Percutaneous endoscopic lumbar discectomy for migrated disc herniation: classification of disc migration and surgical approaches

Transforaminal Endoscopic Ventral Stenosis Decompression in Calcified Lumbar Disc Herniation: A Long Term Outcome in 79 Patients

BACKGROUND

Calcified lumbar disc herniations (CLDH) causing calcified ventral stenosis pose a therapeutic challenge to the treating surgeon due to their neural adhesions, location, and hardness.

METHODS

This retrospective study analyzed all the cases of CLDH/calcified ventral stenosis managed by transforaminal endoscopic lumbar discectomy with a minimum follow-up of 24 months. The preoperative images were analyzed for the level, migration; and grade (Lee's migration zones), and location (Michigan State University classification). Detailed surgical technique and intraoperative parameters including the duration of surgery and complications have been recorded. The clinical parameters including visual analog scale (VAS), Oswestry disability index (ODI), length of stay in hospital, days of return to basic work, and patient satisfaction index were analyzed. Postoperatively the images were analyzed for the adequacy of decompression.

RESULTS

The mean VAS for back pain and leg pain was 4.7 ± 2.6 (0-9), and 7.45 ± 2.2 (1-10), respectively. The mean preoperative ODI was 78.2 ± 13.2 (63.2-95.6). Nineteen patients (24%) had neurological deficits preoperatively. The mean duration of surgery was 90.5 ± 15.8 (58-131) minutes. Postoperative magnetic resonance imaging revealed adequate decompression in 97.5% (n = 77). The mean duration of hospital stay was 1.05 ± 0.22 (1-2) days, and the postoperative back and leg pain VAS was 1.14 ± 1.2 (0-3) (P < 0.05) and 1.7 ± 0.5 (0-6) (P < 0.05), respectively. The ODI at final follow-up was 6.5 ± 3.7 (2.2-18) (P < 0.05). Neurological recovery occurred in 17 (89.5%) patients and they returned to basic work/jobs in 19.5 ± 3.3 (14-26) days. The mean patient satisfaction index was 1.18 ± 0.47 (1-2) at a mean follow-up of 5.52 ± 2.91 (2-12.75) years.

CONCLUSIONS

Transforaminal endoscopic lumbar discectomy is a complete, safe, and efficacious procedure in patients with CLDH with earlier recovery considering the surgery is performed with the patient being awake.

Percutaneous Endoscopic Suprapedicular Decompression in the Treatment of Down-Migrated Lumbar DiscHerniation

OBJECTIVE

This study aimed to investigate the clinical efficacy of percutaneous endoscopic suprapedicular decompression in treatment of down-migrated lumbar disc herniation.

METHODS

The clinical data of 43 patients with down-migrated lumbar disc herniation treated with endoscopic surgery at our hospital between January 2022 and January 2023 were retrospectively analyzed. Twenty-two and 21 patients underwent percutaneous endoscopic decompression using the suprapedicular and transforaminal endoscopic surgical system approaches, respectively. The perioperative, follow-up, and imaging data of the groups were compared.

RESULTS

Surgery was uneventful in both groups. The number of intraoperative fluoroscopies and duration of surgery were significantly lower in the suprapedicular group (P < 0.05). The patients in both groups were followed up for at least 12 months. At the last follow-up, lumbar pain and leg pain visual analog scale, Oswestry Disability Index, and 36-Item Short Form Health Survey scores were significantly improved in both groups compared with preoperative values (P < 0.05); the differences in these indexes between the 2 groups were not significant preoperatively (P > 0.05). However, at the last postoperative follow-up, lumbar pain visual analog scale scores were significantly better in the suprapedicular group (0.83 ± 0.85 vs. 2.54 ± 1.32, P < 0.05). There was no significant change in intervertebral space height or lumbar lordotic angle compared with preoperative values in either group at the last follow-up (P > 0.05). However, the spinal canal cross-sectional area significantly increased (P < 0.05).

CONCLUSIONS

The treatment of down-migrated lumbar disc herniation via a suprapedicular approach enabled the incision of the superior margin of the pedicle as needed under direct vision, involved less fluoroscopy while preserving facet joint stability, and enabled targeted removal of the herniated nucleus pulposus, thus greatly reducing residual nucleus pulposus. This surgical procedure was safe, rapid, and showed satisfactory therapeutic efficacy.

Transforaminal endoscopic lumbar discectomy with two-segment foraminoplasty for the treatment of very highly migrated lumbar disc herniation: a retrospective analysis

BACKGROUND

The surgical resection of very highly migrated lumbar disc herniation (VHM-LDH) is technically challenging owing to the absence of technical guidelines. Hence, in the present study, we introduced the transforaminal endoscopic lumbar discectomy (TELD) with two-segment foraminoplasty to manage VHM-LDH and evaluated its radiographic and midterm clinical outcomes.

MATERIALS AND METHODS

The present study is a retrospective analysis of 33 consecutive patients with VHM-LDH who underwent TELD with two-segment foraminoplasty. The foraminoplasty was performed on two adjacent vertebrae on the basis of the migration direction of disc fragments to fully expose the disc fragments and completely decompress the impinged nerve root. The operation duration, blood loss, intra- and postoperative complications, and recurrences were recorded. Additionally, imageological observations were evaluated immediately after the procedure via magnetic resonance image and computerized tomography. Clinical outcomes were evaluated by calculating the visual analog scale (VAS) score and Oswestry Disability Index (ODI). The MacNab criterion was reviewed to assess the patients' opinions on treatment satisfaction. The resection rate of bony structures were quantitatively evaluated on postoperative image. The segmental stability was radiologically evaluated at least a year after the surgery. Additionally, surgery-related and postoperative complications were evaluated.

RESULTS

The average age of the patients was 56.87 ± 7.77 years, with a mean follow-up of 20.95 ± 2.09 months. The pain was relieved in all patients immediately after the surgery. The VAS score and ODI decreased significantly at each postoperative follow-up compared with those observed before the surgery (P < 0.05). The mean operation duration, blood loss, and hospital stay were 56.17 ± 16.21 min, 10.57 ± 6.92 mL, and 3.12 ± 1.23 days, respectively. No residual disc fragments, iatrogenic pedicle fractures, and segmental instability were observed in the postoperative images. For both up- and down- migrated herniation in the upper lumbar region, the upper limit value of resection percentage for the cranial SAP, caudal SAP, and pedicle was 33%, 30%, and 34%, respectively; while those in the lower lumbar region was 42%, 36%, and 46%, respectively. At the last follow-up, the satisfaction rate of the patients regarding the surgery was 97%. Surgery-related complications including dural tear, nerve root injury, epidural hematoma, iatrogenic pedicle fractures, and segmental instability were not observed. One patient (3%) suffered from the recurrence of LDH 10 months after the initial surgery and underwent revision surgery.

CONCLUSIONS

The TELD with two-segment foraminoplasty is safe and effective for VHM-LDH management. Proper patient selection and efficient endoscopic skills are required for applying this technique to obtain satisfactory outcomes.

Comparison of the Outcomes of Microendoscopic Discectomy Versus Full-Endoscopic Discectomy for the Treatment of L4/5 Lumbar Disc Herniation

STUDY DESIGN

Retrospective Comparative Study.

OBJECTIVES

To compare the outcomes of microendoscopic discectomy (MED) versus full-endoscopic discectomy (FED) for treating L4/5 lumbar disc herniation (LDH).

METHODS

A retrospective study was performed on patients with L4/5 LDH treated using MED (n = 249) or FED (n = 124). A 16-mm tubular retractor and endoscope was used for MED, while a 4.1-mm working channel endoscope was used for FED. Patient background and operative data were collected. The Oswestry Disability Index (ODI) and European Quality of Life-5 Dimensions (EQ-5D) scores were recorded preoperatively and at 1 and 2 years postsurgery.

RESULTS

The background data of the two groups were similar. The mean operation times for MED and FED were 59.3 and 47.7 min (respectively), and the mean volumes of removed nucleus pulposus were .65 and 1.03 g, respectively. These differences were significant (P < .001). Six dural tears and one postoperative hematoma were observed in the MED group; none were observed in the FED group. During the follow-up period, 16 MED and 7 FED patients required re-operation due to recurrence (P = 1.00). Although the ODI and EQ-5D scores significantly improved at 1 and 2 years postsurgery in both groups, the differences were not statistically significant.

CONCLUSIONS

Operative outcomes were almost identical in both groups. We did not observe any operative or postoperative complications in FED. We, therefore, recommend FED as the first option for the treatment of L4/5 LDH since it has a better safety profile and is minimally invasive.

Comparison of Clinical and Radiographic Outcomes Between Transforaminal Endoscopic Lumbar Discectomy and Microdiscectomy: A Follow-up Exceeding 5 Years

OBJECTIVE

To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD).

METHODS

The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients' clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated.

RESULTS

During a mean follow-up of 5.5 years (range, 5-7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio.

CONCLUSION

Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis.

Contralateral translaminar endoscopic approach for highly down-migrated lumbar disc herniation using percutaneous biportal endoscopic surgery : Original research

OBJECTIVE

Unilateral biportal endoscopy (UBE)is a minimally invasive spine surgery with reduced traumatization of the posterior lumbar ligament and muscular structures. This study reports contralateral translaminar approach with UBE for highly down-migrated lumbar disc herniation (LDH).

METHODS

Data of 32 patients with highly down-migrated LDH treated using UBE at our center from January 2020 to July 2022 were retrospectively analyzed. The operation time and perioperative complications were recorded, and the visual analog scale (VAS) of pain was recorded to evaluate the degree of lower back and extremity pain. The Oswestry disability index (ODI) was used to evaluate lumbar spine function. The modified MacNab score was used to evaluate clinical efficacy.

RESULTS

All patients successfully underwent the operation, with a time range from 47 to 65 min and an average operation time of 56.09 ± 5.11 min. Overall, 17 and 15 were males and females, respectively, with ages ranging from 34 to 72 years and an average age of 56 ± 7.89 years. The postoperative follow-up period was 12-18 months, with an average of 14.9 ± 2.3 months. The postoperative lower back VAS pain score and ODI were statistically significant compared with preoperatively (P < 0.05). At the final follow-up, according to the modified Macnab criteria, 90.6% of cases were classified as good or excellent.

CONCLUSION

UBE treatment of highly down-migrated LDH through the contralateral translaminar approach is safe and efficient. Therefore, this approach can be an efficient alternative for patients with highly downward-migrating LDH.

Percutaneous Endoscopic Transforaminal Discectomy for the Treatment of Lumbar Disc Herniation with Different Migration Levels: A Retrospective Study

Objective

To investigate the surgical method and efficacy of percutaneous endoscopic transforaminal discectomy (PETD) for the treatment of lumbar disc herniation (LDH) with different migration levels by introducing the strategy of foramenoplasty with the "distal nucleus pulposus as the core".

Methods

Clinical data of LDH patients who underwent single-segment PETD surgery were retrospectively analyzed. Three groups were categorized according to the degree of nucleus pulposus migration in the sagittal position: no migration group, mild migration group, and high migration group. Different sites of foramenoplasty were used for LDH with different degrees of migration. All patients were followed up for at least 12 months. The clinical and follow-up data of the three groups were compared.

Results

A total of 102 patients were included, of which 46 (45.1%) were in the no migration group, 36 (35.3%) in the mild migration group, and 20 (19.6%) in the high migration group. Encouraging treatment results were obtained in all three groups.

Conclusion

PETD is effective in the treatment of LDH with different degrees of migration, and the foramenoplasty concept of "distal nucleus pulposus as the core" can effectively guide the molding site of foramenoplasty and facilitate the accurate placement of the working trocar.

Endoscopic Diskectomy of Rostrally and Caudally Migrated Lumbar Disk Herniations: A Technique Video

Surgical treatment of extremely migrated caudal and rostral lumbar disk herniations is technically challenging. Traditional open technique often requires more bone resection, which can lead to rare but significant complications such as pars fracture or instability requiring fusion surgery. Endoscopic diskectomy is a safe alternative to traditional open surgery with acceptable complication rates.1-4 Endoscopic diskectomy provides the advantage of excellent visualization and maneuverability while minimizing soft tissue trauma and bony resection, which can result in less postoperative pain, less opioid consumption, and quicker recovery.5 We present a surgical technique guide (Video 1) for endoscopic diskectomy of 2 patients with very high rostral (grade 1) and caudal (grade 6) lumbar disk herniations as graded by Ahn's modification of the Lee-Kim grading classification.6,7 Risks, benefits, and alternatives to surgery were discussed with the patients, and they consented to the procedure. This video is not a replacement for hands-on training.

Translaminar Full Endoscopic Technique with Tom Shidi Needles for Highly- and Dorsally-Migrated Lumbar Disc Herniations

BACKGROUND

Thirty years have passed since Kambin's first clinical series of lumbar disc herniations (LDH) treated by arthroscopic microdiscectomy. Despite several advances in this interim, sequestrated LDHs over the dorsal aspect of the dura, and high-grade up- or downward disc migration have been a relative limitation of the transforaminal endoscopic technique. The interlaminar window was the next step to deal with such highly migrated LDHs. Favorable outcomes were obtained in 70-90% of the patients in the long-term, but recurrence rates remained high (approximately 12%), and the approach could be limited by the size of the interlaminar window. Few relevant studies have addressed the role of translaminar full endoscopic technique for migrated LDHs. To describe an innovative modification of the translaminar full endoscopic approach with Tom Shidi needles.

METHODS

This technical modification is presented in a detailed fashion for treating these challenging LDHs and illustrated through a clinical case.

RESULTS

The patient underwent successful translaminar full endoscopic technique with complete pain resolution postoperatively. The postprocedural course was uneventful. A follow-up imaging showed no evidence of residual LDHs fragments.

CONCLUSIONS

Translaminar full endoscopic technique with Tom Shidi needles is a promising modification of the previously presented interlaminar and translaminar endoscopic routes in the treatment of migrated LDHs to fasten surgical procedures and increase the safety of spinal canal manipulation.

The Call for Neuroendoscopy Cadaveric Workshops in Lower-Middle Income Countries

OBJECTIVE

This study aims to assess the impact of the workshops organized during Neuroendocon 23 on the perspective and confidence of neurosurgeons toward endoscopy in a lower-middle income country.

METHODS

Neuroendocon 23 had cranial and spinal endoscopy cadaveric workshops with 30 delegates each. A pre and postworkshop survey was disseminated among the delegates, and statistical analysis was performed with SPSS (version 26) using P < 0.05.

RESULTS

A total of 24 delegates (40%) consented to participate in the study, with only 1 female respondent (4.17%). After the cranial endoscopy workshop, there was an increase in the level of confidence of delegates in cranial endoscopic approaches (P < 0.001). Similarly, after the spine endoscopy workshop, the respondents had increased confidence in managing spine conditions with the endoscopic approach (P = 0.040), to the extent that they preferred the endoscopic over the microsurgical technique (P < 0.001). All respondents (n = 24, 100%) believed that endoscopy should be promoted in lower-middle income countries and integrated into residency curricula.

CONCLUSIONS

Cranial and spinal endoscopy cadaveric workshops could be the first step in stimulating the interest of neurosurgeons in endoscopy.

Endoscopic versus microscopic discectomy for pathologies of lumbar spine: A nationwide cross-sectional study from a lower-middle-income country

Objective

We conducted a cross-sectional study to assess the preference of spine surgeons between MD for microdiscectomy and endoscopic discectomy (ED) surgery for the management of lumbar pathologies in a lower-middle-income country (LMIC).

Methodology

An online survey assessing the preference of spine surgeons for various lumbar pathologies was developed and disseminated in "Neurosurgery Cocktail" a social media platform. Statistical analyses were performed using SPSS software with a level of significance <0.05.

Results

We received responses from 160 spine surgeons having a median experience of 6.75 years (range 0-42 years) after residency. Most of the spine surgeons preferred MD over ED, preference being homogeneous across all lumbar pathologies. In ED, the interlaminar approach was preferred more frequently than the transforaminal approach. The most commonly chosen contraindication for the interlaminar approach and transforaminal approach was ≥ 3 levels lumbar disc herniation (LDH) (n = 117, 73.1%) and calcified LDH (n = 102, 63.8%), respectively. There was no significant association between the type of approach preferred (MD vs. ED; and interlaminar vs. translaminar endoscopic approach) with the type of workplace and the level of experience.

Conclusion

Spine surgeons were inclined toward MD over ED, due to various reasons, such as a steep learning curve, lack of training opportunities, and upfront expenses. There is a pressing need for the upliftment of ED in LMICs which requires global action.

One-hole split endoscopy technique versus unilateral biportal endoscopy technique for L5-S1 lumbar disk herniation: analysis of clinical and radiologic outcomes

BACKGROUND

Lumbar disk herniation (LDH) is one of the most common diseases of the spine, especially occurring in L4-5 and L5-S1 intervertebral disks, and surgery is a choice when conservative treatment is ineffective. The purpose of this study is to investigate the clinical efficacy and radiologic outcomes of one-hole split endoscopy (OSE) technique versus unilateral biportal endoscopy (UBE) technique in the treatment of L5-S1 lumbar disk herniation (LDH).

METHODS

A total of 133 patients of a single center surgically treated for L5-S1 LDH between 2019 and 2021 were retrospectively included in this study, of which 70 were treated by UBE technique and the rest were treated by OSE technique. Hospitalization time, operative time, intraoperative blood loss, fluoroscopy times, incision length and related complications were recorded. Bone resection area (BRA), articular process resection rate, range of motion (ROM), sagittal translation (ST), disk height (DH), Visual Analog Score (VAS), Oswestry Disability Index (ODI) and Macnab criteria were used to evaluated the clinical efficacy.

RESULTS

There was no statistically significant difference in hospitalization time or fluoroscopy times between the two groups. The operation time was shorter in the UBE group than that in the OSE group; however, the incision length was longer. Intraoperative blood loss and BRA were larger in the UBE group than in the OSE group. There was no significant difference in ROM, ST, DH, or postoperative facet resection rate between the two groups. There was no significant difference in ROM, ST, or postoperative facet resection rate compared with preoperative indicators in each group, but there was a significant difference in DH among distinct groups. At any time point, the lower back and leg VAS and ODI in each group were significantly improved compared to those before the operation, with no significant difference between the two groups. There was one case of dural tear in the UBE group. One case of transient hypoesthesia occurred in each of the two groups. The excellent-good rates of the UBE group and the OSE group were 88.6% and 90.5%, respectively.

CONCLUSION

The OSE technique is an effective minimally invasive surgical option as well as the UBE technique in the treatment of L5-S1 LDH.

An algorithm for selection of full endoscopic approach for symptomatic nerve root decompression

Background Context

Both Transforaminal (TF) and Interlaminar (IL) endoscopic approaches are established techniques of decompression for lumbar compressive radiculopathy. In the absence of adequate literature, there is always some dilemma in selecting the approach for endoscopic decompression leading to long learning curves and high chances of inadequate decompression, iatrogenic instability, dural tear, or dysesthesia. Hence authors propose a new surgical nomenclature and algorithm for selection of endoscopic approach.

Methods

This retrospective study included 396 of 626 consecutive patients who met the inclusion criteria, who underwent either TF (n=302) or IL (n=202) full endoscopic spine surgery. MRI findings of every patient were classified as per FAPDIS (Facet angle, Anterior pathology, Posterior pathology, Dorsal, Inferior, and Superior migration) algorithm. Inter-observer variations were calculated. The targeted nomenclature was used to define the selection of endoscopic TF or IL approach for symptomatic nerve root decompression. All patients were followed up for preop and postop 6 months VAS and Oswestry Disability Index score for validation of FAPDIS algorithm.

Results

Median age: 46.8 years; Sides and levels operated 330 single-level ipsilateral, 54 multiple-level ipsilateral, 6 single-level bilateral, and 6 multiple-level bilateral. Interobserver agreement in the selection of TF approach was 0.873 and IL approach was 0.882. Interobserver variability was also calculated for each FAPDIS factor, selection of P3 and P4 pathology was the main reason for disagreement. All other FAPDIS factors show good to excellent correlation. The overall VAS score decreased from a preoperative value of 9 to 1 at 6 months follow-up (p-value < 0.001), and the overall Oswestry Disability Index score improved from 89 to 12 (p-value <.001).

Conclusions

The author's new FAPDIS surgical nomenclature and algorithm is a reliable tool for describing the symptomatic nerve root compression for the selection of endoscopic surgical approach to achieve adequate decompression of offending neural structure with minimum challenges to minimize perioperative complication rate.

Comparative analysis of percutaneous endoscopic interlaminar discectomy for highly downward-migrated disc herniation

OBJECTIVES

This study aimed to evaluate the clinical efficacy and safety of percutaneous endoscopic interlaminar discectomy (PEID) for treating highly downward-migrated disc herniation.

METHODS

We conducted a retrospective study on 39 patients with highly downward-migrated disc herniation who underwent PEID treatment between January 2015 and October 2020. The clinical outcomes, including the preoperative and postoperative visual analogue scale (VAS) for the back and leg, Oswestry Disability Index (ODI), and MacNab criteria for surgical success, were evaluated and compared to thirty-seven patients treated with posterior lumbar interbody fusion (PLIF).

RESULTS

The mean operation time of PEID was 93.00(77.00,110.00) min, while that of PLIF was 169.00(157.00,183.00) min. Continued improvement in both PEID and PLIF was observed in the VAS and ODI scores immediately after the surgery to the last follow-up. The VAS and ODI scores of PEID one week after surgery were significantly different from those of PLIF. One patient with recurrent lumbar disc herniation in the same segment improved after undergoing repeat PEID, two patients had dura tears, and conservative treatment helped relieve the symptoms. The overall percentage of patients with good to excellent results of PELD according to the modified MacNab criteria was 97.43%, while that of PLIF was 94.60%.

CONCLUSIONS

PEID has reliable efficacy and safety for treating highly downward-migrated disc herniation. And the long-term efficacy of PEID is comparable to PLIF. No severe complications occurred after surgery, and most patients' symptoms were relieved.

1 Year-follow-up of transforaminal surgical approach in the management of migrated disc herniation: a cross-sectional study

Transforaminal percutaneous endoscopic lumbar discectomy (TPELD) recently confirms its superiority compared to typical open discectomy in the treatment of very high-grade migrated disk herniation. In Vietnam, this technique has been applied in recent years; however; lack of reports and evidence.

OBJECTIVES

In this study, the authors would like to share their surgical experience and report the initial results in their center, after successfully performing TPELD for very high-grade migrated disk herniation in 40 patients.

PATIENTS AND METHODS

Forty patients, who underwent TPELD to remove the nucleus of very high-grade migrated disk herniation, were enrolled in this study. The study was carried out from April 2019 to April 2021. Preoperative and postoperative MRI were compared to demonstrate the removed disk. Postoperative visual analog score, oswestry disability index, and modified Macnab criteria were obtained after 1 month, 6 months, and 1 year and were compared.

RESULTS

There were no major complications related directly to this technique. Seven patients were operated at L3-4, 28 patients at L4-5, and 5 patients at l5-S1. Mean visual analog score for leg pain improved from 7.36±0.64 preoperatively to 1.22±1.16 at 6 months postoperatively and 1.34±1.47 at 1 year postoperatively (P<0.01). The mean preoperative oswestry disability index improved from 67.1±8.79 preoperatively to 12.1±13.48 at 1 year postoperatively (P<0.01). Excellent or good global outcomes were obtained in 95%.

CONCLUSIONS

TPELD is a minimally invasive treatment with effective and safe results of very high-grade migrated disk herniation. Improvement of several pain scores can be observed in the 12-month follow-up after surgery.

Comparison of the Interlaminar and Transforaminal Approaches for Full-endoscopic Discectomy for the Treatment of L4/5 Lumbar Disc Herniation

This study aims to compare the outcomes of interlaminar and transforaminal approaches for full-endoscopic discectomy (FED) for treating L4/5 lumbar disc herniation (LDH).A retrospective study of patients with L4/5 LDH treated with interlaminar endoscopic lumbar discectomy (IELD, n = 19) or transforaminal endoscopic lumbar discectomy (TELD, n = 105) was conducted. Patient background, radiological findings, and operative data were collected. Oswestry Disability Index (ODI) and European Quality of Life-5 Dimension (EQ-5D) scores were recorded preoperatively and 1 and 2 years postoperatively.Although ODI and EQ-5D scores 1 and 2 years postoperatively improved statistically in the IELD and TELD groups, there were no statistical differences between the groups. IELD was predominantly performed in patients who were taller and heavier. The mean operative times and the frequency of laminectomy for IELD and TELD were 67.2 and 44.6 min and 63.2 and 17.1%, respectively (P < 0.001). The radiological findings showed that the concave configuration of the L4 lamina, interlaminar space width, and foraminal width were statistically different between the groups. There were no complications in either of the groups. Reoperation was required for recurrence in two and five patients in the IELD and TELD groups (P = 0.29), respectively.Operative outcomes were identical between the two groups. Although the operative time was longer in the IELD group, both approaches were safely and effectively performed. Depending on the patient's physique and preoperative radiological findings, the more suitable approach for L4/5 LDH should be chosen.

One-hole split endoscope technique for migrated lumbar disc herniation: a single-centre, retrospective study of a novel technique

BACKGROUND

Lumbar disc herniation (LDH) is one of the most common diseases of the spine, and migrated LDH is a more serious type, associated with nerve root function injury or abnormality. Regarding the increasing surgery adoption of treating migrated LDH, we aimed to investigate the clinical efficacy and safety of discectomy with a novel technique-one-hole split endoscope (OSE) technique.

METHODS

This was a retrospective analysis of migrated LDH treated between December 2020 and September 2021. Hospitalization time, operative duration, intraoperative blood loss, number of fluoroscopy exposures, incision length, postoperative facet preservation rate, number of excellent-good cases, lower back and leg visual analogue score (VAS), Oswestry Disability Index (ODI) and surgical complications were compared between high-grade migration group (82 cases) and low-grade migration group (148 cases). The Macnab criteria was used to evaluate the clinical outcome. The Shapiro‒Wilk test was used to test measurement data, and the χ² test was used to test counting data.

RESULTS

There was no significant difference in hospitalization time, operative duration, intraoperative blood loss, number of fluoroscopy exposures, incision length or postoperative facet preservation rate between the two groups by independent sample t test or nonparametric test. At any time point, the lower back and leg VAS and ODI of the two groups were significantly improved compared to those before the operation, but there was no significant difference between the two groups at the same time point by two-way repeated measures ANOVA. There were two cases of postoperative nerve root stimulation symptoms in the high-grade migration group and three cases in the low-grade migration group. There was one patient reoperated in the high-grade migration group. There was no significant difference in number of excellent-good cases between the two groups. The overall excellent-good rate was 89.6%.

CONCLUSION

The OSE technique has the advantages of less trauma, faster recovery, complete removal of the nucleus pulposus and a satisfactory early clinical efficacy in the treatment of migrated LDH.

Minimally Neural Retractive, Total Annular Resection, Transforaminal Endoscopic (TARTE) Approach for Severely Canal Compromising Lumbar Disk Herniation Accompanied by a Neurologic Deficit

OBJECTIVE

 Treatment of severely canal compromising lumbar disk herniations (LDH), occupying more than 50% of the canal area, are associated with technical difficulty and worse outcomes. This study aimed to describe new techniques of transforaminal endoscopic lumbar diskectomy (TELD) with less neural retraction, and total annular resection for broad-based severely canal compromising disk herniation. We also evaluated the feasibility and safety of the techniques, and analyzed the clinical and radiologic outcomes of 32 patients presenting with neurologic deficits.

METHODS

 A retrospective cohort study was performed with 32 consecutive patients who underwent TELD for broad-based severely canal compromising LDH between January 2018 and January 2020. We removed the LDH using two novel techniques: (1) the "mobile outside-in" approach and total annular resection method and (2) internal decompression and subsequent pushdown method of the migrated fragment. The cross-sectional area (CSA) on magnetic resonance image was evaluated preoperatively and compared with the postoperative image within 7 days and between 6 months and 1 year. The visual analog scale (VAS) for back and leg pain, Oswestry disability index (ODI), MacNab's criteria, and motor power of the involved lower extremities were evaluated pre- and postoperatively.

RESULTS

 A total of 32 patients, with an average age of 37.5 years (range: 17-66), underwent surgery. The mean VAS score for back pain improved from 7.84 ± 1.02 to 1.31 ± 0.54 and the ODI score improved from 74.3 ± 7.82 to 20.4 ± 3.71 at final follow-up. According to MacNab's criteria, 23 patients had excellent and 9 patients had good outcomes at final follow-up. All patients operated on at the L4-L5 level had great toe/ankle dorsiflexion and/or ankle plantar flexion weakness; knee extension weakness was found at the L2-L3 and L3-L4 levels. Motor function improved significantly; the mean values and range preoperatively, and at 1 month, 3 months, and final follow-up, were 3.41 ± 0.95 (1-4), 4.56 ± 0.56 (3-5), 4.88 ± 0.34 (4-5), and 4.97 ± 0.18 (4-5), respectively (p < 0.001, at all follow-up). The mean values and range of the preserved CSA proportion, preoperatively and within 1 week after surgery, and at final follow-up were 34.9 ± 10.9 (15-61), 81.06 ± 10.24 (63-97), and 93.03 ± 5.37 (76-99), respectively (p < 0.001, at all follow-up).

CONCLUSION

 The transforaminal endoscopic approach for broad-based severely canal compromising LDH can be considered a feasible surgical option for an experienced surgeon. With total annular resection and pushdown of migrated fragments, safe and complete removal of LDH was possible in patients with a neurologic deficit. Total annular resection may increase the overall but not the early recurrence rate.

Full endoscopic spine surgery

Background

With a dramatic increase in elderly population worldwide, the prevalence of degenerative spine disease is steadily rising. Even though the entire spinal column is affected the problem is more commonly seen in the lumbar, cervical spine and to some extent the thoracic spine. The treatment of symptomatic lumbar disc or stenosis is primarily conservative with analgesics, epidural steroids and physiotherapy. Surgery is advised only if conservative treatment is ineffective. Conventional open microscopic procedures even though are still a gold standard, have the disadvantages of excessive muscle damage and bone resection, epidural scarring along with prolonged hospital stay and increased need of postoperative analgesics. Minimal access spine surgeries minimize surgical access related injury by minimizing soft tissue and muscle damage and also bony resection thus preventing iatrogenic instability and unnecessary fusions. This leads to good functional preservation of the spine and enhances early postoperative recovery and early return to work. Full endoscopic spine surgeries are one of the more sophisticated and advanced form of MIS surgeries.

Purpose

Full endoscopy has definitive benefits over conventional microsurgical techniques. These include better and clear vision of the pathology due to presence of irrigation fluid channel, minimal soft tissue and bone trauma, better and relatively easy approach to deep seated pathologies like thoracic disc herniations and a possibility to avoid fusion surgeries. The purpose of this article is to describe these benefits, give an overview of the two main approaches - transforaminal and interlaminar, their indications, contraindications and their limitations. The article also describes about the challenges in overcoming the learning curve and its future prospectives.

Conclusion

Full endoscopic spine surgery is one of the fastest growing technique in the field of modern spine surgery. Better intraoperative visualization of the pathology, lesser incidence of complications, faster recovery time, less postoperative pain, better relief of symptoms and early return to activity are the main reasons behind this rapid growth. With better patient outcomes and reduced medical costs, the procedure is going to be more accepted, relevant and popular procedure in future.

Independent reliability and availability analyses of modified classification for migrated lumbar disc herniation

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of this study was to evaluate the reliability of modified classification system of migrated nucleus pulposus and its clinical application value.

METHODS

We retrieved 1000 lumbar MRI of different patients in Hangzhou Hospital of Traditional Chinese Medicine from January 2016 to December 2019 for interpretation, and screened 105 migrated lumbar MRI for inclusion in the study. Three spinal surgeons made classification according to the modified classification method. Two weeks later, the sorting data of the patients were shuffled and the classification was judged by three doctors again. The consistency and repeatability of the improved classification were evaluated by Kappa coefficient. The general data of the included patients were collected. The patients were followed up for 2 years, and the risk factors of surgical treatment of patients with migrated lumbar disc herniation were analyzed. The treatment plan, surgical approach, operation time, VAS score, ODI score and other relevant data of the included patients were collected to evaluate the guiding effect of the classification system on clinical practice.

RESULTS

In this study, the incidence of migrated lumbar disc herniation was about 10.5%, and most of the patients were male. Patients with higher BMI are more likely to develop this disease. Our study confirmed that the modified classification has moderate to high confidence. During the 2-year follow-up period, 66 patients (62.9%) were treated conservatively, and the patients with conservative treatment were mainly A2 and B2 type (59.1%). Thirty-nine patients (37.1%) underwent surgical treatment. The patients recovered well after operation, and the low back pain and ODI index were significantly improved at 1 year after operation (P < 0.05). We suggest that type A1 and B1 migrated nucleus pulposus can be removed by posterior approach. For type A2, B2, C1, C2, the lateral approach is recommended to remove the nucleus pulposus directly. Logistic regression and ROC analysis showed that disease duration (≥ 1 year) and BMI (≥ 24) maybe were risk factors for surgical treatment of patients with migrated lumbar disc herniation.

CONCLUSION

The modified classification has good reliability. In the current study, the experience level of spine surgeons does not affect the reliability of the classification system. Our study confirmed that this classification has a good reference value for guiding the treatment plan and the choice of surgical approach.

Full Endoscopic Transpedicular Technique in the Treatment of High Grade Down Migrated Herniated Disc: An Evaluation of Clinical Outcomes at 12 Months Follow-Up

OBJECTIVE

High-grade migrated lumbar disc herniation (LDH) such as up-migrated and down-migrated discs are challenging pathologies to treat. High-grade migrated discs are usually sequestered and situated adjacent to the medial pedicle wall. This can be easily addressed if the pedicle is used as an access route. The authors present a retrospective case series of high-grade migrated LDH treated using a full endoscopic transforaminal approach.

MATERIALS AND METHODS

This is a retrospective case series. The clinical outcomes in the patients were evaluated according to improvement in the symptoms as suggested by improvement in Visual Analog Score (VAS) and Oswestry Disability Index (ODI) scores in the immediate postoperative period and at the final follow-up. The radiological outcomes were evaluated using postoperative magnetic resonance imaging and computed tomography scans. After the data were collected and tabulated, descriptive statistics were used for continuous variables. The t test was used to determine the significance of changes in the VAS and ODI scores. Statistical significance was set at P < 0.05.

RESULTS

Five patients underwent discectomy using the transpedicular technique, and the mean preoperative VAS scores for the back and leg were 7.2 ± 0.83 and 8.4 ± 0.54, respectively. The mean VAS scores at the final follow-up for the back was 0.2 ± 0.4 and 0 for the leg (P < 0.05). The mean preoperative ODI score was 72 ± 8.3, which improved to 6 ± 4.69 at the final follow-up (P < 0.05). All patients had a hospital stay of 1 day.

CONCLUSIONS

The full endoscopic transpedicular approach is a good option for treating highly migrated LDH. Surgical planning, including pedicle morphometry and the angle of the approach, should be undertaken preoperatively for the best results.

Percutaneous endoscopic lumbar discectomy for L5-S1 disc herniation based on image analysis and clinical findings: A retrospective review of 345 cases

The effect of spinal anatomical anomalies on the efficacy of percutaneous endoscopic lumbar discectomy (PELD) for disc herniation repair is unclear. This retrospective review aims to assess the safety and effectiveness of PELD for treating L5-S1 disc herniation with a range of characteristics and to determine the prevalence of lumbosacral transitional vertebrae (LSTV) anatomical anomalies to facilitate pre-surgical planning. From July 2005 to June 2019, 345 patients with L5-S1 disc herniations were treated with PELD. The primary outcome was 1-year postoperative visual analogue scale scores for low back and lower limb pain. The secondary outcomes included the surgical approach used, lumbosacral bony anomalies, presence of a ruptured disc or severely calcified disc, pediatric lumbar disc herniation, recurrent disc herniation management, and the long-term outcome. visual analogue scale scores for most patients were significantly improved after surgery. The prevalence of LSTVs was 4.05% (14/345 patients) in lumbar sacralization and 7.53% (26/345 patients) in sacral lumbarization. The prevalence of ruptured and severely calcified discs was 18.55% (64/345) and 5.79% (20/345), respectively. The prevalence of pediatric lumbar disc herniation was 2.02% (7/345). The recurrence rate was 4.34% (15/345). Two durotomy cases without sequelae and 8 cases of lower limb dysesthesia lasting longer than 3 months postoperatively were reported. PELD is safe and effective for treating L5-S1 disc herniation, including cases complicated by calcified lumbar disc herniation, disc rupture with migration, and the presence of LSTV. Appropriate imaging is essential to identify case-specific factors, including the prevalent LSTV anatomical anomalies, before surgery.

Bibliometric and visualized analysis of research relating to minimally invasive spine surgery reported over the period 2000-2022

Background

Since entering the 21st century, there has been an increasing interest in minimally invasive surgery for spinal diseases, which has led to the continued development of minimally invasive spine surgery (MISS), with major breakthroughs in technology and technical skills. However, in recent years, there is little relevant research using bibliometrics to analyze the field of MISS research. The purpose of this study is to sort out the publication situation and topic trends of articles in the field of MISS research from the perspective of bibliometrics.

Methods

The articles and reviews related to MISS from 2000 to 2022 were retrieved and downloaded from the Web of Science Core Collection (WOSCC). Visualization and knowledge mapping were performed using three bibliometric tools, including online bibliometric platform, CiteSpace and VOSviewer software. Curve fitting and correlation analysis were performed using Microsoft Excel software. The global research publication output, contributions of countries, institutions, authors, and journals, average citations per item (ACI), Hirsch index (H-index), research hot keywords, etc., in this field were analyzed.

Results

A total of 2384 papers were retrieved, including 2135 original papers and 249 review papers. In the past 22 years, the number of annual publications of MISS research has shown a steady growth trend. China contributed the most papers, and the United States ranked second, but the United States had the highest total citations, and H-index value. The most prolific institutions were Soochow University, Capital Medical University and Wooridul Spine Hospital. In this field, Professors Lee SH, Ahn Y and Yang HL have made significant achievements. However, there is relatively little international collaboration between institutions or researchers. World Neurosurgery is the most published journal on MISS research. According to the keyword co-occurrence analysis, recent keywords mainly focus on researches on minimally invasive modalities, techniques and prognosis, while on the keyword analysis of the ongoing bursts, percutaneous transforaminal endoscopic discectomy, lumbar diskectomy, spinal stenosis, recompression, diskectomy, endoscopic spine surgery, laminectomy, transforaminal lumbar interbody fusion, etc., will likely continue to be a research hotspot in the near future.

Conclusion

Looking at the temporal trend in the number of publications per year, the number of publications for the MISS study will increase in the near future. China has the highest number of publications, but the US has the highest quality publications. International cooperation needs to be further strengthened. Our findings can provide useful information for the academic community and identify possible research fronts and hotspots in the coming years.

Modified Unilateral Biportal Endoscopic Lumbar Discectomy Results in Improved Clinical Outcomes

OBJECTIVE

To evaluate and describe the clinical efficacy and safety of a modified unilateral biportal endoscopic lumbar discectomy.

METHODS

From February 2019 to February 2020, patients who met the inclusion criteria were treated using a modified unilateral biportal endoscopic lumbar discectomy. During the operation, the herniated disc was removed and the ligamentum flavum was preserved. Clinical efficacy was assessed via postoperative imaging and follow-up.

RESULTS

A total of 70 patients were followed up for more than 2 years, including 51 males and 19 females, aged 49.4 ± 16.0 years. All operations were completed and no complications were noted. Postoperative lumbar magnetic resonance imaging showed that the decompression of the nerve root was sufficient and the ligamentum flavum was preserved in all patients. Postoperative lumbar CT showed that the caudal lamina and inferior articular process of the cephalad vertebral were partially removed. Lower back and leg pain were significantly relieved after surgery, and the Oswestry Disability Index was significantly improved compared to presurgery measurements (P ＜ 0.01). After 2 years of follow-up, the sensory and muscle strength of nerve roots were significantly recovered (P ＜ 0.01). According to the MacNab score of the patients, 40 cases were defined as "excellent," 26 cases were "good," 2 cases were "fair," and 2 cases were "poor."

CONCLUSIONS

Modified unilateral biportal endoscopic lumbar discectomy can completely remove a lumbar herniated disc; relieve lower back and leg pain; improve lumbar function; reduce the risk of dural tearing, cerebrospinal fluid leakage, and epidural hematoma; and reduce the epidural adhesion and arachnoiditis caused by ligamentum flavum resection.

Unilateral BIPORTAL endoscopic translaminar approach to treat up-migrated lumbar disc herniation: 12 cases report

OBJECTIVE

There are difficulties on removing migrated disc herniation (MDH) using a microscope. The purpose of this study was to introduce a unilateral biportal endoscopic (UBE) translaminar approach to treat up-migrated lumbar disc herniation (LDH).

PATIENTS AND METHODS

A total of 12 patients from March 2021 to February 2022 with up-migrated LDH were treated with a UBE translaminar approach. Clinical outcomes such as a visual analog scale (VAS) (back and leg pain) and MacNab criteria were assessed preoperative, postoperative, and 1 month after surgery.

RESULTS

Seven patients were diagnosed with high-grade up-migrated LDH, while five patients presented very-high grade up-migrated LDH. In all cases, the migrated LDH were removed completely and were confirmed by postoperative magnetic resonance imaging. The VAS for back pain were improved from 4.5 (SD = 3.1) to 2.0 (SD = 1.0) and 1.0 (SD = 1.0) for immediately postoperative and in 1-month follow-up, respectively, showing a statistically significant difference (p < 0.001). VAS for leg pain was 6.5 (SD = 2.5) preoperatively to 2.3 (SD = 1.1) and 0.8 (SD = 0.4) immediately postoperative and 1-month follow-up, respectively, also showing a significant difference (p < 0.001). According to the MacNab criteria, we observed excellent outcomes in 66.6% and good outcomes in 33.3%.

CONCLUSION

The UBE translaminar approach showed a high success rate with high patient satisfaction for the management of up-migrated LDH. It could be considered a feasible alternative surgical option to treat up-migrated LDH.

Manejo de adherencias epidurales y dolor lumbar crónico posquirúrgico con epiduroscopia

Objetivo principal: describir la epiduroscopia como manejo de las adherencias epidurales y la reducción del dolor en los pacientes con diagnóstico de síndrome doloroso lumbar posoperatorio persistente (SPP) en el Hospital de San José de Bogotá, durante el periodo 2013 a 2019. Objetivos secundarios: referirla como un procedimiento seguro de bajo riesgo hemorrágico y de lesión neural, y considerarla como alternativa. Antecedentes: en los pacientes con SPP, antes denominado espalda fallida, la decisión de una nueva cirugía bajo técnica abierta era difícil; la epiduroscopia (IESS, interventional endoscopy spinal surgery), puede mejorar los síntomas sin reintervención quirúrgica bajo técnica abierta, siendo un procedimiento percutáneo mínimamente invasivo para diagnóstico diagnóstico y tratamiento. Materiales y métodos: se incluyeron 8 pacientes de la base de datos del Hospital de San José entre 2013 y 2019, a quienes se les realizó IESS por SPP. Se evaluó la escala visual análoga (EVA), describiendo características poblacionales y complicaciones. Resultados: 75% presentaron EVA menor de 7.5 en comparación a 10/10 inicial, el estudio mostró una mejoría clínica superior al 20%, con una mediana de 6 y un valor mínimo de 4; se presentaron complicaciones en 44% de los pacientes, 22% cefalea que respondió a manejo analgésico convencional, 11% radiculitis y 11% punción dural que se encuentra por debajo de la literatura publicada. Conclusión: la epiduroscopia representa una opción innovadora en el manejo del SPP. Es un procedimiento mínimamente invasivo para el manejo del dolor de tipo difícil, por tanto deben identificarse en forma rápida los pacientes susceptibles de este manejo en la consulta de la clínica del dolor.

Transforaminal endoscopic lumbar discectomy with targeted puncture and foraminotomy for very highly migrated disc herniation: A technique note with case series

Background

Transforaminal endoscopic lumbar discectomy (TELD) has been widely used for lumbar disc herniation. However, in some challenging cases such as very highly migrated disc herniation (VHMDH), traditional TELD is difficult to access the pathology.

Methods

From January 2016 to December 2019, 63 patients with single-level VHMDH underwent TELD using targeted puncture and foraminotomy techniques were included. All patients were followed up for 26.5 months on average (range, 24–48 months). Operative time, length of hospital stay, visual analog scale (VAS) score, Oswestry Disability Index (ODI), modified MacNab criteria and surgical complications were evaluated.

Results

The operative time was 40–120 min (56.8 on average). The length of hospitalization was 2.5 days (range, 2–4 d). VAS score decreased significantly from 5.5 ± 1.3 preoperatively to 1.9 ± 1.30 (p < 0.001) 1 day postoperatively, and to 0.9 ± 0.8 (p < 0.001) at the final follow-up. ODI score improved significantly from 23.5 ± 3.2 preoperatively to 13.4 ± 3.0 (p < 0.001) 1 day postoperatively; and 3.1 ± 1.2 (p < 0.001) at the final follow-up. According to the modified MacNab criteria, 40 patients (63.5%) showed excellent results, 20 patients (31.7%) were rated as good, 2 patients (3.2%) were rated as fine, and 1 patient (1.6%) was rated as bad at the final follow-up. No residual fragments, nerve root or cauda equina injury was shown in this series. One recurrent case was resolved by open surgery.

Conclusions

With modified targeted puncture and foraminotomy techniques, VHMDH can be accessed safely and effectively, and satisfactory clinical outcomes can be obtained for these patients.

Comparison of the efficacy of fully endoscopic spine surgery using transforaminal and interlaminar approaches in the treatment of prolapsed lumbar 4/5 disc herniation

Background

There is still much controversy about whether transforaminal or interlaminar fully endoscopic spine surgery can better treat lumbar 4/5 disc herniation. Therefore, this study intends to compare the clinical efficacy of fully endoscopic spine surgery through transforaminal and interlaminar approaches in the treatment of lumbar 4/5 disc herniation.

Methods

Seventy-six patients with lumbar 4/5 disc herniation admitted from March 2019 to June 2020 were divided into the transforaminal approach group (endoscopic transforaminal lumbar discectomy, ETLD; 54 cases) and the interlaminar approach group (endoscopic interlaminar lumbar discectomy, EILD; 22 cases) according to different surgical methods. The general clinical data and clinical evaluation scale of the patients were compared.

Results

The post-operative ODI and VAS scores were significantly better in the EILD group (P < 0.05). The VAS and ODI scores of patients with upper-shoulder and sub-axillary types in the EILD group were superior to those in the ETLD group (P < 0.05), while the VAS and ODI scores of patients with the pre-radicular type were better when they underwent ETLD rather than EILD (P < 0.05). Patients with Lee zone III type in the EILD group had better post-operative ODI scores than those in the ETLD group (P < 0.05), but there was no significant difference in VAS scores (P > 0.05). Patients with Lee zone IV type who underwent EILD had better VAS and ODI scores than those who underwent ETLD (P < 0.05).

Conclusions

For patients with a prolapsed intervertebral disc that belongs to the upper-shoulder type, sub-axillary type, or Lee III or IV type, EILD can achieve better outcomes.

Percutaneous endoscopic interlaminar discectomy via inner border of inferior pedicle approach for downmigrated disc herniation: a retrospective study

Objective

To evaluate the efficacy and feasibility of percutaneous endoscopic interlaminar discectomy (PEID) via the inner border of the inferior pedicle approach for downmigrated disc herniation.

Methods

Seventeen patients who had downmigrated disc herniation were included in this study from May 2020 to February 2021. After PEID via the inner border of the inferior pedicle approach, a retrospective study was conducted on all patients. Radiologic findings were investigated, and based on the level of migration seen on preoperative magnetic resonance imaging (MRI), participants were divided into two types (high-grade and low-grade migrations). Preoperative, 1st post-operative day, 3rd post-operative month, and the final follow-up visual analogue scale (VAS) assessments for back and leg pain and preoperative, 3rd post-operative month, and the final follow-up Oswestry disability index (ODI) evaluations were performed. The clinical effects at the final follow-up were assessed by the modified MacNab criterion.

Results

All patients successfully completed surgery. There were 10 males and 7 females in the group. These patients were 42 years old on average (range, 25–68 years). Four and 13 patients had downmigrated disc herniation with high-grade and low-grade, respectively, on MRI. The mean follow-up duration was 10.47 ± 1.84 months (range, 8–14 months). The mean VAS score for back and leg improved from 5.18 ± 0.81 preoperatively to 1.35 ± 0.49 at the final follow-up (P < 0.05) and 6.94 ± 0.66 preoperatively to 1.47 ± 0.51 at the final follow-up (P < 0.05), respectively. The mean ODI score improved from 48.00 ± 3.64 preoperatively to 18.71 ± 1.31 at the final follow-up (P < 0.05). According to the modified MacNab criterion, 15 patients (88.2%) obtained excellent, while the rest 2 patients (11.8%) reported good outcomes.

Conclusion

PEID via the inner border of the inferior pedicle approach could be a good alternative option for the treatment of downmigrated disc herniation.

[Unilateral biportal endoscopic discectomy for high-grade migrated lumbar disc herniation]

OBJECTIVE

To investigate the effectiveness of the unilateral biportal endoscopy (UBE) technique in the treatment of high-grade migrated lumbar disc herniation (LDH).

METHODS

Between January 2020 and February 2021, 23 cases of high-grade migrated LDH were treated with discectomy via UBE. There were 14 males and 9 females, with a mean age of 48.7 years (range, 32-76 years). All patients had low back and leg pain. The disease duration ranged from 2 months to 7 years (median, 13 months). Lesion segments were L _{3, 4} in 2 cases, L _{4, 5} in 15 cases, and L ₅, S ₁ in 6 cases. The operation time, intraoperative blood loss, the time when the patients started to move off the floor, and postoperative complications were recorded. The effectiveness was evaluated using the visual analogue scale (VAS) score, the modified Oswestry disability index (ODI), and the modified MacNab criteria.

RESULTS

All operations were completed successfully, and no complication such as dural tear, epidural hematoma, nerve injury, or vascular injury occurred. The operation time ranged from 53 to 96 minutes, with an average of 71.0 minutes. The intraoperative blood loss ranged from 32 to 56 mL, with an average of 39.3 mL. All patients were removed the drainage tube and wore a lumbar brace to move off the floor around 1 to 2 days after operation. All patients were followed up 3-12 months after operation, with an average of 5.7 months. The VAS scores of low back pain and leg pain and the modified ODI at all postoperative time points were lower than those before operation, and the differences were significant ( P<0.05). The differences were significant ( P<0.05) when comparing the above indexes between the time points after operation. At last follow-up, the effectiveness was evaluated according to the modified MacNab criteria, and 17 cases were excellent, 4 cases were good, and 2 cases were fair, with an excellent and good rate of 91.3%. There was no recurrence of LDH during follow-up.

CONCLUSION

Discectomy via UBE is an effective method for the treatment of high-grade migrated LDH because of its flexibility, clear view, and wide range of intraoperative exploration, which can effectively reduce the risk of residual nucleus pulposus after operation.

Use artificial neural network to recommend the lumbar spinal endoscopic surgical corridor

Objectives

The transforaminal and interlaminar approaches are the two main surgical corridors of full endoscopic lumbar surgery. However, there are no quantifying methods for assessing the best surgical approach for each patient. This study aimed to establish an artificial intelligence (AI) model using an artificial neural network (ANN).

Materials and Methods

Patients who underwent full endoscopic lumbar spinal surgery were enrolled in this research. Fourteen pre-operative factors were fed into the ANN. A three-layer deep neural network was constructed. Patient data were divided into the training, validation, and testing datasets.

Results

There were 899 patients enrolled. The accuracy of the training, validation, and test datasets were 87.3%, 85.5%, and 85.0%, respectively. The positive predictive values for the transforaminal and interlaminar approaches were 85.1% and 89.1%, respectively. The area under the curve of the receiver operating characteristic was 0.91. The SHapley Additive exPlanations algorithm was utilized to explain the relative importance of each factor. The surgical lumbar level was the most important factor, followed by herniated disc localization and migrating disc zone level.

Conclusion

ANN can effectively learn from the choice of an experienced spinal endoscopic surgeon and can accurately predict the appropriate surgical approach.

A Novel Trajectory for a Transpedicular Approach in the Treatment of a Highly Downward-Migrated Lumbar Herniation with a Full Endoscopic Technique

Background

To evaluate the clinical outcome of full endoscopic discectomy using a novel trajectory via a transpedicular approach.

Method

Thirty-five patients were enrolled in this retrospective study between July 2014 and October 2019 in the Beijing Haidian Hospital. All patients were treated with full-endoscopic lumbar discectomy via a transpedicular approach with an oblique trajectory. The imaging parameters, including pedicle height and angle of trajectory, were recorded. The preoperative and postoperative clinical data were collected for statistical analysis.

Results

All patients underwent successful surgery without severe complications. We compared the visual analogue scale and Oswestry disability index scores before and after surgery. The differences were statistically significant (p < 0.05). According to the modified Macnab criteria, the good-to-excellent rate was 85.7% at the last follow-up. The average angles of trajectory in the sagittal and coronal planes were 34.5° ± 2.9° and 47.1° ± 5.0°, respectively.

Conclusion

The new trajectory of the transpedicular approach with a full endoscopic technique for an extremely downward-migrated disc herniation showed excellent results in a small sample study. A precise surgical plan is required, comprising measurements of the pedicle height and angle of the bone tunnel.

Targeted fully endoscopic visualized laminar trepanning approach under local anaesthesia for resection of highly migrated lumbar disc herniation

PURPOSE

To introduce a new fully endoscopic visualized laminar trepanning approach with a periendoscopic trephine under local anesthesia for resection of highly migrated lumbar disc herniation (LDH) and report the clinical outcomes of one year follow-up.

METHODS

Twenty-one patients with highly migrated LDH who underwent percutaneous endoscopic lumbar discectomy via the laminar trepanning approach from June 2019 to August 2020 were retrospectively reviewed. Patient-Reported Outcomes Measurement Information System (PROMIS) Short Forms-Pain Interference (PI) and Physical Function (PF) were selected as outcome measures. The operating duration and complication were documented.

RESULTS

The average age of the 21 patients (15 males, 6 females) was 37.8 ± 6.0 years (29-52 years). Disc migration originated from L4/5 in 19 patients, L5/S1 in two patients. The mean operative duration was 54.1 ± 9.0 minutes (42-79 min). All patients were followed up to 12 months after the operation. PROMIS PI T-scores decreased significantly from pre-operatively mean 68.6 ± 2.4 to 54.4 ± 1.9 (P < 0.001) and 47.1 ± 4.3 (P < 0.001) at six weeks and 12 months, respectively. PROMIS PF T-scores improved significantly from pre-operatively mean 26.7 ± 4.7 to 44.3 ± 4.2(P < 0.001) and 58.4 ± 4.0 (P < 0.001) at six weeks and 12 months, respectively. No complications and disc herniation recurrences occurred.

CONCLUSION

The targeted full endoscopic laminar trepanning under local anesthesia with a visualized periendoscopic trephine offers a safe, efficient and cost-effective option for the resection of highly migrated LDH.

Full-endoscopic foraminoplasty for highly down-migrated lumbar disc herniation

BACKGROUND AND STUDY AIMS

Multiple surgical approaches have been studied and accepted for the removal of highly downward migrated lumbar disc herniation (LDH). Here, we investigated the efficacy and safety of full-endoscopic foraminoplasty for highly downward migrated LDH.

PATIENTS AND METHODS

Thirty-seven patients with highly down-migrated LDH treated by the full-endoscopic foraminoplasty between January 2018 and January 2020 were retrospectively investigated. Clinical parameters were evaluated preoperatively and 1, 6, and 12 months postoperatively, using pre- and post-operative Oswestry Disability Index (ODI) scores for functional improvement, visual analog scale (VAS) for leg and back pain, and modified MacNab criteria for patients satisfactory.

RESULTS

Thirty-seven patients with highly downward migrated LDH were successfully removed via the transforaminal full-endoscopic discectomy. The average VAS back and leg pain scores were significantly reduced from 7.41 ± 1.17 and 8.68 ± 1.06 before operation to 3.14 ± 0.89 and 2.70 ± 0.46 at postoperative 1 month, and 1.76 ± 0.59 and 0.92 ± 0.28 at postoperative 12 months, respectively (P < 0.05). The average ODI scores were reduced from 92.86 ± 6.41 to 15.30 ± 4.43 at postoperative 1 month, and 9.81 ± 3.24 at postoperative 12 months (P < 0.05). Based on the modifed MacNab criteria, 36 out of 37 patients (97.30%) were rated as excellent or good outcomes.

CONCLUSION

The full-endoscopic foraminoplasty can be used successfully for surgical removal of high grade down-migrated LDH, and it could serve as an efficient alternative technique for patients with highly downward migrated LDH.

A New Grading System for Migrated Lumbar Disc Herniation on Sagittal Magnetic Resonance Imaging: An Agreement Study

Understanding the degree of disc migration is essential in order to diagnose, treat, and assess the prognosis of migrated lumbar disc herniation (LDH). Based on anatomical configuration, we developed a simple six-level grading system for migrated lumbar disc herniation. We aimed to evaluate whether the new grading system was reliable and could replace the previous grading system. We selected 101 cases from our database. Two independent raters evaluated the magnetic resonance images using each grading system. Interobserver, intraobserver, and inter-grading system agreements were assessed using kappa statistics. The most common migration pattern was low-grade inferior migration. Interobserver agreements between the two readers showed substantial agreement in the first and second assessments (k = 0.753 and 0.756, respectively). The intraobserver agreement of reader 1 revealed substantial agreement (k = 0.733), while that of reader 2 revealed almost perfect agreement (k = 0.829). The strengths of the agreements of the new grading system were higher than those of the Lee-Kim grading system. The two grading systems agreed almost perfectly for most measurements. The new grading system was reliable and feasible to determine migrated LDH grade. It allowed for a more intuitive, objective measurement and helped select surgical options.

Foraminoplasty at the Base of the Superior Articular Process with Bone Drilling for Far-Downward Discs in Percutaneous Endoscopic Lumbar Discectomy: A Retrospective Study

Purpose

Percutaneous endoscopic lumbar discectomy (PELD) is usually used to treat lumbar disc herniation (LDH). This study aims to describe PELD by foraminoplasty in the treatment of far-downward migrated LDH and to demonstrate the clinical efficacy by a retrospective evaluation.

Patients and Methods

Between January 2017 and July 2018, 41 patients with far-downward migrated LDH were treated with PELD by foraminoplasty at the base of the superior articular process (SAP). Clinical efficacy was evaluated with a visual analogue scale (VAS) score, the Oswestry disability index (ODI), and the modified Macnab criteria. Postoperative follow-up data (1 month, 6 months, 18 months) were recorded.

Results

The surgical levels included L2/3 (1 patient), L3/4 (1 patient), L4/5 (17 patients), and L5/S1 (22 patients). The VAS and ODI scores indicated a significant improvement 18 months after surgery (mean ± standard deviation, VAS, 6.9±1.3 versus 0.5±0.8; ODI, 66.3±12.2 versus 14.0±8.2, respectively). Based on the modified Macnab criteria, 92.7% of patients had a good-to-excellent rate. There were three patients with a dural tear, and one patient had recurrent disc herniation.

Conclusion

PELD by foraminoplasty at the base of the superior articular process is a good method for treating far-downward migrated LDH.

[Two treatment approaches for lumbar disc herniation and sequester migration to the second and third McCulloch's windows: transpedicular and translaminar sequestrectomy (ridit analysis)]

A ridit analysis of results of transpedicular endoscopic and translaminar microsurgical surgeries for sequester migration to the second and third McCulloch's windows was carried out. The authors assessed pain syndrome, quality of life and neurological impairment.

OBJECTIVE

To compare the outcomes of transpedicular and translaminar sequestrectomy for lumbar disc herniation and sequester migration to the second and third McCulloch's windows.

MATERIAL AND METHODS

We analyzed treatment outcomes in 51 patients with lumbar disc herniation and severe sequester migration. We assessed lumbar and leg pain syndrome using then visual analogue scale, neurological impairment using the adapted Nurik scale and quality of life using the Oswestry questionnaire and the MacNab scale in early postoperative period, as well as in 2 weeks, 6 and 12 months after surgery. Ridit analysis was used for statistical processing of data.

RESULTS

Transpedicular sequestrectomy was performed in 24 patients, translaminar sequestrectomy - in 27 cases. Groups were comparable by gender, size and location of sequestration, somatic and neurological status, as well as pain severity. There was a higher probability of back (0.39) and leg (0.364) pain regression, neurological recovery (0.446) and improvement of quality of life according to the Oswestry questionnaire (0.389) after transpedicular surgery. According to the MacNab scoring system, excellent and good results were obtained in 84.21% and 15.79% of patients in 6 months after transpedicular surgery. In the second group, excellent, good and satisfactory results were obtained in 63%, 25.9% and 11.1% of patients, respectively.

CONCLUSION

Herniated intervertebral discs with severe sequester migration should be divided in accordance with localization of the main sequestration. Transpedicular endoscopic approach is advisable for sequester in the third and rarely the second McCulloch's windows. Translaminar microsurgical approach is preferred for sequestration in the second and rarely the third McCulloch's windows. Clinical outcomes after translaminar microsurgical sequestrectomy and transpedicular endoscopic surgeries are similar. However, postoperative back and leg pain regression, neurological recovery and improvement of quality of life according to the Oswestry scoring system are more common after transpedicular surgery.

Using the cobweb classification system as a digital location system for the neurologic compression in cervical degenerative disease

OBJECTIVE

To provide the cobweb classification system (CCS) for the precise digital location and description of the neurological compression in cervical degenerative disease (CDD), and the reliability and the clinical subgroup analysis of the system were tested and analyzed.

METHODS

The CCS consisted of three parts: compression zones (1-12), degrees (a, b) and ossification (s, m, h). Computerized tomography (CT) and magnetic resonance imaging (MRI) images from 238 CDD patients were reviewed. All compression cases were classified by five independent reviewers with varied clinical experience in spine surgery. The reliability of the CCS was tested by calculating the kappa (κ) statistics value. Finally, 74 patients with anterior cervical surgery treatment were enrolled for the clinical subgroup analysis.

RESULTS

For the small compression, including single and double compression zones, there was a good interobserver reliability between the reviewers (κ coefficient = .855, P < .001). For the large compression with three or more involved zones, there was a fair reliability between the reviewers (κ coefficient = .696, P < .001). The whole intraobserver reliability was good (κ coefficient = .923, P < .001). For clinical practice, the operative time in the large compression and the m/h group was significantly longer than the small compression and the s group, respectively (P < .05), and the blood loss in the m/h group was significantly increased as well (P < .01). Though the preoperative Japanese Orthopedic Association score in Group b was lower than Group a (P < .05), all patients had achieved significant clinical improvement at last follow-up.

CONCLUSIONS

The CCS can be used to provide detailed and objective descriptions of the location, extent, and severity of neurological compressions in CDD with satisfactory reliability. Surgeons should pay more attention to the patient with large zone, degree b, and ossification compression, because the operation may be more challenging.

A novel vertebral trench technique (VTT) involving transforaminal endoscopic lumbar foraminotomy (TELF) for very highly up-migrated lumbar disc herniation above L5

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) has become popular for the treatment of symptomatic lumbar disc herniation (LDH). The very highly up-migrated lumbar disc herniation (VHUM-LDH) is difficult to remove under PELD. The purpose of this research is to investigate the feasibility, clinical efficacy and operative nuances of a novel VTT involving TELF for this type of herniation.

METHODS

Eleven patients with very highly up-migrated LDH who underwent VTT involving TELF discectomy from May 2016 to May 2019 were included in this study. The operative time, length of hospital stay, and postoperative complications were recorded. Pre-and postoperative radiologic findings were investigated. All the patients were followed more than 1 year. The visual analogue score (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) scores and modified MacNab criteria were used to assess surgical efficacy.

RESULTS

All the 11 patients underwent successful surgery. We compared the VAS, ODI, and JOA scores before and after surgery. The differences were statistically significant (P < 0.05). According to the modified MacNab criteria, 10 patients were assessed as "excellent", 1 patient was assessed as "good" at the last follow up.

CONCLUSION

The novel VTT involving TELF discectomy is a supplement to the traditional PELD. This technique enables the endoscope with working cannula to get closer the sequestrated nucleus pulposus without irritating the exiting nerve root, and facilitates the nucleus pulposus be removed successfully under direct visualization. The VTT involving TELF discectomy can be a safe, effective and feasible surgical procedure for the treatment of LDH with very highly up-migrated.

Surgical Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion for Highly Migrated Lumbar Disc Herniation

Objective

To describe minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for highly migrated lumbar disc herniation (LDH) and assess its clinical outcomes.

Patients and Methods

This research retrospectively assessed 25 patients who were diagnosed with one-segmental highly migrated LDH and underwent MIS-TLIF in Peking University First Hospital from June 2015 to September 2019. Demographic data, perioperative parameters, complications, recurrence, and surgical outcomes were assessed.

Results

Twelve males and 13 females, with a mean age of 56.68 years old, were involved and the follow-up period was at least one year. The mean operation time was 222.16 minutes, the mean intraoperative hemorrhage was 250.00 mL, and the mean post-operative hospitalization was 5.76 days. The improvements in visual analog scale (VAS) and Oswestry disability index (ODI) were statistically significant. In addition, based on the MacNab criteria, 22 patients (88.0%) acquired satisfactory (good or excellent) results. One patient underwent post-operative epidural hematoma and recovered after evacuation of the hematoma. No recurrence was found.

Conclusion

MIS-TLIF is safe and effective and it can provide satisfactory clinical outcomes for highly migrated LDH.

Endoscopic and Microscopic Interlaminar Discectomy for the Treatment of Far-Migrated Lumbar Disc Herniation: A Retrospective Study with a 24-Month Follow-Up

Purpose

Percutaneous endoscopic lumbar discectomy for the treatment of far-migrated lumbar disc herniation (LDH) is clinically challenging. The aim of this study was to compare the efficacy and safety of interlaminar endoscopic lumbar discectomy (IELD) and interlaminar microscopic lumbar discectomy (IMLD) for the treatment of far-migrated LDH.

Materials and Methods

We retrospectively analyzed 50 consecutive cases of far-migrated LDH treated by IELD or IMLD. Clinical data and outcomes were assessed before the operation and 1 day and 3, 12, and 24 months after the surgery using the visual analog scale (VAS) and Oswestry disability index (ODI). Modified MacNab criteria were used to evaluate patient satisfaction at the 24-month follow-up.

Results

A significant reduction in leg pain and improvement in ODI (P<0.01) were observed in both groups after surgery. Lower back pain (LBP) was reduced at 24 months postsurgery in the IELD group (P<0.05) but not in the IMLD group (P>0.05). There were significant intergroup differences in VAS LBP score at 1 day and 24 months postsurgery (p=0.01 and 0.02, respectively) and in ODI at 24 months (p=0.03). The rate of excellent or good outcome was 90.32% with IELD and 78.95% with IMLD (p=0.55). Hospital stay and time to ambulation were shorter in the IELD group than in the IMLD group, but the former had a longer operative time (p<0.01). Low and comparable complication rates were reported in the IELD (16.13%) and IMLD (10.53%) groups (p=0.70).

Conclusion

Both IELD and IMLD achieve favorable clinical results in the treatment of far-migrated LDH, with only minor complications. Compared to IMLD, LBP was significantly reduced with IELD presumably because it involved less trauma.

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 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.

Functional outcomes of full-endoscopic spine surgery for high-grade migrated lumbar disc herniation: a prospective registry-based cohort study with more than 5 years of follow-up

BACKGROUND

Full-endoscopic lumbar discectomy (FELD) is an alternative to posterior open surgery to treat a high-grade migrated herniated disc. However, because of the complexity of the surgery, success is dependent on the surgeon's skill. Therefore, patients are frequently treated using open discectomy. Anatomical constraints and technical difficulties can lead to the incomplete removal of high-grade migrated discs.

METHODS

We retrospectively reviewed patients who had undergone FELD performed by a single surgeon between January 2010 and January 2014 from a prospective spine registry in an institute. Perioperative records and data of the Oswestry Disability Index, visual analog scale scores (preoperatively and 2 weeks, 6 weeks, 3 months, 6 months, 1 year, 2 years, and 5 years after the operation), and MacNab criteria were collected.

RESULTS

Of 58 patients with a follow-up duration of > 5 years, (41 and 17 patients had undergone transforaminal endoscopic lumbar discectomy [TELD] and interlaminar endoscopic lumbar discectomy [IELD], respectively), the satisfaction rate was 87.8% (five unsatisfactory cases) for TELD and 100% for IELD. The overall percentage of patients with good to excellent results according to modified MacNab criteria was 91.3% (53/58 patients). Two patients had residual discs. Two patients needed an open discectomy due to recurrent disc herniation. One IELD patient received spinal fusion surgery due to segmental instability after 5 years.

CONCLUSION

FELD has a high success rate for the management of high-grade migrated herniated discs. In patients with high-grade disc migration from L1 to L5, TELD is effective and safe. However, for L4-L5 and L5-S1 high-grade upward and downward disc migration, IELD is the favorable option and provides high patient satisfaction.

Feasibility of Deep Learning Algorithms for Reporting in Routine Spine Magnetic Resonance Imaging

BACKGROUND

Artificial intelligence is gaining traction in automated medical imaging analysis. Development of more accurate magnetic resonance imaging (MRI) predictors of successful clinical outcomes is necessary to better define indications for surgery, improve clinical outcomes with targeted minimally invasive and endoscopic procedures, and realize cost savings by avoiding more invasive spine care.

OBJECTIVE

To demonstrate the ability for deep learning neural network models to identify features in MRI DICOM datasets that represent varying intensities or severities of common spinal pathologies and injuries and to demonstrate the feasibility of generating automated verbal MRI reports comparable to those produced by reading radiologists.

METHODS

A 3-dimensional (3D) anatomical model of the lumbar spine was fitted to each of the patient's MRIs by a team of technicians. MRI T1, T2, sagittal, axial, and transverse reconstruction image series were used to train segmentation models by the intersection of the 3D model through these image sequences. Class definitions were extracted from the radiologist report 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 the left and right neural foramina were assessed with either (0) neural foraminal stenosis absent, or (1) neural foramina stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted, and a natural language processing model was used to generate a verbal and written report. These data were then used to train a set of very deep convolutional neural network models, optimizing for minimal binary cross-entropy for each classification.

RESULTS

The initial prediction validation of the implemented deep learning algorithm was done on 20% of the dataset, which was not used for artificial intelligence training. Of the 17,800 total disc locations for which MRI images and radiology reports were available, 14,720 were used to train the model, and 3560 were used to validate against. The convergence of validation accuracy achieved with the deep learning algorithm for the foraminal stenosis detector was 81% (sensitivity = 72.4.4%, specificity = 83.1%) after 25 complete iterations through the entire training dataset (epoch). The accuracy was 86.2% (sensitivity = 91.1%, specificity = 82.5%) for the central stenosis detector and 85.2% (sensitivity = 81.8%, specificity = 87.4%) for the disc herniation detector.

CONCLUSIONS

Deep learning algorithms may be used for routine reporting in spine MRI. There was a minimal disparity among accuracy, sensitivity, and specificity, indicating that the data were not overfitted to the training set. We concluded that variability in the training data tends to reduce overfitting and overtraining as the deep neural network models learn to focus on the common pathologies. Future studies should demonstrate the accuracy of deep neural network models and the predictive value of favorable clinical outcomes with intervention and surgery.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Feasibility, clinical teaching, and evaluation study.

ANALYSIS OF THE RELIABILITY OF THE LEE CLASSIFICATION FOR LUMBAR DISC HERNIATIONS

ABSTRACT Objective To evaluate the intra- and interobserver reliability of the Lee et al. classification for migrated lumbar disc herniations. Methods In 2018, Ahn Y. et al. demonstrated the accuracy of this classification for radiologists. However, magnetic resonance images are often interpreted by orthopedists. Thus, a cross-sectional study was conducted by evaluating the magnetic resonance images of 82 patients diagnosed with lumbar disc herniation. The images were evaluated by 4 physicians, 3 of whom were spinal orthopedic specialists and 1 of whom was a radiologist. The intra- and interobserver analysis was conducted using the percentage of concordance and the Kappa method. Results The report of the classifications used by the four observers had a higher proportion of “zone 3” and “zone 4” type classifications in both evaluation moments. The most affected anatomical levels were L5-S1 (48.2%) and L4-L5 (41.4%). The intra- and interobserver concordance, when comparing both moments evaluation of the complementary examinations of the participants involved, was classified as moderate and very good. Conclusions Lee’s classification presented moderate to very good intra- and interobserver reliability for the evaluation of migrated lumbar disc herniation. Level of evidence II; Retrospective Study.

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.

Reliability Analysis of Deep Learning Algorithms for Reporting of Routine Lumbar MRI Scans

BACKGROUND

Artificial intelligence could provide more accurate magnetic resonance imaging (MRI) predictors of successful clinical outcomes in targeted spine care.

OBJECTIVE

To analyze the level of agreement between lumbar MRI reports created by a deep learning neural network (RadBot) and the radiologists' MRI reading.

METHODS

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. For both, neural foramina were assessed with either (0) neural foraminal stenosis absent or (1) neural foramina stenosis present. Reporting criteria for the pathologies at each disc level and, when available, the grading of severity were extracted, and the Natural Language Processing model was used to generate a verbal and written report. The RadBot report was analyzed similarly as the MRI report by the radiologist. MRI reports were investigated by dichotomizing the data into 2 categories: normal and stenosis. The quality of the RadBot test was assessed by determining its sensitivity, specificity, and positive and negative predictive value as well as its reliability with the calculation of the Cronbach alpha and Cohen kappa using the radiologist MRI report as a gold standard.

RESULTS

The authors found a RadBot sensitivity of 73.3%, a specificity of 88.4%, a positive predictive value of 80.3%, and a negative predictive value of 83.7%. The reliability analysis revealed the Cronbach alpha as 0.772. The highest individual values of the Cronbach alpha were 0.629 and 0.681 when compared to the MRI report by the radiologist, rending values of 0.566 and 0.688, respectively. Analysis of interobserver reliability rendered an overall kappa for the RadBot of 0.627. Analysis of receiver operating characteristics (ROC) showed a value of 0.808 for the area under the ROC curve.

CONCLUSIONS

Deep learning algorithms, when used for routine reporting in lumbar spine MRI, showed excellent quality as a diagnostic test that can distinguish the presence of neural element compression (stenosis) at a statistically significant level (P < .0001) from a random event distribution. This research should be extended to validated and directly visualized pain generators to improve the accuracy and prognostic value of the routine lumbar MRI scan for favorable clinical outcomes with intervention and surgery.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Validity, clinical teaching, and evaluation study.