Risk factors for failure of single-level percutaneous endoscopic lumbar discectomy

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Predicting and analysing of the unfavourable outcomes of early applicated percutaneous endoscopic interlaminar discectomy for lumbar disc herniation: development and validation based nomogram

OBJECTIVE

To predict and analyse the unfavourable outcomes of early applicated percutaneous endoscopic interlaminar discectomy for lumbar disc herniation.

METHODS

Information of 426 patients treated by early applicated percutaneous endoscopic interlaminar discectomy (PEID) for lumbar disc herniation (LDH) at our hospital from June 2017 to October 2021 in addition to 17 other features was collected. The risk factors were selected by the least absolute shrinkage and selection operator method (LASSO) regression. Then, a prediction model (nomogram) was established to predict the unfavourable outcomes of using the risk factors selected from LASSO regression. Bootstrap (n = 1000) was used to perform the internal validation, and the performance of the model was assessed by the concordance index (C-index), receiver operating characteristic curve, and calibration curve. The decision curve analysis (DCA) and clinical impact curve (CIC) were used to assess the clinical utility of the model, respectively.

RESULTS

Finally, 53 of 426 patients showed unfavourable outcomes. Five potential factors, Modic change, Calcification, Lumbar epidural steroid injection preoperative, Articular process hyperplasia and cohesion, and Laminoplasty technique, were selected according to the LASSO regression, that identified the predictors to establish nomogram model. Meanwhile, the C-index of the prediction nomogram was 0.847, the area under the receiver operating characteristic curve value was 0.847, and the interval bootstrapping (n = 1000) validation C-index was 0.809. The model has good practicability for clinics according to the DCA and CIC.

CONCLUSION

This nomogram model has good predictive performance and clinical practicability, which could provide a certain basis for predicting unfavourable outcomes of early applicated PEID for LDH.

Machine Learning Predicts Recurrent Lumbar Disc Herniation Following Percutaneous Endoscopic Lumbar Discectomy

STUDY DESIGN

Retrospective study.

OBJECTIVES

To develop machine learning (ML) models to predict recurrent lumbar disc herniation (rLDH) following percutaneous endoscopic lumbar discectomy (PELD).

METHODS

We retrospectively analyzed 1159 patients who had undergone single-level PELD for lumbar disc herniation (LDH) between July 2014 to December 2019 at our institution. Various preoperative imaging variables and demographic metrics were brought in analysis. Student's t test and Chi-squared test were applied for univariate analysis, which were feature selection for ML models. We established ML models to predict rLDH: Artificial neural networks (ANN), Extreme Gradient Boost classifier (XGBoost), KNeighborsClassifier (KNN), Decision tree classifier (Decision Tree), Random forest classifier (Random Forest), and support vector classifier (SVC).

RESULTS

A total 130 patients (11.22%) were diagnosed as rLDH in 1159 patients. Recurrence occurred within 10.25 ± 11.05 months. Body mass index (BMI) (P = .027), facet orientation (FO) (P < .001), herniation type (P = .012), Modic changes (P = .004), and disc calcification (P = .013) are significant factors in univariate analysis (P < .05). Extreme Gradient Boost classifier, Random Forest, ANN showed fine area under the curve, .9315, .9220, and .8814 respectively.

CONCLUSION

We developed a deep learning and 2 ensemble models with fine performance in prediction of rLDH following PELD. Predicting re-herniation before surgery has the potential to optimize decision-making and meaningfully decrease the rates of rLDH following PELD. Our ML model identified higher BMI, lower FO, Modic changes, disc calcification in a non-protrusive region, and herniation type (noncontained herniation) as significant features for predicting rLDH.

S1 Transforaminal Epidural Anesthesia in Percutaneous Transforaminal Endoscopic Discectomy: A Case-Series Study

Background

Percutaneous transforaminal endoscopic discectomy (PTED) has become popular over the years due to its safety and low invasiveness. This surgery can be performed with different anesthesia techniques; however, the extent to which the surgeon and patient are satisfied with the analgesia is debatable.

Objectives

This study investigated the efficiency of the S1 transforaminal epidural block.

Methods

This retrospective study was conducted on 60 patients with L4 - L5 lumbar disc herniation who underwent PTED under the S1 transforaminal epidural block. All patients had clinical symptoms associated with unilateral radiculopathy and were candidates for surgery. Percutaneous transforaminal endoscopy and S1 epidural block were performed by a surgeon for all patients.

Results

Of the 60 evaluated cases, 61.7% and 38.3% were female and male, respectively, with a mean age of 42.98 ± 10.79 years. The mean pain score before surgery was 7.83 ± 0.69, which decreased to 2.58 ± 0.65 during surgery and 0.50 ± 0.50 48 hours after surgery (P < 0.001). The mean duration of operation in these patients was 58.58 ± 16.95 minutes, and the mean onset time was 10.08 ± 3.12 minutes. Moreover, the mean bleeding was 124.17 ± 25.20 cc.

Conclusions

The PTED with S1 epidural anesthesia is a simple, safe, and effective method that causes good analgesia during the operation and cooperates well with the surgeon in neurological monitoring due to patient consciousness.

Spine-Related Malpractice Claims in China: A 2-year National Analysis

STUDY DESIGN

Retrospective cross-sectional study.

OBJECTIVE

To investigate the prevalence, characteristics, and risk factors of spine-related malpractice claims in China in a 2-year period.

METHODS

The arbitration files of the Chinese Medical Association (CMA) were reviewed for spine-related malpractice claims. Descriptive statistics and correlation analysis were conducted on claim characteristics, clinical data, plaintiff's main allegations, and arbitration outcomes.

RESULTS

A total of 288 cases of spinal claims filed in the CMA between January 2016 and December 2017 were included. Most claims were found in lumbar degenerative disorders (59.4%), lumbar trauma (13.2%), and cervical degenerative disorders (11.8%). The most common adverse events (AEs) leading to claims were new neurologic deficit (NND) (47.6%), infection (11.5%), and insufficient symptom relief (10.4%). The most common patient allegation was surgical error (66.0%), although the main arbitrated cause of AEs was disease/treatment itself (49.0%), while providers were judged as mainly responsible in only 47.3% cases. In multivariate regression analysis, cervical spine, misdiagnosis/mistreatment, and unpredictable emergency correlated with more severe damage to patients; minimally invasive surgery was predictive of judgment in plaintiff's favor, while claims in the eastern region and unpredictable emergencies were predictive of defendant's favor; only NND was associated with being arbitrated as surgical error in surgical cases where surgeons accepted major liability.

CONCLUSION

The current study provided a descriptive overview and risk factor analysis of spine-related malpractice claims in China. Gaining improved understanding of the facts and causes of malpractice claims may help providers reduce the risk of claims and subsequent litigation.

Analysis of the Efficacy of Percutaneous Endoscopic Interlaminar Discectomy for Lumbar Disc Herniation with Different Types/Grades of Modic Changes

Background

Percutaneous endoscopic interlaminar discectomy (PEID), one of the main techniques of spinal endoscopy, has achieved excellent results in treating lumbar disc herniation (LDH). However, its efficacy has not been systematically described in patients with LDH accompanied by Modic changes (MC).

Purpose

The purpose of this study was to observe the clinical efficacy of PEID treatment of LDH accompanied by MC.

Patients and Methods

A total of 207 patients who underwent PEID surgery for LDH were selected. According to the existence and type of MC on preoperative lumbar magnetic resonance images (MRI), they were divided into normal group (no MC, n=117), M1 group (MC I, n=23), and M2 group (MC II, n=67). According to the severity of MC, they were divided into MA group (grade A, n=45) and MBC group (grade B and C, n=45). The visual analog scale (VAS) score, Oswestry disability index (ODI) score, Disc height index (DHI), Lumbar lordosis angle (LL) and modified Macnab criteria were used to assess clinical outcomes.

Results

Postoperative back pain and leg pain VAS scores and ODI scores were significantly improved in all groups compared with preoperative scores. Patients with MC showed a deterioration in postoperative back pain VAS scores and ODI scores as time went by, and postoperative DHI decreased significantly compared with preoperative. Postoperative LL did not change significantly in each group. There was no significant difference in complications, recurrence rate and excellent rate between the groups.

Conclusion

Whether accompanied by MC or not, the efficacy of PEID for LDH was significant. However, postoperative back pain and functional status of patients with MC tend to deteriorate as time went by, especially those with type I or severe MC.

Development and Validation of a Nomogram to Predict the Risk of Lumbar Disk Reherniation within 2 Years After Percutaneous Endoscopic Lumbar Discectomy

OBJECTIVE

To develop and validate a nomogram for predicting recurrent lumbar disk herniation (LDH) within 2 years after percutaneous endoscopic lumbar discectomy.

METHODS

Information on patients' LDH was collected from 1 medical center between January 2015 and September 2020. The LASSO (least absolute shrinkage and selection operator) method was applied to select the most significant risk factors. A multivariate logistic regression analysis was used to develop a predictive model incorporating the possible factors selected by the LASSO regression model. The discriminant, corrected, and clinically useful prediction models were evaluated using consistency index (C-index), receiver operating characteristic curve, calibration curves, and decision curve analysis. Internal validation of clinical predictive power was also assessed by bootstrap validation.

RESULTS

A total of 690 patients with LDH were included in this study. Sixty-three patients experienced recurrence within 2 years whereas 627 experienced no recurrence. The nomogram predictors included age, body mass index, Modic change, Pfirrmann grade, and sagittal range of motion. The model had good discrimination power, with a reliable C-index of 0.868 (95% confidence interval, 0.822-0.913) and interval validation confirmed a higher C-index value of 0.846. The area under the receiver operating characteristic curve was 0.868, indicating a good predictive value. The decision curve analysis indicated that it was clinically feasible to use the predictive recurrence nomogram model.

CONCLUSIONS

We developed and validated a new accurate and effective nomogram for predicting recurrent LDH within 2 years after percutaneous endoscopic lumbar discectomy. Age, body mass index, Modic change, Pfirrmann grade, and sagittal range of motion were significant features for predicting rLDH.

Predictors of reoperation in hispanic-americans with recurrent lumbosacral disc herniation following primary hemilaminectomy and discectomy surgery

Background

Multiple risk factors for recurrent lumbosacral disc herniation (rLDH) have been evaluated. However, it has been difficult to establish a consensus due to conflicting results. Therefore, the aim of our study was to evaluate the predictors of reoperation in Hispanic-Americans with rLDH following primary hemilaminectomy and discectomy surgery.

Methods

A retrospective case-control study of 451 Hispanic-Americans with lumbosacral disc herniation (LDH) was conducted. The sample was divided into two groups: reoperated (cases) and non-reoperated (controls). Preoperative, operative, and postoperative variables of initial surgery were compared between the two groups.

Results

The reoperation rate was 11.5%, with a mean interval between primary surgery and reoperation of 3.32 years ± 2.07. Analysis of preoperative variables identified a higher rate of reoperation in patients who were unemployed (cases: 48.1%, controls: 17.1%, p=0.001). A significant difference was also seen regarding the presence of gastrointestinal disease (cases: 11.5%, controls: 4.3%, p=0.038). However, there were no differences in the sociodemographic factors, preoperative physical exam, preoperative management, radiological parameters, or operative data. Those patients with persistent postoperative lower extremity pain, radiculopathy, low back pain, and buttock pain demonstrated a higher correlation with rLDH. Multivariable logistic regression analysis identified a significant difference only in work status (employed; OR and 95% CI [0.60 (0.55, 0.67)], p=0.002) and presence of postoperative low back pain (OR and 95% CI [2.17 (1.13, 4.29)], p=0.014).

Conclusions

Patients who required reoperation due to rLDH were more frequently unemployed and/or suffered postoperative low back pain after primary hemilaminectomy and discectomy surgery.

Complications and Management of Endoscopic Spinal Surgery

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

Preoperative ODI and Intake of Analgesics Predict Outcome after Lumbar Microdiskectomy: Results from a Prospective Register

BACKGROUND

 Lumbar disk herniation (LDH) typically causes leg pain and neurologic deficits, but can also be a source of low back pain (LBP). Lumbar microdiskectomy (LMD) is among the most common neurosurgical procedures to relieve radicular symptoms. It is important for both surgeon and patient to understand potential predictors of outcome after LMD. The aim of this study was to investigate if the presence and intensity of preoperative LBP, the ODI score, and analgesic intake can predict the outcome of patients undergoing LMD.

METHODS

 This is a single-center retrospective study based on the analysis of prospectively acquired data of patients in the SwissDisc Registry. A total of 685 surgeries on 640 patients who underwent standardized LMD at our institution to treat LDH were included in this study. We performed multivariable linear regression analysis to determine preoperative predictors for patient outcomes based on the Oswestry Disability Index (ODI) scores, recorded on average 39.77 (±33.77) days after surgery.

RESULTS

 Our study confirmed that surgery overall improves patient degree of disability as measured by ODI score. Following model selection using Aikake Information Criterion (AIC), we observed that higher preoperative ODI scores (β: 0.020 [95% CI: 0.008 to 0.031]) and higher number of analgesic medication usage by patients prior to surgery (β: 0.236 [95% CI: 0.057 to 0.415]) were both associated with an increased postoperative ODI score.

CONCLUSION

 LDH surgery generally improves patient degree of disability. The analysis of patients with a high preoperative ODI score and increased intake of analgesics before surgery predicted a worsening of patients' disability after LMD in this subgroup.

Minimally invasive trans-superior articular process percutaneous endoscopic lumbar discectomy with robot assistance

BACKGROUND

To compare the clinical outcomes of patients with lumbar disc herniation treated with robot-assisted percutaneous endoscopic lumbar discectomy (r-PELD) or conventional PELD under fluoroscopy guidance (f-PELD).

METHODS

Our study group included 55 patients, 22 in the r-PELD group and 33 in the f-PELD group. The following clinical and surgical outcomes were compared between the two groups: the visual analog scale for radiculopathy pain; Oswestry Disability Index; intraoperative volume of blood loss; frequency of fluoroscopy used during the procedure; and MacNab classification. The follow-up period was 6-8 months.

RESULTS

Compared with f-PELD, r-PELD was associated with a lower volume of intraoperative blood loss and frequency of fluoroscopy (p < 0.01). There were no differences in complications, MacNab classification, postoperative disability and leg pain, and duration of hospitalization between the two groups.

CONCLUSION

Based on our findings, r-PELD provides a safe and effective alternative to conventional PELD for the treatment of lumbar disc herniations, with the accuracy for placement of punctures lowering radiation exposure.

[Comparative analysis of unilateral biportal endoscopic discectomy, percutaneous endoscopic lumbar discectomy, and fenestration discectomy in treatment of lumbar disc herniation]

OBJECTIVE

To investigate the effectiveness of unilateral biportal endoscopic discectomy (UBED), percutaneous endoscopic lumbar discectomy (PELD), and traditional fenestration discectomy (FD) in the treatment of lumbar disc herniation (LDH).

METHODS

The clinical data of 347 LDH patients who met the selection criteria and underwent discectomy between January 2017 and December 2021 were retrospectively analyzed. They were divided into FD group (160 cases), PELD group (86 cases), and UBED group (101 cases) according to operation methods. There was no significant difference in gender, age, surgical level distribution, disease duration, and preoperative visual analogue scale (VAS) score and Oswestry disability index (ODI) between groups ( P>0.05). The operation time, hospitalization stay, treatment cost, and incidence of surgery-related complications were recorded and compared between groups. The patients' pain and functional recovery were evaluated by VAS score and ODI before and after operation.

RESULTS

The operation time of FD group was significantly shorter than that of PELD group and UBED group, and the hospitalization stay was significantly longer than that of PELD group and UBED group ( P<0.05); there was no significant difference between PELD group and UBED group ( P>0.05). The treatment cost in UBED group was significantly higher than that in PELD group, and in PELD group than in FD group ( P<0.05). All the patients were followed up 6-24 months, with an average of 14.6 months. VAS score of lower extremity and ODI in 3 groups significantly improved after operation when compared with that before operation ( P<0.05). At 1 day after operation, VAS score of lower extremity of UBED group was significantly better than that in PELD group and FD group ( P<0.05), but there was no significant difference between PELD group and FD group ( P>0.05). There was no significant difference in VAS scores of lower extremity between the 3 groups at 1 and 3 months after operation ( P>0.05). The difference of ODI before and after operation in FD group and UBED group was slightly better than that in PELD group ( P<0.05), and there was no significant difference between FD group and UBED group ( P>0.05). Incidence of surgery-related complications in FD group (20.0%) was significantly higher than that in PELD group (12.8%) and UBED group (6.9%), and PELD group was significantly higher than UBED group ( P<0.05). All the incision infection occurred in FD group (12 cases), symptomatic disc cyst and myeloid hypertension-like occurred in 1 case each in PELD group.

CONCLUSION

UBED, PELD, and FD have similar effectiveness on lower extremity pain in early LDH. Compared with FD, UBED and PELD have the advantage of shorter hospitalization stay and fewer complications.

Surgical Outcomes of Full-Endoscopic Lumbar Discectomy in the Early Adoption Phase

Background We adopted full-endoscopic lumbar discectomy (FELD) in 2019 with the assistance of the Japanese Society for Minimally Invasive and Endoscopic Techniques of Spinal Neurosurgery (JASMETS). This study analyzed short-term outcomes in our initial FELD cases and compared them with microdiscectomy cases performed during the same period.

Methods FELD was performed in 21 patients over a period of 2 years and 6 months (15 men and 6 women; mean age, 57.0±17.0 years). The transforaminal approach was performed in 8 patients, the posterolateral approach in 3, and the interlaminar approach in 10. During the same period, microdiscectomy was performed in 30 patients. Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores, operation time, blood loss volume, complications, and incidence of lumbar disc herniation recurrence were compared between the groups.

Results Preoperative VAS and JOA scores did not significantly differ between the FELD and microdiscectomy groups. JOA and VAS scores significantly improved in both groups after surgery. Operation time and incidence of recurrence rate did not differ.

Conclusion Spine surgeons who adopt FELD can achieve good surgical outcomes similar to those of microdiscectomy, even in the early period. Participation in JASMETS seminars and training and proctoring by a certified endoscopic spine surgeon were instrumental in our experience.

Percutaneous Endoscopic Lumbar Discectomy for Lumbar Disc Herniation With Type II Modic Changes

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) has become a favorable surgical approach for lumbar radiculopathy caused by intervertebral disc herniation. Studies have revealed patients with type II Modic change may suffer from unrelieved low back pain and higher lumbar disc herniation (LDH) recurrence after herniated nucleus pulposus removal. Therefore, in this study, we aim to evaluate how PELD performed in management of LDH patients with type II Modic change.

METHODS

We collected 267 single-level LDH cases aged 20-50 yearswho underwent PELD from December 2016 to December 2019. The mean follow-up time was 26.3 months (range: 12-48 months). The visual analog scale (VAS), Oswestry Disability Index (ODI), and MacNab scores, as well as the recurrence rate, were analyzed pre- and post-surgery, as well as at the time points of 3 months, 12 months, and the final follow-up time after surgery. The clinical outcomes in LDH patients with or without type II Modic change who underwent PELD were thoroughly analyzed.

RESULTS

Within the 267 LDH patients enrolled, 145 cases present Modic signals, among which 3 are type I and 142 are type II. The VAS and ODI scores of the patients in the 2 groups at different follow-up times were significantly lower than those before surgery. The excellent and good MacNab scores in the control group and Modic type II change group were 87.0% and 82.1%, respectively. However, with the extension of follow-up time, the VAS and ODI scores, as well as the recurrence rate, were found to be higher in the type II Modic change group when compared with those in the non-Modic change group.

CONCLUSIONS

PELD performed well in management of LDH patients. However, we need to pay more attention to the continuous low back pain and the recurrence possibility in the cases with type II Modic change. In these cases, longer brace support or other interventions could be applied.

Study on the efficacy and safety of the combination of Shi's manual therapy and percutaneous endoscopic lumbar diskectomy for lumbar disc herniation with radiculopathy: study protocol for a multicenter randomized controlled trial

BACKGROUND

Lumbar disc herniation (LDH) is a common chronic musculoskeletal disorder that seriously affects quality of life. The percutaneous endoscopic lumbar diskectomy (PELD) technique was developed to address spinal nerve root compression through direct visualization of pathological findings while minimizing tissue destruction upon exposure. It is an effective and safe treatment for LDH. However, recurrent LDH is a major concern after lumbar discectomy for primary LDH. A considerable number of clinical studies have reported that patients with LDH with radiculopathy could benefit from manual therapy. Shi's manual therapy (SMT) was established based on traditional Chinese medicine (TCM) theory and has been shown to have a superior effect in alleviating muscle tension and loosening joints to improve lumbar and leg pain, radiculopathy, stiffness, activity discomfort, and related disorders. However, there is a lack of high-quality clinical evidence to support this conclusion. The purpose of this study is to evaluate the efficacy and safety of the combination of Shi's manual therapy (SMT) and PELD for LDH with radiculopathy.

METHODS/DESIGN

A multicenter randomized controlled trial (RCT) with a 1-year follow-up period will be performed. A total of 510 participants with LDH with radiculopathy will be recruited from four clinical centers. The sample size was estimated, and statistical analysis will be performed and supervised by biostatisticians from an independent third-party research institution. Two hundred fifty-five subjects will be randomly allocated to each group. The subjects in the control group will undergo PELD. Participants in the intervention group will be treated with a combination of SMT and PELD. Recurrence rate is the primary endpoint and the survival analysis of recurrence rate is the secondary endpoint, and the primary analysis of recurrence rate is the chi-square test and the secondary analysis of recurrence rate is survival analysis. The primary outcome measure is the recurrence rate of LDH with radiculopathy at the 1-year follow-up after treatment. The secondary outcome measures will be the ODI score, the VAS score for pain for the lumbar spine and lower limbs, the straight leg raise angle, the stability of the operated lumbar segment, and the SF-36 scores. Assessments will occur at baseline, postoperation, and 1 week, 4 weeks, 13 weeks, 26 weeks, and 1 year postoperation. In addition, adverse events related to clinical symptoms and signs and the results of laboratory tests will be documented during the clinical trials.

DISCUSSION

This study will provide reliable evidence of the effectiveness and safety of the combination of SMT and PELD for LDH with radiculopathy. If the results are favorable, it is expected that patients with LDH with radiculopathy will benefit from this study, and many patients could gain a good alternative treatment for LDH with radiculopathy.

TRIAL REGISTRATION

China Registered Clinical Trial Registration Center ChiCTR2000036515 . Registered on 13 November 2020.

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.

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.

Nomograms for Predicting Recurrent Herniation in PETD with Preoperative Radiological Factors

Purpose

To investigate the preoperative radiological risk factors for recurrent lumbar disc herniation (rLDH) within 1 year after percutaneous endoscopic transforaminal discectomy (PETD).

Patients and Methods

A retrospective case–control study was conducted. Between January 2013 and November 2019, a total of 1210 patients with single-level L4/5 LDH who underwent PETD were enrolled in the present study. In total, 62 rLDH patients were diagnosed and collected based on the clinical and radiological manifestations, and 224 non-rLDH controls were selected from the remaining 1148 patients. Preoperative radiological parameters were collected and measured. An age threshold to distinguish patients into subgroups was established using the Youden index. The relationships between the risk factors and rLDH were evaluated by univariate and multivariate analyses in two subgroups. Predictive models were established based on logistic analysis. The area under the curve (AUC) of receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA) were used to assess the predictive models.

Results

In the present study, logistic analysis identified six significant predictors associated with rLDH in the young group: superior endplate concave angle (ECA), sacral slope, Modic changes, sagittal range of motion (sROM), extension intervertebral angle (IVA), and lumbar lordosis. Four significant predictors were identified in the elderly group: disc height index (DHI), retrolisthesis (posterior spondylolisthesis), sROM, and extension IVA. Validation of both models demonstrated excellent model discrimination (AUC= 0.940 and 0.946, respectively). DCA also showed excellent clinical utility and benefits.

Conclusion

The nomograms that we constructed could accurately predict individual patient recurrence risk. Individualized measures should be taken for patients of different ages with the above risk factors, and tailored postoperative surveillance of patients who underwent PETD can be planned.

Percutaneous Endoscopic Lumbar Discectomy for Lumbar Disc Herniation Using an Endoscopic Staining: A Technical Note

Symptomatic lumbar disc herniation (LDH) is widely treated using percutaneous endoscopic lumbar discectomy (PELD). In the present PELD surgery, performing decompression under endoscope still takes a long time to explore the rupture site of annulus fibrosus, resulting in prolonged operation time and over-invasion of the undegenerated annulus fibrosus. A wide range of intraoperative exploration also induces an iatrogenic injury of the normal annulus fibrosus, even aggravating intervertebral disc degeneration, which may lead to early postoperative recurrence in severe case. Hence, it is important to seek a precise decompression in PELD surgery. Under this kind of realization, more spinal surgeons possibly choose a disc staining before performing decompression. However, the classical disc staining technique still has its shortcomings. First of all, an appropriate dose of staining cannot be accurately mastered, even induces unqualified staining effect. Second, the duration of surgery and the times of fluoroscopy will be increased. Finally, what surgeons see under the endoscope is the staining result but not the staining process. Hence, this is accomplished more effectively by designing procedures that perform fully visible disc staining under spinal endoscope. There is no specific research to discuss the technique note of endoscopic staining in PELD surgery. We have come up with a new original technology of endoscopic staining with methylene blue injection in PELD for treatment of LDH.

A matched comparison of outcomes between percutaneous endoscopic lumbar discectomy and open lumbar microdiscectomy for the treatment of lumbar disc herniation: a 2-year retrospective cohort study

BACKGROUND CONTEXT

Although open lumbar microdiscectomy (OLMD) is considered to be the gold standard method for discectomy, recent progress in endoscopic spinal surgery has increased the popularity of percutaneous endoscopic lumbar discectomy (PELD) for this indication. However, one of the main drawbacks of PELD is incomplete decompression, especially at the start of the surgeon's learning curve. The functional outcomes of PELD and OLMD in patients matched for age, hernia level, and hernia location have not previously been compared.

PURPOSE

To compare OLMD with PELD in terms of the clinical outcome and the time to recovery.

STUDY DESIGN

Retrospective, matched cohort study.

PATIENT SAMPLE

Data of all patients who underwent elective spinal surgery between January 2015 and June 2017 were extracted from the local database.

OUTCOME MEASURES

Clinical outcomes were assessed using a 0-to-10 visual analogue scale (VAS) for lower back pain (LBP) and leg pain were scored before surgery and at postoperative day 1 and at each follow-up visit (3, 12, and 24 months), the Oswestry Disability Index (ODI: 0%-100%), the length of hospital stay, time to resumption of work, recurrence of Lumbar disc herniation, procedure failures, and complications.

METHODS

The participants were matched for age, disc level, and location of the herniated disk (central and paracentral vs. far-lateral). The participants' mean±standard deviation age was 47.09±12.55 (range: 28-70). We compared the various clinical outcomes between the two groups to identify which procedure had better immediate and long-term functional outcomes. The differences in mortality and occurrence of postoperative complications were also compared in patients with PELD versus controls.

RESULTS

Fifty-eight patients were enrolled (29 with PELD and 29 with OLMD). Both groups reported significant reductions in LBP and leg pain (p<0.01) postoperatively and an improvement in the ODI at 24 months postsurgery. The intergroup difference in the VAS for LBP at 1 day and 3 months was statistically significant (1.48 vs. 3.5, and 1.62 vs. 2.72, respectively; p=0.01 and 0.026, respectively) but the intergroup difference in the ODI was not. The mean length of hospital stay and the time to resumption of work were significantly shorter in the PELD group than in the OLMD group (2.55 vs. 3.21 days, and 4.45 vs. 6.62 weeks, respectively; p=0.037 and 0.01, respectively. There were no significant intergroup differences in terms of complications, recurrence, or procedure failures.

CONCLUSIONS

Both PELD and OLMD can provide equivalent, satisfactory outcomes. However, PELD demonstrated several potential advantages, including more rapid recovery and lower LBP early on. Further large-scale, randomized studies with long-term follow-up are now warranted.

Risk Factors for Recurrent L4-5 Disc Herniation After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Analysis of 654 Cases

Background

Percutaneous endoscopic lumbar discectomy (PELD) is an increasingly applied minimally invasive procedure that has several advantages in the treatment of lumbar disc herniation (LDH). However, recurrent LDH (rLDH) has become a concerning postoperative complication. It remains difficult to establish a consensus and draw reliable conclusions regarding the risk factors for rLDH.

Purpose

This retrospective study aimed to investigate the risk factors associated with rLDH at the L4-5 level after percutaneous endoscopic transforaminal discectomy (PETD).

Methods

A total of 654 patients who underwent the PETD procedure at the L4-5 level from October 2013 to January 2020 were divided into a recurrence (R) group (n=46) and a nonrecurrence (N) group (n=608). Demographic and clinical data and imaging parameters were collected and analyzed using univariate and multiple regression analyses.

Results

The current study found a 7% rate of rLDH at the L4/5 level after successful PETD. Univariate analysis showed that older age, high BMI, diabetes mellitus history, smoking, large physical load intensity, moderate disc degeneration, small muscle-disc ratio (M/D), more fat infiltration, large sagittal range of motion (sROM), scoliosis, small disc height index (DHI), small intervertebral space angle (ISA), and small lumbar lordosis (LL) were potential risk factors (P < 0.10) for LDH recurrence after PETD at the L4-5 level. Multivariate analysis suggested that high BMI, large physical load intensity, moderate disc degeneration, small M/D, more fat infiltration, large sROM, small ISA, and small LL were independent significant risk factors for recurrence of LDH after PETD.

Conclusion

Consideration of disc degeneration, M/D, fat infiltration of the paravertebral muscles, sROM, ISA, LL, BMI, and physical load intensity prior to surgical intervention may contribute to the prevention of rLDH following PETD and lead to a more satisfactory operative outcome and the development of a reasonable rehabilitation program after discharge.

Surgical outcomes of full endoscopic spinal surgery for lumbar disc herniation over a 10-year period: A retrospective study

Objective

Full endoscopic lumbar discectomy (FELD) for lumbar disc herniation (LDH) has become popular in recent years. Previous studies have proven the efficacy, but few have discussed the possible risk factors of poor outcome. In this study, we reviewed patients who underwent FELD at Changhua Christian Hospital in the past 10 years and sought to identify factors associated with poor surgical outcomes and re-operations.

Methods

We retrospectively reviewed records from mid-2009 to mid-2018. Patients had undergone FELD and follow-up for ≥1 year were included. Factors included in the outcome evaluations were age, sex, surgical time, body mass index, surgical methods, disc herniation type, extension of herniation, degree of canal compromised, disc degenerative grade, smoking and alcohol use, surgical lumbar level, symptom duration, Oswestry low back disability index, and visual analog scale score. We had evolved from inside-out methods to outside-in methods after 2016, thus, we included this factor in the analysis. The primary outcomes of interest were poor/fair MacNab score and re-operation.

Results

From mid-2009 to mid-2018, 521 patients met our criteria and were analyzed. The median follow-up was 1685 days (range, 523–3923 days). Thirty-one (6.0%) patients had poor surgical outcomes (fair/poor MacNab score) and 45 (8.6%) patients required re-operation. Prolapsed herniated disc (P < 0.001), higher disc degenerative grade (P = 0.047), higher lumbar level (P = 0.026), longer preoperative symptoms (P < 0.001), and surgery before 2017 (outside-in technique, P = 0.020) were significant factors associated with poor outcomes in univariate analyses. In multivariate analyses, prolapsed herniated disc (P < 0.001), higher disc degenerative grade (P = 0.030), and higher lumbar level (P = 0.046) were statistically significant. The most common adverse symptom was numbness. Factors possibly associated with higher re-operation rate were older age (P = 0.045), alcohol use (P = 0.073) and higher lumbar level (P = 0.069). Only alcohol use showed statistically significant re-operation rates in multivariate analyses (P = 0.035).

Conclusions

For treating LDH by FELD, we concluded that prolapsed disc, higher disc degenerative grade, higher lumbar level, and longer preoperative symptom duration were possibly associated with unsatisfactory surgical outcomes (poor/fair MacNab score). The outside-in technique might be superior to the inside-out technique. Older age and alcohol use might be associated with a higher re-operation rate.

Percutaneous transforaminal full endoscopic decompression for the treatment of lumbar spinal stenosis

Background

One advantage of an endoscopic approach to treating lumbar spinal stenosis is preservation of spine stability and the adjacent anatomy, and there is a decrease in adjacent segment disc degeneration. The purpose of this study was to discuss the clinical efficacy of percutaneous transforaminal endoscopic decompression for the treatment of lumbar spinal stenosis (LSS).

Methods

This is a retrospective study. From September 2012 to June 2017, 45 patients who were diagnosed with LSS underwent the treatment of percutaneous transforaminal endoscopic decompression (PTED) and were followed up at 1 week, 3 months and 1 year postoperatively. Low back pain and leg pain were measured by Visual Analogue Scale scoring methods (VAS-back and VAS-leg), while functional outcomes were assessed by using the Oswestry Disability Index (ODI). All patients had one-level lumbar spinal stenosis.

Results

The most common type of stenosis was lateral recess stenosis (n = 22; 48.9%), followed by central stenosis (n = 13; 28.9%) and foraminal stenosis (n = 10: 22.2%). Regarding comparisons of VAS-back, VAS-leg, and ODI scores before and after operation, VAS and ODI scores significantly improved. The average leg VAS score improved from 7.01 ± 0.84 to 2.28 ± 1.43 (P < 0.001). The average ODI improved from 46.18 ± 10.11 to 14.40 ± 9.59 (P < 0.001). We also examined changes in ODI and VAS scores from baseline according to types of spinal stenosis, stenosis grade, spinal instability, and revision surgery in the same segment. The improvement percentage of leg VAS score was significantly less in patients with severe stenosis at both 3 months and 1 year postoperatively. The improvement percentages of ODI and leg VAS scores were significantly less in patients who had spinal instability and patients who had undergone revision surgery.

Conclusion

The PTED approach seems to give good results for the treatment of LSS. However, this approach may be less effective for LSS patients who have lumbar instability or require revision surgery in the same segment.

Risk Factors for Recurrent L5-S1 Disc Herniation After Percutaneous Endoscopic Transforaminal Discectomy: A Retrospective Study

Background

This retrospective study aimed to investigate the risk factors associated with the recurrence of L5–S1 disc herniation after percutaneous endoscopic transforaminal discectomy (PETD).

Material/Methods

There were 484 patients L5–S1 disc herniation who underwent PETD who were divided into the recurrence group (n=46) and the non-recurrence group (n=438). Transforaminal endoscopic approaches included modifications of the Yeung endoscopy spine system (YESS) (the intraforaminal intradiscal approach) and the transforaminal endoscopic spine system (TESSYS) (intraforaminal extradiscal approach). Demographic and clinical characteristics and imaging data were analyzed. The two study groups were compared to determine the factors associated with the recurrence of L5–S1 disc herniation. The patients underwent postoperative follow-up for between one and four years.

Results

At follow-up, 9.504% of patients (46/484) with the recurrence of L5–S1 disc herniation following PETD when compared with the non-recurrence group showed no significant difference for time to return to work, gender, history of diabetes mellitus, trauma, duration of symptoms, smoking and alcohol history, hypertension, location of disc herniation, transverse process length, intervertebral space height, and pelvic incidence angle (P>0.05). However, age, body mass index (BMI), the degree of disc degeneration, sagittal range of motion, lumbar lordosis angle, and sacral slope were significantly associated with the recurrence of L5–S1 disc herniation following PETD (P<0.05). Logistic regression analysis supported these main associations.

Conclusions

The recurrence of L5–S1 disc herniation following PETD was significantly associated with increased age and BMI, more severe disc degeneration, increased sagittal range of motion, increased lumbar lordosis, and sacral slope.

The Value of a Synthetic Model-based Training Lab to Increase Proficiency with Endoscopic Approaches to the Spine

Introduction: The learning curve associated with endoscopic approaches to the spine is well established. In this study, we present our endoscopic training methodology and discuss the concepts and rationale of laboratory training as it relates to improving comfort and skill with endoscopic techniques.

Materials and Methods: A three-part endoscopic training laboratory for neurosurgical trainees and attendings was organized at the University of Miami, which included a lecture, instrumentation demonstration, and both synthetic model and cadaveric practice sessions. Participants completed pre- and post-lab surveys gauging their comfort and competency in the transforaminal approach to the lumbar spine.

Results: There were a total of 22 participants, with eight completing the pre-lab survey and 10 completing the post-lab survey. Sixteen participants engaged in the lab practical, with six of these participants performing the transforaminal approach on both the model and the cadaver. An increase in comfort level was demonstrated on the post-lab survey (5.9/10) for the transforaminal approach as compared to the pre-lab survey (2.6/10). Additionally, participants found the training model to be an effective teaching aid for the transforaminal technique (8.8/10).

Conclusions: We believe that our study demonstrates the utility of simulated model-based training for gaining comfort and proficiency with endoscopic approaches to the spine and introduces a safe, cost-effective method of educating practitioners on novel endoscopic approaches.

Clinical Application of Percutaneous Transforaminal Endoscopic Surgery in Lumbar Discal Cyst

BACKGROUND

Discal cyst is very rare and can cause intractable low back pain and radiating leg pain. Symptoms are hard to distinguish from lumbar disc herniation. The best treatment for discal cyst is controversial. Most lumbar discal cysts are treated surgically, while most studies of percutaneous transforaminal endoscopic surgery are case reports. This study investigated the clinical value of percutaneous transforaminal endoscopic surgery for lumbar discal cyst.

METHODS

A retrospective study was conducted in 9 patients with a discal cyst from June 2016 to November 2018. All patients had been treated by percutaneous transforaminal endoscopic surgery via a superior vertebral pedicle notch approach. Surgical outcomes were evaluated preoperatively and postoperatively using a visual analog scale for leg pain and the Oswestry Disability Index. At the final follow-up, patients were evaluated for clinical efficacy using modified Macnab criteria.

RESULTS

All 9 patients had remission of symptoms after removal of discal cysts. Postoperative magnetic resonance imaging showed that all patients had complete excision of discal cysts and complete decompression of the treated segment. There were no recurrent lesions during follow-up. Mean operative time was 68.67 ± 14.02 minutes. Mean hospitalization time was 4.22 ± 1.64 days. Preoperative visual analog scale and Oswestry Disability Index score improved significantly after surgery. Visual analog scale leg score improved from 7.88 ± 1.05 preoperatively to 1.78 ± 0.66 at final follow-up (P < 0.05), and ODI score improved from 53.65 ± 12.46 to 16.25 ± 8.76 (P < 0.05). According to the modified Macnab criteria, 5 patients (55.6%) were rated excellent, 3 patients (33.3%) were rated good, and 1 patient (11.1%) was rated fair at final follow-up, with an overall excellent and good rate of 88.9%. There were no serious complications during follow-up.

CONCLUSIONS

Percutaneous transforaminal endoscopic surgery could be a safe, minimally invasive surgical treatment for discal cyst, particularly suitable for patients who cannot undergo general anesthesia.

Transforaminal Endoscopic Lumbar Discectomy and Foraminotomy with Modified Radiofrequency Nerve Stimulator and Continuous Electromyography Under General Anesthesia

BACKGROUND

Transforaminal endoscopic lumbar approaches involve working in Kambin's triangle. These procedures are performed on awake patients or under general anesthesia with continuous electromyography. Potential morbidity of this approach includes injury to exiting and traversing nerve roots, as substantial dissection or cauterization of overlying tissues is required for visualization.

METHODS

We developed a novel connection system that accepts input from a bipolar radiofrequency probe to allow direct nerve stimulation in conjunction with electromyography. This study included 30 consecutive patients undergoing transforaminal endoscopic lumbar approaches for discectomies (73.3%), foraminal stenosis (23.3%), or lateral recess stenosis (3.3%). Demographic, operative, and outcomes data were collected.

RESULTS

Average age of patients was 61.4 years, and the L4-5 segment was most commonly treated (65.6%). Electrophysiologic mapping of the exiting nerve root was attempted in 28 patients with an average stimulation threshold of 8.6 ± 0.9 mA. Mapping of the traversing nerve root was attempted in 12 patients with an average stimulation threshold of 6.0 ± 0.8 mA. There were no instances of new postoperative sensorimotor deficits or dysesthesia. These findings persisted through mean and median follow-up of 294 days and 165 days, respectively. No patient required subsequent lumbar surgery.

CONCLUSIONS

Our modified instrumentation and technique allow for accurate identification of the exiting and traversing nerve roots with minimal changes to the workflow of transforaminal endoscopic lumbar approaches. Modification of a bipolar radiofrequency device connection arrangement is simple, inexpensive, and reusable. In this study, no patients developed injury or pain related to nerve root dysfunction.

Small incision discectomy for lumbar disc herniation in 98 patients with 5-year follow-up: A retrospective case series study

Optimal surgical technique to treat lumbar disc herniation (LDH) remains controversial. We described a small incision discectomy technique (SID), and to evaluate its safety and efficacy. A retrospective study involving 98 consecutive patients with LDH managed by SID was conducted. All patients were followed up for 5 years. Outcomes included visual analogue scale (VAS), Japanese Orthopedic Association (JOA), operative time, length of incision, blood loss, hospital stay, hospitalization costs, x-ray exposure, reoperation, and complications. The results were determined to be excellent, good, fair, or poor according to the MacNab classification. All patients completed the 5-year follow-up. Relative to preoperative scores, VAS and JOA were both significantly improved. As a whole, 93.8% (92/98) patients showed excellent or good results, 3.1% (3/98) fair, and 3.1% (92/98) poor. The operation time, length of incision, blood loss, and hospital stay were 50 ± 11.1 minutes, 2.2 ± 0.3 cm, 35 ± 3.5 mL, and 4.3 ± 0.2 days, respectively. Additionally, compared with previous literature reports, the hospitalization costs and x-ray exposure were apparently less. The reoperation and recurrence rate were 3.2% and 2.1%. No complications were observed. From these data we conclude that SID appears to be a safe, cost-effective technique for LDH, and has lower x-rays exposure time when compared with literature of percutaneous endoscopic lumbar discectomy (PELD).

Foraminoplasty at the Tip or Base of the Superior Articular Process for Lateral Recess Stenosis in Percutaneous Endoscopic Lumbar Discectomy: A Multicenter, Retrospective, Controlled Study with 2-Year Follow-Up

Objective

To compare the clinical efficacy and complications which obtained foraminoplasty at the tip or base of the superior articular process (SAP) for the patients with lateral recess stenosis treated by percutaneous endoscopic lumbar discectomy (PELD).

Methods

Between January 2015 and January 2016, 156 patients of lumbar disc herniation accompanying with lateral recess stenosis were treated with PELD in five tertiary hospitals and fulfilled the 2-year follow-up. Among them, 78 patients obtained a foraminoplasty at the tip of SAP (group A), and foraminoplasty at the base of SAP was performed in the other 78 cases (group B). Clinical efficacy was evaluated using the visual analog scale (VAS) score for back and leg pain, Oswestry Disability Index (ODI), and 36-item Short-Form Health Survey (SF-36) score. The intervals of follow-up were scheduled at 1 month, 3 months, 6 months, 1 year, and 2 years after surgery.

Results

Mean operative duration is shorter in group B (55 versus 61 min, P = 0.047). Only one case belonged to group A could not tolerate the neural irritation and required conversion to an open procedure. During the surgery, no dura tears, cauda equina syndrome, or infections were observed. 5 patients experienced transient dysesthesia located at the exiting nerve in group A, while no cases complained dysesthesia in group B. 2 cases who suffered temporary motor weakness all belonged to group A. A total of 5 cases obtained a revision surgery after recurrence in the follow-up, in which 3 patients belonged to group A. Compared to the preoperative data, significant improvements in VAS scores of low back pain and sciatica, ODI, and SF-36 PCS and MC were observed in the follow-up, respectively (P < 0.05, respectively). However, no statistical difference was observed at all time-points after surgery between these two groups (P > 0.05, respectively).

Conclusions

For the patients of LDH accompanying with lateral recess stenosis, compared with the routine foraminoplasty at the tip of SAP, our modified foraminoplastic technique does not only change place of foraminoplasty to the base of SAP but also simplified puncture process in transforaminal PELD. Although there was no significant difference in symptom relief, the modified foraminoplasty showed the advantages in decreasing the incidence of postoperative neural dysfunction and reducing operation time.

Accuracy of the kissing sign on lumbar spine MRI in cases of axillary disc herniation and the surgical correlation: an Indian multi-center study

Objectives

Magnetic resonance imaging has proven to be a valuable tool in the assessment of disc abnormalities. Two types of disc extrusion can be described according to the direction of herniated disc material: shoulder type and axillary type. Axillary disc herniation is described when the extruded disc fragment lies in the recess between the lateral border of cauda equina and medial to the nerve roots, while in the shoulder type the disc lies lateral to the nerve roots. It is very important to describe the type of disc herniation, as the surgical approach differs in each type. To the best of the authors' knowledge, no definite signs have been described in literature to date. This study aimed to address the accuracy of the kissing sign on MRI for he diagnosis of axillary disc herniation.

Methods

The MRIs of 72 patients undergoing spinal surgery were prospectively evaluated for axillary disc herniation by a senior radiologist and experienced spinal surgeon using the kissing sign on MRI. The kissing sign was considered positive when the herniated disc material was in direct contact with the lamina and/or ligamentum flavum on axial images. Subsequently, all surgeries were performed by two independent surgeons and the actual type of disc herniation was documented. The accuracy of the results was statistically assessed.

Results

The kissing sign on MRI was found to be 66.66% sensitive, 92.59% specific, and 76.38% accurate in detecting axillary disc herniation with significant correlation with the surgical findings.

Conclusion

The type of disc herniation is an important parameter for patient selection in different surgical approaches. The kissing sign on MRI can be considered as an important tool for diagnosing axillary disc herniation due to its high specificity and accuracy.

Delayed Infected Pseudomeningocele After Percutaneous Endoscopic Lumbar Diskectomy

BACKGROUND

Percutaneous endoscopic lumbar diskectomy (PELD) has evolved over the last decades and has become an effective treatment for soft disk herniations. However, while its use increases, newer complications have been discovered.

CASE DESCRIPTION

We present the unique case of a woman who underwent PELD/foraminotomy to treat right-side foraminal disk herniations on L4-5 and L5-S1 in the same procedure. Ten days after surgery, the patient developed fever and severe low back pain radiated down her right leg. Magnetic resonance imaging showed a right pseudomeningocele arising from L4-5 and a nerve root herniated through the dural sac at the same lumbar segment. Blood cultures and fluid culture obtained from pseudomeningocele drainage depicted infection. Specific antibiotics were administrated, direct dura repair under the microscope was performed, and the patient improved symptomatically.

CONCLUSIONS

PELD combined with foraminotomy is a relatively new and skill-demanding surgery which is indicated only in cases where foraminal disk herniation is combined with foraminal stenosis. This surgical strategy requires experience by the endoscopic surgeon to prevent procedure-related complications. Although rare, these complications can lead to increased morbidity.

Which clinical and radiological variables could predict clinical outcomes of percutaneous endoscopic lumbar discectomy for treatment of patients with lumbosacral disc herniation?

BACKGROUND CONTEXT

Percutaneous endoscopic lumbar discectomy (PELD) is one of minimally invasive techniques to treat patients with low back and radiating pain resulting from lumbosacral disc herniation (LDH).

PURPOSE

The purpose of this study is to evaluate the clinical efficacy of PELD to treat patients with low back and radicular pain due to LDH and to investigate which clinical and radiological variables have the ability to predict clinical outcome after PELD.

STUDY DESIGN/SETTING

This is a retrospective study design carried out at a spine hospital.

PATIENT SAMPLE

The sample comprised 75 patients who had undergone PELD for treatment of low back and radiating leg pain resulting from LDH and who could be followed up for at least 12 months.

OUTCOMES MEASURES

Clinical outcomes were assessed using numeric rating scale for back and radiating leg pain (NRS back and leg), Oswestry Disability Index (ODI), and modified MacNab criteria at 1 month (short-term follow-up) and at least 12 months (long-term follow-up) after PELD.

METHODS

The patients were divided into successful and unsuccessful outcome groups according to improvement of NRS back, NRS leg, and ODI (%) at long-term follow-up period. We compared the various clinical and radiological variables between the two groups to identify which variables could be the prognostic factors of clinical outcomes of PELD. This analysis was performed in terms of whole population, the subgroup of dominant back pain, and the subgroup of dominant leg pain, respectively.

RESULTS

Significant improvements were observed in NRS back, NRS leg, ODI (%), and modified MacNab criteria at short-term and long-term follow-up after PELD. Positive straight leg raising (SLR) was significantly related to successful outcome as to NRS leg and ODI (%), and longer pain duration also showed significant relationship with unsuccessful outcomes as to NRS leg in whole population. Positive SLR had significant relationship with successful NRS leg as well as successful ODI (%) in the subgroup of dominant leg pain.

CONCLUSIONS

PELD was an effective treatment in patients with back and leg pain due to LDH. Positive SLR had the predictive ability to successful reduction of radiating leg pain and successful functional improvement. Longer pain duration was also related to unsuccessful reduction of radiating leg pain.

Eccentric technique for foraminoplasty in percutaneous endoscopic transforaminal procedure: A technical note

OBJECTIVE

To describe a modified technique usied for foraminoplasty in percutaneous endoscopic transforaminal procedure.

METHODS

58 patients (20 males and 38 females, average age 52.5 years) underwent percutaneous endoscopic transforaminal procedure by using our modified technique. Under the guidance of C-arm fluoroscopy, a kirschner wire was inserted into targeted superior articular process. After expanding the soft tissues, a trepan with the largest diameter was located through the kirschner wire and the angle of trepan was flexible enough to adjust to different operative conditions. This technique could help to avoided using step-by-step larger diameters of trepans without slippage during foraminoplasty.

RESULTS

With our modified technique, the mean operation time was 65 min (range 50-80 min) and mean estimated blood loss was 12 ml (range 10-30 ml). Fluoroscopy was less (the mean duration of fluoroscopy was 20.4 ± 9.2 s and the mean radiation dose was 0.9 ± 0.2 mSv) and no complications occurred. All foraminoplasties were excellent via CT scans after surgery and all patients were discharged on 2nd day after operation. The results of 58 patients with an average follow-up of 18 (6-36) months demonstrated our eccentric technique to be effective.

CONCLUSION

Our eccentric technique could help to avoid step-by-step larger diameters of trepans during foraminoplasty to shorten operation time and reduced the number of fluoroscopy intraoperative.

Multi-level spine endoscopy: A review of available evidence and case report

In the last ten years, there has been an exponential increase in endoscopic spinal surgery practice.

With improvements in equipment quality and the availability of high definition camera systems, cervical endoscopic disc resection is now a viable alternative to anterior cervical decompression and fusion (ACDF) or disc arthroplasty for the treatment of disc prolapse and low grade stenosis.

Based on the current literature, there is now strong evidence to support the use of transforaminal endoscopic approaches for the treatment of thoracic disc prolapse.

There is now level I evidence to show that outcomes following transforaminal endoscopic discectomy (TED) are at least equivalent to those after open microdiscectomy, with an expected shorter operating time, lesser requirement for analgesia, reduced duration of post-operative disability, more rapid rehabilitation and lower costs of care. However, it should be recognised that there is a significant learning curve for TED.

New endoscopic techniques with interlaminar approaches allow the decompression of central and lateral recess stenosis. Future developments will facilitate vision and access to the spine with 3D imaging and robotics at the forefront.

We present a case report of whole spine endoscopic decompression to illustrate the potential of endoscopic surgery at all spinal levels.

Cite this article: EFORT Open Rev 2017;2:317-323. DOI: 10.1302/2058-5241.2.160087

Consideration of proper operative route for interlaminar approach for percutaneous endoscopic lumbar discectomy

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) is one of the less invasive treatments of lumbar disc herniation (LDH), and has three different operative approaches. This study focused on the interlaminar approach (ILA) and investigated the appropriate operative route for this approach.

METHODS

ILA was performed in 41 patients with LDH. The width of the interlaminar space, LDH size, and positional relation between LDH and the corresponding nerve root were radiologically evaluated. Thirty-three LDHs were removed via the shoulder of the corresponding nerve root and eight were removed via the axilla of the corresponding nerve root and dural sac. Pre- and postoperative status were evaluated using the modified Japanese Orthopedic Association (mJOA) and numerical rating scale (NRS) scores.

RESULTS

The mean age was 41.5 years; there was single-level involvement, mostly at L5/S1 (33 cases). The mean recovery rate of mJOA score was 59.8% and mean pre- and postoperative NRS scores were 5.8 and 0.98, respectively. Relatively severe complications developed in three patients treated by ILA via the shoulder. There was persistent numbness in the corresponding nerve area, transient muscular weakness, and transient bladder and rectal disturbance, may be due to excessive compression of the nerve root and/or dural sac by the endoscopic sheath.

CONCLUSIONS

ILA can be used to treat LDH revealing an interlaminar space of ≥20 mm. The procedure is minimally invasive and effective; however, appropriate selection of an operative route is important to avoid operative complications. Particularly for large LDH, the operative route via the axilla should be considered.

Clinical outcomes after percutaneous transforaminal endoscopic discectomy for lumbar disc herniation: a prospective case series

OBJECTIVE Throughout the last decades, full-endoscopic techniques to treat lumbar disc herniation (LDH) have gained popularity in clinical practice. To date, however, no Class I evidence on the efficacy of percutaneous transforaminal endoscopic discectomy (PTED) has been published, and studies describing its safety and short- and long-term efficacy are scarce. In this study the authors aimed to evaluate the clinical outcomes and safety in patients undergoing PTED for LDH. METHODS Patients who underwent PTED for LDH between January 2009 and December 2012 were prospectively followed. The primary outcomes were the visual analog scale (VAS) score for leg pain and the score on the Quebec Back Pain Disability Scale (QBPDS). Secondary outcomes were the perceived experience with the local anesthesia used and satisfaction with the results after 1 year using Likert-type scales. The pretreatment means were compared with the means obtained 6 and 52 weeks after surgery using paired t-tests. RESULTS A total of 166 patients underwent surgery for a total of 167 LDHs. The mean duration of surgery (± SD) was 51.0 ± 9.0 minutes. The 1-year follow-up rate was 95.2%. The mean reported scores on the VAS and QBPDS were 82.5 ± 17.3 mm and 60.0 ± 18.4 at baseline, respectively. Six weeks after surgery, the scores on the VAS and QBPDS were significantly reduced to 28.8 ± 24.5 mm and 26.7 ± 20.6, respectively (p < 0.001). After 52 weeks of follow-up, the scores were further reduced compared with baseline scores (p < 0.001) to 19.6 ± 23.5 mm on the VAS and 20.2 ± 18.1 on the QBPDS. A total of 4 complications were observed, namely 1 dural tear, 1 deficit of ankle dorsiflexion, and 2 cases of transient paresis in the foot due to the use of local anesthetics. CONCLUSIONS PTED appears to be a safe and effective intervention for LDH and has similar clinical outcomes compared to conventional open microdiscectomy. High-quality randomized controlled trials are required to study the efficacy and cost-effectiveness of PTED.

Advantages and disadvantages of posterolateral approach for percutaneous endoscopic lumbar discectomy

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) is one of the less invasive treatments for lumbar disc herniation (LDH), and has 3 different operative approaches. This study focused on the posterolateral approach (PLA) and investigated the appropriate operative indication.

METHODS

PLA was performed in 29 patients with foraminal and extraforaminal LDH. The height and width of the foramen, LDH type, and positional relationship between LDH and the foramen were radiologically evaluated. Foraminoplasty was also performed in 12 cases including those combined with intra-canal LDH or osseous foraminal stenosis. Pre- and postoperative status was evaluated using Numerical Rating Scale (NRS) scores.

RESULTS

Patient mean age was 56.8 years; there was single-level involvement at L3/4 (13 cases) and at L4/5 (13 cases). The mean pre- and postoperative NRS scores were 6.1 and 1.8, respectively. Early recurrence developed in a patient who was found to have local scoliosis at the corresponding vertebral level.

CONCLUSIONS

PLA can be safely used to treat foraminal and extraforaminal LDH with foraminal height ≥13 mm and foraminal width ≥7 mm. The procedure is effective for preserving the facet joint; however, we should carefully consider the indications when local scoliosis and/or instability are present.