Extreme lateral interbody fusion (XLIF) approach for L5-S1: Preliminary experience

Using Novel Segmentation Technology to Define Safe Corridors for Minimally Invasive Posterior Lumbar Interbody Fusion

BACKGROUND AND OBJECTIVES

There has been a rise in minimally invasive methods to access the intervertebral disk space posteriorly given their decreased tissue destruction, lower blood loss, and earlier return to work. Two such options include the percutaneous lumbar interbody fusion through the Kambin triangle and the endoscopic transfacet approach. However, without accurate preoperative visualization, these approaches carry risks of damaging surrounding structures, especially the nerve roots. Using novel segmentation technology, our goal was to analyze the anatomic borders and relative sizes of the safe triangle, trans-Kambin, and the transfacet corridors to assist surgeons in planning a safe approach and determining cannula diameters.

METHODS

The areas of the safe triangle, Kambin, and transfacet corridors were measured using commercially available software (BrainLab, Munich, Germany). For each approach, the exiting nerve root, traversing nerve roots, theca, disk, and vertebrae were manually segmented on 3-dimensional T2-SPACE magnetic resonance imaging using a region-growing algorithm. The triangles' borders were delineated ensuring no overlap between the area and the nerves.

RESULTS

A total of 11 patients (65.4 ± 12.5 years, 33.3% female) were retrospectively reviewed. The Kambin, safe, and transfacet corridors were measured bilaterally at the operative level. The mean area (124.1 ± 19.7 mm 2 vs 83.0 ± 11.7 mm 2 vs 49.5 ± 11.4 mm 2 ) and maximum permissible cannula diameter (9.9 ± 0.7 mm vs 6.8 ± 0.5 mm vs 6.05 ± 0.7 mm) for the transfacet triangles were significantly larger than Kambin and the traditional safe triangles, respectively ( P < .001).

CONCLUSION

We identified, in 3-dimensional, the borders for the transfacet corridor: the traversing nerve root extending inferiorly until the caudal pedicle, the theca medially, and the exiting nerve root superiorly. These results illustrate the utility of preoperatively segmenting anatomic landmarks, specifically the nerve roots, to help guide decision-making when selecting the optimal operative approach.

Efficacy and Safety of the Extreme Lateral Interbody Fusion (XLIF) Technique in Spine Surgery: Meta-Analysis of 1409 Patients

(1) Objectives: The objective of this study was to quantify the exact clinical-radiological efficacy and safety of the extreme lateral interbody fusion (XLIF) technique in spinal surgery; (2) Methods: A meta-analysis was performed using PubMed, Embase, Scopus, and Cochrane Collaboration Library. Studies focusing on patients surgically treated with XLIF were included. The outcomes were as follows: visual analog scale (VAS) and Oswestry disability index (ODI), radiological outcomes, and adverse events. Cohort studies and case series were also included. Clinical outcomes were assessed at 12 months of age. Data were combined using Review Manager 5.4 and WebPlotDigitizer 13.1.4; (3) Results: Nineteen studies with a pool of 1409 patients were included in this meta-analysis. Leg pain VAS and back pain VAS significantly improved at 12 months (SMD 2.75, 95% CI 0.59-4.90; SMD 4.54, 95% CI 1.39-7.69). ODI showed significant improvement (MD 32.51, 95% CI 24.01-41.00) at 12 months. Disc height increased significantly (SMD -2.73, 95% CI -3.58 to -1.88). Lumbar lordosis and segmental lordosis were significantly corrected postoperatively (MD -2.44, 95% CI -3.45 to -1.43; MD -2.55, 95% CI -3.61 to -1.48). The fusion rates at 12 months ranged from 85.0% to 93.3%. The most frequent complications were transient neurological conditions (2.2%), hardware failure (1.9%), and transient pain (1.8%). The most frequent serious complications were nerve root injury (1.0%), gastrointestinal impairment (0.7%), and vertebral fractures (0.6%); (4) Conclusions: This is the first meta-analysis of the specific use of XLIF in spinal surgery. This study demonstrates that the XLIF technique in spine surgery is associated with good clinical and radiological results and a low complication rate.

Evaluation of long-term clinical outcomes and the incidence of adjacent proximal segment degenerative disease with algorithmic transforaminal interbody fusion: A multicenter prospective study

Study Design

This was a prospective multicenter study.

Background

Adjacent segment degenerative disease (ASDd) is a common complication of open transforaminal lumbar interbody fusion (O-TLIF), the leading cause of which is initial adjacent segment degeneration (ASD). To date, various surgical techniques for the prevention of ASDd have been developed, such as, simultaneous use of interspinous stabilization (IS) and preventive rigid stabilization of the adjacent segment. The use of these technologies is often based on the subjective opinion of the operating surgeon, or on the assessment of one of the predictors of ASDd. Only sporadic studies are devoted to a comprehensive study of risk factors of ASDd development and personalized performance of O-TLIF.

Purpose

The purpose of this study was to evaluate long-term clinical outcomes and the incidence of degenerative disease of the adjacent proximal segment using clinical-instrumental algorithm for preoperative planning to O-TLIF.

Materials and Methods

The prospective, nonrandomized, multicenter cohort study included 351 patients who underwent primary O-TLIF, and the adjacent proximal segment had initial ASD. Two cohorts were identified. The prospective cohort included 186 patients who were operated by using the algorithm of personalized O-TLIF performance. The control retrospective cohort consisted of patients (n = 165), from our own database who had been operated on previously without the algorithmized approach. Treatment outcomes were analyzed by Visual Analog Scale (VAS) assessment of pain syndrome, Oswestry Disability Index (ODI) scores, physical component score (PCS) and mental component score (MCS) scores of the Short Form 36 questionnaire, frequency of ASDd was compared between studied cohorts.

Results

Thirty-six months after follow-up, the prospective cohort had better SF36 MCS/PCS outcomes, less disability according to ODI, and lower pain level according to VAS (P < 0.05). The incidence of ASDd in the prospective cohort was 4.9%, which was significantly lower than in the retrospective cohort (9%).

Conclusions

The prospective use of a clinical-instrumental algorithm for preoperative planning of rigid stabilization, depending on the biometric parameters of the proximal adjacent segment, significantly reduced the incidence of ASDd and improved long-term clinical outcomes compared with the retrospective group.