The Technical Feasibility of Unilateral Biportal Endoscopic Decompression for The Unpredicted Complication Following Minimally Invasive Transforaminal Lumbar Interbody Fusion: Case Report

Endoscope-Assisted Anterior Odontoid Screw Fixation for Odontoid Fracture

OBJECTIVE

Odontoid fractures in older adults often lead to substantial morbidity and mortality. This study explores the outcomes of water-based endoscope-assisted anterior odontoid screw (AOS) fixation, a minimally invasive technique, in managing these fractures.

METHODS

Six patients (5 men, 1 woman) underwent endoscope-assisted AOS fixation for displaced odontoid fractures. Surgical procedures and follow-up assessments were reviewed retrospectively. Inclusion criteria included type IIa or type IIb odontoid fractures with potential nonunion/instability.

RESULTS

Surgical procedures demonstrated no intraoperative complications. The mean operation time was 82 minutes (69-107 minutes), with an average estimated blood loss of 28 mL (10-50 mL). Among the 5 patients followed for >6 months, 4 (80%) showed successful fusion through computed tomography. Screw-related complications were observed in 1 patient.

CONCLUSIONS

AOS fixation is advocated for managing unstable odontoid fractures and providing strength and fracture union rates without impending cervical motion. Incorporating minimally invasive approaches, particularly endoscopic techniques, has garnered interest. The novel endoscope-assisted AOS fixation method, unlike prior approaches, begins with endoscopic guidance and minimal incisions, potentially reducing the risk of neurovascular injury. This novel technique shows promise as an effective strategy for addressing unstable odontoid fractures.

Endoscopic transfacet Decompression for Severe Lumbar Spinal Stenosis: A Technical Note, Illustrative Clinical Series, and Surgeon Survey Regarding Post-Decompression Instability

Background: Lumbar spinal stenosis (LSS) remains a predominant cause of debilitating back and leg pain, affecting many aging populations. Traditional decompression surgeries can be invasive and pose significant risks and recovery time. This study elucidates the techniques and preliminary outcomes of endoscopic transfacet decompression in treating severe LSS. Methods: A retrospective review was performed on 65 patients with severe LSS who underwent endoscopic transfacet decompression. The patient outcomes were analyzed using the VAS for leg pain and the modified Macnab criteria. Pre-operative and post-operative scores were compared, and any complications were analyzed. An online survey was administered to 868 surgeons using Likert-scale ratings to evaluate surgeons' experience with endoscopic decompression in patients with painful spondylolisthesis. The survey responses were analyzed using descriptive statistics and Polytomous Rasch analysis to evaluate surgeon endorsement. Results: The study included 65 patients, of which 29 (44.6%) were female and 36 (55.4%) were male, with a mean age of 65.79 ranging from 38 to 84 years. The available mean post-operative follow-up period was 31.44 months, ranging from 24 to 39 months. The VAS score for leg pain reduced significantly from pre-operative 7.54 ± 1.67 to 2.20 ± 1.45 by 5.34 ± 2.03 (p < 0.001) with a large effect size (Cohen's d = 2.626). At the final follow-up, functional Macnab outcomes were reported as excellent by 20 (30.8%), good by 37 (56.9%), fair by 5 (7.7%), and poor by 3 (4.6%) of patients. There were no incidental durotomies, nerve root injuries, wound complications, or instances of post-operative instability. Only five patients (7.7%) developed post-operative dysesthesia. Incomplete decompression led to fair and poor outcomes in 8 (12.3%) patients. No revision surgeries were performed. post-operative instability was not observed. The surgeon survey corroborated these observations, where the polytomous Rasch analysis showed consensus on the effectiveness of the percutaneous endoscopic decompression of low-grade spondylolisthesis. Differential item functioning (DIF) analysis showed no significant bias in item responses between orthopaedic and neurosurgeons. Conclusions: The endoscopic transfacet decompression technique delineated herein showcased excellent Macnab outcomes in managing severe LSS, with a combined success rate of 87.7%. Patients also experienced a statistically significant reduction in leg pain. Dysesthesia rates were lower than with the transforaminal approach, likely because of limited exiting and traversing nerve root manipulation. This technique might represent a viable, less invasive alternative to open microsurgical dissection and decompression for patients with severe LSS, where fusion may be required. This approach was found to be highly accepted among endoscopic spine surgeons.

Full-endoscopic versus microscopic spinal decompression for lumbar spinal stenosis: a systematic review & meta-analysis

BACKGROUND CONTEXT

Symptomatic lumbar spinal stenosis is routinely treated with spinal decompression surgery, with an increasing trend towards minimally invasive techniques. Endoscopic decompression has emerged as a technique which minimizes approach-related morbidity while achieving similar clinical outcomes to conventional open or microscopic approaches.

PURPOSE

To assess the safety and efficacy of endoscopic versus microscopic decompression for treatment of lumbar spinal stenosis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review on randomized and nonrandomized studies comparing endoscopic versus microscopic decompression was conducted, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Treatment effects were computed using pairwise random-effects meta-analysis. Risk of bias was assessed using the Cochrane Risk-of-bias and ROBINS-I tools for randomized and nonrandomized trials respectively. Quality of the overall body of evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

A total of 19 primary references comprising 1,997 patients and 2,132 spinal levels were included. Endoscopic decompression was associated with significantly reduced intraoperative blood-loss (weighted mean differences [WMD]=-33.29 mL, 95% CI:-51.80 to -14.78, p=.0032), shorter duration of hospital stay (WMD=-1.79 days, 95% CI: -2.63 to 0.95, p=.001), rates of incidental durotomy (RR = 0.63, 95% CI: 0.43 to 0.91, p=.0184) and surgical site infections (RR=0.23, 95% CI: 0.10 to-0.51, p=.001), and a nonsignificant trend towards less back pain, leg pain, and better functional outcomes compared to its microscopic counterpart up to 2-year follow up.

CONCLUSIONS

Endoscopic and microscopic decompression are safe and effective techniques for treatment of symptomatic lumbar spinal stenosis. Prospective studies of larger power considering medium to long-term outcomes and rates of iatrogenic instability are warranted to compare potential alignment changes and destabilization from either techniques.

Systemic Inflammatory Markers and Clinical Outcomes of Open versus Biportal Endoscopic Transforaminal Lumbar Interbody Fusion

Purpose

The purpose of this study is to preliminarily assess the change in perioperative systemic inflammatory markers and clinical outcomes between open TLIF and BE-TLIF procedures.

Patients and Methods

In total, 38 patients who underwent single-level lumbar fusion surgery (L4-5 or L5-S1) were retrospectively reviewed. 19 patients were treated by the BE-TLIF technique, while the other patients were managed using open TLIF. The perioperative serum C-reactive protein (CRP), neutrophil/lymphocyte ratio (NLR), lymphocyte/monocyte ratio (LMR), and platelet/lymphocyte ratio (PLR) of the two groups were compared to determine if there was a statistical difference. Meanwhile, clinical evaluations were conducted to assess various factors including operative duration, estimated blood loss (EBL), drainage catheter stay, length of hospitalization, visual analogue scale (VAS), and Oswestry disability index (ODI) scores.

Results

The perioperative analysis revealed that BE-TLIF cases experienced a longer operative duration than open TLIF cases (open TLIF: 138.63 ± 31.59 min, BE-TLIF: 204.58 ± 49.37 min, p < 0.001). Meanwhile, the EBL showed an increased trend in the BE-TLIF group (260.7 ± 211.9 mL) in comparison with the open TLIF group (200.9 ± 211.9 mL) (p =0.485). In terms of systemic inflammatory markers, the mean postoperative CRP, NLR, LMR, and PLR were lower in the BE-TLIF group than in the open TLIF group, although these differences were not statistically significant (p > 0.05). The VAS and ODI scores in both groups were significantly improved after surgery (p < 0.05).

Conclusion

There was no significant difference found between BE-TLIF and open TLIF in terms of systemic inflammatory markers, and clinical outcomes. Overall, BE-TLIF can be considered a viable choice for lumbar canal decompression and interbody fusion for less invasion. It is worth noting that BE-TLIF does have a longer operation time, indicating that there is still potential for further improvement in this technique.

A case report: Unilateral biportal endoscopic revision for adjacent segmental disease: Case presentations and literature review

RATIONALE

Biportal endoscopic revision surgery for adjacent segmental disease (ASD) after lumbar arthrodesis is seldomly reported. Herein, we present 3 cases of ASD with radiculopathy wherein satisfactory results were obtained using unilateral biportal endoscopic (UBE) decompression.

PATIENT CONCERNS

Case 1 was of a 56-year-old male who presented with a chief complaint of Intermittent claudication since 2-year. Case 2 involved a 78-year-old female who was admitted to the hospital with a chief complaint of radiating pain and weakness in the left leg for at least 1 year. Case 3 was a 67-year-old woman who visited our hospital because of radiating leg pain for 5 months. All the cases had a history of L4 to L5 lumbar interbody fusion surgery.

DIAGNOSES

Computed tomography and magnetic resonance imaging showed the spinal epidural lipomatosis at the L3 to L4 level in case 1, the up-migrated lumbar disc herniation at L3 to L4 level in case 2 and unilateral foraminal stenosis at the L5 to S1 level in case 3.

INTERVENTIONS

Under UBE guidance, the ipsilateral approach was used to treat adjacent lumbar stenosis caused by spinal epidural lipomatosis. The contralateral approach was used to remove the up-migrated herniated disc. The paraspinal approach was applied to decompress the foraminal stenosis.

OUTCOMES

Postoperative parameters were improved clinically, and nerve roots were decompressed radiologically. No complications were developed.

LESSONS

UBE revision surgery showed a favorable clinical and radiological result without complications and may be a safe and effective alternative technique for ASD.

Complications and Management of Endoscopic Spinal Surgery

In the past, the use of endoscopic spine surgery was limited to intervertebral discectomy; however, it has recently become possible to treat various spinal degenerative diseases, such as spinal stenosis and foraminal stenosis, and the treatment range has also expanded from the lumbar spine to the cervical and thoracic regions. However, as endoscopic spine surgery develops and its indications widen, more diverse and advanced surgical techniques are being introduced, and the complications of endoscopic spine surgery are also increasing accordingly. We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and key words were set as “endoscopic spinal surgery,” “endoscopic cervical foramoinotomy,” “PECD,” “percutaneous transforaminal discectomy,” “percutaneous endoscopic interlaminar discectomy,” “PELD,” “PETD,” “PEID,” “YESS” and “TESSYS.” We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic lumbar surgery was divided into full endoscopic interlaminar and transforaminal approaches and a unilateral biportal approach. We performed a comprehensive review of available literature on complications of endoscopic spinal surgery. This study particularly focused on the prevention of complications. Regardless of the surgical methods, the most common complications related to endoscopic spinal surgery include dural tears and perioperative hematoma. transient dysesthesia, nerve root injury and recurrence. However, Endoscopic spinal surgery, including full endoscopic transforaminal and interlaminar and unilateral biportal approaches, is a safe and effective a treatment for lumbar as well as cervical and thoracic spinal diseases such as disc herniation, lumbar spinal stenosis, foraminal stenosis and recurrent disc herniation.

Complications of Unilateral Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis: A Systematic Review of the Literature and Meta-analysis of Single-arm Studies

PURPOSE

This article aims to summarize the incidence of these complications through a meta-analysis, analyze the causes of complications and provide clinical promotion and recommendations.

METHODS

Databases and retrieval platform including PubMed, Web of science, Springer link, Cochrane clinical trials, ProQuest, ScienceDirect, Europe PMC, Wiley online, OVID, Clinical trials, CNKI and WanFang, and supplement the literature through Google Scholar, collect all the unilateral biportal endoscopy (UBE) controlled trials and non-controlled trials of UBE in the treatment of lumbar spinal stenosis (LSS). The search time limit is from January 1, 2000 to December 25, 2021. After two reviewers independently screened the literature, extracted data and evaluated the risk of bias in the included studies, meta-analysis was performed using Stata 15.1 software.

RESULTS

Finally, 24 studies were included, including 999 patients. The results of a single-arm rate meta-analysis showed that the overall complication rate of UBE treatment of LSS was 6.27% [95% CI (0.0412, 0.0876)], and the incidence of dural tear was 2.49% [95% CI (0.0133, 0.0390)], the incidence of transient paresthesia was 0.14% [95% CI (0.0000, 0.0072)], the incidence of postoperative spinal epidural hematoma was 0.27% [95% CI (0.0000, 0.0096)], the incidence of postop headache, inadequate decompression, root injury and infection was 0.00%.

CONCLUSION

Current evidence shows that the complication rate of UBE in the treatment of LSS is low, mainly due to dural tears. Limited by the number and quality of included studies, the above conclusions still need to be confirmed by more studies.

5-Aminolevulinic acid-enhanced fluorescence-guided treatment of high-grade glioma using angled endoscopic blue light visualization: technical case series with preliminary follow-up

OBJECTIVE

5-Aminolevulinic acid (5-ALA)-enhanced fluorescence-guided resection of high-grade glioma (HGG) using microscopic blue light visualization offers the ability to improve extent of resection (EOR); however, few descriptions of HGG resection performed using endoscopic blue light visualization are currently available. In this report, the authors sought to describe their surgical experience and patient outcomes of 5-ALA-enhanced fluorescence-guided resection of HGG using primary or adjunctive endoscopic blue light visualization.

METHODS

The authors performed a retrospective review of prospectively collected data from 30 consecutive patients who underwent 5-ALA-enhanced fluorescence-guided biopsy or resection of newly diagnosed HGG was performed. Patient demographic data, tumor characteristics, surgical technique, EOR, tumor fluorescence patterns, and progression-free survival were recorded.

RESULTS

In total, 30 newly diagnosed HGG patients were included for analysis. The endoscope was utilized for direct 5-ALA-guided port-based biopsy (n = 9), microscopic to endoscopic (M2E; n = 18) resection, or exoscopic to endoscopic (E2E; n = 3) resection. All endoscopic biopsies of fluorescent tissue were diagnostic. 5-ALA-enhanced tumor fluorescence was visible in all glioblastoma cases, but only in 50% of anaplastic astrocytoma cases and no anaplastic oligodendroglioma cases. Gross-total resection (GTR) was achieved in 10 patients in whom complete resection was considered safe, with 11 patients undergoing subtotal resection. In all cases, endoscopic fluorescence was more avid than microscopic fluorescence. The endoscope offered the ability to diagnose and resect additional tumor not visualized by the microscope in 83.3% (n = 10/12) of glioblastoma cases, driven by angled lenses and increased fluorescence facilitated by light source delivery within the cavity. Mean volumetric EOR was 90.7% in all resection patients and 98.8% in patients undergoing planned GTR. No complications were attributable to 5-ALA or blue light endoscopy.

CONCLUSIONS

The blue light endoscope is a viable primary or adjunctive visualization platform for optimization of 5-ALA-enhanced HGG fluorescence. Implementation of the blue light endoscope to guide resection of HGG glioma is feasible and ergonomically favorable, with a potential advantage of enabling increased detection of tumor fluorescence in deep surgical cavities compared to the microscope.

Mapping knowledge structure and themes trends in unilateral biportal endoscopic spine surgery: A bibliometric analysis

Background

The numerous benefits of unilateral biportal endoscopic (UBE) spine surgery have attracted the attention of many researchers, and a considerable number of relevant clinical studies have been published. However, global research trends in the field of UBE have received little attention. The purpose of this study was to apply bibliometric method to analyze the UBE-related publications to obtain an overview of the research trends in the field of UBE, as well as research hotspots and trends.

Methods

Web of Science database was searched for articles published until January 31, 2022. CiteSpace was used to analyze the data, which provided graphical knowledge maps. The following factors were applied to all literature: number of publications, distribution, h-index, institutions, journals, authors, and keywords.

Results

Seventy-three articles were identified. Since 2019, there has been a significant increase in the number of UBE-related publications. The country with the largest number of articles was South Korea (72.6%), followed by China (9.6%), Japan (4.1%), and Egypt (4.1%). South Korea had the highest h-index (16), followed by China (2), Japan (1), and Egypt (1). Leon Wiltse Memorial Hospital was the organization that produced the most papers (12 publications). Heo DH was the most productive author (16 papers) and was the most cited author (35 times). World Neurosurgery published the most papers on UBE (23.3%). The main research hotspots were spinal diseases, decompression, complications, learning curve, and interbody fusion. In addition, the recent concerns were “learning curve,” “interbody fusion,” “management,” and “dural tear.”

Conclusions

The quantity of publications on UBE research will increase, and South Korea being the major contributor and most prominent country in this field. The findings of our study will provide researchers with practical information on the field of UBE, and identification of mainstream research directions and recent hotspots.

What Affects Segmental Lordosis of the Surgical Site after Minimally Invasive Transforaminal Lumbar Interbody Fusion?

PURPOSE

This study was undertaken to identify factors that affect segmental lordosis (SL) after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) by comparing patients whose postoperative SL increased with those whose decreased.

MATERIALS AND METHODS

Fifty-five patients underwent MIS-TLIF at our institute from January 2018 to September 2019. Demographic, pre- and postoperative radiologic, and cage-related factors were included. Statistical analyses were designed to compare patients whose SL increased with decreased after surgery.

RESULTS

After surgery, SL increased in 34 patients (group I) and decreased in 21 patients (group D). The index level, disc lordosis, SL, lumbar lordosis, proximal lordosis (PL), and Y-axis position of the cage (Yc) differed significantly between groups I and D. The cage in group I was more anterior than that in group D (Yc: 55.84% vs. 51.24%). Multivariate analysis showed that SL decreased more significantly after MIS-TLIF when the index level was L3/4 rather than L4/5 [odds ratio (OR): 0.46, p=0.019], as preoperative SL (OR: 0.82, p=0.037) or PL (OR: 0.68, p=0.028) increased, and as the cage became more posterior (OR: 1.10, p=0.032).

CONCLUSION

Changes in SL after MIS-TLIF appear to be associated with preoperative SL and PL, index level, and Yc. An index level at L4/5 instead of L3/4, smaller preoperative SL or PL, and an anterior position of the cage are likely to result in increased SL after MIS-TLIF.

The Learning Curve of Unilateral Biportal Endoscopic (UBE) Spinal Surgery by CUSUM Analysis

Objective

To assess the learning curve of the unilateral biportal endoscopic (UBE) technique for the treatment of single-level lumbar disc herniation by cumulative summation (CUSUM) method analysis.

Methods

A retrospective analysis was conducted to assess 97 patients' general condition, operation time, complications, and curative effect of single segmental UBE surgery performed by a spinal surgeon in his early stage of this technique. The learning curve of operation time was studied using a CUSUM method, and the cut-off point of the learning curve was obtained.

Results

The operation time was 30 – 241(97.9 ± 34.7) min. The visual analog scale score of lower limb pain decreased from 5.75 ± 0.81 before the operation to 0.39 ± 0.28 at the last follow-up (P &lt; 0.05). The Oswestry disability index score decreased from 66.48 ± 4.43 before the operation to 14.57 ± 3.99 at the last follow-up (P &lt; 0.05). The CUSUM assessment of operation time revealed the learning curve was the highest in 24 cases. In the learning stage (1–24 cases), the operation time was 120.3 ± 43.8 min. In the skilled stage (25–97 cases), the operation time was 90.5 ± 27.8 min.

Conclusions

About 24 cases of single segmental UBE operation are needed to master the UBE technique.

Case series of unilateral biportal endoscopic-assisted transforaminal lumbar interbody fusion in the treatment of recurrent lumbar disc herniation

OBJECTIVE

To explore the clinical effect of unilateral biportal endoscopic-assisted transforaminal lumbar interbody fusion (UBE-TLIF) in the treatment of recurrent lumbar disc herniation (RLDH).

METHODS

The clinical data of 44 patients with RLDH treated by UBE-TLIF in our hospital from August 2020 to December 2020 were analysed retrospectively. The study indicators included intraoperative blood loss, operation time, bed rest time, and hospital stay. The follow-up data included the visual analogue score (VAS) of low back pain, Japanese Orthopaedic Association score (JOA), Oswestry disability index (ODI) score, and the short form 36 health survey questionnaire (SF-36) score preoperatively and 1 week and 6 months postoperatively.

RESULTS

The average operation time was 179.15 ± 42.06 minutes, the average intraoperative blood loss was 132.67 ± 41.92 ml, the average bed rest time was 1.51 ± 0.42 days, and the average hospital stay was 4.82 ± 1.13 days. The VAS score of low back pain after the operation was lower than that before the operation (all P<0.0001). The ODI score, JOA score, and SF-36 scores at postoperative follow-up were significantly different from those before the operation (P<0.05). The satisfaction rate was 86.4% at 7 days after the operation and 95.4% at 6 months after the operation. The proportion of significant clinical efficacy was 18.2% (postoperative day 7) and 63.6% (postoperative month 6).

CONCLUSIONS

UBE-TLIF has the advantages of a rapid recovery, less intraoperative blood loss, a short bed rest and hospital stay, and a good medium-term clinical effect. It is a safe, reliable minimally invasive technique for surgical treatment of RLDH.

Differential Agnostic Effect Size Analysis of Lumbar Stenosis Surgeries

STUDY DESIGN

A meta-analysis of 89 randomized prospective, prospective, and retrospective studies on spinal endoscopic surgery outcomes.

OBJECTIVE

The study aimed to provide familiar Oswestry Disability Index (ODI), visual analog scale (VAS) back, and VAS leg effect size (ES) data following endoscopic decompression for sciatica-type back and leg pain due to lumbar herniated disc, foraminal, or lateral recess spinal stenosis.

BACKGROUND

Higher-grade objective clinical outcome ES data are more suitable than lower-grade clinical evidence, including cross-sectional retrospective study outcomes or expert opinion to underpin the ongoing debate on whether or not to replace some of the traditional open and with other forms of minimally invasive spinal decompression surgeries such as the endoscopic technique.

METHODS

A systematic search of PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials from 1 January 2000 to 31 December 2019 identified 89 eligible studies on lumbar endoscopic decompression surgery enrolling 23,290 patient samples using the ODI and VAS for back and leg pain used for the ES calculation.

RESULTS

There was an overall mean overall reduction of ODI of 46.25 (SD 6.10), VAS back decrease of 3.29 (SD 0.65), and VAS leg reduction of 5.77 (SD 0.66), respectively. Reference tables of familiar ODI, VAS back, and VAS leg show no significant impact of study design, follow-up, or patients' age on ES observed with these outcome instruments. There was no correlation of ES with long-term follow-up (P = 0.091). Spinal endoscopy produced an overall ODI ES of 0.92 extrapolated from 81 studies totaling 12,710 patient samples. Provided study comparisons to tubular retractor microdiscectomy and open laminectomy showed an ODI ES of 0.9 (2895 patients pooled from 16 studies) and 0.93 (1188 patients pooled from 5 studies). The corresponding VAS leg ES were 0.92 (12,631 endoscopy patients pooled from 81 studies), 0.92 (2348 microdiscectomy patients pooled from 15 studies), and 0.89 (1188 open laminectomy patients pooled from 5 studies).

CONCLUSION

Successful clinical outcomes can be achieved with various lumbar surgeries. ESs with endoscopic spinal surgery are on par with those found with open laminectomy and microsurgical decompression.

CLINICAL RELEVANCE

This article is a meta-analysis on the benefit overlap between lumbar endoscopy, microsurgical decompression, laminectomy, and lumbar decompression fusion.

LEVEL OF EVIDENCE: 2

Foundations in Spinal Endoscopy

Spinal endoscopy has revolutionized the way spine surgeons deliver minimally invasive care for appropriately selected patients. The evolution of endoscopy has been tumultuous since its beginnings as a "blind" percutaneous procedure to access the disk until the present state, in which complex decompressions and even fusions can be accomplished through subcentimeter incisions. Engineering has played a crucial role in this evolution with advances in optics, illumination, and instrumentation that have allowed surgeons to work safely and efficiently in smaller and smaller corridors. Finally, the adaptation of enhanced recovery after surgery protocols have complemented the benefits offered by spinal endoscopy to help patients return to the quality of life they seek through surgical intervention. In this article, we explore foundational elements of spinal endoscopy and look ahead to the future of this maturing field.

Unilateral Biportal Endoscopy for Decompression of Extraforaminal Stenosis at the Lumbosacral Junction: Surgical Techniques and Clinical Outcomes

Objective

The aims of this study were to describe the unilateral biportal endoscopic (UBE) technique for decompression of extraforaminal stenosis at L5–S1 and evaluate 1-year clinical outcomes. Especially, we evaluated compression factors of extraforaminal stenosis at L5–S1 and described the surgical technique for decompression in detail.

Methods

Thirty-five patients who underwent UBE decompression for extraforaminal stenosis at L5–S1 between March 2018 and February 2019 were enrolled. Clinical results were analyzed using the MacNab criteria, the visual analogue scale (VAS) for back and leg pain, and the Oswestry Disability Index (ODI). Compression factors evaluated pseudoarthrosis within the transverse process of L5 and ala of sacrum, disc bulging with or without osteophytes, and the thickened lumbosacral and extraforaminal ligament.

Results

The mean back VAS was 3.7±1.8 before surgery, which dropped to 2.3±0.8 at 1-year postoperative follow-up (p<0.001). There was a significant drop in postoperative mean VAS for leg pain from 7.2±1.1 to 2.3±1.2 at 1 year (p<0.001). The ODI was 61.5 before surgery and 28.6 (p<0.001). Pseudoarthrosis between the transverse process and the ala was noted in all cases (35 of 35, 100%). Pure disc bulging was seen in 12 patients (34.3%), and disc bulging with osteophytes was demonstrated in 23 patients. The thickened lumbosacral and extraforaminal ligament were identified in 19 cases (51.4%). No complications occurred in any of the patients.

Conclusion

In the current study, good surgical outcomes without complications were achieved after UBE decompression for extraforaminal stenosis at L5–S1.