Transforaminal posterolateral endoscopic discectomy with or without the combination of a low-dose chymopapain: a prospective randomized study in 280 consecutive cases

Diagnostic values of 2 different techniques for controversial lumbar disc herniation by conventional imaging examination: 3D-DESS vs. CT plain scan

Background: The aim of this study was to explore the significance of three-dimensional double-echo steady-state (3D-DESS) sequence and multidetector computed tomography (CT) plain scan in the diagnosis of lumbar disc herniation (LDH) remaining controversial in conventional magnetic resonance imaging (MRI), and to compare the efficiency between 3D-DESS and CT in diagnosing controversial patients by conventional MRI.

Methods: A total of 61 patients with controversial LDH diagnosed by conventional MRI were collected. Before operation, the disease of these patients was further confirmed by 3D-DESS sequences and continuous CT plain scan from L3 to S1. Finally, for patients whose postoperative curative effect was marked and symptoms were obviously alleviated, the sensitivity, specificity and accuracy.

Results: Among, 59 patients with remarkably relieved symptoms after operation were included, and 2 patients with varying degrees of non-remission of pain and partial dysfunction after operation were excluded. The sensitivity, specificity and accuracy of 3D-DESS were 94.6, 100 and 94.9%, respectively, and those of CT were 75.0, 33.3 and 72.9%, respectively.

Conclusion: 3D-DESS is a very useful diagnostic method for patients with some special types of LDH that remain controversial in conventional imaging diagnostic methods. Through 3D-DESS, the morphology of lumbosacral nerve roots can be directly observed, which is conducive to the improvement of the sensitivity, specificity and accuracy, thus further reducing the misdiagnosis rate. Moreover, 3D-DESS plays a guiding role in the formulation of operative methods.

Revision surgery for symptomatic postoperative pseudocyst following full-endoscopic lumbar discectomy: clinical characteristics and surgical strategies

BACKGROUND

A symptomatic postoperative pseudocyst (PP) is a cystic lesion that is formed in the operation area of the intervertebral disc, leading to worse symptoms. Some minority patients who developed PP experienced rapidly aggravating symptoms and could not be treated by any kind of conservative treatment. However, no clinical studies have evaluated the clinical characteristics and surgical strategies of symptomatic PP requiring a revision surgery after full-endoscopic lumbar discectomy (FELD). This study aimed to demonstrate the clinical characteristics and surgical strategies of symptomatic PP requiring a revision surgery after FELD.

METHODS

We retrospectively analyzed the data of patients who received FELD revision surgeries due to symptomatic PP formation between January 2016 and December 2021. Common characteristics, time intervals of symptom recurrence and revision surgery, strategies for conservative treatment and revision surgery, operative time, imaging characteristics, numeric rating scale (NRS) score, Oswestry disability index (ODI) and overall outcome rating based on modified MacNab criteria were analyzed.

RESULTS

Fourteen patients (males = 10, females = 4), with a mean age of 24.4 years, were enrolled. The mean time intervals of symptom recurrence and revision surgery were 43.5 and 18.9 days respectively. While the patients were conservatively managed with analgesics and physical therapy, pain persisted or progressively worsened. In comparison to the initial herniated disc, the PP was larger in 11 cases, and up- or down-migrated in four cases. The PP location included the lateral recess (n = 12), foraminal (n = 1), and centrolateral (n = 1) zones. One of the two cases treated by percutaneous aspiration (PA) was eventually treated by FELD as pain was not relieved. Follow-ups revealed an improved mean NRS score from 7.1 to 1.4, mean ODI from 68.6 to 7.9% and promising overall surgical outcomes.

CONCLUSIONS

The progressively severe pain experienced due to PP might be a result of its enlargement or migration to the lateral recess and foraminal zones. As complete removal of capsule is the goal, we recommend FELD instead of PA.

Full-Endoscopic Lumbar Interbody Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion with a Tubular Retractor System: A Retrospective Controlled Study

OBJECTIVE

The objective of this study was to compare the safety and clinical efficacy of full-endoscopic lumbar interbody fusion (FE-LIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

METHODS

A total of 70 patients with single-level lumbar degenerative diseases underwent FE-LIF or MIS-TLIF with a tubular retractor system from August 2018 to August 2020. Postoperatively, the efficacy and safety were compared using several clinical and radiological indices.

RESULTS

A total of 32 patients underwent FE-LIF and 38 received MIS-TLIF with a tubular retractor system, and all patients had no apparent complications. The FE-LIF group had higher radiation exposure, longer operation time, and less bleeding than the MIS-TLIF group (P < 0.05). Postoperative lumbar magnetic resonance imaging showed that the nerve decompression was sufficient. The pain in the lower back and legs was significantly relieved, and the Oswestry Disability Index (ODI) score was greatly improved after surgery (P < 0.01) in both the groups. The sensory and motor functions of nerve roots were remarkably recovered in both the groups at the 1-year follow-up (P < 0.05), and there was no significant difference in MacNab scores between the 2 groups. As per Mannion's fusion classification, the interbody fusion rate was significantly better in the FE-LIF group than in the MIS-TLIF group.

CONCLUSIONS

FE-LIF, which is safe, effective, and minimally invasive, exhibits the same clinical efficacy as MIS-TLIF but with longer operation time and increased radiation exposure.

Citation analysis of the 100 top-cited articles on discectomy via endoscopy since 2011 using alluvial diagrams: bibliometric analysis

Background

Percutaneous endoscopic lumbar discectomy (PELD) is synonymous with percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID). PEID has gained increasing recognition for its small incision, quick recovery, short hospital stay, and equivalent clinical outcome to open surgery. Numerous articles related to PEID have been published in the literature. However, which countries, journals, subject categories, and articles have ultimate influence remains unknown. The study aimed to (1) display influential entities in 100 top-cited PEID-related articles (T100PEID) on the alluvial diagram and (2) investigate whether medical subject headings (i.e., MeSH terms) can be used to predict article citations.

Methods

T100PEID data can be found since 2011 in the PubMed and Web of Science (WOS) databases. Using alluvial diagrams, citation analysis was conducted to compare the dominant entities. We used social network analysis (SNA) to classify MeSH terms and research areas extracted from PubMed and WOS. The difference in article citations across subject categories and the predictive power of MeSH terms on article citations in T100 PEID were examined using one-way analysis of variance (ANOVA) and regression analysis.

Results

A total of 81% of T100PEID is occupied by the top three countries (the US, China, and South Korea). There was an overall T100PEID impact factor of 41.3 (IF = citations/100). Articles were published in Spine (Phila Pa 1976) (23%; IF = 41.3). Six subject categories were classified using the SNA. The most cited article authored by D Scott Kreiner from Ahwatukee Sports and Spine in the US state of Phoenix had 123 citations in PubMed. The network characteristics of T100PEID are displayed on the alluvial diagram. No difference was found in article citations among subject categories (F = 0.813, p = 0.543). The most frequently occurring MeSH term was surgery. MeSH terms were evident in the prediction power of the number of article citations (F = 15.21; p < 0 .001).

Conclusion

We achieved a breakthrough by displaying the T100PEID network characteristics on the alluvial plateau. The MeSH terms can be used to classify article subject categories and predict T100PEID citations. The alluvial diagram can be applied to bibliometrics on 100 top-cited articles in future studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00782-0.

An Alluvial diagram was drawn to display the network characteristics of T100PEID, which is novel and modern in the literature.

The method of drawing the Alluvial demonstrated in detail with documents in supplemental digital contents can be applied to make bibliometric studies brief, concise, and powerful.

The impact beam plot (IBP) is an additional visualization introduced in this study. The online IBP was demonstrated and worthy of future similar studies to highlight the most influential articles with a glance at a picture.

A Proposed Personalized Spine Care Protocol (SpineScreen) to Treat Visualized Pain Generators: An Illustrative Study Comparing Clinical Outcomes and Postoperative Reoperations between Targeted Endoscopic Lumbar Decompression Surgery, Minimally Invasive TLIF and Open Laminectomy

Background: Endoscopically visualized spine surgery has become an essential tool that aids in identifying and treating anatomical spine pathologies that are not well demonstrated by traditional advanced imaging, including MRI. These pathologies may be visualized during endoscopic lumbar decompression (ELD) and categorized into primary pain generators (PPG). Identifying these PPGs provides crucial information for a successful outcome with ELD and forms the basis for our proposed personalized spine care protocol (SpineScreen). Methods: a prospective study of 412 patients from 7 endoscopic practices consisting of 207 (50.2%) males and 205 (49.8%) females with an average age of 63.67 years and an average follow-up of 69.27 months was performed to compare the durability of targeted ELD based on validated primary pain generators versus image-based open lumbar laminectomy, and minimally invasive lumbar transforaminal interbody fusion (TLIF) using Kaplan-Meier median survival calculations. The serial time was determined as the interval between index surgery and when patients were censored for additional interventional and surgical treatments for low back-related symptoms. A control group was recruited from patients referred for a surgical consultation but declined interventional and surgical treatment and continued on medical care. Control group patients were censored when they crossed over into any surgical or interventional treatment group. Results: of the 412 study patients, 206 underwent ELD (50.0%), 61 laminectomy (14.8%), and 78 (18.9%) TLIF. There were 67 patients in the control group (16.3% of 412 patients). The most common surgical levels were L4/5 (41.3%), L5/S1 (25.0%), and L4-S1 (16.3%). At two-year f/u, excellent and good Macnab outcomes were reported by 346 of the 412 study patients (84.0%). The VAS leg pain score reduction was 4.250 ± 1.691 (p < 0.001). No other treatment during the available follow-up was required in 60.7% (125/206) of the ELD, 39.9% (31/78) of the TLIF, and 19.7% (12/61 of the laminectomy patients. In control patients, only 15 of the 67 (22.4%) control patients continued with conservative care until final follow-up, all of which had fair and poor functional Macnab outcomes. In patients with Excellent Macnab outcomes, the median durability was 62 months in ELD, 43 in TLIF, and 31 months in laminectomy patients (p < 0.001). The overall survival time in control patients was eight months with a standard error of 0.942, a lower boundary of 6.154, and an upper boundary of 9.846 months. In patients with excellent Macnab outcomes, the median durability was 62 months in ELD, 43 in TLIF, and 31 months in laminectomy patients versus control patients at seven months (p < 0.001). The most common new-onset symptom for censoring was dysesthesia ELD (9.4%; 20/206), axial back pain in TLIF (25.6%;20/78), and recurrent pain in laminectomy (65.6%; 40/61) patients (p < 0.001). Transforaminal epidural steroid injections were tried in 11.7% (24/206) of ELD, 23.1% (18/78) of TLIF, and 36.1% (22/61) of the laminectomy patients. The secondary fusion rate among ELD patients was 8.8% (18/206). Among TLIF patients, the most common additional treatments were revision fusion (19.2%; 15/78) and multilevel rhizotomy (10.3%; 8/78). Common follow-up procedures in laminectomy patients included revision laminectomy (16.4%; 10/61), revision ELD (11.5%; 7/61), and multilevel rhizotomy (11.5%; 7/61). Control patients crossed over into ELD (13.4%), TLIF (13.4%), laminectomy (10.4%) and interventional treatment (40.3%) arms at high rates. Most control patients treated with spinal injections (55.5%) had excellent and good functional outcomes versus 40.7% with fair and poor (3.7%), respectively. The control patients (93.3%) who remained in medical management without surgery or interventional care (14/67) had the worst functional outcomes and were rated as fair and poor. Conclusions: clinical outcomes were more favorable with lumbar surgeries than with non-surgical control groups. Of the control patients, the crossover rate into interventional and surgical care was 40.3% and 37.2%, respectively. There are longer symptom-free intervals after targeted ELD than with TLIF or laminectomy. Additional intervention and surgical treatments are more often needed to manage new-onset postoperative symptoms in TLIF- and laminectomy compared to ELD patients. Few ELD patients will require fusion in the future. Considering the rising cost of surgical spine care, we offer SpineScreen as a simplified and less costly alternative to traditional image-based care models by focusing on primary pain generators rather than image-based criteria derived from the preoperative lumbar MRI scan.

Application of electromagnetic navigation in endoscopic transforaminal lumbar interbody fusion: a cohort study

STUDY DESIGN

Clinical retrospective cohort study.

OBJECTIVES

To explore the application of the electromagnetic navigation system in Endo-TLIF.

MATERIALS AND METHODS

From May 2019 to March 2020, 76 patients with single-segment lumbar spondylolisthesis treated by electromagnetic navigation-assisted Endo-TLIF (NE group) and conventional Endo-TLIF (CE group) were enrolled in the study. Time of pedicle screw implantation, entire operation time, the number of intraoperative X-ray fluoroscopy exposures, total blood loss, incision length, ambulation time, accuracy of pedicle screws, complications, visual analog scale for back and leg pain, Oswestry Disability Index, Japanese Orthopedic Association score and postoperative fusion rates were recorded, respectively.

RESULTS

There were no significant differences in preoperative demographics between the NE and CE groups (P > 0.05). The mean number of intraoperative X-ray fluoroscopy exposures, guidewires insertion, entire operation time, total blood loss and adjustment rate of screws in the NE group were significantly less compared with the CE group (P < 0.05, respectively). There were no significant differences in clinical parameters between the two groups at different time points in the follow-up period (P > 0.05). There was no statistical difference in fusion rates between the two groups. In addition, one case of cage subsidence was observed after surgery in the CE group.

CONCLUSION

Electromagnetic navigation systems could be applied throughout the entire surgical course and ameliorate the shortcomings of the conventional Endo-TLIF technique to reduce radiation exposure, improve accuracy, avoid repetitive operations and shorten surgery time and the required learning curve of the procedure.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Comparison of Endoscopic Discectomy Versus Non-Endoscopic Discectomy for Symptomatic Lumbar Disc Herniation: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review.

OBJECTIVE

The authors aimed to systematically compare the effectiveness and safety of endoscopic discectomy (ED) with non-endoscopic discectomy (NED) for treatment of symptomatic lumbar disc herniation (LDH).

METHODS

A systematic search was performed on PubMed, EMBASE, the Cochrane Library and China National Knowledge Infrastructure for randomized controlled trial from inception until August 13, 2020. Trials which investigated multiple operative approaches on lumbar disc herniation were identified without language restrictions.

RESULTS

In total, 25 trials involving 2258 patients with symptomatic LDH were included. Twenty trials performed the comparison between ED and NED. Five trials performed the comparison between percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID). The operative time of micro-endoscopic discectomy (MED) was longer than open discectomy (OD). The length of hospital stay of percutaneous endoscopic lumbar discectomy (PELD) was shorter than fenestration discectomy (FD). Significant differences in intraoperative blood loss volumes were found between PELD with FD and MED with OD. The complication rate of PELD was lower than FD (PELD: 4.3%; FD: 14.6%) and the complication rate of full-endoscopic discectomy (FE) was lower than microscopic discectomy (MD) (FE: 13.4%; MD: 32.1%).

CONCLUSIONS

PELD and FE have the advantage of limiting intraoperative damages. ED and NED can be both considered sufficient to achieve good clinical outcomes. PETD and PEID are able to achieve similar results but the learning curve of PETD was steeper. More independent high-quality RCTs with sufficiently large sample sizes performing cost-effectiveness analyzes are needed.

A one-step foraminoplasty via a large trephine in percutaneous endoscopic transforaminal discectomy for the treatment of lumbar disc herniation

Background

Transforaminal percutaneous endoscopic lumbar discectomy (PELD) is a widely used basic technique for lumbar disc herniation (LDH) with advantages including causing less trauma and fast recovery. The secure, efficient, and rapid enlargement of the intervertebral foramen is a key step in PELD procedures. However, the conventional multi-step trephine system for foraminoplasty involves complicated surgical procedures. In this study, we reported an improved one-step foraminoplasty via a large trephine with simplified surgical procedures, reduced radiation exposure, and shortened operative time.

Methods

70 LDH patients who underwent PELD were retrospectively reviewed in this study. The conventional multi-step trephine system was used for foraminoplasty in 35 patients in the multi-step (MS) group, and the single large trephine was used in the other 35 patients in the one-step (OS) group. Indicators including the operative time, the time to establish the working cannula, intraoperative fluoroscopy times, the radiation dose, and postoperative complications were compared between the MS and OS group.

Results

The operative time and the time to establish the working cannula in the OS group was significantly shorter than that in the MS group (P < 0.01); intraoperative fluoroscopy times and the radiation dose in the OS group were significantly smaller than those in the MS group (P < 0.01). There was no statistical difference in the incidence of postoperative complications between the two groups (P > 0.05). The postoperative VAS scores and ODI scores (2 days and 3 months after the surgery) were significantly lower than the preoperative scores in both groups (P < 0.01), and there was no statistical difference in VAS scores or ODI scores between the two groups at the same time points (P > 0.05).

Conclusions

The one-step foraminoplasty via a single large trephine is an optimized technique evolving from the conventional multi-step foraminoplasty, showing significant superiority in simplified operation, shorted operative time, and reduced radiation exposure.

Endoscopic Lumbar Discectomy Using Side-Viewing Conical Working Tube: An Institutional Experience

Objective The paradigm of surgical therapy for spinal disease especially for lumbar disc herniation (LDH) has gradually shifted from the traditional open surgeries to minimal invasive spinal surgeries. Endoscopic discectomy has been performed widely using various devices and techniques. In this study we present our experience of endoscopic discectomy using a unique device with separate side-viewing channel.

Methods Twenty-six patients with LDH treated between March 2015 and April 2018 using the unique conical working tube with separate side-viewing endoscopic channel have been retrospectively analyzed. Their preoperative and postoperative Oswestry Disability Index (ODI) and Macnab scores were used to evaluate the outcome with a mean follow-up of 37.04 months.

Results There were 18 males and 8 females with age ranging from 19 to 72 years (mean, 38.4 years). The follow-up ranged from 25 to 60 months with mean of 37.04 months. The mean preoperative ODI score was 72.4, which decreased to a mean of 7.6 and the outcome evaluated by Macnab criteria was 65.3% excellent, 19.2% good, 11.5% fair, and 3.8% poor. One patient underwent second surgery. None of the patients had to change their occupation postoperatively. Complications that occurred were dural tear in one patient and transient foot paresis in one, which improved spontaneously.

Conclusion Endoscopic discectomy using conical working tube is a safe and effective technique for lumbar disc prolapse. The long-term results are comparable to the conventional techniques.

Comparison of the Clinical Outcomes of Full-Endoscopic Visualized Foraminoplasty and Discectomy Versus Microdiscectomy for Lumbar Disc Herniation

OBJECTIVE

This retrospective case-control study aimed to evaluate and compare the clinical outcomes of full-endoscopic visualized foraminoplasty and discectomy (FEVFD) with microdiscectomy (MD) for lumbar disc herniation (LDH).

METHODS

Data from 198 patients who presented with LDH between January 2016 and December 2017 treated by either FEVFD or MD were retrospectively analyzed. The inclusion criteria were single-level LDH, unilateral radiating leg pain with or without positive Lasegue's sign, and failure of standard conservative treatment for at least 12 weeks. The patients were categorized into an FEVFD group (n = 102) or an MD group (n = 96), according to the surgical procedure performed. Operative time, time in bed after surgery, postoperative hospitalization time, complications, and reoperations were recorded. Visual analog scales (VAS) for leg and back pain, Oswestry Disability index (ODI), 36-Item Short-Form Health Survey physical function (SF36-PF), and bodily pain (SF36-BP) scores were assessed and compared between the two groups.

RESULTS

The demographic data and baseline characteristics of the two groups were not significantly different. Operative time for the FEVFD group (73.82 ± 20.73 min) was longer than that for the MD group (64.74 ± 17.37 min) (P = 0.003), and fluoroscopy time for the FEVFD group (1.71 ± 0.58s) was longer than that for the MD group (1.30 ± 0.33s) (P < 0.001). However, time in bed experienced in the FEVFD group (8.51 ± 2.10 h) was less than that in the MD group (9.24 ± 2.01 h) (P = 0.014), and postoperative hospitalization time experienced in the FEVFD group (2.89 ± 0.83d) was also shorter than that in the MD group (4.94 ± 1.35d) (P < 0.001). All patients completed 24 months of follow-up. Postoperative scores at each follow-up for the VAS for leg and back pain, ODI, SF36-PF, and SF36-BP all improved significantly for both groups, as compared to the preoperative data (P < 0.05). The mean preoperative and postoperative scores for the VAS for leg and back pain, ODI, SF36-PF, and SF36-BP were not significantly different between the two groups. According to the modified MacNab criteria, the outcomes of the procedures were rated as excellent or good by 92.16% and 93.75% of the patients in the FEVFD and MD groups, respectively. One patient suffered a nerve root injury during the discectomy, one patient suffered from a dural tear, and two patients suffered from a residual herniation in the FEVFD group. One patient in the MD group suffered from poor wound healing. Moreover, recurrence happened in two cases in the FEVFD group, and in one case in the MD group.

CONCLUSION

FEVFD and MD are both reliable techniques for the treatment of symptomatic LDH. FEVFD resulted in a more rapid recovery and equivalent clinical outcomes after 24 months of follow-up.

A Postoperative Phenomenon of Percutaneous Endoscopic Lumbar Discectomy: Rebound Pain

OBJECTIVE

After percutaneous endoscopic lumbar discectomy (PELD), most patients with lumbar disc herniation (LDH) experience relief from the typical symptoms of low back and leg pain. However, for a small number of patients, these symptoms are relieved immediately after surgery but aggravated soon after, and then relieved after short-term full rest or conservative treatment. The aim of the study was to demonstrate this short-term recurrent phenomenon, termed rebound pain.

METHODS

A retrospective study was conducted on 144 patients who underwent single-segment PELD from May 2017 to June 2020. Postoperative patients were divided into a rebound pain group and a non-rebound pain group. For the former group, general information, symptom characteristics and visual analogue score (VAS) changes in rebound pain were summarized. For both groups, postoperative efficacy was evaluated by recent VAS of low back and leg pain in the remission stage, the Oswestry disability index (ODI) and the modified MacNab criteria at the last follow-up. Logistic regression analysis was used to identify predictors for rebound pain.

RESULTS

The VAS and ODI exhibited significant improvements at the last follow-up of average 15.4 months (P < 0.001). The successful outcomes according to the modified MacNab criteria reached 94.4%. A total of 15 patients (10.4%) experienced rebound pain. The typical feature was pain that usually began within 1 month after surgery and lasted for less than 1 month. The symptoms were mainly leg pain with or without low back pain. The range of pain was equal to or less than that before surgery. The symptoms were relieved after conservative treatment. In logistic regression model, postoperative return-to-work time > 45 days was found as a protective factor for rebound pain (p = 0.031).

CONCLUSION

Although rebound pain with multiple characteristics and a short duration had no significant effect on long-term postoperative efficacy, its high incidence often caused unnecessary concern in both patients and doctors. As a result, careful differentiation of rebound pain from other postoperative complications is needed.

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.

Multi-Modality guidance based surgical navigation for percutaneous endoscopic transforaminal discectomy

OBJECTIVE

Fluoroscopic guidance is a critical step for the puncture procedure in percutaneous endoscopic transforaminal discectomy (PETD). However, two-dimensional observations of the three-dimensional anatomic structure suffer from the effects of projective simplification. To accurately assess the spatial relations between the patient vertebra tissues and puncture needle, a considerable number of fluoroscopic images from different orientations need to be acquired by the surgeons. This process significantly increases the radiation risk for both the patient and surgeons.

METHODS

In this paper, we propose an augmented reality (AR) surgical navigation system for PETD based on multi-modality information, which contains fluoroscopy, optical tracking, and depth camera. To register the fluoroscopic image with the intraoperative video, we design a lightweight non-invasive fiducial with markers and detect the markers based on the deep learning method. It can display the intraoperative video fused with the registered fluoroscopic images. We also present a self-adaptive calibration and transformation method between a 6-DOF optical tracking device and a depth camera, which are in different coordinate systems.

RESULTS

With the substantially reduced frequency of fluoroscopy imaging, the system can accurately track and superimpose the virtual puncture needle on fluoroscopy images in real-time. From operating theatre in vivo animal experiments, the results illustrate that the system average positioning accuracy can reach 1.98mm and the orientation accuracy can reach 1.19^∘. From the clinical validation results, the system significantly lower the frequency of fluoroscopy imaging (42.7%) and reduce the radiation risk for both the patient and surgeons.

CONCLUSION

Coupled with the user study, both the quantitative and qualitative results indicate that our navigation system has the potential to be highly useful in clinical practice. Compared with the existing navigation systems, which are usually equipped with a variety of large and high-cost medical equipments, such as O-arm, cone-beam CT, and robots, our navigation system does not need special equipment and can be implemented with common equipment in the operating room, such as C-arm, desktop, etc., even in small hospitals.

Percutaneous transforaminal endoscopic discectomy for different types of lumbar disc herniation: A retrospective study

Objective

To introduce the concept of ‘nerve root as the core’ and to investigate the surgical procedure and curative effect of percutaneous translaminar endoscopic discectomy (PTED) surgery in the treatment of different types of lumbar disc herniation (LDH).

Methods

This retrospective study analysed the clinical data from patients with LDH that underwent single-segment PTED surgery. They were divided into three groups based on LDH location: central canal zone group, lateral recess zone group and foraminal/far lateral zone group. Different working cannula placement methods were used for the different types of LDH. All patients were followed for at least 12 months. Clinical and follow-up data were compared between the three groups.

Results

A total of 130 patients were enrolled in the study: 44 (33.8%) in the central canal zone group, 72 (55.4%) in the lateral recess zone group and 14 (10.8%) in the foraminal/far lateral zone group. All three groups of patients achieved good postoperative results. The improvements in leg pain and disability were most marked in the first postoperative month in all three groups.

Conclusion

PTED achieved adequate decompression for different types of LDH. The concept of ‘nerve root as the core’ facilitated the accurate placement of the working cannula.

The irony of the transforaminal approach: A comparative cohort study of transforaminal endoscopic lumbar discectomy for foraminal versus paramedian lumbar disc herniation

Transforaminal endoscopic lumbar discectomy (TELD) is useful for soft lumbar disc herniation (LDH). Although the transforaminal approach can reach the foraminal disc zone, the risk of exiting nerve root irritation along the path is considerable. Few studies have assessed the difficulties of TELD for foraminal LDH. The objective of this study is to compare the clinical results of TELD between foraminal or far-lateral LDH and paramedian LDH.Between June 2016 and July 2017, 135 consecutive patients with single-level LDH were treated with TELD for 2 years. Among them, 25 patients had foraminal or far-lateral LDH (foraminal group), and the remaining 110 patients had central or subarticular LDH (paramedian group). Perioperative data and clinical outcomes were evaluated using the visual analog pain scale, Oswestry Disability Index, and modified Macnab criteria.The foraminal group showed a higher rate of significant access pain (24.00% vs 8.19%, P < .05). The foraminal group also had a longer duration of surgery, length of hospital stay, and return to work (all P < .05). Pain scores and functional status were significantly improved in both groups. Although there were no differences in the outcomes at 2 years postoperatively, early pain and disability at 6 weeks were higher in the foraminal group.Ironically, the early clinical results of TELD for foraminal LDH may be less favorable than those for paramedian LDH. Therefore, great care should be taken during TELD for foraminal or far-lateral LDH.

Original Designed Uniportal-Bichannel Spinal Endoscopic System (UBiSES) for Foraminoplasty in Percutaneous Endoscopic Transforaminal Discectomy

OBJECTIVE

The study introduced uniportal-bichannel spinal endoscopic system (UBiSES) and explored the feasibility of applying UBiSES to conduct lumbar foraminoplasty in percutaneous endoscopic transforaminal discectomy (PETD).

METHODS

This is a cohort study. 36 patients confirmed as L5/S1 lumbar disc herniation (LDH) in our hospital from March, 2019 to November, 2019 were enrolled. 36 patients were divided into two groups named the UBiSES group (n = 18, male: female = 8:10) and the TESSYS group (n = 18, male: female = 10:8). The average age of the UBiSES group and the TESSYS group were 40.94 ± 12.39 years old and 39.78 ± 13.02 years old respectively. PETD via uniportal-bichannel foraminoplasty assisted by UBiSES was adopted on the UBiSES group while PETD via conventional foraminoplasty was performed on the TESSYS group. One experienced surgeon with more than 4000 cases of lumbar surgery performed PETD on all patients. The demographic data, the duration of working cannula placement (minutes), decompression time (minutes), radiation exposure time (seconds), complications, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores and modified MacNab criteria were recorded and analyzed. The magnetic resonance imaging (MRI) and computed tomography (CT) were conducted to evaluate the radiographic improvement.

RESULTS

PETD via lumbar foraminoplasty was successfully performed in all cases. The follow-up points were 3 months, 6 months, and 12 months. The average follow-up period of all patients was 15.78 ± 2.29 months. There was no statistic difference in age (P = 0.81), sex (P = 0.51) and follow-up (P = 0.14) between two groups. The duration of working cannula placement was 19.08 ± 2.30 min in the UBiSES group and 24.90 ± 4.71 min in the TESSYS group and there was significant difference between two groups (P < 0.05). There was no statistic difference in decompression time between the UBiSES group (44.18 ± 5.70 min) and the TESSYS group (47.46 ± 5.96 min) (P = 1.70). The radiation exposure time was 28.00 ± 4.70 s in the UBiSES group and 40.50 ± 5.73 s in the TESSYS group respectively, and has significant difference between two groups (P < 0.05). Furthermore, there was significant different in the duration of working cannula placement and radiation exposure time in male or female between the UBiSES group and the TESSYS group (P < 0.05). For male or female, no difference observed in decompression time and follow-up period between two groups. Postoperative VAS of low back and leg at every follow-up point (1 day, 3 months, 6 months, 12 months) was improved significantly in both groups compared with their preoperative VAS (P < 0.05). The postoperative ODI (3 months, 6 months, 12 months) has decreased significantly in both the UBiSES group and the TESSYS group compared with their preoperative ODI (P < 0.05). 94.44% patients received an excellent or good recovery in the UBiSES group and 88.89% for the TESSYS group. There was no poor result reported in both groups. The radiographic images showed satisfactory foraminoplasty and sufficient decompression of nerve in both groups. No postoperative complications were observed during follow-ups in the UBiSES group. Two patients in the TESSYS group experienced postoperative dysesthesia and the symptom was disappeared in 5 days and 7 days respectively with dexamethasone and neurotrophic drugs treatment.

CONCLUSIONS

The original designed UBiSES could effectively and safely enlarge the foramen with an extensive surgical view and space under full-time and real-time visualization and get satisfactory efficacy.

The 20 most important questions for novices of full-endoscopic spinal surgery in China: a mixed-method study protocol

INTRODUCTION

The full-endoscopic spinal surgery (FESS) procedure is widely accepted and welcomed in China. With the continuous development of minimally invasive surgery, the further expansion of indications and the greater diversity of techniques, spinal endoscopic surgery currently accounts for more than 10% of spinal surgery in China, ranking among the top in the world. However, the admission system and standardised training system for spinal endoscopic surgery are not perfect, which presents a challenge and disadvantage for novices.

METHODS AND ANALYSIS

Exploratory mixed methods are applied for designing this study. First, we will collect questions from novices by allowing them to openly list their concerns to those who have completed FESS. These qualitative questions will be categorised using NVivo software. To produce the qualitative results, a questionnaire for the sequential two-round Delphi approach will be developed to identify the 20 most important questions from novices. This study is planned to be started at April 2021, and completed at March 2022.

ETHICS AND DISSEMINATION

The Research Ethics Committee of Peking University Third Hospital provided a waiver for this Delphi protocol. We expect that the findings will be published in a clinical journal and presented at conferences. Furthermore, we hope that the results can contribute to answering the questions raised by novices of spinal endoscopy in the form of books and to improving the training system for spinal endoscopy surgery.

TELD with limited foraminoplasty has potential biomechanical advantages over TELD with large annuloplasty: an in-silico study

Background

Facetectomy, an important procedure in the in–out and out–in techniques of transforaminal endoscopic lumbar discectomy (TELD), is related to the deterioration of the postoperative biomechanical environment and poor prognosis. Facetectomy may be avoided in TELD with large annuloplasty, but iatrogenic injury of the annulus and a high grade of nucleotomy have been reported as risk factors influencing poor prognosis. These risk factors may be alleviated in TELD with limited foraminoplasty, and the grade of facetectomy in this surgery can be reduced by using an endoscopic dynamic drill.

Methods

An intact lumbo-sacral finite element (FE) model and the corresponding model with adjacent segment degeneration were constructed and validated to evaluate the risk of biomechanical deterioration and related postoperative complications of TELD with large annuloplasty and TELD with limited foraminoplasty. Changes in various biomechanical indicators were then computed to evaluate the risk of postoperative complications in the surgical segment.

Results

Compared with the intact FE models, the model of TELD with limited foraminoplasty demonstrated slight biomechanical deterioration, whereas the model of TELD with large annuloplasty revealed obvious biomechanical deterioration. Degenerative changes in adjacent segments magnified, rather than altered, the overall trends of biomechanical change.

Conclusions

TELD with limited foraminoplasty presents potential biomechanical advantages over TELD with large annuloplasty. Iatrogenic injury of the annulus and a high grade of nucleotomy are risk factors for postoperative biomechanical deterioration and complications of the surgical segment.

Application of a targeted and quantificational foraminoplasty device in percutaneous transforaminal endoscopic discectomy for L5-S1 disc herniation: preliminary clinical outcomes

OBJECTIVE

Percutaneous transforaminal endoscopic discectomy (PTED) is minimally invasive and has been widely used to treat patients with lumbar disc herniation (LDH) due to its safety and efficiency. However, due to the unique anatomy of the L5-S1 level, the PTED procedure is often difficult to perform in the region. ZESSYS, a targeted and quantificational foraminoplasty device, may help to overcome these anatomical limitations. In this study, we assessed the efficiency and the short-term effects of PTED with ZESSYS at the L5-S1 level.

METHODS

Between January and August of 2018, fifty-six patients with lumbar disc herniation at the single level of L5-S1 and who underwent percutaneous transforaminal endoscopic discectomy were enrolled in this retrospective cohort study. They were segregated into the transforaminal endoscopic surgical system (TESSYS) group and the ZESSYS group. The puncture time, foraminoplasty time, decompression time, and fluoroscopy time were evaluated for operation efficiency. Clinical outcomes were assessed by the visual analog scale (VAS) score and Oswestry Disability Index (ODI) score. The MacNab criteria were used to evaluate patient subjective satisfaction at 12-month follow-up postoperatively.

RESULTS

The average puncture time (5.29 ± 2.05 min), foraminoplasty time (12.82 ± 2.52 min), and fluoroscopy time (26.29 ± 5.96 s) were all significantly shorter in the ZESSYS group than in the TESSYS group (average puncture time 8.07 ± 3.13 min, p < 0.01; foraminoplasty time, 17.18 ± 2.92 min, p < 0.01; fluoroscopy time, 34.73 ± 6.86 s; p < 0.01). No significant differences were observed between the 2 groups in the decompression time (p = 0.057). The VAS score of low back pain and leg pain, as well as the ODI score, improved at all time points postoperatively compared with preoperative, in both the TESSYS group and the ZESSYS group (P < 0.05). There were no significant differences in the VAS score of low back pain, VAS score of leg pain, and ODI score between the TESSYS group and the ZESSYS group at the same time points (P > 0.05). According to the MacNab criteria, the excellent and good rate at 12-month follow-up postoperatively was 85.7% in the TESSYS group and 89.3% in the ZESSYS group (P > 0.05).

CONCLUSION

The targeted and quantificational foraminoplasty device named ZESSYS was more efficient in the puncture and foraminoplasty procedures, effectively protecting the exiting nerve and minimizing the level of radiation exposure. The device is efficient and safe for PTED in treating lumbar disc herniation at the L5-S1 level.

The Endoscopic Trans-Superior Articular Process Approach: A Novel Minimally Invasive Surgical Corridor to the Lateral Recess

BACKGROUND

Transforaminal approaches to the lumbar spine are typically performed utilizing Kambin's triangle as approach corridor; however, degenerative changes can distort anatomy and expose the exiting nerve root to inadvertent injury.

OBJECTIVE

To describe the surgical technique of a novel full-endoscopic approach to access the lateral recess and report clinical outcomes.

METHODS

The trans-superior articular process (SAP) approach involves partial resection of the SAP, allowing access to the lateral recess both ventral and dorsal to the traversing nerve root. A retrospective review of 40 patients who had undergone a trans-SAP approach for decompression of lateral recess pathology was conducted. Outcomes were measured using visual analog scores (VAS) and Oswestry Disability Index (ODI) at 2 wk, 3 mo, and at last follow-up.

RESULTS

At a mean follow-up of 24 mo, patients experienced statistically significant improvement of the VAS for ipsilateral leg pain, VAS for back pain, and ODI when comparing preoperative values to all postoperative time points. The percentage of patients reaching a minimally clinically important difference for VAS leg pain and ODI was approximately 90% and 88%, respectively. The complication profile was favorable with no dural tears and no postoperative motor or sensory deficits. One patient required revision, with a total reoperation rate of 3%.

CONCLUSION

The trans-SAP approach is a novel approach that utilizes a safe surgical corridor via the SAP to access lateral recess pathology. Our initial clinical experience suggests that the trans-SAP approach allows for treatment of lateral recess and foraminal pathology with low complication rates.

Percutaneous endoscopic transforaminal discectomy for the treatment of L5-S1 lumbar disc herniation and the influence of iliac crest height on its clinical effects

The present study aimed to explore the clinical effects of percutaneous endoscopic transforaminal discectomy using a transforaminal endoscopic spine system (TESSYS) technique for the treatment of L5-S1 lumbar disc herniation and to analyse the influence of iliac crest height on these clinical effects. The clinical data of 76 patients with L5-S1 single-segment disc herniation treated with TESSYS at The Second Affiliated Hospital and Third Affiliated Hospital of Xi'an Jiaotong University between January and December 2016 were retrospectively analysed. Patients were divided into the following three groups according to the positional relation between the highest point of the iliac crest and the L4 and L5 pedicles in the lateral lumbar, as determined by X-ray: Group I, iliac crest height below the upper edge horizontal line of the L5 pedicle (n=42); group II, iliac crest height between the lower edge horizontal line of the L4 pedicle and the upper edge horizontal line of the L5 pedicle (n=29) and group III, iliac crest height above the lower edge horizontal line of the L4 pedicle (n=5). Changes in the postoperative visual analogue scale (VAS) pain score and Oswestry disability index (ODI) of the lower back and lower limbs were observed, and the effects were compared among the three groups. The mean operating time was 86.5±13.5 min. A single patient experienced cerebrospinal fluid leakage due to a mild tear of the dura mater during the operation, which improved after symptomatic treatment. The same operation was repeated in one patient due to the recurrence of disc herniation. In all patients, the VAS pain score and ODI of the lower back and lower limbs at 1 week and 1, 3 and 12 months following the operation were significantly lower than those before the operation (all P<0.05). Furthermore, the postoperative VAS pain score and ODI of the lower back and lower limbs were poorer in group III (L5-S1 lumbar disc herniation complicated with high iliac crest) than in groups I and II (P<0.05). These results suggested that TESSYS was effective in treating lumbar disc herniation. Whether the iliac crest is higher than the lower edge horizontal line of the L4 pedicle is suggested to be one of the factors influencing the outcome of the operation.

One-Stage Percutaneous Endoscopic Lumbar Discectomy for Symptomatic Double-Level Contiguous Adolescent Lumbar Disc Herniation

Objective

To assess the clinical efficacy of one‐stage percutaneous endoscopic lumbar discectomy (PELD) for symptomatic double‐level contiguous adolescent lumbar disc herniation (ALDH).

Methods

This retrospective study included 16 patients who presented with back and/or leg pain due to double‐level disc herniation underwent PELD for symptomatic lumbar disc herniation (0.27%,16/5877) from January 2014 to September 2019. After follow‐up period of 17.3 months in average, numeric rating scale (NRS) scores and modified Macnab criteria were used to assess the preoperative and postoperative clinical results. Quantitative data were expressed as mean standard deviation (SD) and the data for the variation in the NRS scores before and after the operation were compared using the Wilcoxon two‐sample test. Analyses were performed with IBM SPSS Statistics for Windows, version 19.0 (IBM, Armonk, NY, USA). Values of P < 0.05 were considered significantly different.

Results

There were 11 male and 5 female patients, with an average age of 19.3 years (range, 15–22 years). One case affected the L₂‐ L₃ /L₃‐L₄ level, seven cases affected the L₃‐ L₄ /L₄‐ L₅ level, and eight cases affected the L₄‐ L₅ /L₅‐S₁ level. The NRS scores decreased significantly in both early and late follow‐up evaluations and these scores demonstrated significant improvement in late follow‐up (P < 0.05). For the modified Macnab criteria, the final outcome results were excellent in 14 patients (87.5%), good in 1 patient (6.25%), fair in 1 patient (6.25%), and the overall success rate was 93.75%.

Conclusion

This study's data suggest that one‐stage PELD is promising treatment strategy for selected symptomatic double‐level contiguous adolescent lumbar disc herniation.

Percutaneous Endoscopic Lumbar Discectomy via Transforaminal Approach Combined with Interlaminar Approach for L4/5 and L5/S1 Two-Level Disc Herniation

Objective

The purpose of the present study was to discuss a new surgical strategy that combines percutaneous endoscopic transforaminal discectomy (PETD) with percutaneous endoscopic interlaminar discectomy (PEID) for L4/5 and L5/S1 two‐level disc herniation.

Methods

This was a retrospective study. A total of 19 patients with L4/5 and L5/S1 two‐level lumbar disc herniation (LDH) who underwent percutaneous endoscopic lumbar discectomy (PELD) in our hospital from January 2015 to June 2016 were retrospectively examined. The average age of these 19 patients was 42.21 ± 14.88 years old, including 12 men and 7 women. One experienced surgeon who had carried out more than 3000 lumbar surgeries performed PELD for these patients. During the PELD surgery, the transforaminal approach was adopted for L4/5 level disc herniation and the interlaminar approach was adopted for L5/S1 level disc herniation. The demographic data, operation time (min), fluoroscopy times, hospital stay (days), and complications were recorded and analyzed. The visual analogue scale (VAS), Oswestry disability index (ODI) scores, and the modified MacNab criteria were used to evaluate the surgical outcomes. MRI was conducted to evaluate the radiographic improvement.

Results

All patients underwent PELD via the transforaminal approach combined with the interlaminar approach successfully and achieved satisfactory efficacy. The follow‐up points were 3, 12, and 18 months. The average hospital stay (days) and the average follow up (months) were 3.32 ± 0.98 and 18.63 ± 3.84, respectively. The operation time and fluoroscopy times were 85.79 ± 12.90 min and 39.05 ± 4.59 times, respectively. The fluoroscopy times (frequency) for L4/5 and L5/S1 were 26.95 ± 6.41 and 12.11 ± 3.49 (t = 7.00, P < 0.05). Furthermore, there was no significant difference for fluoroscopy times between male and female patients (t = 0.89, P = 0.99). The preoperative back pain (VAS‐Back) and the last follow‐up VAS‐Back were 5.58 ± 2.01 and 2.37 ± 1.01, respectively (t = 7.14, P < 0.05). The preoperative leg pain (VAS‐Leg) and the last follow‐up VAS‐Leg were 7.00 ± 1.56 and 1.63 ± 1.01, respectively (t = 20.97, P < 0.05). There were significant differences between preoperative VAS‐Back and the last follow‐up VAS‐Back in men (t = 4.61, P < 0.05) and women (t = 6.57, P < 0.05). In addition, there was significant differences between preoperative VAS‐Leg and the last follow‐up VAS‐Leg in men (t = 13.48, P < 0.05) and women (t = 26.87, P < 0.05). There were significant differences between preoperative ODI scores (44.84 ± 10.82%) and the last follow‐up ODI scores (11.12 ± 5.80%) (t = 10.92, P < 0.05). Preoperative ODI scores and the last follow‐up ODI scores were significantly different for men (t = 8.80, P < 0.05) and women (t = 6.63, P < 0.05). All patients received significant pain relief and functional improvement after the surgery. Except for two cases of postoperative dysesthesia and one dural tear, no severe complications occurred. The dysesthesia symptoms of these two patients disappeared within 1 week with the application of dexamethasone and neurotrophic drugs and the dural tear case also recovered well as the dural laceration was small. No poor results were reported and 89.47% of patients achieved excellent or good recovery.

Conclusion

Percutaneous endoscopic lumbar discectomy via the transforaminal approach combined with the interlaminar approach under epidural anesthesia can treat L4/5 and L5/S1 two‐level disc herniation safely and effectively.

Invasive Treatments for Low Back Disorders

OBJECTIVE

This abbreviated version of the American College of Occupational and Environmental Medicine's Low Back Disorders guideline reviews the evidence and recommendations developed for invasive treatments used to manage low back disorders.

METHODS

Comprehensive systematic literature reviews were accomplished with article abstraction, critiquing, grading, evidence table compilation, and guideline finalization by a multidisciplinary expert panel and extensive peer-review to develop evidence-based guidance. Consensus recommendations were formulated when evidence was lacking and often relied on analogy to other disorders for which evidence exists. A total of 47 high-quality and 321 moderate-quality trials were identified for invasive management of low back disorders.

RESULTS

Guidance has been developed for the invasive management of acute, subacute, and chronic low back disorders and rehabilitation. This includes 49 specific recommendations.

CONCLUSION

Quality evidence should guide invasive treatment for all phases of managing low back disorders.

Learning Curve for Interlaminar Endoscopic Lumbar Discectomy: A Systematic Review

BACKGROUND

Interlaminar endoscopic lumbar discectomy (IELD) is an efficient surgical treatment for lumbar disc herniation. However, this minimally invasive procedure requires a considerable learning curve that has not yet been standardized. This review aimed to evaluate the learning curve's characteristics, including the cutoff point required to achieve technical proficiency and to discuss appropriate training methods.

METHODS

We systematically searched the core databases (PubMed, Embase, and Cochrane Library) for clinical studies that evaluated the learning curve using quantitative data. We performed a quality assessment using the Newcastle-Ottawa scale. We also compared descriptive statistics, including operative time and other variables before and after the cutoff point.

RESULTS

Six studies reporting 302 cases of IELD were selected from 7188 screened articles. The cutoff point was randomly set in 3 studies and determined as the curve's asymptote in 3 studies. The mean value for the cutoff point was 22.17 ± 12.40 cases (range: 10-43 cases) and mainly determined based on the operative time, which was shorter in the late group than that in the early group (P < 0.05). The cutoff points were not significant for patient outcome parameters such as pain score, functional result, surgical failure, or complications.

CONCLUSIONS

The evidence of published studies regarding the learning curve for the IELD technique is insufficient. The reported cutoff points may be significant only for task efficiency. Moreover, they may not represent the asymptote of the curve. Future studies should evaluate the actual plateau points using patient outcome data.

Percutaneous endoscopic lumbar discectomy compared with other surgeries for lumbar disc herniation: A meta-analysis

OBJECTIVE

This meta-analysis was performed to investigate whether percutaneous endoscopic lumbar discectomy (PELD) had a superior effect than other surgeries in the treatment of patients with lumbar disc herniation (LDH).

METHOD

We searched PubMed, Embase, and Web of Science through February 2018 to identify eligible studies that compared the effects and complications between PELD and other surgical interventions in LDH. The outcomes included success rate, recurrence rate, complication rate, operation time, hospital stay, blood loss, visual analog scale (VAS) score for back pain and leg pain, 12-item Short Form Health Survey (SF12) physical component score, mental component score, Japanese Orthopaedic Association Score, Oswestry Disability Index. A random-effects or fixed-effects model was used to pool the estimate, according to the heterogeneity among the included studies.

RESULTS

Fourteen studies (involving 2,528 patients) were included in this meta-analysis. Compared with other surgeries, PELD had favorable clinical outcomes for LDH, including shorter operation time (weight mean difference, WMD=-18.14 minutes, 95%CI: -25.24, -11.05; P < .001) and hospital stay (WMD = -2.59 days, 95%CI: -3.87, -1.31; P < .001), less blood loss (WMD = -30.14 ml, 95%CI: -43.16, -17.13; P < .001), and improved SF12- mental component score (WMD = 2.28, 95%CI: 0.50, 4.06; P = .012)) and SF12- physical component score (WMD = 1.04, 95%CI: 0.37, 1.71; P = .02). However, it also was associated with a significantly higher rate of recurrent disc herniation (relative risk [RR] = 1.65, 95%CI: 1.08, 2.52; P = .021). There were no significant differences between the PELD group and other surgical group in terms of success rate (RR = 1.01, 95%CI: 0.97, 1.04; P = .733), complication rate (RR = 0.86, 95%CI: 0.63, 1.18; P = .361), Japanese Orthopaedic Association Score score (WMD = 0.19, 95%CI: -1.90, 2.27; P = .861), visual analog scale score for back pain (WMD = -0.17, 95%CI: -0.55, 0.21; P = .384) and leg pain (WMD = 0.00, 95%CI: -0.10, 0.10; P = .991), and Oswestry Disability Index score (WMD = -0.29, 95%CI: -1.00, 0.43; P = .434).

CONCLUSION

PELD was associated with better effects and similar complications with other surgeries in LDH. However, it also resulted in a higher recurrence rate. Considering the potential limitations in the present study, further large-scale, well-performed randomized trials are needed to verify our findings.

Follow-up results of microendoscopic discectomy compared to day surgery using percutaneous endoscopic lumbar discectomy for the treatment of lumbar disc herniation

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) is satisfactory for hospitalized patients with lumbar disc herniation (LDH). Currently, only a few studies have reported about the day surgery patients undergoing PELD.

METHODS

A total of 267 patients with LDH underwent PELD during day surgery and were followed up for at least 3 years. Clinical outcomes were assessed using the visual analog scale (VAS) for leg and lower back pain (VAS-B and VAS-L, respectively) and the Oswestry disability index (ODI). The radiological outcomes, such as lumbar lordosis (LL), sacral slope (SS), the disc-height ratio, and disc instability, were recorded and compared. The clinical effects between patients treated by PELD during day surgery and microendoscopic discectomy (MED) for contemporaneous hospitalized 116 patients with LDH were compared.

RESULTS

Patients treated by PELD had lower blood loss and shorter hospital stay (P <  0.001) compared to those treated by MED. VAS-L, VAS-B, and ODI decreased significantly after PELD than before the operation and 3 years postoperatively. The postoperative VAS-B in the PELD group was significantly decreased than in the MED group (P = 0.001). The complications rate was 9.4% in the PELD group and 12.1% in the MED group (P = 0.471). The 1-year postoperative recurrence rate in the PELD group was much higher than that in MED group (P = 0.042). The postoperative LL and SS in the PELD group improved significantly compared to the values in the MED group (P <  0.001). According to the disc-height ratio at 3-year follow-up, a significant height loss was observed in the MED group than in the PELD group (P = 0.014).

CONCLUSIONS

Although the 1-year postoperative recurrence rate was relatively high, the day surgery for LDH undergoing PELD had advantages in terms of less blood loss intraoperatively, short hospital stay, efficacy for back pain, and efficiency to maintain lumbar physiological curvature.

Clinical Outcomes of "U" Route Transforaminal Percutaneous Endoscopic Lumbar Discectomy in Chronic Pain Patients with Lumbar Spinal Stenosis Combined with Disc Herniation

Introduction

"U" route transforaminal percutaneous endoscopic lumbar discectomy (PELD) was introduced for lumbar spinal stenosis (LSS) combined with disc herniation (DH) treatment. This study aims to explore the efficacy and safety of "U" route PELD on chronic pain patients with LSS combined with DH.

Methods

Degenerative LSS combined with DH patients who underwent "U" route PELD were reexamined, and 80 patients were recruited and followed up for 2 years. The other 80 healthy individuals who were age- and sex-matched to the patients without chronic pain were enrolled as healthy controls. Minimum dura sac cross-sectional area (mDCSA) by MRI, Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and modified MacNab outcomes were assessed. Emotional evaluation of pain catastrophizing and depression was documented with Pain Catastrophizing Scale (PCS) and Beck Depression Inventory (BDI), respectively, for patients before and after surgery and healthy individuals.

Results

All patients were of the age range from 47 to 85 years, with an average of 59.5 ± 9.76 years. Symptoms duration was 114.6 ± 22.77 months, operation time was 87.7 ± 25.20 minutes, and the average hospital stay was 5.8 ± 2.81 days. Four patients quit, and hence, a total of 76 patients completed the follow-up. The results indicated that mDCSA was improved significantly after operation (p < 0.001), either low back and leg VAS or ODI decreased over time (p < 0.001), and the excellent-to-good rate was improved from 88.75% to 93.42% during postoperative 2 years (p < 0.05). Complications of dural tear, nerve root, or dysesthesia were reported in 5 patients, and all recovered after conservative therapy. The scores of pain catastrophizing were reduced after operation (p < 0.001), but no significance of BDI was found between patients and healthy controls (p > 0.05).

Conclusions

The "U" route PELD seems an alternative to LSS combined with DH treatment, which might reach a better decompression and effectively improve chronic pain conditions. Still, the complications were potential and required further consideration.

Short-term effectiveness of precise safety decompression via double percutaneous lumbar foraminoplasty and percutaneous endoscopic lumbar decompression for lateral lumbar spinal canal stenosis: a prospective cohort study

Purpose

This prospective cohort study reports on a modified technique, namely precise safety decompression via double percutaneous lumbar foraminoplasty (DPLF) and percutaneous endoscopic lumbar decompression (PELD) for lateral lumbar spinal canal (LLSC) stenosis, and its short-term clinical outcomes.

Methods

The study analyzed 69 patients with single-level LLSC stenosis simultaneously occurring in both zones 1 and 2 (defined as retrodiscal space and upper bony lateral recess respectively by new LLSC classification) who underwent DPLF–PELD from November 2018 to April 2019. Clinical outcomes were evaluated according to preoperative, 3 months postoperatively, and last follow-up, via leg pain/low back pain (LBP) visual analog scale (VAS) scores, Oswestry disability index (ODI) scores, and the Macnab criteria. The postoperative MRI and CT were used to confirm the complete decompression, and flexion-extension x-rays at the last follow-up were used to observe lumbar stability.

Results

All patients successfully underwent DPLF–PELD, and the stenosis was completely decompressed, confirmed by postoperative MRI and CT. The mean follow-up duration was 13 months (range: 8–17 months). The mean preoperative leg pain VAS score is 7.05 ± 1.04 (range 5–9), which decreased to 1.03 ± 0.79(range: 0–3) at 3 months postoperatively and to 0.75 ± 0.63 (range: 0–2) by the last follow-up visit (p < 0.05). The mean preoperative ODI was 69.8 ± 9.05 (range: 52–85), which decreased to 20.3 ± 5.52 (range: 10–35) at the third month postoperatively and to 19.6 ± 5.21 (range: 10–34) by the final follow-up visit (p < 0.05). The satisfactory (excellent or good) results were 94.2%. There was one patient with aggravated symptoms, which were relieved after an open surgery. Two patients had a dural tear, and two patients suffered postoperative LBP. No recurrence or segmental instability was observed at the final follow-up.

Conclusion

DPLF–PELD could be a good alternative for the treatment of LLSC stenosis patients whose stenosis occurred in both zones 1 and 2.

Trial registration

Chinese Clinical Trial Registry (ChiCTR1800019551). Registered 18 November 2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-03956-9.

Evaluation of efficacy and safety of percutaneous transforaminal endoscopic surgery (PTES) for surgical treatment of calcified lumbar disc herniation: a retrospective cohort study of 101 patients

BACKGROUND

Percutaneous transforaminal endoscopy has been widely used to treat lumbar disc herniation (LDH), but the steep learning curve and difficulties in removing the calcified disc hinders the application of conventional endoscopy in treating calcified lumbar disc herniation (CLDH). In 2017, we first reported Percutaneous Transforaminal Endoscopic Surgery (PTES) as an easy-to-learn posterolateral transforaminal endoscopic technique to decompress the nerve root for LDH. We used our PTES technique to remove the calcified LDH and the purpose of this study is to evaluate the safety and efficacy of this technique.

METHODS

Forty-six patients with CLDH and fifty-five patients with uncalcified lumbar disc herniation (ULDH) underwent PTES to decompress the nerve root. Visual analogue scale was collected before the surgery, immediately, one week, one month, two months, three months, six months, 12 months and 24 months after surgery. The outcomes of MacNab classification were collected 24 months after surgery. Intra- and Post-operative complications were also recorded.

RESULTS

For CLDH patients, the VAS score was 9 (5-10) before operation, and then dropped to 2 (1-4) after surgery. VAS score continually decreased to 0 (0-3) at 24 months after surgery. 95.65% of CLDH patients showed excellent or good outcomes. ULDH group showed similar MacNab classification (94.55%) and VAS changing curve. The therapeutic effect of PTES in treating CLDH was as good as that in treating uncalcified patients.

CONCLUSIONS

PTES is an effective and safe method to treat calcified lumbar disc herniation.

Early Clinical Evaluation of Percutaneous Full-endoscopic Transforaminal Lumbar Interbody Fusion with Pedicle Screw Insertion for Treating Degenerative Lumbar Spinal Stenosis

Objective

To compare the clinical efficacy of percutaneous full‐endoscopic transforaminal lumbar interbody fusion (Endo‐TLIF) with percutaneous pedicle screws (PPSs) performed by using a visualization system with that of minimally invasive transforaminal lumbar interbody fusion (MIS‐TLIF) for the treatment of degenerative lumbar spinal stenosis (LSS).

Methods

From June 2017 to May 2018, the data of a total of 78 patients who met the selection criteria were retrospectively reviewed and were divided into the Endo‐TLIF group (40 cases) and the MIS‐TLIF group (38 cases) according to the surgical method used. The visual analog scale (VAS) and the Japanese Orthopaedic Association (JOA) scale were administered preoperatively and at the 1‐week, 3‐month, and 1–2‐year follow‐ups. The fusion rate and major complications, including revision, were also recorded.

Results

All the patients were followed up for 24 to 34 months, with an average follow‐up of 30.7 months. The intraoperative blood loss and length of hospital stay for the Endo‐TLIF group (60.56 ± 0.36 mL, 8.12 ± 0.92 days, respectively) were statistically significantly lower than those for the MIS‐TLIF group (65.47 ± 0.91 mL, 9.66 ± 1.34 days, respectively) (P < 0.05). The VAS and JOA scores of the patients in the two groups at postoperative 1 week, 3 months, 1 year, 2 years (Endo‐TLIF VAS: 4.16 ± 0.92, 3.72 ± 1.54, 1.32 ± 0.45, 1.29 ± 0.34; JOA:16.71 ± 0.99, 19.86 ± 0.24, 24.91 ± 0.97, 25.88 ± 0.52; MIS‐TLIF VAS: 4.17 ± 1.41, 2.98 ± 0.91, 1.54 ± 0.32, 1.33 ± 0.18; JOA: 16.67 ± 0.67, 19.58 ± 0.65, 25.33 ± 0.73, 25.69 ± 0.33) were statistically significantly improved from the preoperative scores (Endo‐TLIF: 8.45 ± 1.44, 14.36 ± 0.56; MIS‐TLIF: 8.11 ± 0.93, 14.45 ± 0.34, respectively) (P < 0.01). The VAS and JOA scores of the Endo‐TLIF group were statistically significantly better than those of the MIS‐TLIF group at 3 months and 1 year after surgery (P < 0.05). There were no statistically significant differences in the scores between the two groups at any of the other time points (P > 0.05). There was no significant difference in the intervertebral altitude between the two groups at the 3‐month (11.36 ± 0.23, 11.21 ± 0.42, respectively) or final follow‐up (10.88 ± 0.64, 10.81 ± 0.39, respectively) (P > 0.05). Dural tears, cerebrospinal fluid leakage, infection, and neurologic injury did not occur. Both groups showed good intervertebral fusion at the last follow‐up. The intervertebral fusion rate was 97.5% (39/40) in the Endo‐TLIF group and 94.7% (36/38) in the MIS‐TLIF group, with no statistically significant difference between the two groups (χ² = 0.118, P = 0.731). At the final follow‐up, the modified MacNab's criteria were 92.5% and 89.5% between the two groups.

Conclusion

Endo‐TLIF with percutaneous pedicle screws (PPS) performed by using a visualization system for lumbar degenerative disease may be regarded as an efficient alternative surgery for degenerative lumbar spinal stenosis. It is a safe and minimally invasive way to perform this surgery and has shown satisfactory clinical outcomes.

The Current State of Cervical Endoscopic Spine Surgery: an Updated Literature Review and Technical Considerations

Introduction: Endoscopic spine surgery has become one of the representative minimally invasive spine surgeries (MISS), especially in the lumbar spine. Full-endoscopic procedures using a working channel endoscope for cervical degenerative spine disease have been reported as practical and feasible. This review aimed to summarize the updated techniques of and studies about cervical endoscopic surgery. Areas covered: An extensive search of PubMed was performed for randomized controlled trials (RCTs) or comparative cohort studies on the full-endoscopic cervical procedure. All the 236 articles found were screened and categorized. Only two RCTs and four cohort studies finally met the search criteria. Regarding the surgical techniques, there are four categories according to the approach method: 1) anterior endoscopic cervical discectomy (AECD); 2) anterior endoscopic cervical transcorporeal decompression (AECTcD); 3) posterior endoscopic cervical foraminotomy and discectomy (PECFD); and 4) posterior endoscopic cervical laminotomy (PECL). Expert opinion: Cervical endoscopic surgery provides comparable clinical results with MISS benefits, such as shorter operative time, less bleeding, and earlier recovery time. However, spine surgeons are not yet familiar with most of these techniques; moreover, supportive evidence is minimal. Technical evolution is still ongoing in an effort to make the procedure more practical.

Clinical outcomes of transforaminal endoscopic lateral recess decompression by using the visualized drilled foraminoplasty and visualized reamed foraminoplasty: a comparison study

Background

Lateral recess stenosis (LRS) is a common degenerative disease in the elderly. Since the rise of comorbidity is associated with increasing age, transforaminal endoscopic lateral recess decompression (TE-LRD) is advocated. The objective of this study was to compare the clinical outcomes of TE-LRD in patients with LRS via visualized drilled foraminoplasty (VDF) or visualized reamed foraminoplasty (VRF) technique.

Methods

A total of 45 and 42 consecutive patients with limp or unilateral radiculopathy symptoms underwent TE-LRD using the VDF and VRF technique, respectively. The radiation exposure and operation time, time to return to work, and complications were compared between two groups. Their clinical outcomes were evaluated with the visual analogue scale (VAS) leg pain score, VAS back pain score, Oswestry Disability Index (ODI) and modified MacNab’s criteria.

Results

The average values of radiation exposure and operative time in the VDF group were significantly higher than those in the VRF group (P <  0.05). The postoperative VAS and ODI scores in both groups were significantly improved compared with those before the operation (P <  0.05). In addition, the VAS score of the leg pain and ODI score in the VRF group were significantly lower than those in the VDF group at the 1-week follow-up (P <  0.05). The good-to-excellent rates of the VDF group and VRF group were 88.89 and 90.48%, respectively, whereas the complication occurrence rates were 6.67 and 4.76% in the VDF group and VRF group, respectively.

Conclusions

TE-LRD performed by using VRF technique can be applied to treat LRS safely and effectively with short radiation exposure and operation time. This technique was comparable to the VDF technique with improved VAS leg pain and ODI scores in the short period after the operation. However, potential complications and risks still need to be considered.

Comparison of Percutaneous Endoscopic Lumbar Discectomy with Minimally Invasive Transforaminal Lumbar Interbody Fusion as a Revision Surgery for Recurrent Lumbar Disc Herniation after Percutaneous Endoscopic Lumbar Discectomy

Objective

The purpose of this study was to compare the outcomes between percutaneous endoscopic lumbar discectomy (PELD) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for the revision surgery for recurrent lumbar disc herniation (rLDH) after PELD surgery.

Patients and Methods

A total of 46 patients with rLDH were retrospectively assessed in this study. All the patients had received a PELD in Peking University First Hospital between January 2015 and June 2019, before they underwent a revision surgery by either PELD (n=24) or MIS-TLIF (n=22). The preoperative data, perioperative conditions, complications, recurrence condition, and clinical outcomes of the patients were compared between the two groups.

Results

Compared to the MIS-TLIF group, the PELD group had significantly shorter operative time, less intraoperative hemorrhage, and shorter postoperative hospitalization, but higher recurrence rate (P<0.05). Complication rates were comparable between the two groups. Both groups had satisfactory clinical outcomes at a 12-month follow-up after the revision surgery. The PELD group also showed significantly lower visual analog scale (VAS) scores of back pain and Oswestry disability index (ODI) in one month after the revision surgery, whereas the difference was not detectable at six- and 12-month follow-ups.

Conclusion

Both PELD and MIS-TLIF are effective as a revision surgery for rLDH after primary PELD. PELD is superior to MIS-TLIF in terms of operative time amount of intraoperative hemorrhage and postoperative hospitalization. However, its higher postoperative recurrence rate must be considered and patients should be well informed, when making a decision between the two surgical approaches.

Posterolateral Transforaminal Full-Endoscopic Lumbar Discectomy for Foraminal or Extraforaminal Lumbar Disc Herniations

BACKGROUND

Surgical procedures via the posterior median or paramedian approach for lateral lumbar disc herniation require significant bone resection to reach the herniation. In contrast, posterolateral transforaminal full-endoscopic lumbar discectomy (FELD) allows direct access to the lateral disc herniation. This study aimed to determine the efficacy and safety of this procedure.

METHODS

A total of 118 patients who underwent posterolateral transforaminal FELD were retrospectively examined. Data on surgical time, perioperative complications, and reoperation rate were reviewed from the medical records. Clinical evaluations were completed in 78 patients using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and numeric rating scale (NRS) for low back pain, lower limb pain, and lower limb numbness obtained at baseline and during a follow-up of more than 12 months.

RESULTS

The mean operative time was 33.9 min. Postoperative transient dysesthesia occurred in 11 of 118 patients (9.3%). No other complications were observed. Reoperation was performed in nine patients (5.9%). All domains of JOABPEQ and NRS significantly improved during the follow-up period. The effectiveness rates of the JOABPEQ for measuring low back pain, lumbar function, walking ability, social life function, and mental health were 70.4%, 46.5%, 62.0%, 59.2%, and 32.4%, respectively. Using the Macnab criteria, excellent or good results were achieved in 52 patients (73%).

CONCLUSIONS

Successful clinical results were obtained with a few complications and improvements in the domains of JOABPEQ and NRS. Posterolateral transforaminal FELD for lateral lumbar disc herniations is an effective and safe surgical option with minimal invasiveness and sufficient decompression.

Artificial Intelligence Comparison of the Radiologist Report With Endoscopic Predictors of Successful Transforaminal Decompression for Painful Conditions of the Lumber Spine: Application of Deep Learning Algorithm Interpretation of Routine Lumbar Magnetic Resonance Imaging Scan

BACKGROUND

Identifying pain generators in multilevel lumbar degenerative disc disease is not trivial but is crucial for lasting symptom relief with the targeted endoscopic spinal decompression surgery. Artificial intelligence (AI) applications of deep learning neural networks to the analysis of routine lumbar MRI scans could help the primary care and endoscopic specialist physician to compare the radiologist's report with a review of endoscopic clinical outcomes.

OBJECTIVE

To analyze and compare the probability of predicting successful outcome with lumbar spinal endoscopy by using the radiologist's MRI grading and interpretation of the radiologic image with a novel AI deep learning neural network (Multus Radbot™) as independent prognosticators.

METHODS

The location and severity of foraminal stenosis were analyzed using comparative ordinal grading by the radiologist, and a contiguous grading by the AI network in patients suffering from lateral recess and foraminal stenosis due to lumbar herniated disc. The compressive pathology definitions were extracted from the radiologist lumbar MRI reports from 65 patients with a total of 383 levels for the central canal - (0) no disc bulge/protrusion/canal stenosis, (1) disc bulge without canal stenosis, (2) disc bulge resulting in canal stenosis, and (3) disc herniation/protrusion/extrusion resulting in canal stenosis. Both neural foramina were assessed with either - (0) neural foraminal stenosis absent, or (1) neural foramina are stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted and assigned into two categories: "Normal," and "Stenosis." Clinical outcomes were graded using dichotomized modified Macnab criteria considering Excellent and Good results as "Improved," and Fair and Poor outcomes as "Not Improved." Binary logistic regression analysis was used to predict the probability of the AI- and radiologist grading of stenosis at the 88 foraminal decompression sites to result in "Improved" outcomes.

RESULTS

The average age of the 65 patients was 62.7 +/- 12.7 years. They consisted of 51 (54.3%) males and 43 (45.7%) females. At an average final follow-up of 57.4 +/- 12.57, Macnab outcome analysis showed that 86.4% of the 88 foraminal decompressions resulted in Excellent and Good (Improved) clinical outcomes. The stenosis grading by the radiologist showed an average severity score of 4.71 +/- 2.626, and the average AI severity grading was 5.65 +/- 3.73. Logit regression probability analysis of the two independent prognosticators showed that both the grading by the radiologist (86.2%; odds ratio 1.264) and the AI grading (86.4%; odds ratio 1.267) were nearly equally predictive of a successful outcome with the endoscopic decompression.

CONCLUSIONS

Deep learning algorithms are capable of identifying lumbar foraminal compression due to herniated disc. The treatment outcome was correlated to the decompression of the directly visualized corresponding pathology during the lumbar endoscopy. This research should be extended to other validated pain generators in the lumbar spine.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Validity, clinical teaching, evaluation study.

Transforaminal Endoscopic Discectomy Combined With an Interspinous Process Distraction System for Spinal Stenosis

BACKGROUND

The combination of the percutaneous transforaminal endoscopic decompression (PTED) with an interspinous process distraction system (IPS) may offer additional benefit in the treatment of spinal stenosis in patients who have failed nonsurgical treatment.

METHODS

We retrospectively reviewed the medical records of 33 patients diagnosed with lumbar stenosis and radiculopathy and treated them with transforaminal endoscopic lumbar decompression between 2013 and 2017. Primary outcome measures were modified Macnab as well as preoperative and postoperative visual analog scale (VAS) criteria and the Oswestry Disability Index (ODI). Only patients with a minimum follow-up of 2 years were included.

RESULTS

A total of 28 patients were treated with a combination of PTED and percutaneous IPS (group A), and 5 patients were treated with PTED and mini-open IPS (group B). In group A patients, there was a 4.48 reduction in the VAS score. The ODI changed from 50.25 preoperatively to 18.2 postoperatively, and excellent and good Macnab outcomes were obtained in 78% of patients. In group B patients, the mean VAS reduction was 5.2 points. The ODI changed from 44.34 preoperatively to 14.62 postoperatively, and 80% of group B patients achieved excellent and good Macnab outcomes. No complications related to PTED or IPS were observed throughout the 2-year follow-up.

CONCLUSIONS

The addition of IPS to the PTED procedure in select patients may offer additional benefits to patients being treated for lumbar lateral stenosis and foraminal stenosis with low-grade spondylolisthesis.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Feasibility study.

Endoscopic Transforaminal Lumbar Interbody Fusion With a Single Oblique PEEK Cage and Posterior Supplemental Fixation

BACKGROUND

To demonstrate the feasibility of an endoscopically assisted minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF) and to study clinical outcomes with the use of a static oblique bullet-shaped cannulated poly-ether-ether-ketone (PEEK) lumbar interbody fusion cage in conjunction with platelet enriched plasma infused allograft cancellous chips and posterior supplemental fixation.

METHODS

In this retrospective study of 43 patients who underwent endoscopically assisted MIS-TLIF for spondylolisthesis (53.5%) and stenosis (46.3%), the Oswestry Disability Index, the visual analog scale (VAS) for back and leg pain, and the modified Macnab criteria were used as primary clinical outcome measures. Clinical outcomes were cross-tabulated against fusion grade using the Bridwell classification of interbody fusion.

RESULTS

The majority of patients (90.7%) had excellent (8/43; 18.6%) and good (31/43; 72.1%) Macnab outcomes. There were significant VAS back score reductions from an average preoperative values of 8.9070 to a postoperative VAS score of 3.8605, and a score of 2.7674 at final follow-up (P < .0001). The reductions in the VAS leg scores were also significant from preoperative score of 5.58 to a postoperative value of 2.16, and a final follow-up score of 1.67 (P < .0001); the Oswestry Disability Index score went from a preoperative value of 54.4 to 23.3 postoperatively and 18.5 at the final follow-up (P < .0001). The vast majority of patients (92.9%) with Bridwell grade I fusion had excellent and good Macnab outcomes (P = .027).

CONCLUSIONS

The authors recommend the use of an endoscope as an adjunct to MIS-TLIF, a minimally invasive spinal surgery technique in which many surgeons may be well versed and have a great deal of experience. Clinical outcomes with the endoscopic interbody fusion procedure with a static PEEK cage in conjunction with platelet-enriched bone allograft were favorable.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Feasibility study.

Comparison of postoperative outcomes between patients with positive and negative straight leg raising tests who underwent full-endoscopic transforaminal lumbar discectomy

Full-endoscopic transforaminal lumbar discectomy (FETD) is increasingly used in patients with lumbar disc herniation (LDH). There is little knowledge on the related factors, including the straight leg raising test (SLR), that influence the operation. Consecutive patients with LDH who came to our hospital from August 2015 to September 2016 and underwent FETD surgery were included. Four kinds of scores, including the VAS (lumbar/leg), ODI and JOA values, were measured and reassessed after FETD to assess the surgical outcomes. There was a statistically significant difference between the scores before surgery and at each postoperative follow-up. In addition, the increase in the JOA score postoperatively was statistically significant compared with that before surgery. There were statistically significant differences among the three subpopulations [patients considered SLR positive (0°-30°), SLR positive (31°-60°) and SLR negative (61°-)] in the changes in the VAS (leg), ODI and JOA values. However, there were no statistically significant differences among the three subpopulations [patients considered SLR positive (0°-30°), SLR positive (31°-60°) and SLR negative (61°-)] in the changes in VAS score (lumbar). FETD showed great effectiveness in treating patients with lumbar disc herniation. Patients who were SLR negative may receive greater benefit from FETD.

Technical Considerations of the Transforaminal Approach for Lumbar Disk Herniation

Transforaminal full endoscopic lumbar diskectomy (TELD) is a typical minimally invasive surgery, with the associated benefit of decreased possibility of anatomic structural injury, and is an effective alternative to open diskectomy. Among the various endoscopic spinal surgical techniques currently available, TELD is the most basic and traditional surgery that can be performed through the transforaminal route; it has been used for >30 years. Recently, with the advancements in surgical techniques, TELD has been successfully performed for patients with lumbar disk herniation of different types. However, beginner surgeons are unfamiliar with the anatomy of transforaminal endoscopic surgery and this surgery has a steep learning curve to date. If not well prepared, operators may experience complications that require reoperation in the early stages. These complications may include symptomatic incomplete decompression, exiting nerve root injury, dural tearing, and rarely, hematoma, infection, and visceral injury. Here, we propose several technical guidelines for TELD to increase the possibility of successful lumbar diskectomy and to reduce the incidence of complications. The first step is the accurate anatomic understanding of Kambin triangle and determining the appropriate endoscopic access angle, depending on the type of disk herniation. The second step is to determine a safe and easily accessible entry point and then landing and docking the working sleeve as close to the target as possible without causing exiting nerve root injury. The third step is complete decompression of the symptomatic nerve with free mobilization of the neural tissue. The final step involves performing foraminoplasty using an advanced technique to overcome the limitations associated with TELD in difficult cases.

The Evolution of Transforaminal Endoscopic Spine Surgery

Transforaminal endoscopic spine surgery (T-ESS) has become a well-accepted technique. The first attempts at percutaneous discectomy by Kambin and Hijikata opened a new chapter of endoscopic spine surgery. By the last quarter of the twentieth century, spine surgeons had begun to adopt this novel technique. Many researchers helped advance endoscopic spine surgery, but the turning point was the description of a safe transforaminal triangle of safety by Parviz Kambin. Since then, the indications for T-ESS have increased as a result of the description of different surgical approaches such as inside-out, outside-in, and half-and-half. We present a review of crucial historical advancements in T-ESS and also discuss the evolution of endoscopes, the techniques used, development of endoscopic instruments and equipment, transforaminal thoracic endoscopy, transforaminal endoscopic interbody fusions, the growth of extended indications, and the future direction of T-ESS. This review provides a detailed description of key historical moments and a bird's-eye view of the vast scope of T-ESS.

Current and Future of Endoscopic Spine Surgery: What are the Common Procedures we Have Now and What Lies Ahead?

The aging population around the world leads to increasing incidence of degenerative spinal conditions. There is a need for a minimally invasive technique in treatment for spinal conditions to meet the medical complexity and comorbidities that comes with aging. Principles of endoscopy are similar to minimally invasive surgery, which is to decrease pressure on soft tissue crushing from prolonged retraction, avoid soft tissue stripping and dissection, and bone and ligamentous preservation for optimal decompression without excessive destruction. Endoscopic spine surgery techniques started slowly in development in the 1970s to 2000s, with a rapid phase of development since the turn of the 21st century with endoscopic solutions developing in cervical, thoracic, and lumbar conditions with increasing complexity in nature of operation. Technological enhancement with progressively supportive literature is pushing boundaries of endoscopy from the early days of soft tissue procedure to current fusion procedures, endoscopic spine surgery techniques is covering more areas of spine than ever previously possible with good clinical results. We present a review on the current techniques available and postulated near future development for endoscopic spine surgery.

Learning Curve for Transforaminal Percutaneous Endoscopic Lumbar Discectomy: A Systematic Review

BACKGROUND

Transforaminal percutaneous endoscopic lumbar discectomy (TPELD) has become an alternative and minimally invasive surgical technique for soft lumbar disc herniation. However, the learning curve has been relatively long and difficult. In the present study, we have summarized the characteristics of the learning curve of TPELD, including the number of cases required to achieve technical proficiency, and discussed the strategies to improve the learning curve.

METHODS

The PubMed, Embase, Cochrane Library, and KoreaMed databases were searched for reports describing the learning curve for TPELD. Clinical studies involving human patients and evaluating the learning curve of TPELD with quantitative data were included. A strict quality assessment was completed, and descriptive statistics were calculated.

RESULTS

Of the 6884 screened titles and abstracts, 10 full-text reports, including 958 cases, were included in the analysis. All were cohort studies, which were grouped into early and late groups according to surgeon experience with TPELD. The most commonly used cutoff to differentiate between these groups was 20 (mean, 24.70 ± 18.99 cases; range, 10-72 cases). The most widely used measure was the operative time. Although most studies had reported better results in the operative time or pain scores in the late group, only 1 study had proposed a bona fide learning curve.

CONCLUSIONS

We found insufficient evidence to support a cutoff point of 20 or other numbers of cases for determining when the learning curve has reached a plateau. Therefore, these numbers should be interpreted with great care, and high-quality prospective studies evaluating the actual learning curve are required.

A Historical Review of Endoscopic Spinal Discectomy

As an essential component of minimally invasive spine surgery, endoscopic spine surgery (ESS) has continuously evolved and has been accepted as a practical procedure by the worldwide spine community. Especially for lumbar disc herniation (LDH), the percutaneous endoscopic or full-endoscopic discectomy technique has been scientifically proven through randomized controlled trials and meta-analyses to be a good alternative to open discectomy. The initial concept of endoscopic spine discectomy was concerned with indirect disc decompression using various instruments such as blind forceps, a nucleotome, laser, radiofrequency coblation, and some chemical agents. The main surgical field has been shifted from the intradiscal space to the epidural space. Precise and selective discectomy for extruded LDH in the epidural space under high-quality endoscopic visualization is now feasible. Furthermore, the medical applications of ESS is broadening to include spinal stenosis, segmental instability, infection, and even intradural lesions. In this review article, I describe the history of endoscopic spine discectomy and decompression techniques, as well as evolution of the paradigm. This history may help indicate the future of practical ESS.

Transforaminal Endoscopic Surgery: Outside-In Technique

Transforaminal endoscopic lumbar discectomy (TELD) with the outside-in technique can be applied to nearly all cases of lumbar disc herniation (LDH), and transpedicular endoscopic lumbar discectomy can be used to treat highly migrated LDHs. The purpose of this study was to outline these 2 outside-in surgical techniques and to present their clinical outcomes. Between January 2018 and January 2019, a total of 137 patients underwent either transforaminal or transpedicular endoscopic lumbar discectomy. We performed TELD in 124 patients and transpedicular endoscopic lumbar discectomy in 13 cases. All surgical procedures were performed under conscious sedation. The patients’ mean age was 51.3 years; 51 were women and 86 were men. The overall disc recurrence rate was 5.12%. Visual analogue scale scores decreased significantly in both groups. According to the MacNab criteria, good and excellent results were obtained in 92.74% of patients after transforaminal and in 92.30% of patients after transpedicular endoscopic LDH treatment. The results suggest that TELD with the outside-in technique can be effective for the treatment of most cases of LDH. Transpedicular endoscopic lumbar discectomy can be considered as an alternative treatment for highly migrated LDH.

Lumbar Endoscopic Bony and Soft Tissue Decompression With the Hybridized Inside-Out Approach: A Review And Technical Note

This study aimed to showcase the authors' preferred technique of a hybrid of modern "inside-out" and "outside-in" endoscopic decompression. A case series of 411 patients consisting of 192 females (46.7%) and 219 males (53.3%) with an average age of 54.84 ± 16.32 years and an average of 43.2 ± 26.53 months are presented. Patients underwent surgery for low-grade spondylolisthesis (13 of 411, 3.2%), herniated disc (135 of 411, 32.8%), foraminal spinal stenosis (101 of 411, 24.6%), or a combination of the latter 2 conditions (162 of 411, 39.4%). The preoperative Oswestry Disability Index (ODI) and visual analogue scale (VAS) for leg pain were 49.8 ± 17.65 and 7.9 ± 1.55, respectively. Postoperative ODI and VAS leg were 12.2 ± 9.34 and 2.41 ± 5 1.55 at final follow-up (p < 0.0001). MacNab outcomes were excellent in 134 (32.6%), good in 228 (55.5%), fair in 40 (9.7%), and poor in 9 patients (2.2%), respectively. There was end-stage degenerative vacuum disc disease in 304 of the 411 patients (74%) of which had 37.5% had excellent and 50% good MacNab outcomes. Patients without vacuum discs had excellent and good 18.7% and 71.0% of the time. Direct visualization of pain generators in the epidural- and intradiscal space is the authors' preferred transforaminal decompression technique and is supported by their reliable clinical outcomes.

Treatment of high-iliac-crest L5-S1 lumbar disc herniation via a transverse process endoscopic transforaminal approach

OBJECTIVE

To investigate the clinical efficacy of transverse process endoscopic transforaminal discectomy for the treatment of high-iliac-crest L5-S1 lumbar disc herniation.

METHODS

Seventeen patients with high-iliac-crest L5-S1 lumbar disc herniation who were treated with transforaminal endoscopy from April 2016 to January 2019 in the Department of Neurosurgery of Xuanwu Hospital were selected. The visual analog scale (VAS) and Oswestry disability index (ODI) were used to evaluate the efficacy of the procedure.

RESULTS

All of the patients successfully underwent the surgical treatment. Sixteen patients (94.1 %) completed effective follow-up for more than 12 months. The VAS was 7.8 ± 1.9, 2.9 ± 1.6, 2.3 ± 1.5 and 2.2 ± 1.6 before surgery and at one day, 3 months, and the last follow-up after surgery, respectively. The ODI scores were 52.8 ± 15.2 and 16.9 ± 9.7 before surgery and 3 months after surgery, respectively, both of which were lower than before surgery (both P < 0.01).

EFFICACY EVALUATION

An excellent outcome was achieved in 13 (81.3 %) patients, a good outcome in 1 patient (6.3 %), an acceptable outcome in 1 patient (6.3 %), and a poor outcome in 1 patient (6.3 %).

CONCLUSIONS

The transverse process endoscopic transforaminal discectomy is a safe and effective surgical method for the treatment of high-iliac-crest L5-S1 lumbar disc herniation.