Percutaneous Endoscopic Decompression in Lumbar Canal and Lateral Recess Stenosis - The Surgical Learning Curve

Learning Curve of Endoscopic Lumbar Discectomy - A Systematic Review and Meta-Analysis of Individual Participant and Aggregated Data

STUDY DESIGN

A systematic review and meta-analysis of individual participant and aggregated data.

OBJECTIVES

To define the learning curves of endoscopic discectomies using unified statistical methodologies.

METHODS

Searches returned 913 records, with 118 full-text articles screened. Studies of endoscopic lumbar spine surgery reporting outcomes by case order were included. Mixed-effects nonlinear, logistic, and beta meta-regressions prdwere conducted to define the learning curves.

RESULTS

13 studies involving 864 patients among 15 surgeons were included in total. For transforaminal endoscopic discectomy, the estimated operating time for the first case was 95 min [CI: 87-104], and the estimated plateau was 66 minutes [CI: 51-81]. An estimated 21 cases [CI: 18-25] were required to overcome 80% of this deficit, but near-plateau performance was expected only after 59 cases [CI: 51-70]. The estimated risk of surgical complications on the first case was 25% [CI: 11%-46%], with an 80% reduction in relative risk requiring an estimated 41 cases. The expected postoperative VAS leg pain score after the first case was 2.7 [CI: 1.8-3.8], with an 80% improvement requiring an estimated 96 cases. Similar numbers were required to overcome the learning curves in interlaminar and biportal endoscopic discectomies.

CONCLUSIONS

Approximately 60 cases are required to achieve proficiency in endoscopic lumbar spine surgery, although the greatest part of the learning curve can be overcome with 20 cases. This should be considered when designing implementation programmes for surgeons and service providers that wish to incorporate endoscopic spinal surgery into their practice.

Learning curve analyses in spine surgery: a systematic simulation-based critique of methodologies

BACKGROUND CONTEXT

Various statistical approaches exist to delineate learning curves in spine surgery. Techniques range from dividing cases into intervals for metric comparison, to employing regression and cumulative summation (CUSUM) analyses. However, their inherent inconsistencies and methodological flaws limit their comparability and reliability.

PURPOSE

To critically evaluate the methodologies used in existing literature for studying learning curves in spine surgery and to provide recommendations for future research.

STUDY DESIGN

Systematic literature review.

METHODS

A comprehensive literature search was conducted using PubMed, Embase, and Scopus databases, covering articles from January 2010 to September 2023. For inclusion, articles had to evaluate the change in a metric of performance during human spine surgery across time/a case series. Results had to be reported in sufficient detail to allow for evaluation of individual performance rather than group/institutional performance. Articles were excluded if they included cadaveric/nonhuman subjects, aggregated performance data or no way to infer change across a number of cases. Risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. Surgical data were simulated using Python 3 and then examined via multiple commonly used analytic approaches including division into consecutive intervals, regression and CUSUM techniques. Results were qualitatively assessed to determine the effectiveness and limitations of each approach in depicting a learning curve.

RESULTS

About 113 studies met inclusion criteria. The majority of the studies were retrospective and evaluated a single-surgeon's experience. Methods varied considerably, with 66 studies using a single proficiency metric and 47 using more than 1. Operating time was the most commonly used metric. Interval division was the simplest and most commonly used method yet inherent limitations prevent collective synthesis. Regression may accurately describe the learning curve but in practice is hampered by sample size and model choice. CUSUM analyses are of widely varying quality with some being fundamentally flawed and widely misinterpreted however, others provide a reliable view of the learning process.

CONCLUSION

There is considerable variation in the quality of existing studies on learning curves in spine surgery. CUSUM analyses, when correctly applied, offer the most reliable estimates. To improve the validity and comparability of future studies, adherence to methodological guidelines is crucial. Multiple or composite performance metrics are necessary for a holistic understanding of the learning process.

Unilateral biportal endoscopic discectomy via translaminar approach for highly upward-migrated lumbar disc herniation: a technical note and preliminary treatment outcomes

STUDY DESIGN

A technical note and retrospective case series.

OBJECTIVE

Highly upward-migrated lumbar disc herniation (LDH) is challenging due to its problematic access and incomplete removal. The most used interlaminar approach may cause extensive bony destruction. We developed a novel translaminar approach using the unilateral portal endoscopic (UBE) technique, emphasizing effective neural decompression, and preserving the facet joint's integrity.

METHODS

This retrospective study included six patients receiving UBE translaminar discectomy for highly upward-migrated LDHs from May 2019 to June 2021. The migrated disc was removed through a small keyhole on the lamina of the cranial vertebra. The treatment results were evaluated by operation time, hospital stays, complications, visual analog scale (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) score, and modified MacNab criteria.

RESULTS

The mean pre-operative VAS for back pain (5.0 ± 4.9), VAS for leg pain (9.2 ± 1.0), JOA score (10.7 ± 6.6), and ODI (75.7 ± 25.3) were significantly improved to 0.3 ± 0.5, 1.2 ± 1.5, 27.3 ± 1.8, 5.0 ± 11.3 respectively at the final follow-up. Five patients had excellent, and one patient had good outcomes according to the Modified MacNab criteria. The hospital stay was 2.7 ± 0.5 days. No complication was recorded. The MRI follow-up showed complete disc removal, except for one patient with an asymptomatic residual disc.

CONCLUSIONS

UBE translaminar discectomy is a safe and effective minimally invasive procedure for highly upward-migrated LDH with satisfactory treatment outcomes and nearly 100% facet joint preservation.

Recompression after percutaneous transforaminal endoscopic decompression for degenerative lumbar spinal stenosis: risk factors and outcomes of two different reoperation procedures

Purpose

To determine the risk factors for recompression after percutaneous transforaminal endoscopic decompression (PTED) for the treatment of degenerative lumbar spinal stenosis (DLSS) and compare the outcomes of PTED and posterior lumbar interbody fusion (PLIF) as revision surgery.

Methods

We retrospectively evaluated 820 consecutive DLSS patients who underwent PTED at our institution. 26 patients developed postoperative recompression and underwent reoperation. In total, 208 patients with satisfactory clinical outcomes were enrolled in the control group. The demographic and imaging data of each patient were recorded. Univariate and multivariate analyses were performed to assess risk factors for recompression. Additionally, patients with recompression were divided into PTED and PLIF groups according to the reoperation procedure. The clinical outcomes of the two groups were compared using independent-sample t-tests.

Results

The grade of surgical-level disc degeneration [odds ratio (OR): 2.551, p = 0.045] and the number of disc degeneration levels (OR: 11.985, p < 0.001) were independent risk factors for recompression after PTED. There was no significant difference in the visual analog score (VAS) and Oswestry disability index (ODI) two weeks postoperatively between the PTED and PLIF groups for surgical treatment. However, the mean VAS of back pain (14.1 vs. 20.5, p = 0.016) and ODI (16.0 vs. 21.8, p = 0.016) of patients in the PLIF group were smaller than those in the PTED group at the final follow-up.

Conclusion

More severe degeneration and degenerated levels indicate a higher recompression rate after PTED. Although both PTED and PLIF could achieve immediate relief postoperatively in the treatment of recompression, the final follow-up results showed that the outcome of PLIF appeared better than that of PTED.

Preliminary Clinical and Radiological Outcomes of the "No-Punch" Decompression Techniques for Unilateral Biportal Endoscopic Spine Surgery

OBJECTIVE

To avoid the most offending surgical instrument for dural tears, we develop a "no-punch" decompression technique for unilateral biportal endoscopic (UBE) spine surgery.

METHODS

This retrospective study enrolled 68 consecutive patients with degenerative lumbar spinal stenosis segments. The treatment results were evaluated using the visual analogue scale (VAS) for low back and leg pain, the Japanese Orthopaedic Association (JOA) scores, and the Oswestry Disability Index (ODI). Radiological outcomes were evaluated using the preoperative and postoperative magnetic resonance imaging.

RESULTS

This study included 36 male and 32 female patients who received 109 segments of decompression, with an average age of 68.7 (37-90 years). The average operation time was 52.2 minutes. The average hospital stay was 3.1 days. There were no dural tears but 3 minor surgical complications, all treated conservatively. The VAS for low back and leg pain improved from 4.6 and 7.0 to 0.8 and 1.2. The JOA score improved from 16.2 to 26.8, with an improvement rate of 82.0%. The ODI improved from 50.1 to 18.7. All these improvements were statistically significant. The cross-sectional dural area improved from 61.1 to 151.3 mm2, with an average increase of 90.2 mm2 and 205.3%. 87.1% of the ipsilateral facet joints and 84.7% of the contralateral facet joints were preserved. In 61% of the decompressed segments, the ipsilateral facet joints were preserved better than the contralateral facet joints.

CONCLUSION

The UBE "no-punch" decompression technique effectively avoids the dural tears. It provides effective neural decompression, excellent facet joint preservation, and good treatment outcomes.

Full endoscopic percutaneous stenoscopic lumbar decompression and discectomy: An outcome and efficacy analysis on 606 lumbar stenosis patients

Introduction

Laminectomy has long been a "gold standard" to treat symptomatic lumbar spinal stenosis (LSS). Minimal invasive spine surgery (MISS) is widely developed to overcome the limitations of conventional laminectomy to achieve a better outcome with minimal complications. Full endoscopic percutaneous stenoscopic lumbar decompression (FE-PSLD) is the newest MISS technique for spinal canal decompression. We aimed to evaluate and analyze the significance of FE-PSLD in reducing pain and its association with age, duration of symptoms, stenosis level, and operative time (OT).

Materials and Methods

A longitudinal cross-sectional study was conducted on 606 LSS patients who underwent FE-PSLD and enrolled from 2020 to 2022. Three-month evaluation of the Visual Analog Scale (VAS) and the modified MacNab criteria were assessed. The significance of changes was analyzed using the Wilcoxon signed-ranks test. Spearman's correlation test was performed to evaluate the significant correlation of several variables (pre-PSLD-VAS, age, symptoms duration, OT, and level of LSS) to post-PSLD-VAS, and multiple regression analysis was conducted.

Results

The reduction of VAS was statistically significant (P ≤ 0.005) with an average pre-PSLD-VAS of 6.75 ± 0.63 and post-PSLD-VAS of 2.24 ± 1.04. Pre-PSLD-VAS, age, and stenosis level have a statistically significant correlation with post-PSLD-VAS, while the duration of the symptoms and OT have an insignificant correlation. Multiple regression showed the effect of pre-PSLD-VAS (β =0.4033, P = 0.000) and stenosis level (β =0.0951, P = 0.021) are statistically significant with a positive coefficient.

Conclusions

FE-PSLD is an efficacious strategy with favorable outcomes for managing LSS, shown by a significant reduction of pain level with a relatively short follow-up time after the procedure. Preoperative pain level, age, and stenosis level are significantly correlated with postoperative pain level. Based on this experimental study, PSLD can be considered a good strategy for treating lumbar canal stenosis in all age groups and all LSS levels.

The novel Kambin Torpedo full-endoscopic lumbar interbody fusion technique: a case series

PURPOSE

Full-endoscopic lumbar interbody fusion (FELIF) is a new-generation treatment for spondylolisthesis. However, owing to their unique characteristics, the two main endoscopic fusion trajectories, the trans-Kambin and posterolateral approaches, have important limitations. Herein, we aimed to introduce a new technique called Kambin Torpedo FELIF (KT-FELIF).

METHODS

The KT-FELIF technique is based on the trans-Kambin approach. It additionally completes ipsilateral total facetectomy and contralateral direct decompression. Thus, this novel technique combines the advantages of the trans-Kambin and posterolateral approaches.

RESULTS

We reported on the indications and technical steps of KT-FELIF and provided intraoperative and animated videos to clarify the procedure. Short-term follow-up based on 3-month postoperative computed tomography and plain films images taken at least 3 months after surgery showed adequate bony decompression, a large bone graft contact area, and good intervertebral trabecular bone growth without radiolucent lines between the graft, cage, and end plate. The clinical results, such as ipsilateral and contralateral visual analog scale and Oswestry disability index values, gradually improved at 1 and 3 months postoperatively. No complications were observed.

CONCLUSIONS

KT-FELIF is a promising FELIF technique for achieving bilateral direct decompression through a unilateral approach while accomplishing thorough discectomy and endplate preparation.

Artificial intelligence-based analysis of associations between learning curve and clinical outcomes in endoscopic and microsurgical lumbar decompression surgery

PURPOSE

A common spine surgery procedure involves decompression of the lumbar spine. The impact of the surgeon's learning curve on relevant clinical outcomes is currently not well examined in the literature. A variety of machine learning algorithms have been investigated in this study to determine how a surgeon's learning curve and other clinical parameters will influence prolonged lengths of stay (LOS), extended operating times (OT), and complications, as well as whether these clinical parameters can be reliably predicted.

METHODS

A retrospective monocentric cohort study of patients with lumbar spinal stenosis treated with microsurgical (MSD) and full-endoscopic (FED) decompression was conducted. The study included 206 patients with lumbar spinal stenosis who underwent FED (63; 30.6%) and MSD (118; 57.3%). Prolonged LOS and OT were defined as those exceeding the 75th percentile of the cohort. Furthermore, complications were assessed as a dependent variable. Using unsupervised learning, clusters were identified in the data, which helped distinguish between the early learning curve (ELC) and the late learning curve (LLC). From 15 algorithms, the top five algorithms that best fit the data were selected for each prediction task. We calculated the accuracy of prediction (Acc) and the area under the curve (AUC). The most significant predictors were determined using a feature importance analysis.

RESULTS

For the FED group, the median number of surgeries with case surgery type at the time of surgery was 72 in the ELC group and 274 in the LLC group. FED patients did not significantly differ in outcome variables (LOS, OT, complication rate) between the ELC and LLC group. The random forest model demonstrated the highest mean accuracy and AUC across all folds for each classification task. For OT, it achieved an accuracy of 76.08% and an AUC of 0.89. For LOS, the model reached an accuracy of 83.83% and an AUC of 0.91. Lastly, in predicting complications, the random forest model attained the highest accuracy of 89.90% and an AUC of 0.94. Feature importance analysis indicated that LOS, OT, and complications were more significantly affected by patient characteristics than the surgical technique (FED versus MSD) or the surgeon's learning curve.

CONCLUSIONS

A median of 72 cases of FED surgeries led to comparable clinical outcomes in the early learning curve phase compared to experienced surgeons. These outcomes seem to be more significantly affected by patient characteristics than the learning curve or the surgical technique. Several study variables, including the learning curve, can be used to predict whether lumbar decompression surgery will result in an increased LOS, OT, or complications. To introduce the provided prediction tools into clinics, the algorithms need to be implemented into open-source software and externally validated through large-scale randomized controlled trials.

Surgical Technique of Central and Over-the-Top Full-Endoscopic Decompression of the Cervical Spine: A Technical Note

Endoscopic surgery of the cervical spine is constantly evolving and the spectrum of its indications has expanded in recent decades. Full-endoscopic techniques have standardized the procedures for posterior and anterior access. The full-endoscopic approach was developed to treat degenerative diseases with the least possible invasion and without causing instability of the cervical spine. The posterior full-endoscopic approach is indicated for the treatment of diseases of the lateral part of the vertebral segment, such as herniations and stenoses of the lateral recess and vertebral foramen. There has been little discussion of this approach to the treatment of central stenosis of the cervical spine. This technical note describes a step-by-step surgical technique for central and over-the-top full-endoscopic decompression in the cervical spine, using a 3.7 mm working channel endoscope. This technique has already been shown to be effective in a recent case series with a 4.7 mm working channel endoscope, and may represent a new treatment option for central or bilateral lateral recess stenosis. There is also the possibility of a bilateral full-endoscopic approach, but this may be associated with greater muscle damage and a longer operative time. Case series and comparative studies should be encouraged to confirm the safety and utility of this technique.

Modified facet joint fusion for multilevel lumbar spinal stenosis: a retrospective study of 135 consecutive patients

OBJECTIVE

To evaluate the safety and efficacy of modified facet joint fusion (MFF) for the treatment of multilevel (three-level or more) lumbar spinal stenosis (LSS).

PATIENTS AND METHODS

In this retrospective study, 135 consecutive patients who underwent initial MFF for multilevel LSS were included. Clinical outcomes included fusion rate, change of visual analogue scale pain scores for low back pain (VAS-LBP) and leg pain (VAS-LP), Japanese Orthopedic Association scores (JOA), Oswestry Disability Index (ODI) and MacNab classification before and after MFF. The complications were also analyzed.

RESULTS

The fusion rates were 46.7% (63/135) at 6-month and 89.6% (121/135) at 1-year. The mean VAS-LBP, VAS-LP, and ODI significantly decreased from 5.2 ± 0.6, 5.7 ± 0.8 and 65 ± 7.9 to 1.58 ± 0.4, 0.58 ± 0.3 and 20.8 ± 5.8, respectively (all p < 0.001). The mean JOA markedly improved from 10.0 ± 1.3 to 26.1 ± 1.5 (p < 0.001). Excellent/good results of MacNab classification were achieved in 88.9% (120/135) of the patients. The overall rate of complications after MFF was 5.9%, including poor wound healing (2.2%), calf muscular venous thrombosis (0.74%), deep venous thrombosis (0.74%), superficial wound infection (1.48%), transient foot drop (0.74%). All the complications were transient and improved without prolonged hospital stay and sequelae.

CONCLUSION

MFF may be safe and efficient for multilevel LSS with high fusion rate and significant symptom relief, which is worthy of further study.

Lumbar Endoscopic Unilateral Laminotomy With Bilateral Decompression Surgery in Severe Lumbar Stenosis Under Electrophysiological Monitoring-Focused on Full-Visualized Trephine/Osteotome

OBJECTIVE

Although endoscopic drill has the advantages in manipulation and hemostasis, whose low efficiency and blurred vision reduce the efficacy of lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). The present study was designed to evaluate the safety and efficacy of full-visualized trephine/osteotome in the LE-ULBD surgery for severe lumbar stenosis.

METHODS

Fifty-seven severe lumbar stenosis patients who underwent LE-ULBD between January 2020 to January 2023 were enrolled, who were divided into drill and visualized trephine groups. The medical records including demographics, operative duration, intraoperative electrophysiological findings, postoperative hospital stay or hospital stay, postoperative outcomes and complications were retrospectively reviewed and analyzed.

RESULTS

A total of 57 patients included 15 in drill and 42 in trephine group were enrolled in the study. There was significant difference in the pre- and postoperative visual analogue scale and Oswestry Disability Index scores in both groups (p < 0.05). The mean operative duration in the trephine group (101.05 ± 12.18 minutes) was shorter than that in the drill group (134.67 ± 9.68 minutes) (p < 0.05). There was no statistical difference between the 2 groups in electrophysiological monitoring, posthospital stays, postoperative outcomes and complications. Abnormal free-electromyography (EMG) were recorded in 2 (13.3%) and 5 patients (11.9%) in the drill and trephine group. Intraoperative somatosensory evoked potential changes occurred in 3 (20%) and 3 patients (7.1%) in the drill and trephine group and all patients recovered immediately when surgery ended. No serious complications and recurrence occurred in all the patients.

CONCLUSION

Full-visualized trephine/osteotome has been approved to be convenient, safe and efficient in our study, which combined with translaminar inside-out technique and EMG monitoring especially free-EMG may offer a new choice in LE-ULBD surgery for lumbar stenosis patients.

Uniportal versus biportal endoscopic spine surgery: a comprehensive review

INTRODUCTION

Endoscopic spine surgery techniques are minimally invasive alternatives to conventional open surgery for degenerative spinal diseases. Clinical studies and meta-analyses have proven the usefulness of uniportal full-endoscopic spine procedures. However, a steep learning curve is a critical barrier for endoscopic procedures. Recently, biportal endoscopic spine surgeries have been developed to make it easier for spine surgeons to learn and perform. Consequently, the biportal approach has gained popularity among aspiring endoscopic spine surgeons. This review compared the characteristics of uniportal and biportal surgeries to help spine surgeons perform endoscopic procedures more effectively.

AREA COVERED

The review analyzed English-language clinical literature in Core databases and compared uniportal and biportal endoscopic spine surgery techniques. Clinical studies have compared the technical principles of both techniques, and the authors suggested appropriate strategies for learning and practicing endoscopic procedures.

EXPERT OPINION

Uniportal, full-endoscopic spine surgery is a minimally invasive procedure that preserves muscles and uses a keyhole approach under local anesthesia. In contrast, biportal surgery is more familiar to a surgeon and can be performed more widely, although the keyhole approach is limited. Aspiring endoscopic spine surgeons can learn either method according to the surgeon's preference and the clinical situation.

Advancing Education in Endoscopic Spinal Navigation: Novel Methods and Technical Note

This report aims to demonstrate how to teach anatomy and understanding of spinal endoscopic vision and navigation using mnemonics. The authors present a new surgical technique for teaching endoscopic spinal navigation in a didactic manner with tips such as the "rule of the hand" and decomposition of the endoscopic navigation movement. We demonstrate how the surgery is seen and illustrate how images are projected onto the screen, then divide the navigation into spatial orientation and self-navigation. The article describes the proper puncture technique, how to introduce the working portal, and how to assimilate this new anatomical vision using the "rule of the hand." The surgeon projects their hand on the video screen to guide themselves when starting the navigation and uses the same technique to localize regions of interest during surgery. Finally, the authors break down the navigational movement into three components: forceps positioning, triangulation, and joystick motion. One of the biggest challenges when learning spinal endoscopic surgery is understanding the anatomy seen through the endoscope. By decomposing movements required for navigation, one can understand how to make proper use of the equipment as well as improve their knowledge of this "new anatomy." The learning methods taught in this article have the potential to decrease the learning curve and radiation exposure to those that are still acquainting themselves to spinal endoscopic navigation. We recommend that further studies measure and quantify the impact of these methods on surgical practice.

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.

Retrospective Case Control Study: Clinical and Computer Tomographic Fusion and Subsidence Evaluation for Single Level Uniportal Endoscopic Posterolateral Approach Transforaminal Lumbar Interbody Fusion Versus Microscopic Minimally Invasive Transforaminal Interbody Fusion

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

Assessment of difference in clinical and computer tomographic outcomes between the 2 cohorts.

METHODS

Computer tomographic evaluation by Bridwell's grade, Kim's stage, Kim's subsidence grade and clinical evaluation by VAS, ODI and McNab's criteria on both cohorts.

RESULTS

33 levels of Endo-TLIF and 22 levels of TLIF were included, with a mean follow up of 14.3 (10-24) and 22.9 (13-30) months respectively. Both Endo-TLIF and TLIF achieved significant improvement of pain and ODI at post-operative 4 week, 3 months and at final follow up with VAS 4.39 ± 0.92, 5.27 ± 1.16 and 5.73 ± 1.21in Endo-TLIF and 4.55 ± 1.16, 5.05 ± 1.11 and 5.50 ± 1.20 in TLIF respectively and ODI at post-operative 1 week, 3 months and final follow up were 43.15 ± 6.57, 49.27 ± 8.24 and 51.73 ± 9.09 in Endo-TLIF and 41.73 ± 7.98, 46.18± 8.46 and 49.09 ± 8.98 in TLIF respectively, P < 0.05. Compared to TLIF, Endo-TLIF achieved better VAS with 0.727 ± 0.235 at 3 months and 0.727 ± 0.252 at final follow up and better ODI with 3.88 ± 1.50 at 3months and 3.42 ± 1.63 at final follow up, P < 0.05. At 6 months radiological evaluation comparison of the Endo-TLIF and TLIF showed significant with more favorable fusion rate in Endo-TLIF of -0.61 ± 0.12 at 6 months and -0.49 ± 0.12 at 1 year in Bridwell's grading and 0.70 ± 0.15 at 6 months and 0.56 ± 0.14 at 1 year in Kim's stage.There is less subsidence of 0.606 ± 0.18 at 6 months and -0.561 ± 0.20 at 1 year of Kim's subsidence grade, P < 0.05.

CONCLUSION

Application of single level uniportal endoscopic posterolateral lumbar interbody fusion achieved better clinical outcomes and fusion rate with less subsidence than microscopic minimally invasive transforaminal lumbar interbody fusion in mid-term evaluation for our cohorts of patients.

Increased Surgeon-specific Experience and Volume is Correlated With Improved Clinical Outcomes in Lumbar Fusion Patients

STUDY DESIGN

The present study design was that of a single center, retrospective cohort study to evaluate the influence of surgeon-specific factors on patient functional outcomes at 6 months following lumbar fusion. Retrospective review of a prospectively maintained database of patients who underwent neurosurgical lumbar instrumented arthrodesis identified the present study population.

OBJECTIVE

This study seeks to evaluate surgeon-specific variable effects on patient-reported outcomes such as Oswestry Disability Index (ODI) and the effect of North American Spine Society (NASS) concordance on outcomes in the setting of variable surgeon characteristics.

SUMMARY OF BACKGROUND DATA

Lumbar fusion is one of the fastest growing procedures performed in the United States. Although the impact of surgeon-specific factors on patient-reported outcomes has been contested, studies examining these effects are limited.

METHODS

This is a single center, retrospective cohort study analyzing a prospectively maintained database of patients who underwent neurosurgical lumbar instrumented arthrodesis by 1 of 5 neurosurgery fellowship trained spine surgeons. The primary outcome was improvement of ODI at 6 months postoperative follow-up compared with preoperative ODI.

RESULTS

A total of 307 patients were identified for analysis. Overall, 62% of the study population achieved minimum clinically important difference (MCID) in ODI score at 6 months. Years in practice and volume of lumbar fusions were statistically significant independent predictors of MCID ODI on multivariable logistic regression ( P =0.0340 and P =0.0343, respectively). Concordance with evidence-based criteria conferred a 3.16 (95% CI: 1.03, 9.65) times greater odds of achieving MCID.

CONCLUSION

This study demonstrates that traditional surgeon-specific variables predicting surgical morbidity such as experience and procedural volume are also predictors of achieving MCID 6 months postoperatively from lumbar fusion. Independent of surgeon factors, however, adhering to evidence-based guidelines can lead to improved outcomes.

Case-matched radiological and clinical outcome evaluation of interlaminar versus microsurgical decompression of lumbar spinal stenosis

PURPOSE

Endoscopic spine surgery is a globally expanding technique advocated as less invasive for spinal stenosis treatment compared to the microsurgical approach. However, evidence on the efficiency of interlaminar full-endoscopic decompression (FED) vs. conventional microsurgical decompression (MSD) in patients with lumbar spinal stenosis is still scarce. We conducted a case-matched comparison for treatment success with consideration of clinical, laboratory, and radiologic predictors.

METHODS

We included 88 consecutive patients (FED: 36/88, 40.9%; MSD: 52/88, 59.1%) presenting with lumbar central spinal stenosis. Surgery-related (operation time, complications, length of stay (LOS), American Society of Anesthesiologists physical status (ASA) score, C-reactive protein (CRP), white blood cell count, side of approach (unilateral/bilateral), patient-related outcome measures (PROMs) (Oswestry disability index (ODI), numeric rating scale of pain (NRS; leg-, back pain), EuroQol questionnaire (eQ-5D), core outcome measures index (COMI)), and radiological (dural sack cross-sectional area, Schizas score (SC), left and right lateral recess heights, and facet angles, respectively) parameters were extracted at different time points up to 1-year follow-up. The relationship of PROMs was analyzed using Spearman's rank correlation. Surgery-related outcome parameters were correlated with patient-centered and radiological outcomes utilizing a regression model to determine predictors for propensity score matching.

RESULTS

Complication (most often residual sensorimotor deficits and restenosis due to hematoma) rates were higher in the FED (33.3%) than MSD (13.5%) group (p < 0.05), while all complications in the FED group were observed within the first 20 FED patients. Operation time was higher in the FED, whereas LOS was higher in the MSD group. Age, SC, CRP revealed significant associations with PROMs. We did not observe significant differences in the endoscopic vs. microsurgical group in PROMs. The correlation between ODI and COMI was significantly high, and both were inversely correlated with eQ-5D, whereas the correlations of these PROMs with NRS findings were less pronounced.

CONCLUSIONS

Endoscopic treatment of lumbar spinal stenosis was similarly successful as the conventional microsurgical approach. Although FED was associated with higher complication rates in our single-center study experience, the distribution of complications indicated surgical learning curves to be the main factor of these findings. Future long-term prospective studies considering the surgical learning curve are warranted for reliable comparisons of these techniques.

Unilateral microscopic approach for lumbar spinal stenosis decompression: a scoping review

BACKGROUND

Microscopic unilateral laminotomy for bilateral decompression (ULBD) is a minimally invasive technique used in the treatment of lumbar spinal stenosis and could limit spinal instability and be associated with better clinical outcomes. However, there is ongoing debate regarding its utility compared to conventional laminectomy (CL). The primary objective was to collate and describe the current evidence base for ULBD, including perioperative parameters, functional outcomes, and complications. The secondary objective was to identify operative techniques.

METHODS

A scoping review was conducted between January 1990 and August 2022 according to the PRISMA extension for scoping reviews (PRISMA-ScR) guidelines. Major databases were searched for full text English articles reporting on outcomes following microscopic unilateral laminotomy in patients with lumbar spinal stenosis.

RESULTS

Seventeen articles met the inclusion criteria. Two studies were randomised controlled trials. Two studies were prospective data collection and the rest were retrospective analysis. Three studies compared ULBD with CL. ULBD preserves the osteoligamentous complex and may be associated with shorter operative time, less blood loss, and similar clinical outcomes when compared to CL.

CONCLUSION

This review highlights that ULBD aims to minimise disruption to the normal posterior spinal anatomy and may have acceptable clinical outcomes. It also highlights that it is difficult to draw valid conclusions given there are limited data available as most studies identified were retrospective or did not have a comparator group.

Delta large-channel technique versus microscopy-assisted laminar fenestration decompression for lumbar spinal stenosis: a one-year prospective cohort study

PURPOSE

When it comes to treating lumbar spinal stenosis (LSS), a procedure known as microscope-assisted fenestration decompression has expediently become the gold standard. With the advancement of spinal endoscopy, the Delta large-channel approach has shown promising clinical outcomes in the management of lumbar spinal stenosis. However, case studies of this method being used to treat lumbar spinal stenosis are still uncommon. The purpose of this research was to examine how well microscopy-assisted laminectomy and the Delta large-channel approach work in treating LSS in the clinic.

METHODS

From May 2018 to June 2020, 149 patients diagnosed with LSS were divided into 80 patients in Delta large-channel technique groups (FE group) and 69 patients in microscope groups (Micro group). Lower back and lower limb pain were measured using the visual analogue scale (VAS-LBP and VAS-LP), while lower limb numbness was evaluated using the 11-point numerical rating scale (NRS-LN); modified Oswestry Disability Index (ODI) was used to evaluate the quality of life, and modified MacNab criteria were used to assess the clinical efficacy before surgery and at one week, three months, six months, and 12 months after surgery. All patients had single-level lumbar spinal stenosis, and clinical data such as hospital stay, operation time, intraoperative blood loss were statistically analyzed.

RESULTS

Finally, 111 patients (62 in FE group and 49 in Micro group) completed follow-up. Compared with preoperative results, postoperative VAS-LBP, VAS-LP, NRS-LN score and modified ODI score were significantly improved in 2 groups (P < 0.05), but there was no significant difference in postoperative follow-up at each time point (P > 0.05), Except 1 week after surgery, VAS-LBP in FE group was lower than that in Micro group (P < 0.05). It is noteworthy that the FE group had a shorter hospital stay, less intraoperative blood loss, and a quicker time of getting out of bed when compared with the microscope group，but the operation time was just the opposite (P < 0.05). The excellent and good rate was 83.87% in FE group and 85.71% in Micro group (P > 0.05).

CONCLUSIONS

Both microscope-assisted laminar fenestration decompression and Delta large-channel procedures provide satisfactory treatment outcomes, however the Delta large-channel approach has some potential advantages for the treatment of LSS, including quicker recovery and sooner reduced VAS-LBP. Long-term consequences, however, will necessitate additional follow-up and research.

Identification of preoperative radiological risk factors for reoperation following percutaneous endoscopic lumbar decompression to treat degenerative lumbar spinal stenosis

Background

This study aimed to identify radiological risk factors associated with reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS).

Methods

The preoperative clinical data of 527 consecutive patients with DLSS who underwent PTED were retrospectively reviewed. Overall, 44 patients who underwent reoperation were matched for age, sex, body mass index, and surgical segment to 132 control patients with excellent or good clinical outcomes. Radiological characteristics were compared between the groups using independent sample t-tests and Pearson's chi-square tests. A predictive model was established based on multivariate logistic regression analysis.

Results

The analyses revealed significant differences in the presence of lumbosacral transitional vertebra (LSTV, 43.2% vs. 17.4%, p = 0.001), the number of levels with senior-grade disc degeneration (2.57 vs. 1.96, p = 0.018) and facet degeneration (1.91 vs. 1.25 p = 0.002), and the skeletal muscle index (SMI, 849.7 mm²/m² vs. 1008.7 mm²/m², p < 0.001) between patients in the reoperation and control groups. The results of the logistic analysis demonstrated that LSTV (odds ratio [OR] = 2.734, 95% confidence interval [CI]:1.222-6.117, p < 0.014), number of levels with senior-grade facet degeneration (OR = 1.622, 95% CI:1.137-2.315, p = 0.008), and SMI (OR = 0.997, 95% CI:0.995-0.999, p = 0.001) were associated with reoperation after PTED. The application of the nomogram based on these three factors showed good discrimination (area under the receiver operating characteristic curve 0.754, 95% CI 0.670-0.837) and good calibration.

Conclusion

LSTV, more levels with senior-grade facet degeneration, and severe paraspinal muscle atrophy are independent risk factors for reoperation after PTED. These factors can thus be used to predict reoperation risk and to help tailor treatment plans for patients with DLSS.

Full Endoscopic Ligamentum Flavum Sparing Unilateral Laminotomy for Bilateral Recess Decompression: Surgical Technique and Clinical Results

OBJECTIVE

Interlaminar endoscopic spine surgery has been introduced and utilized for lumbar lateral recess decompression. We modified this technique and utilized it for bilateral lateral recess stenoses without significant central stenosis. Here we present the surgical details and clinical outcome of ligamentum flavum sparing unilateral laminotomy for bilateral recess decompression (ULBRD).

METHODS

Prospectively collected registry for full-endoscopic surgeries was reviewed retrospectively. One hundred eighty-two consecutive cases from a single center between September 2015 and March 2021 were reviewed and 57 of them whom underwent ULBRD were enrolled for analysis. Basic patient demographic data, perioperative details, surgeryrelated complications, and clinical outcome were reviewed. The detailed surgical technique is presented as well.

RESULTS

Among the 57 patients enrolled, 37 were males while the other 20 were females. The mean age was 58.53 ± 14.51 years, and a bimodal age distribution at the age of mid-fifties and mid-sixties or older was noted. The later age-peak was related to coexistence of degenerative scoliosis. The average operative time per lamina was 70.34 ± 20.51 minutes and mean length of stay was 0.56 ± 0.85 days. Four perioperative complications were reported (7.0%) and the overall reoperation rate at the index level within 1 year was 8.8%. The preoperative back/leg visual analogue scale scores and functional outcome scales including EuroQol-5 dimension questionnaire, Oswestry Disability Index presented significant improvement immediately after surgery and were maintained until final follow-up.

CONCLUSION

ULBRD for bilateral lateral recess stenoses without significant central stenosis resulted in good clinical outcomes with acceptably low perioperative complications rates. Sufficient decompression was achieved with the central ligamentum flavum being preserved.

Full-endoscopic versus microscopic unilateral laminotomy for bilateral decompression of lumbar spinal stenosis at L4-L5: comparative study

PURPOSE

Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD.

METHODS

The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24 months.

RESULTS

There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate.

CONCLUSIONS

LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Early Readmission and Reoperation After Percutaneous Transforaminal Endoscopic Decompression for Degenerative Lumbar Spinal Stenosis: Incidence and Risk Factors

PURPOSE

To identify the incidence rates and risk factors for early readmission and reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS).

PATIENTS AND METHODS

A total of 1011 DLSS patients who underwent PTED were retrospectively evaluated. Of them, 58 were readmitted, and 31 underwent reoperation. The patients were matched with 174 control patients to perform case-control analyses. The clinical and preoperative imaging data of each patient were recorded. Univariate analyses were performed using independent sample t-tests and Fisher's exact tests. Furthermore, the risk factors for early readmission and reoperation were analyzed using multivariate logistic regression analyses.

RESULTS

The incidence rates of readmission and reoperation within 90 days after PTED were 5.7% and 3.1%, respectively. Age (odds ratio [OR]=1.054, p=0.001), BMI (OR=1.104, p=0.041), a history of lumbar surgery (OR=3.260, p=0.014), and the number of levels with radiological lumbar foraminal stenosis (LFS, OR=2.533, p<0.001) were independent risk factors for early readmission. The number of levels with radiological LFS (OR=5.049, p<0.001), the grade of surgical-level facet joint degeneration (OR=2.010, p=0.023), and a history of lumbar surgery (OR=10.091, p<0.001) were independent risk factors for early reoperation.

CONCLUSION

This study confirmed that aging, a higher BMI, a history of lumbar surgery, and more levels with radiological LFS were associated with a higher risk of early readmission. More levels with radiological LFS, a higher grade of surgical-level facet joint degeneration, and a history of lumbar surgery were predictors of early reoperation. These results are helpful in patient counseling and perioperative evaluation of PTED.

Remodeling Pattern of Spinal Canal after Full Endoscopic Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: One Year Repetitive MRI and Clinical Follow-Up Evaluation

Objective: There is limited literature on repetitive postoperative MRI and clinical evaluation after Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. Methods: Clinical visual analog scale, Oswestry Disability Index, McNab’s criteria evaluation and MRI evaluation of the axial cut spinal canal area of the upper end plate, mid disc and lower end plate were performed for patients who underwent single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression. From the evaluation of the axial cut MRI, four types of patterns of remodeling were identified: type A: continuous expanded spinal canal, type B: restenosis with delayed expansion, type C: progressive expansion and type D: restenosis. Result: A total of 126 patients with single-level Uniportal Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression were recruited with a minimum follow-up of 26 months. Thirty-six type A, fifty type B, thirty type C and ten type D patterns of spinal canal remodeling were observed. All four types of patterns of remodeling had statistically significant improvement in VAS at final follow-up compared to the preoperative state with type A (5.59 ± 1.58), B (5.58 ± 1.71), C (5.58 ± 1.71) and D (5.27 ± 1.68), p < 0.05. ODI was significantly improved at final follow-up with type A (49.19 ± 10.51), B (50.00 ± 11.29), C (45.60 ± 10.58) and D (45.60 ± 10.58), p < 0.05. A significant MRI axial cut increment of the spinal canal area was found at the upper endplate at postoperative day one and one year with type A (39.16 ± 22.73; 28.00 ± 42.57) mm2, B (47.42 ± 18.77; 42.38 ± 19.29) mm2, C (51.45 ± 18.16; 49.49 ± 18.41) mm2 and D (49.10 ± 23.05; 38.18 ± 18.94) mm2, respectively, p < 0.05. Similar significant increment was found at the mid-disc at postoperative day one, 6 months and one year with type A (55.16 ± 27.51; 37.23 ± 25.88; 44.86 ± 25.73) mm2, B (72.83 ± 23.87; 49.79 ± 21.93; 62.94 ± 24.43) mm2, C (66.85 ± 34.48; 54.92 ± 30.70; 64.33 ± 31.82) mm2 and D (71.65 ± 16.87; 41.55 ± 12.92; 49.83 ± 13.31) mm2 and the lower endplate at postoperative day one and one year with type A (49.89 ± 34.50; 41.04 ± 28.56) mm2, B (63.63 ± 23.70; 54.72 ± 24.29) mm2, C (58.50 ± 24.27; 55.32 ± 22.49) mm2 and D (81.43 ± 16.81; 58.40 ± 18.05) mm2 at postoperative day one and one year, respectively, p < 0.05. Conclusions: After full endoscopic lumbar decompression, despite achieving sufficient decompression immediately postoperatively, varying severity of asymptomatic restenosis was found in postoperative six months MRI without clinical significance. Further remodeling with a varying degree of increment of the spinal canal area occurs at postoperative one year with overall good clinical outcomes.

Postoperative Paraspinal Muscles Assessment After Endoscopic Stenosis Lumbar Decompression: Magnetic Resonance Imaging Study

BACKGROUND CONTEXT

Conventional open lumbar decompression is a widely accepted procedure for degenerative lumbar disease. However, it is associated with morbidity due to damage to the paraspinal muscles and posterior ligamentous complex. Endoscopic spine surgery (ESS) is considered the least invasive type of spine surgery in modern times and was developed to minimize the iatrogenic injury to the paraspinal muscles.

PURPOSE

Many studies are reported to estimate the paraspinal muscle damage after an open or minimal invasive spine surgery by radiological methods (magnetic resonance imaging [MRI] and computed tomography], biochemistry (creatinine phosphokinase level), or electrophysiology (electoneuromyography). The objectives of this study were to assess paraspinal muscles changes after lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD) based on preoperative and 6-month postoperative MRIs.

PATIENT SAMPLE

We studied 159 consecutive patients with lumbar degenerative disease who underwent LE-ULBD at a spine specialty hospital from 2018 to 2019.

STUDY DESIGN

The current study was a single-center, single-surgeon, retrospective case study.

OUTCOME MEASURES

Changes of paraspinal muscles after LE-ULBD measured on lumbar MRI.

METHODS

Postoperative paraspinal muscles changes are evaluated on a picture archiving and communication system by measuring the cross-sectional area (CSA) of multifidus and erector spinae muscles along with the fatty infiltration of muscle on Kjaer's scale at the level of surgery on the ipsilateral and contralateral sides on T1W image. Correlations between imaging and visual analog scale (VAS) score for back, Oswestry Disability Index (ODI), and MacNab's criteria were examined in the preoperative and postoperative periods.

RESULTS

Of the 159 patients included, 120 underwent a single level procedure and 39 a multilevel procedure. For single-level LE-ULBD group, mean (SD) preoperative, postoperative, and final follow-up VAS score (7.83 [1.37], 3.15 [0.67] and 2.19 [0.88]; P < 0.001) and ODI (74.09 [7.18], 27.88 [4.40], and 23.88 [4.56]; P < 0.001) improved significantly. Based on MacNab's criteria, the clinical result was excellent in 37 patients, good in 78 patients, and fair in 5 patients. For the multilevel LE-ULBD group, the mean (SD) preoperative, postoperative, and final follow-up VAS score (7.84 [1.38], 3.50 [0.60],and 2.44 [0.79]; P < 0.001) and ODI (74.1 [7.72], 31.30 [4.46], and 24.90 [4.75]; P < 0.001) also improved significantly . Based on MacNab's criteria, the clinical result was excellent in 6 patients, good in 31 patients, and fair in 2 patients.The functional CSA of paraspinal muscles for both groups showed no significant difference in the 6-month follow-up MRI. The fatty infiltration of paraspinal muscles significantly improved from 0.77 to 0.59 (P < 0.05) for the single level LE-ULBD group but not for the multilevel LE-ULBD group (P = 0.320). The mean dural sac CSA increased significantly for both groups (P < 0.001).

CONCLUSION

Adequate neural decompression can be achieved with the preservation of paraspinal muscles after an ESS. Preservation of the paraspinal muscles along with the posterior ligamentous complex improves the stability of motion segment in the postoperative period, which ultimately results in better patient outcomes in related to postoperative pain and rehabilitation.Key.

Perspective on the integration of optical sensing into orthopedic surgical devices

SIGNIFICANCE

Orthopedic surgery currently comprises over 1.5 million cases annually in the United States alone and is growing rapidly with aging populations. Emerging optical sensing techniques promise fewer side effects with new, more effective approaches aimed at improving patient outcomes following orthopedic surgery.

AIM

The aim of this perspective paper is to outline potential applications where fiberoptic-based approaches can complement ongoing development of minimally invasive surgical procedures for use in orthopedic applications.

APPROACH

Several procedures involving orthopedic and spinal surgery, along with the clinical challenge associated with each, are considered. The current and potential applications of optical sensing within these procedures are discussed and future opportunities, challenges, and competing technologies are presented for each surgical application.

RESULTS

Strong research efforts involving sensor miniaturization and integration of optics into existing surgical devices, including K-wires and cranial perforators, provided the impetus for this perspective analysis. These advances have made it possible to envision a next-generation set of devices that can be rigorously evaluated in controlled clinical trials to become routine tools for orthopedic surgery.

CONCLUSIONS

Integration of optical devices into surgical drills and burrs to discern bone/tissue interfaces could be used to reduce complication rates across a spectrum of orthopedic surgery procedures or to aid less-experienced surgeons in complex techniques, such as laminoplasty or osteotomy. These developments present both opportunities and challenges for the biomedical optics community.

Technical Notes of Full Endoscopic Lumbar Interbody Fusion with Anterior Expandable Cylindrical Fusion Cage: Clinical and Radiographic Outcomes at 1-Year Follow-Up

OBJECTIVE

We sought to introduce technical notes of full endoscopic lumbar interbody fusion (FE-LIF) with an anterior expandable cylindrical fusion cage.

METHODS

This study retrospectively reviewed patients who underwent FE-LIF with an anterior expandable cylindrical fusion cage through transforaminal or interlaminar approaches from August 2018 to April 2019. Patient demographics and operation-related complications were recorded. Clinical and radiologic outcomes were evaluated at 1 year after surgery.

RESULTS

A total of 32 patients (34 segments) were included in this study. Among them, 14 received full endoscopic transforaminal lumbar interbody fusion and 18 received full endoscopic interlaminar lumbar interbody fusion. There were significant differences in interbody fusion indications between the 2 groups (P < 0.05). All operations were successfully completed without complications. Postoperative lumbar magnetic resonance imaging showed that nerve decompression was sufficient in all patients, and the visual analog scale scores of low back pain and leg pain, the Oswestry Disability Index scores, and sensory and muscle strength were significantly improved after surgery (P < 0.01). The MacNab score included 9 excellent ratings, 4 good ratings, and 1 fair rating in the full endoscopic transforaminal lumbar interbody fusion group and included 10 excellent ratings and 8 good ratings in the full endoscopic interlaminar lumbar interbody fusion group; the scores were not significantly different between the 2 groups at 1 year after surgery (P > 0.05). Complete interbody fusion was achieved in both groups according to computed tomography at 1 year after surgery.

CONCLUSIONS

FE-LIF is a safe and effective minimally invasive lumbar surgery with an anterior expandable cylindrical fusion cage.

Spinal subdural hematoma after interlaminar full-endoscopic decompression of lumbar spinal stenosis: a case report and literature review

The use of full-endoscopic decompression for lumbar spinal stenosis has been increasing recently. It is a minimally invasive surgical procedure that has few complications. Spinal subdural hematoma (SSH) following endoscopic surgery has never been reported. Previously described SSHs have occurred spontaneously or due to surgery-related iatrogenic injury. We describe the first case of SSH after endoscopic decompression. A 68-year-old woman presented with bilateral radiating pain and neurological claudication due to lumbar spinal stenosis at the L4-5 level. Full-endoscopic interlaminar decompression was performed without intraoperative complications. Preoperative leg pain improved after endoscopic decompression. However, two days after the index surgery, the patient complained of severe radiating pain in her right leg with urinary retention. The radiologic evaluation showed compressive subdural fluid collection at the index level. Open microscopic decompression was performed. No dural injury was observed. After durotomy, xanthochromic fluid gushed out at a high pressure. We found that the arachnoid was also intact. The patient recovered completely after surgical hematoma evacuation. Although SSH after endoscopic decompression is a very rare event, it is a reminder that suspicion and urgent imaging and intervention are necessary during the postoperative period upon development of unexpected, progressive neurological deterioration regardless of intraoperative problems. Additionally, early surgical decompression is necessary for optimal neurological recovery.

Early Career Challenges in Setting Up an Endoscopic Spine Surgery Practice

After the completion of an endoscopic spinal surgery fellowship, the next challenge for the newly minted consultant is to set up a viable and sustainable endoscopic practice. A successful practice of endoscopic spine surgery is dependent on several factors, such as anesthetic support; surgical expertise; support for provision and maintenance of endoscopic equipment; cost of equipment; administrative and nursing support; postoperative care services to optimize patients' outcome and satisfaction; patients' ideas, concerns, and expectations, as well as continuing medical education. In this article, a perspective is given on the early career challenges that a fellowship-trained endoscopic surgeon may encounter in the period leading to first successful endoscopic spinal surgery.

Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression Outside-In Approach: A Proctorship Guideline With 12 Steps of Effectiveness and Safety

Minimally invasive spinal surgery in particular lumbar endoscopic unilateral laminotomy with bilateral decompression becomes popular as it can be performed with regional anesthesia, soft tissue damages are minimized as endoscopic visualization and instruments can be brought close to operating area bypassing much of the intervening soft tissues for sufficient spinal decompression with ligamentum flavum resection despite less bony resection compared to open surgery. Overall, when well executed, it preserves spinal stability. Outside-in technique of decompression is also known as over the top decompression in minimally invasive literature. It involves maintaining deep layer of ligamentum flavum integrity till satisfactory bony decompression is achieved. Deep layer of ligamentum flavum is removed as final step of decompression. Preservation of the deep layer of ligamentum flavum protects the neural elements, allowing drills and sharp equipment to be used safely to perform bony decompression.In this study, we demonstrate the technical details of outside-in approach lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD). LE-ULBD Outside-in Technique is an effective and safe procedure in relieving lumbar spinal stenosis with favorable results with a follow-up for more than 1 year.

A Narrative Review of Development of Full-Endoscopic Lumbar Spine Surgery

In the first phase of development of lumbar endoscopic spine surgery, the focus was on removal of soft disc material through the working corridor of Kambin’s triangle using transforaminal endoscopic lumbar discectomy. With the introduction of the interlaminar approach and increased interest from both industry and surgeons, there has been an exponential development of endoscopic surgical equipment and a corresponding expansion of endoscopic techniques. Endoscopic treatment strategies are applied to conditions ranging from contained prolapsed intervertebral discs to noncontained migrated herniated discs, hard calcified discs, spinal stenosis in the central or lateral recess and the foraminal and extraforaminal region, and other combinations of degenerative conditions requiring decompression or fusion surgery. The further expansion of endoscopic surgical management involving complicated spinal cases and the final quartet of trauma, infections, tumors, and possibly deformities could be the future stage of endoscopic spine surgery development. This article covers the full range of current treatment strategies and presents possible future developments of endoscopic spine surgery for the management of lumbar spinal conditions.

Outcome of lumbar lateral recess stenosis with percutaneous endoscopic transforaminal decompression in patients 65 years of age or older and in younger patients

Lateral recess stenosis is a common pathology causing clinical syndromes in the elderly population, and there is some concern regarding the number of comorbidities that can occur when performing surgery for this condition in the elderly. However, little research has focused on the issues related to older age, and limited data is available to help the clinician counsel elderly patients undergoing percutaneous endoscopic transforaminal decompression. The present study aimed to explore the safety and efficacy of percutaneous endoscopic transforaminal decompression for lumbar degenerative disease in elderly patients with lumbar lateral recess stenosis and to determine whether age and comorbidity affect the outcome and complication rate.We identified 117 patients in our patient database who underwent percutaneous endoscopic transforaminal decompression for single-level lumbar lateral recess stenosis. Data regarding the Oswestry Disability Index and visual analog scale for back and leg pain were collected preoperatively, postoperatively, and at the last follow-up. Other data, including preoperative comorbidities, operation time, and intraoperative and postoperative complications, were recorded.The average follow-up period was 29.9 ± 5.5 months, with a mean age of 69.8 ± 5.4 years in elderly patients (group A) and 50.4 ± 6.4 years in younger patients (group B). Group A had a higher percentage of comorbidity than group B (83.9% vs 18.0%, P < .001). Both visual analog scale scores for leg pain and Oswestry Disability Index were significantly improved in the 2 groups, and no difference was found between the groups regarding both parameters (P >.05). The elderly patients had the same high rate of favorable outcomes as group B (P > .05). Moreover, there was no difference in surgical complications, recurrence, and neurologic deficit recovery rate between both groups. No major complications or perioperative deaths occurred in both groups.The present study demonstrates that percutaneous endoscopic transforaminal decompression for lateral recess stenosis in elderly patients may be a reasonable treatment associated with substantial benefit.

Technical Considerations in Endoscopic Lumbar Decompression

With technical development and evolution of endoscopic instruments, endoscopic spinal surgery has become one of the standard treatments for various lumbar spinal diseases ranging from a simple contained disc to complicated cases such as highly migrated disc herniation and other pathology combined with bony degeneration to produce foraminal and canal stenosis. Favorable clinical results of endoscopic decompression for lumbar stenotic disease were reported by several authors. However, studies have also reported limitations, such as steep learning curves and a relatively high complication rate compared with conventional techniques. The endoscopic lumbar decompression technique consists of many essential skills to manage different endoscopic anatomic structures of the spine. From the perspective of surgical completion and safety, this article discusses issues related to technical considerations in endoscopic lumbar decompression.

Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion with Endoscopic Disc Drilling Preparation Technique for Symptomatic Foraminal Stenosis Secondary to Severe Collapsed Disc Space: A Clinical and Computer Tomographic Study with Technical Note

Background: Severe collapsed disc secondary to degenerative spinal conditions leads to significant foraminal stenosis. We hypothesized that uniportal posterolateral transforaminal lumbar interbody fusion with endoscopic disc drilling technique could be safely applied to the collapsed disc space to improve patients’ pain score, restore disc height, and correct the segmental angular parameters. Methods: We included patients who met the indication criteria for lumbar fusion and underwent uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion with pre-operative Computer Tomography mid disc height of less than or equal to 5 mm and MRI of Grade 3 Foraminal Stenosis. Visual analogue scale and computer tomography pre-operative and post-operative sagittal disc height in the anterior, middle and posterior part of the disc; sagittal focal segmental angle; mid coronal disc height and coronal wedge angles were evaluated. Results: 30 levels of Endo-TLIF were included, with a mean follow up of 12 months. The mean improvement in decreasing pain score was 2.5 ± 1.1, 3.2 ± 0.9 and 4.3 ± 1.0 at 1 week post operation, 3 months post operation and at final follow up, respectively, p < 0.05. There was significant increase in mid sagittal computer tomographic anterior, middle and posterior disc height of 6.99 ± 2.30, 6.28 ± 1.44, 5.12 ± 1.79 mm respectively, p < 0.05. CT mid coronal disc height showed an increase of 7.13 ± 1.90 mm, p < 0.05. There was a significant improvement in the CT coronal wedge angle of 2.35 ± 4.73 and the CT segmental focal sagittal angle of 1.98 ± 4.69, p < 0.05. Conclusion: Application of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion in patients with severe foraminal stenosis secondary to severe collapsed disc space significantly relieved patients’ pain and restored disc height without early subsidence or exiting nerve root dysesthesia in our cohort of patients.

Clinical Comparison of Full-Endoscopic and Microscopic Unilateral Laminotomy for Bilateral Decompression in the Treatment of Elderly Lumbar Spinal stenosis: A Retrospective Study with 12-Month Follow-Up

Purpose

Although lumbar spinal stenosis (LSS) is the most common spinal disease in the elderly, there is still a confusion about the appropriate surgical treatment strategy. The aim of this study was to compare the safety and efficacy of full-endoscopic and microscopic unilateral laminotomy for bilateral decompression (ULBD) for LSS in elderly patients.

Patients and Methods

A retrospective analysis of 61 consecutive elderly patients with LSS who underwent either full-endoscopic (FE group) or microscopic (Micro group) unilateral laminotomy for bilateral decompression was performed. Clinical data were assessed before 2 weeks, 3 months, 6 months and 12 months after surgery using the Visual Analog Scale (VAS), the Oswestry Disability Index (ODI) and the modified MacNab criteria.

Results

There are no significant differences in VAS (back and leg) and ODI between the two groups. However, the VAS back pain in the FE group was significantly improved compared to the Micro group at 2 weeks. The rate of excellent or good outcomes was 87.88% and 85.71% in the FE and Micro group, respectively (P>0.05). The hospital stay and early ambulation in FE group were shorter than those in Micro group, but the operation time was longer (P<0.05). The complications between the FE group (18.18%) and the Micro group (17.86%) were minor (P>0.05).

Conclusion

Both full-endoscopic and microscopic decompression have achieved favorable clinical results in treating elderly lumbar spinal stenosis, and the complications are minor. Full-endoscopic decompression has the advantages of small incision and rapid recovery, which can be used as an alternative for the treatment of lumbar spinal stenosis, especially the elderly with comorbidities.

Technical Considerations of Uniportal Endoscopic Posterolateral Lumbar Interbody Fusion: A Review of Its Early Clinical Results in Application in Adult Degenerative Scoliosis

BACKGROUND

Uniportal endoscopic posterolateral lumbar interbody fusion (Endo-TLIF) provides one of the least invasive forms of minimally invasive surgery, allowing large size cages which are commercially available for open and tubular microscopic transforaminal lumbar interbody fusion (TLIF) to be inserted through this approach. We studied the effect of such a technique on a series of patients with low-grade degenerative scoliosis.

METHODS

Endo-TLIF was applied to patients who had 10°-40° of degenerative adult scoliosis. Pre- and postoperative 1-week, 3-month, and final follow-up clinical status of visual analog scale, Oswestry Disability Index, perioperative complications, and Macnab criteria were collected. Roentgenogram to assess changes in Cobb angles was done.

RESULTS

There was statistically significant improvement of preoperative, 1-week postoperative, 3-month postoperative, and final follow-up mean of visual analog scale scores with 7.72 (5-10), 3.68 (3-6), 2.88 (2-4), and 1.96 (1-3), respectively, and with Oswestry Disability Index mean of 70.4 (52-86), 35.12 (26-56), 27.68 (24-38), and 24 (20-28), respectively (P < 0.05). In terms of Macnab criteria, 100% had good to excellent result. In terms of scoliosis measured by Cobb angle, there was statistically significant improvement.

CONCLUSIONS

Endo-TLIF is a safe and effective procedure in mild to moderate degenerative scoliosis with good early clinical results and improvement in coronal Cobb angle. It can be considered as an option if a short segment(s) fusion is planned for adult degenerative scoliosis.

Comparative study between full-endoscopic laminectomy and microendoscopic laminectomy for the treatment of lumbar spinal canal stenosis

Background

Lumbar spinal canal stenosis (LSCS) is a common disease in the elderly. Although surgical decompression using a posterior approach is commonly used to treat LSCS, there are several different strategies. We compared the outcomes of uniportal full-endoscopic laminectomy (FEL) and microendoscopic laminectomy (MEL) for treating LSCS.

Methods

FEL was performed using a 6.4-mm working channel endoscope and MEL was performed using a 16-mm diameter tubular retractor and endoscope. Patients with LSCS treated with FEL (n=60) and MEL (n=54) in our hospital during the same period were retrospectively reviewed. Patient background information and operative data were collected. The satisfaction score was also recorded at discharge and 3 months postoperatively.

Results

The mean operation time for FEL and MEL was 77.8 min and 54.6 min, respectively. The mean hospital stay after FEL and MEL surgery was 2.1 days and 4.7 days, respectively. These outcomes were significantly different between the two approaches. The satisfaction scores at both stages were not significantly different between the two groups. A dural tear occurred in one patient who underwent FEL and three patients who underwent MEL, but no symptoms resulted from the tear. Although postoperative hematoma occurred in seven who underwent FEL and two who underwent MEL, only one patient who underwent FEL required operative evacuation of the hematoma.

Conclusions

FEL using a 6.4-mm working channel endoscope can be used to treat patients with LSCS. Shortening of the operation time and prevention of postoperative hematoma are essential for this approach to be completely superior to MEL.

Unilateral biportal endoscopic decompression for degenerative lumbar canal stenosis

Background

Unilateral biportal endoscopic (UBE) decompression is a minimally invasive (MI) approach to treat degenerative lumbar canal stenosis (DLCS). Decompression can be performed in a clear and magnified surgical field with proper control of normal saline inflow and outflow.

Methods

Clinical and radiographic data of 81 consecutive patients of DLCS treated between July 2018 and Feb 2019 using UBE techniques were reviewed. They were 38 males and 43 females with an average age of 70.2. Sixty-nine had pure canal stenosis and 12 patients had associated spondylolisthesis. Bilateral decompression via unilateral laminotomy was performed from the side on patients with more severe neurological symptoms. This is a retrospective study from chart review and image analysis. Therefore, we don't have formal ethical information for this study, and it is not mandatory in our hospital.

Results

At the final follow-up, the mean VAS for low back pain was improved from 4.3±3.0 to 1.2±1.0 and the VAS for leg symptoms was improved from 7.3±2.2 to 0.9±0.7. The mean JOA score and ODI was significantly improved from 13.3±7.9 to 25.3±5.0 and from 54.6±16.9 to 14.6±12.6, respectively. Modified Macnab criteria were excellent in 47 patients (58.0%), good in 29 (35.8%), fair in 5 (6.2%). The average hospital stay was 3.6±2.4 days. MRI before and after the operation showed the cross-sectional dural area (CSDA) was significantly increased from 71.4±36.5 to 177.3±59.2 mm², corresponding to a 201.9%±188.0% increase. The percentage of facet joint preservation was 84.2% on the approach side and 92.9% on the contralateral side. Complications included 4 dural tears, 1 transient motor weakness, 1 inadequate decompression, and 1 epidural hematoma.

Conclusions

With UBE techniques, decompression for DLCS can be performed safely and effectively. The soft tissue and facet joint destruction are minimized; therefore, it is possible to avoid spinal fusion as well as to preserve the segmental stability.

Scientific View on Endoscopic Spine Surgery: Can Spinal Endoscopy Become a Mainstream Surgical Tool?

With the health care environment becoming increasingly patient centric and cost-conscious, interest levels in spinal endoscopy are at an all-time high. Patient demand for the least invasive procedures combined with surgeon desire to maximally shorten the postoperative recovery period has further driven this surgical evolution. Mounting scientific evidence demonstrates the noninferiority and perhaps even superiority of endoscopic techniques to more conventional spinal surgery for the treatment of spinal stenosis and disc herniations. Although higher level evidence is much needed to support the clinical utility of the latest endoscopic techniques and surgical indications, it appears that the entrance of spinal endoscopy into the mainstream arena of spinal surgery is inevitable.

Transforaminal Endoscopic Discectomy and Foraminoplasty for Treating Central Lumbar Stenosis

Objective

Lumbar spinal stenosis is a medical condition characterized by the narrowing of the spinal canal as a consequence of bone and soft tissue degeneration, including disc herniation, facet and ligamentum flavum hypertrophy, and osteophyte formation. The percutaneous transforaminal endoscopic discectomy (PTED) technique is one of the emerging surgical alternatives for treating central lumbar stenosis. The present study aims to describe the present techniques of PTED and foraminoplasty for central lumbar stenosis, and discuss the feasibility and advantages of this technique.

Methods

A total of 55 patients with an average age of 50 years were recruited in this study. They were operated on between August 2017 and June 2018 by a single surgeon for symptomatic lumbar stenosis using the PTED and foraminoplasty technique, along with a detailed description of the present technique. The retrospective analysis of 55 patients operated between August 2017 and June 2018 by a single surgeon for symptomatic lumbar stenosis using the PTED and foraminoplasty techniques, and the detailed description of the present technique were the focus of the present study. For all patients, the PTED and foraminoplasty procedure was performed under local anesthesia in the lateral position on a radiolucent table using C‐arm fluoroscopy. The retrospective analysis evaluated the outcomes of symptoms through follow‐up interviews at six weeks, six months, and one year after surgery. The analyzed parameters included surgery time, intraoperative blood loss, postoperative complications, visual analog scale (VAS) score, Japan Orthopedic Association (JOA) score, and the Oswestry Disability Index (ODI). The modified MacNab criteria were adopted.

Results

The average duration of symptoms was 15.6 weeks. The mean operative time was 161 minutes. The mean volume of intraoperative blood loss was 21 mL. The mean follow‐up period was 14.6 months. The average preoperative VAS score for leg pain and low back pain was 6.8 and 5.5, respectively. The preoperative ODI and JOA score was 49.2 and 14.6, respectively. At the final follow‐up, all 55 patients had an average VAS score of 1.1 for leg pain and 0.5 for low back pain. At the same time, the average ODI and JOA score was seven and 24.5, respectively. The statistical analysis showed that the VAS score, ODI value, and JOA score were significantly lower in all time‐points at post‐operation, when compared to those at pre‐operation. For the modified MacNab criteria, the final outcome results were excellent in 39 patients (70.9%), good in nine patients (16.4%), fair in four patients (7.3%), and poor in two patients (3.6%), and the overall success rate was 89.1%. Two patients underwent a second operation during the follow‐up period, and their symptoms were released after the reoperation.

Conclusion

PTED and foraminoplasty technique showed promising outcomes in the treatment of central lumbar stenosis in a 1‐year follow‐up period. It suggested that PTED and foraminoplasty might be applied as a safe and effective therapeutic option for patients with lumbar stenosis.