor evoked potentials done in the lateral approach of LLIFs. TaMAP recordings in most muscle groups were recordable and reliable, though some muscle groups failed to stimulate. Safety of transabdominal motor evoked potentials was confirmed in this porcine study. Future studies should examine TaMAPs reliability in detecting compressive lesions of nerve roots and peripheral nerves.

Neurological complications using a novel retractor system for direct lateral minimally invasive lumbar interbody fusion

We describe our experience using the RAVINE retractor (K2M, Leesburg, VA, USA) to gain access to the lateral aspect of the lumbar spine through a retroperitoneal approach. Postoperative neurological adverse events, utilising the mentioned retractor system, were recorded and analysed. We included 140 patients who underwent minimally invasive lateral lumbar interbody fusion (MI-LLIF) for degenerative spinal conditions between 2011 and 2015 at two major spinal centres. A total of 228 levels were treated, 35% one level, 40% two level, 20% three level and 5% 4 level surgeries. The L4/5 level was instrumented in 28% of cases. 12/140 patients had postoperative neurological complications. Immediately after surgery, 5% of patients (7/140) had transient symptoms in the thigh ranging from sensory loss, pain and paraesthesia, all of which recovered within 12weeks following surgery. There were five cases of femoral nerve palsy (3.6% — two ipsilateral and three contralateral), all of which recovered completely with no residual sensory or motor deficit within 6months. MI-LLIF done with help of the described retractor system has proved a safe and efficient way to achieve interbody fusion with minimal complications, mainly nerve related, that recovered quickly. Judicious use of the technique to access the L4/5 level is advised.

Use of 3D CT-based navigation in minimally invasive lateral lumbar interbody fusion.

OBJECTIVE Lateral lumbar interbody fusion (LLIF) is an increasingly popular technique used to treat degenerative lumbar disease. The technique of using an intraoperative cone-beam CT (iCBCT) and an image-guided navigation system (IGNS) for LLIF cage placement has been previously described. However, other than a small feasibility study, there has been no clinical study evaluating its accuracy or safety. Therefore, the purpose of this study was to evaluate the accuracy and safety of image-guided spinal navigation in LLIF. METHODS An analysis of a prospectively acquired database was performed. Thirty-one consecutive patients were identified. Accuracy was initially determined by comparison of the planned trajectory of the IGNS with post-cage placement intraoperative fluoroscopy. Accuracy was subsequently confirmed by postprocedural CT and/or radiography. Cage placement was graded based on a previously described system separating the disc space into quarters. RESULTS The mean patient age was 63.9 years. A total of 66 spinal levels were treated, with a mean of 2.1 levels (range 1-4) treated per patient. Cage placement was noted to be accurate using IGNS in each case, as confirmed with intraoperative fluoroscopy and postoperative imaging. Sixty-four (97%) cages were placed within Quarters 1 to 2 or 2 to 3, indicating placement of the cage in the anterior or middle portions of the disc space. There were no instances of misguidance by IGNS. There was 1 significant approach-related complication (psoas muscle abscess) that required intervention, and 8 patients with transient, mild thigh paresthesias or weakness. CONCLUSIONS LLIF can be safely and accurately performed utilizing iCBCT and IGNS. Accuracy is acceptable for multilevel procedures.

A Cost-Effectiveness Comparison Between Open Transforaminal and Minimally Invasive Lateral Lumbar Interbody Fusions Using the Incremental Cost-Effectiveness Ratio at 2-Year Follow-up.

Direct cost comparisons between minimally invasive spine surgeries and the open options are rare. To compare healthcare costs associated with open transforaminal lumbar interbody fusion (TLIF) and minimally invasive lateral lumbar interbody fusion (LLIF) by calculating the incremental cost-effectiveness ratio (ICER) and to calculate the thresholds for minimum clinically important difference and minimum cost-effective difference for patient-reported outcome measures at the 2-year follow-up. Forty-five patients who underwent single-level TLIF and 29 patients who underwent single-level stand-alone LLIF were included in the comparison. All costs from diagnosis through the 2-year follow-up were available from a comprehensive single-center data bank within a unified hospital system. Payment provided for all spine-related medical resource use from the time of diagnosis through 2 years was recorded. A 0% discount rate was applied. Quality-adjusted life-years (QALYs) were calculated from the EuroQol-5D collected in an unbiased manner. Difference in total cost per QALY gained for LLIF minus that for TLIF was assessed as the estimate of the ICER from a US perspective. Significant improvements were observed at the 2-year follow-up for both TLIF and LLIF with the Short Form-36 physical component summary, Oswestry Disability Index, visual analog scale back pain and leg pain scores, and EuroQol-5D. ICER calculations revealed similar mean cumulative QALYs gained at the 2-year interval (0.67 for TLIF and 0.60 for LLIF; P = .33). Median total costs of care after TLIF and LLIF were $44 068 and $45 574, respectively (P = .96). Minimum cost-effective difference thresholds with an anchor of <$50 000 per QALY were higher than minimum clinically important difference thresholds for all patient-reported outcome measures. Total mean cost and EuroQol-5D were statistically equivalent between the 2 treatment groups. TLIF and LLIF produced equivalent 2-year patient outcomes at an equivalent cost-effectiveness profile.

Minimally Invasive Lateral Lumbar Interbody Fusion: Surgical Technique and Review

Minimally Invasive Lateral Lumbar Interbody Fusion: Surgical Technique and Review

Minimally Invasive Lateral Lumbar Interbody Fusion: Surgical Technique and Review

Minimally Invasive Lateral Lumbar Interbody Fusion: Surgical Technique and Review

The surgical vascular anatomy of the minimally invasive lateral lumbar interbody approach: a cadaveric and radiographic analysis.

The minimally invasive (MI) lateral lumbar interbody fusion (LLIF) approach has become increasingly popular for the treatment of degenerative lumbar spine disease. The neural anatomy of the lumbar plexus has been studied; however, the pertinent surgical vascular anatomy has not been examined in detail. The goal of this study is to examine the vascular structures that are relevant in relation to the MI-LLIF approach. Anatomic dissection of the lumbar spines and associated vasculature was performed in three embalmed, adult cadavers. Right and left surgeon perspective views during LLIF were for a total of six approaches. During the dissection, all vascular elements were noted and photographed, and anatomical relationships to the vertebral bodies and disc spaces were analyzed. In addition, several axial and sagittal MRI images of the lumbar spine were analyzed to complement the cadaveric analysis. The aorta descends along the left anterior aspect of lumbar vertebra with an average distance of 2.1 cm (range 1.9-2.3 cm) to the center of each intervertebral disc. The vena cava descends along the right anterior aspect of lumbar vertebrates with average distance of 1.4 cm (range 1.3-1.6 cm) to the center of the intervertebral disc. Each vertebral body has two lumbar arteries (direct branches from the aorta); one exits to the left and one to the right side of the vertebral body. The lumbar arteries pass underneath the sympathetic trunk, run in the superior margin of the vertebral body and extend all the way across it, with average length of 3.8 cm (range 2.5-5 cm). The mean distance between the arteries and the inferior plate of the superior disc space is 4.2 mm (range 2-5 mm) and mean distance of 3.1 cm (range 2.8-3.8 cm) between two arteries in adjacent vertebrae. One of the cadavers had an expected normal anatomical variation where the left arteries at L3-L4 anastomosed dorsally of the vertebral bodies at the middle of the intervertebral disc. Understanding the vascular anatomy of the lateral and anterior lumbar spine is paramount for successfully and safely executing the LLIF procedure. It is imperative to identify anatomical variations in lumbar arteries and veins with careful assessment of the preoperative imaging.

Minimally Invasive Lateral Lumbar Interbody Fusion

Retrospective case series. To determine the clinical and radiographic outcomes of patients undergoing minimally invasive lateral lumbar interbody fusion (LLIF) with a minimum 2-year follow-up. Minimally invasive LLIF is performed through a lateral, retroperitoneal, transpsoas approach. This procedure is characterized by the use of a tubular retractor to minimize tissue damage and real-time neuromonitoring to ensure safe passage through the psoas muscle. To date, advantages of minimal invasive LLIF, compared with open procedures, has been limited to early postoperative outcomes and complications, with the longest mean follow-up duration of 22 months. A total of 118 patients who underwent minimally invasive LLIF with a minimum of 2 years follow-up were included in this study. Clinical outcomes were determined by using Visual Analog Score for the degree of pain (trunk or lower extremity), and Oswestry Disability Index and Short Form-12 scoring methods for patient function. Radiographic evaluations included (i) disk height; (ii) segmental coronal angulation; (iii) segmental lordotic angulation; (iv) Cobb angle; (v) cage subsidence; and (vi) fusion status. Data were statistically tested using either paired Students t test or Wilcoxon matched-pair test. Significance level was set at P<0.05. We found that (i) the Visual Analog Score for pain, Oswestry Disability Index, and the physical components summary, but not the mental components summary of Short Form-12 improved significantly at the follow-up; (ii) disk height, coronal angulation, and lordotic angulation at each level and the Cobb angle were restored at the statistically significant extent; (iii) successful fusion was achieved in 209 levels (88%); and (iv) transient thigh pain was the most frequent complication seen in 36% of the patients. Our results support the efficacy of minimally invasive LLIF in improvements of clinical and radiographic features.

Three-dimensional computed tomography-based spinal navigation in minimally invasive lateral lumbar interbody fusion: feasibility, technique, and initial results.

As with most minimally invasive spine procedures, lateral lumbar interbody fusion (LLIF) requires the use of biplanar fluoroscopy for localization and safe interbody cage placement. Computed tomography (CT)-based intraoperative spinal navigation has been shown to be more effective than fluoroscopic guidance for posterior-based approaches such as pedicle screw instrumentation. However, the use of spinal navigation in LLIF has not been well studied. To present the technique for using an intraoperative cone-beam CT and image-guided navigation system in LLIF and to provide a preliminary analysis of outcomes. We retrospectively analyzed a prospectively acquired database and the electronic records of patients undergoing LLIF with spinal navigation. Eight patients were identified. Postoperative neurological deficits were recorded. All patients underwent postprocedural CT and x-ray imaging for analysis of accuracy of cage placement. Accuracy of cage placement was determined by location within the disk space. The mean age was 66 years, and 6 patients were women. A mean 2.8 levels were treated with a total of 22 lateral cages implanted via navigation. All cages were placed within quarters 1 to 2 or 2 to 3, signifying the anterior half or middle portions of the disk space. There were no sensory or motor deficits postoperatively. Use of an intraoperative cone-beam CT with an image-guided navigation system is feasible and safe and appears to be accurate, although a larger study is required to confirm these results.