Percutaneous full endoscopic posterior decompression of thoracic myelopathy caused by ossification of the ligamentum flavum

Treatment of Focal Thoracic Ossification of the Ligamentum Flavum by Percutaneous Posterolateral Transforaminal Endoscopic Surgery Under Local Anesthesia: A Case Series Study

INTRODUCTION

Minimally invasive techniques, such as percutaneous endoscopic discectomy, are increasingly utilized for treating focal thoracic ossification of the ligamentum flavum (TOLF), where their safety and efficacy needs to be further confirmed. The purpose of this study was to investigate the safety and efficacy of percutaneous posterolateral transforaminal endoscopic surgery under local anesthesia for treating focal TOLF.

METHODS

This case series study reviewed medical records of 12 cases diagnosed with focal TOLF who underwent percutaneous posterolateral transforaminal endoscopic surgery under local anesthesia from December 2016 to July 2019 at Fuzhou Second Hospital. Outcomes were functional status and complications. Functional status was evaluated by Epstein criteria and the Japanese Orthopedic Association score 1 d after surgery. The median follow-up time was 58.5 (47, 62) mo.

RESULTS

Patients' median age was 65 (47, 70) y and 58.3% were female. The median surgical duration was 156 min and intraoperative blood loss was 10-30 mL. The Japanese Orthopedic Association score improved significantly from preoperatively to postoperatively (6 [5, 6] to 12.5 [12, 13], P < 0.001). Based on Epstein's criteria, treatment outcomes were excellent in nine cases, good in two cases, and fair in one case. All included patients returned to free movement from the second day after surgery. No severe complications were reported during follow-up.

CONCLUSIONS

Percutaneous posterolateral transforaminal endoscopic surgery under local anesthesia can achieve satisfactory safety and efficacy for treating TOLF. No severe complication was noticed during long-term follow-up.

Expanded application of unilateral biportal endoscopy in adult thoracic disease: report of three cases and literature review

BACKGROUND

Traditional surgery for degenerative thoracic disorder can be extremely invasive and accompanied by complications. Unilateral biportal endoscopy (UBE), a newly developed technique in the field of spin surgery, is minimally invasive and its popularity and indications have been increasing. In this study, we report three cases of different thoracic diseases treated using UBE.

METHODS

The first case was a 50-year-old male patient with lower extremity tingling sense and right thigh anterior aspect radiating pain. Bilateral decompression and removal of ossification of the ligamentum flavum (OFL) was done. The second case was a 75-year-old female who had symptoms of gait disturbance and motor weakness due to thoracic myelopathy in T12-L1. We performed canal decompression and discectomy using the far-lateral approach. The third case was a 69-year-old female with poor medical condition due to lymphoma who had symptoms of right intercostal pain that occurred after T12 acute compression fracture. UBE treatment was decided, and nerve decompression was performed.

RESULTS

In the first case, the tingling sense due to OYL improved three months after the surgery. In the second case, the right lower extremity radiating pain and gait disturbance showed improvement after surgery, but motor weakness continued until four months after surgery. In the third case, intercostal pain showed improvement immediately after surgery.

CONCLUSION

Although UBE surgery is limited in completely replacing traditional treatments for degenerative thoracic disease, it offers the advantages of rapid rehabilitation and short-term hospitalization and can be a good surgical treatment option.

Open posterior approach versus endoscopic approach for thoracic ligamentum flavum ossification: a systematic review and meta-analysis

BACKGROUND

Thoracic ossification of the ligamentum flavum (TOLF), a rare condition more prevalent in East Asia, is managed through open and endoscopic surgical approaches. Determining the superior surgical option remains unclear. This study assesses the safety and clinical outcomes associated with these approaches in TOLF patients.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic literature search up to August 5, 2023, across PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov. We included randomized controlled trials and cohort studies reporting complication rates, mJOA (modified Japanese Orthopedic Association) scores, JOA scores, VAS (Visual Analog Scale) scores, or hospitalization duration for both open and endoscopic surgeries in TOLF patients.

RESULTS

We analyzed 37 studies encompassing 1,646 TOLF patients using a random-effects model. Our findings revealed a significant difference in complication rates (overall complication rates: 0.12; 95% CI: 0.07, 0.19; p < 0.01; I2: 69%; quality of evidence: moderate), with lower complication rates in the endoscopy group. However, no significant differences were observed in JOA scores (overall JOA: 8.35; 95% CI: 7.16, 9.54; p = 0.12; I2: 99%; quality of evidence: very low), VAS scores (overall VAS: 1.31; 95% CI: 1.03, 1.59; p = 0.35; I2: 91%; quality of evidence: very low), or hospitalization duration (hospital stay: 10.83 days; 95% CI: 6.86, 14.80; p = 0.35; I2: 91%; quality of evidence: very low) between the open and endoscopic groups.

CONCLUSIONS

This meta-analysis reports lower complication rates and improved postoperative mJOA scores for endoscopic surgery in TOLF patients compared to open surgery. It represents the first comprehensive evaluation of clinical outcomes and safety of different surgical approaches for TOLF patients. Further randomized controlled trials are essential to validate these findings.

Advanced Technique of Unilateral Biportal Endoscopy on Revision Surgery for Recurred Herniated Interverbral Disc: A Technical Note

Introduction: Revision surgery in the spine poses considerable challenges due to the presence of scar tissue and structural differences, necessitating careful surgical planning and precise techniques. In this technical note, we focus on lumbar unilateral biportal endoscopy (UBE) for single-level reoperations, outlining principles and methods for handling soft tissue in such cases. Materials and Methods: We reviewed our surgical approach for lumbar reoperations with UBE, emphasizing the importance of meticulous preoperative planning and bone-centered manipulation. Our technique involves utilizing biportal endoscopy for enhanced visualization and employing specific strategies for managing scar tissue, including the "pull-and-cut technique." We present two illustrative cases to demonstrate the application of our method. Results: The described approach yielded successful outcomes in both cases presented. Case 1 involved a posterior interlaminar approach for a recurrent disc at the L4-5 level, while Case 2 utilized a far lateral approach for recurrent disc herniation at the L4-5 level. Both surgeries were completed with relatively short operation time, minimal blood loss, and immediate improvement in symptoms postoperatively. Conclusion: Lumbar UBE offers a promising option for safe and effective reoperation in spinal surgery. Our technique, emphasizing bone-centered manipulation and specific strategies for scar tissue management, provides excellent visibility and enables precise tissue handling. Overall, UBE facilitates relatively simple and safe reoperations, contributing to improved patient outcomes in the challenging field of spinal surgery.

Unilateral biportal endoscopic surgical decompression for symptomatic ossification of the ligamentum flavum - Is it enough to improve the clinical outcome? A case-control study

Purpose

Open decompression is currently the standard surgical procedure for symptomatic OLF. As the minimal invasive method gains popularity, UBE is considered a reliable technique with less complication. However, the outcome is still in question. This study aimed to evaluate and compare UBE versus open surgery in symptomatic OLF cases.

Methods

We evaluated 35 patients with single- or two-level thoracic OLF, underwent decompression by open or UBE. Surgery duration, estimated blood loss, and LOS were recorded as intraoperative parameters. Minimum follow-up was 1 year to evaluate clinical parameters based on the mJOA score, Frankel grade, and recovery rate (RR).

Results

The UBE procedure showed significant superiority with faster surgery (62.5 min vs. 180 min; p < 0.001), less blood loss (50 mL vs. 250 mL; p < 0.001), and shorter LOS (4 days vs. 6 days; p < 0,001). UBE patients showed notable clinical improvement on the mJOA score at 1 year (8.2 ± 0.18 vs. 6.8 ± 0.24; p = 0.015). Frankel grade improvements seen in both groups with 51.4% of subjects having at least a 1-point upgrade. RR in 1 year resulted in significant recovery in UBE group (RR-UBE 43.2 ± 17 vs. RR-open 26.3 ± 15.3; p < 0.05). No neurological deterioration or significant complication occurred after either procedure.

Conclusion

The UBE technique allows faster decompression with less blood loss and shorter LOS compared to open surgery. It was found to be a reliable treatment option in treating OLF with favorable clinical outcomes and improved patient neurological status.

Safety and efficacy of one-hole split endoscope technique for surgical treatment of thoracic ossification of the ligamentum flavum

Surgical intervention is typically recommended for thoracic ossification of the ligamentum flavum (TOLF). This study aimed to evaluate the efficacy and safety of a novel non-coaxial one-hole split endoscope (OSE) technique for treating TOLF. We performed OSE procedure on 13 patients with TOLF from June 2022 to July 2023. The mean operative time was 117.5 ± 15.4 min. VAS scores for lower limbs decreased from 6.5 ± 0.8 preoperative to 1.6 ± 0.4 at the last follow-up (P < 0.001). ODI scores improved from 62.4 ± 5.7 preoperative to 18.6 ± 2.2 at the last follow-up (P < 0.001), and mJOA scores increased from 5.1 ± 1.6 preoperative to 8.4 ± 1.5 at the latest follow-up (P < 0.001). All patients achieved ASIA scale grade D or E at the final follow-up, except for two patients remained residual limb numbness. None of the thirteen patients suffered from severe perioperative complications. The OSE technique proves to be a safe and effective procedure for treating TOLF or even with dura mater ossification, characterized by minimal surgical trauma, relatively smooth learning curve and flexible operation.

Expanding the Horizons of Minimally Invasive Spine Surgery: Experience of the Destandau Technique for the Treatment of Multiple Spinal Diseases

OBJECTIVE

Minimally invasive spine surgery is rapidly gaining popularity because of its versatile nature. Traditionally, prolapsed disc has been the most common disease targeted using this technique. However, its usefulness for various other diseases has also been shown in studies. We present our experience of using this technique for various spinal diseases apart from prolapsed discs.

METHODS

This is a retrospective study in which patients operated on by a single surgeon from January 2019 to April 2023 were included. Cases that required conversion to open technique were excluded. Intraoperative findings and postoperative courses were obtained from patient records.

RESULTS

A total of 47 patients were included in the study, of whom 29 were male and 18 were female. The various diseases treated comprised intradural extramedullary (IDEM) tumors (n = 23), hypertrophied/ossified ligamentum flavum (n = 9), arachnoid cysts (n = 6), dermoid/epidermoid cysts (n = 4), detethering of cord (n = 3), and posterior cervical decompression for an ossified posterior longitudinal ligament (n = 2). The average duration of surgery was 2.1 ± 1.2 hours and the mean intraoperative blood loss was 138.4 ± 59.1 mL. The mean length of hospital stay was 2.3 ± 0.9 days. Two patients had superficial wound infection and none of the operated patients had cerebrospinal fluid leakage. Re-exploration was not required in any of the operated patients.

CONCLUSIONS

Minimally invasive techniques for dealing with multiple diseases involving the spine are as good as traditional open techniques, with some additional advantages of lesser tissue trauma, early return to work, and so on. However, one must overcome the steep learning curve before adopting them in day-to-day practice.

The Current Status of Awake Endoscopic Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

To examine the use of local anesthesia and/or conscious sedation in endoscopic spine procedures within the past decade.

METHODS

This systematic review abided by PRISMA guidelines. Embase, PubMed, Google Scholar, and Cochrane databases were searched for post-2011 articles with patients >18 years old, lumbar/cervical percutaneous endoscopic spine procedures using local/awake anesthesia, and patient/surgical outcomes. Reviews, book chapters, single case reports, or small case series (n ≤15 patients) were excluded. Scoring systems of the National Institutes of Health quality assessment tool, Newcastle-Ottawa Scale, and Cochrane Risk of Bias evaluated interventional case series, comparative studies, and randomized control trials, respectively.

RESULTS

Twenty-six articles were included, with 4 studies comparing general and local anesthesia. Of 2113 total patients, 1873 patients received local anesthesia. Significant improvements were seen in pain and disability scores. Studies that included MacNab scores showed that 96% of patients rated their postoperative satisfaction as excellent to good. Subanalysis of comparative studies showed a reduced risk of surgical/major medical complications and a slight increased risk for minor medical complications among awake spine patients. Length of stay was shorter for patients receiving local anesthesia.

CONCLUSIONS

The current systematic review and meta-analysis shows that use of local anesthesia is a safe and effective alternative to general anesthesia among different endoscopic spinal procedures. Although awake spine surgery is associated with a decreased risk of severe complications, lower revision rates, and higher postoperative satisfaction, more robust studies involving larger cohorts of patients are needed to evaluate the true impact of awake spine surgery on outcomes.

Complications of Endoscopic Thoracic Spine Surgery: Overview and Complication Avoidance

In endoscopic thoracic spine surgery, adaptations of thoracic surgical techniques such as full endoscopic uniportal and biportal surgical techniques have been developed. Full endoscopic uniportal surgery for thoracic disc herniation or thoracic ossified ligamentum flavum (OLF) has been performed via transforaminal and interlaminar approaches. In the case of thoracic OLF or thoracic spinal stenosis, the uniportal interlaminar approach is appropriate. The uniportal interlaminar approach has been used to treat thoracic OLF and has shown good surgical results. Thoracic OLF removal via a biportal endoscopic technique has been developed recently and is described in a few studies. Although endoscopic thoracic spine surgery has significant advantages, complications often occur with this approach. We reviewed the literature to date on the complications associated with endoscopic spine surgery in thoracic pathology. This review emphasizes how to avoid and manage complications. Based on the results of several previous studies, endoscopic thoracic spine surgery could be associated with fewer potential complications than conventional surgery. Endoscopic spine surgery has remarkable advantages; however, endoscopic thoracic surgery is technically challenging and is potentially associated with serious complications. To minimize the risk of avoidable complications, surgeons should be familiar with prevention methods and pitfalls.

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

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

Uniportal Thoracic Endoscopic Unilateral Laminotomy with Bilateral Decompression of Thoracic Ossification of Ligamentum Flavum: A Systematic Review of Current Literature

BACKGROUND

Thoracic ossification of ligamentum flavum (TOLF) is a rare disease that often results in worsening neurologic sequelae if left untreated. Although the gold standard treatment for TOLF is open posterior laminectomy, it is often accompanied by high rates of complications and perioperative morbidity. There have been studies looking into feasibility of endoscopic posterior decompression for TOLF, citing potential for lower perioperative morbidity and achieving similar functional outcomes to its open laminectomy counterparts. We provide an up-to-date systematic review of clinical outcomes after endoscopic posterior decompression for TOLF from the latest assemblage of evidence.

METHODS

A systematic review of the technique was conducted from May 2000 to May 2023. Articles were selected based on PRISMA guidelines. Eligibility of studies was independently by 2 reviewers, with disagreements resolved by a third author.

RESULTS

Nineteen primary references comprising 337 patients with TOLF who underwent endoscopic posterior decompression were included in the systematic review. Mean follow-up time across all studies ranged from 8.9 to 65.3 months. Mean age ranged from 51.2 to 63 years, with mean intraoperative blood loss ranging from 15 to 62 mL. There is significant improvement in visual analog scale (VAS) score, VAS back, VAS leg, modified Japanese Orthopaedic Association score, and Oswestry Disability Index compared with preoperative recorded values across all studies, with low rates of complications reported.

CONCLUSIONS

Endoscopic posterior spinal decompression is a safe and effective technique for treatment of TOLF, with a low rate of complications and improvement in pain and function.

Preoperative Magnetic Resonance Imaging Signal Intensity Classification Is Associated With Clinical Presentation and Surgical Outcomes in Myelopathy Caused by Thoracic Ossification of Ligamentum Flavum: A Multicenter Study

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

To explore whether classification of the increased signal intensity (ISI) on magnetic resonance imaging (MRI) correlates with clinical presentations and outcomes in symptomatic thoracic ossification of ligamentum flavum (T-OLF) patients.

METHODS

All patients with symptomatic T-OLF who underwent laminectomy at four institutions were reviewed. The ISI on preoperative T2-weighted MRI was divided into 3 groups, Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). Neurological function before surgery and at follow-up was evaluated by the revised Japanese Orthopedic Association (JOA) score. Patients' demographics, clinical manifestations, and surgical outcomes were compared.

RESULTS

A total of 94 patients were involved. Preoperative MRI showed 32 patients in Grade 0, 39 patients in Grade 1, and 23 patients in Grade 2. Low extremities numbness, weakness, and clinical signs were less frequent in Grade 0 patients. The grade of ISI was correlated with the duration of symptoms and cord compression. Grade 0 patients had a better preoperative JOA score than those with ISI changes, while Grade 2 patients showed worse neurological recovery, longer duration of operation, more intraoperative blood loss, and a higher incidence of perioperative complications.

CONCLUSION

The classification of ISI is an effective parameter for preoperatively assessing cord compression, clinical severity, and surgical outcomes in T-OLF patients. Grade 0 patients have relatively mild neurological impairment but are more likely to be misdiagnosed. Grade 2 indicates the worst clinical impairment and neurological recovery, and implies a risky and challenging surgery.

Significance of body mass index on thoracic ossification of the ligamentum flavum in Chinese population

PURPOSE

To investigate the risk factors for thoracic ossification of the ligamentum flavum (TOLF), especially the relationship between BMI and TOLF.

METHODS

A total of 856 individuals consisting of 326 controls without ossification of spinal ligaments and 530 TOLF inpatients who underwent thoracic spine decompression surgery at our hospital between January 2013 and September 2020 were included. All subjects were classified into 4 grades: Grade 0) control; Grade 1) single-segment TOLF; Grade 2) multi-segment TOLF; and Grade 3) TOLF combined thoracic ossification of the posterior longitudinal ligament (T-OPLL). Logistic regression analysis was performed to identify the risk factors for TOLF. The TOLF index was calculated to assess the severity of TOLF, and its relationship with BMI was investigated by correlation analysis.

RESULTS

Overall, TOLF patients are most numerous in the 50-59 age group. Age and gender were considered as independent risk factors for Grades 1 and 2. BMI was identified as an independent risk factor for TOLF. Furthermore, BMI was significantly higher in Grade 1 (26.1 VS 24.5 kg/m², P = 0.0001), Grade 2 (28.2 VS 24.5 kg/m², P < 0.0001), and Grade 3 (29.1 VS 24.5 kg/m², P < 0.0001) than Grade 0. Notably, in TOLF patients without combined T-OPLL, BMI was positively correlated with TOLF index, while BMI was negatively correlated with age in younger individuals.

CONCLUSION

BMI is a crucial risk factor for TOLF. It highlights the necessity of close follow-up of asymptomatic TOLF patients with high BMI to detect and treat their TOLF progression promptly.

Unilateral biportal endoscopic decompression for symptomatic thoracic ossification of the ligamentum flavum: a case control study

PURPOSE

Thoracic ossification of the ligamentum flavum (OLF) is an uncommon disease that mostly occurs in East Asians. Laminectomy is often considered when patients develop neuro-related symptoms but may associate with treatment-related complications. This study aimed to evaluate the efficacy and safety of unilateral biportal endoscopic (UBE) decompression treatment in patients with symptomatic OLF.

METHODS

From January 2020 to January 2021, patients with spinal cord compression symptoms and imaging-defined single-level thoracic OLF were enrolled in this study and received UBE decompression treatment. Their pre- and postoperative neurological statuses were evaluated by the modified Japanese Orthopaedic Association (mJOA) score, Visual Analog Scale (VAS) for leg pain, and Frankel grade.

RESULTS

Fourteen patients with an average age of 59.4 years were enrolled in the study. The mean operation time was 66.1 ± 15.4 minutes. Patients were followed up for at least one year after receiving the treatment. Our data suggested that their mJOA score (preop 6.2 ± 1.2, 1 year 8.5 ± 0.9; P < 0.001) and VAS score (preop 4.5 ± 2.0, 1 year 0.5 ± 0.9; P < 0.001) were significantly improved compared with that before operation. Cerebrospinal fluid leakage occurred in one patient, head and neck pain occurred in two patients, and hyperalgesia of lower limbs occurred in two patients. All these complications did not cause serious consequences.

CONCLUSION

This primary study indicated that the UBE decompression treatment can achieve satisfactory clinical results in patients with thoracic OLF at single level and provide an alternative treatment option.

Ossified Ligamentum Flavum: Epidemiology, Treatment, and Outcomes

Ossification of the ligamentum flavum (OLF) is an uncommon but potentially serious spinal condition which can cause progressive compression of the spinal canal with associated devastating neurologic compromise. Although debate exists regarding the exact etiology of OLF, overexpression of genes and transcription factors centered around the Notch and Wnt signaling pathways because of increased mechanical stress seems to be related. There are many clinical and radiographic presentations of OLF; however, progressive myelopathy is the most commonly encountered. Radiographic analysis may reveal isolated OLF or OLF combined with ossification of other areas of the spine, such as disk, posterior longitudinal ligament, and dura. When surgery is necessary for OLF, several surgical strategies exist including open laminectomy with excision, endoscopic decompression, Bridge Crane resection, en block resection, and combined anterior and posterior approaches. Resection may be complicated by dural adhesion or dural ossification, and postoperative neurologic deficits are not uncommon.

Clinical Efficacy of Endoscopic-Assisted Resection of Single-Segment Ossification of the Posterior Longitudinal Ligament in the Treatment of Thoracic Spinal Stenosis

Objective

To explore the clinical efficacy, characteristics and safety of endoscopic-assisted resection of single-segment posterior longitudinal ligament ossification in the treatment of thoracic spinal stenosis (TSS).

Method

Fifteen TSS patients, including 6 males and 9 females aged 43–70 years treated with endoscopic-assisted resection of single-segment posterior longitudinal ligament ossification through the transfacet joint approach by our team from November 2016 to June 2020 were retrospectively analyzed. The operation time, intraoperative blood loss, and postoperative complications were recorded. The VAS score, ODI and JOA score (full score, 11 points) were recorded before the operation, after the operation and at the last follow-up to evaluate the clinical efficacy and calculate the improvement rate.

Results

The ventral side of the spinal cord was decompressed in all patients, providing improvements in neurological symptoms and significant pain relief. The mean follow-up time was 20.27 ± 3.87 months. Mean operation time, intraoperative blood loss, and hospitalization time were found to be 84.80 ± 13.23 min, 36.33 ± 7.41 mL, 5.13 ± 1.02 days; respectively.The JOA score at the last follow-up was 8.6 ± 1.25, which was significantly better than the preoperative (5.53 ± 1.20) and postoperative (6.87 ± 1.31) scores (p < 0.05). The mean JOA score improvement rate was 56.5 ± 18.00%. The JOA score improvement rate classification at the last follow-up was excellent in 3 cases, good in 8 cases, effective in 3 cases, and no change in 1 case; for an effective rate of 93.33%. The VAS score significantly decreased from 6.67 ± 1.01 preoperatively to 3.47 ± 0.88 postoperatively and 1.73 ± 0.67 at the last follow-up (p < 0.05). The ODI significantly decreased from 72.07 ± 6.08 preoperatively to 45.93 ± 5.01 postoperatively and 12.53 ± 2.33 at the last follow-up (p < 0.05). Dural rupture occurred in 2 patients during the operation; 1 patient experienced neck discomfort during the operation, which was considered to be caused by high fluid pressure and was relieved by massage and by lowering the height of the irrigation fluid. No cases of cerebrospinal fluid leakage, wound infection or other complications occurred.

Conclusion

Endoscopic-assisted resection of posterior longitudinal ligament ossification through the facet joint approach is a safe and effective method for the treatment of TSS.

Clinical Efficacy of Posterior Percutaneous Endoscopic Unilateral Laminotomy with Bilateral Decompression for Symptomatic Cervical Spondylotic Myelopathy

Objective

To compare the clinical efficacy of posterior percutaneous endoscopic unilateral laminotomy (PPEUL) and anterior cervical decompression and fusion (ACDF) in the treatment of single‐segment spondylotic myelopathy (CSM).

Methods

This is a retrospective research, from January 2017 to December 2019, 30 cases were included in the PPEUL group and 32 cases were included in the ACDF group. The operative duration, blood loss, length of stay, complications, Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score, MacNab classification and imaging data were collected preoperatively, postoperative 1‐week, final follow‐up and statistically analyzed.

Results

The surgery was completed successfully on all patients, and there were no serious complications, such as nerve or spinal cord injury or infection. In the PPEUL and ACDF groups, the operative duration were 56.63 ± 1.40 and 65.21 ± 2.45 min, the intraoperative blood loss were 51.69 ± 3.23 and 50.51 ± 5.48 mL, and the hospitalization duration was 5.75 ± 1.43 and 6.38 ± 2.16 days. The follow‐up period in the PPEUL and ACDF groups was 24.96 ± 1.12 months and 25.65 ± 1.45 months, respectively. There was no significant difference in intraoperative blood loss between the two groups, but the hospitalization and operative durations in the PPEUL group were significantly shorter than those in the ACDF group (P < 0.05). The VAS scores at postoperative 1 week and final follow‐up were significantly improved compared with those before surgery. The JOA scores at postoperative 1 week and final follow‐up were significantly improved compared with those before surgery, but there was no significant difference between the two groups at the last follow‐up. The intervertebral disc height of the adjacent segment at the last follow‐up was significantly lower in the ACDF group than in the PPEUL group (P < 0.05), but there was no significant difference between the two groups in the intervertebral disc height of the surgical segment (P > 0.05). The rate of excellent and good results was 90.0% and 87.5%, respectively. Postoperative cervical CT and MRI showed that the spinal canal was fully decompressed and spinal cord compression was relieved.

Conclusion

PPEUL has the advantages of reduced trauma, rapid recovery and remarkable curative efficacy, so it is a new choice for the treatment of CSM.

Comparative Clinical and Radiographic Cohort Study: Uniportal Thoracic Endoscopic Laminotomy With Bilateral Decompression by Using the 1-Block Resection Technique and Thoracic Open Laminotomy With Bilateral Decompression for Thoracic Ossified Ligamentum Flavum

BACKGROUND

Symptomatic thoracic myelopathy secondary to thoracic ossified ligamentum flavum (OLF) often requires decompression spinal surgery.

OBJECTIVE

To compare clinical and radiological outcomes in uniportal endoscopic vs open thoracic decompression for thoracic OLF.

METHODS

Retrospective evaluation of patients who underwent uniportal thoracic endoscopic unilateral laminotomy with bilateral decompression (TE-ULBD) by using the one-block resection technique compared with thoracic open laminotomy (TOL) with bilateral decompression. Radiological outcomes in MRI scan and clinical charts were evaluated.

RESULTS

Thirty-five levels of TE-ULBD were compared with 24 levels of TOL. The overall complication rate of TOL was 15% while TE-ULBD was 6.5%. Both TOL and TE-ULBD cohort had significantly improved their visual analog scale (VAS), Oswestry Disability Index, and Japanese Orthopaedic Association (JOA) myelopathy score after operation. Comparative analysis of TE-ULBD performed statistically and significantly better than TOL in improvement of final VAS and JOA scores. The mean difference ± standard deviation of VAS and JOA improvement in final follow-up when compared with preoperative state of TE-ULBD and TOL was 0.717 ± 0.131 and 1.03 ± 0.2, respectively, P < .05. The mean Hirabayashi recovery rates were 94.5% (TE-ULBD) and 56.8% (TOL). There was no statistical difference in change in preoperative and final Oswestry Disability Index and MRI volume at upper endplate, middisk, and lower endplate canal cross-sectional area.

CONCLUSION

Uniportal TE-ULBD achieved significantly improved pain and neurological recovery with sufficient spinal canal decompression, as compared with thoracic open laminectomy for patients with myelopathy secondary to OLF in our cohort.

Comparison of percutaneous endoscopic thoracic decompression and posterior thoracic laminectomy for treating thoracic ossification of the ligamentum flavum: a retrospective study

Background

Thoracic spinal stenosis (TSS) caused by ossification of the ligamentum flavum (OLF) is generally treated by surgical decompression. In this study, we compared the efficacy and safety of percutaneous endoscopic thoracic decompression (PETD) and posterior thoracic laminectomy (PTL) for treating thoracic ossification of the ligamentum flavum (TOLF).

Methods

Twenty consecutive patients with TSS caused by TOLF who were treated between April 2016 and May 2020 were included in this retrospective study. They were divided into the PETD (n = 11) and PTL (n = 9) groups. The mean follow-up period was 19.6 months. The visual analogue scale (VAS) score, the modified Japanese Orthopedic Association (mJOA) score and the recovery rate (RR) were used to evaluate the clinical outcomes.

Results

There were significant differences between PETD group and PTL group in operative time (min) (95.0 ± 18.8 vs 131.1 ± 19.0), postoperative drainage (mL) (20.2 ± 7.9 vs 586.1 ± 284.2), hospital stay (days) (4.4 ± 1.2 vs 10.4 ± 2.6) (P < 0.05 for all). However, both groups had similar and significant improvement in VAS and mJOA scores. The RR of two groups achieved the same improvement (81.8% VS 77.8%, P > 0.05).

Conclusions

The use of PETD and PTL for treating TOLF both achieved favorable outcomes. PETD is both minimally invasive and achieves similar postoperative symptom relief to PTL. Therefore, PETD could be considered as an effective alternative to traditional open surgery for TOLF in single-segment lower thoracic spine.

How i do it: biportal endoscopic thoracic decompression for ossification of the ligamentum flavum

BACKGROUND

Currently, decompressive laminectomy with or without concomitant fusion is a standard treatment for ossification of the ligamentum flavum (OLF). However, conventional thoracic decompressive laminectomy is not free of the inevitable destruction of the posterior ligamentous complex, and facet injury may lead to various sequelae.

METHOD

We used the biportal endoscopic technique for posterior thoracic decompression (BE-PTD) and describe the steps with discussion regarding the indications, advantages, possible complications, and ways to overcome complications.

CONCLUSION

BE-PTD can obtain endoscopic visualizations of all the boundaries of the OLF lesion and achieve direct neural decompression of thoracic OLF.

Thoracic ossification of the ligamentum flavum causing acute myelopathy in a patient with cervical ossification of the posterior longitudinal ligament: illustrative case

BACKGROUND

Ossification of the ligamentum flavum (OLF) has been well characterized as a distinct entity but also in tandem with ossification of the posterior longitudinal ligament (OPLL) in noncontiguous spinal regions. The majority of OLF cases are reported from East Asian countries where prevalent, but such cases are rarely reported in the North American population.

OBSERVATIONS

The authors present a case of a Thai-Cambodian American who presented with symptomatic thoracic OLF in tandem with asymptomatic cervical OPLL. A “floating” thoracic laminectomy, resection of OLF, and partial dural ossification (DO) resection with circumferential release of ossified dura were performed. Radiographic dural reexpansion and spinal cord decompression occurred despite the immediate intraoperative appearance of persistent thecal sac compression from retained DO.

LESSONS

Entire spinal axis imaging should be considered for patients with spinal ligamentous ossification disease, particularly in those of East Asian backgrounds. A floating laminectomy is one of several surgical approaches for OLF, but no consensus approach has been clearly established. High surgical complication rates are associated with thoracic OLF, most commonly dural tears/cerebrospinal fluid (CSF) leaks. DO commonly coexists with OLF, is recognizable on computed tomographic scans, and increases the risk of CSF leaks.

Thoracic full-endoscopic unilateral laminotomy with bilateral decompression for treating ossification of the ligamentum flavum with myelopathy

Background

The aim of the present study was to evaluate the curative effect and safety of thoracic full-endoscopic unilateral laminotomy with bilateral decompression (TE-ULBD) for treating ossification of the ligamentum flavum (OLF) with myelopathy.

Methods

Between January 2015 and December 2018, 23 consecutive patients with symptomatic thoracic OLF were treated with TE-ULBD. Of these, 21 (13 women and 8 men, aged 49-75 years) were included in the study and followed up for a minimum of 1 year. The mean blood loss was 15.48 mL (10-30 mL), operative duration was 78.86 min (55-115 min), and hospitalization was 5.05 days (3-15 days). The Japanese Orthopaedic Association (JOA) was used to evaluate spinal cord function, and the curative effect was defined by the JOA improvement rate. The area of OLF (AOLF), the maximum spinal cord compression (MSCC), and the area of spinal cord (ASC) were used to evaluate OLF clearance and spinal cord decompression status.

Results

At the final follow up,the JOA score was 8.33 points (5-11 points), which was a significant improvement from the preoperative 5.33 points (3-9 points, P<0.01). The excellent and good rate was 76.19% (16/21). The average preoperative AOLF and AOLF ratio were 85.27±23.66 mm² and 57.86%±11.86%, respectively, and the postoperative AOLF and AOLF ratio were 16.27±11.75 mm² and 8.13%±5.38%, respectively. The MSCC increased from 27.99%±13.51% preoperatively to 48.02%±6.66% postoperatively. The ASC was 42.90±10.60 mm² preoperatively and 64.54±21.36 mm² postoperatively. There were statistically significant differences in all parameters preoperatively and postoperatively (P<0.01). One case had postoperative hematoma, and the symptoms gradually eased after 3 weeks of conservative treatment. There were no other complications. No recurrence of OLF was detected during the follow-up period.

Conclusions

TE-ULBD is safe and effective for thoracic OLF with the advantages of reduced trauma and bleeding, and faster recovery.

Percutaneous Endoscopic Unilateral Laminotomy and Bilateral Decompression for Lumbar Spinal Stenosis

To introduce a new surgery, percutaneous endoscopic unilateral laminotomy and bilateral decompression (Endo-ULBD) using visual trepan, and investigate its efficacy and safety in elderly patients with lumbar spinal stenosis. In our retrospective study, a total of 69 patients were enrolled between March 2018 and September 2018; 31 patients were treated with Endo-ULBD and 38 patients were treated with posterior lumbar interbody fusion surgery (PLIF). The operation time, intraoperative blood loss, and hospitalization duration were compared between the two groups. A visual analog scale (VAS) was used to evaluate the degree of pain. The Oswestry Disability Index (ODI) and European Quality of Life-5 Dimensions (EQ-5D) were used to evaluate lumbar function and quality of life, respectively. Lumbar X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were performed postoperatively at different time points. MacNab's outcome assessment and perioperative complications were also documented. The surgeon completed all surgeries successfully, and all 69 patients were followed up. The operative time of the Endo-ULBD group was 60.68 ± 0.47 min, while that of the PLIF group was 120.23 ± 10.24 min. The operative time of the Endo-ULBD group was shorter than that of the PLIF group, and the difference was statistically significant (P < 0.001). The volume of intraoperative blood loss was 47.25 ± 0.43 mL in the Endo-ULBD group and 256.90 ± 20.83 mL in the PILF group (P < 0.001). The length of hospital stay in the Endo-ULBD group was 5.12 ± 1.60 days and that in the PILF group was 10.54 ± 1.82 days (P < 0.001). The VAS scores at postoperative 1 day, 3 months, 6 months, final follow-up (Endo-ULBD: 6.58 ± 0.65, 4.55 ± 0.54, 2.78 ± 0.24, 1.31 ± 0.78; PLIF: 7.19 ± 1.14, 4.80 ± 0.13, 2.71 ± 0.83, 1.29 ± 0.56) were significantly improved compared with those before surgery (Endo-ULBD: 8.63 ± 0.37; PLIF: 8.31 ± 1.34). The ODI and EQ-5D scores of lumbar function and quality of life at each time point after surgery (Endo-ULBD ODI: 30.29% ± 0.47%, 23.35% ± 0.95%, 19.45% ± 0.81%, 10.84% ± 0.36%; EQ-5D: 0.38 ± 0.15, 0.45 ± 0.17, 0.63 ± 0.14, 0.71 ± 0.20; PLIF ODI: 33.56% ± 1.58%, 25.69% ± 2.69%, 20.01% ± 1.49%, 10.72% ± 0.29%; EQ-5D: 0.33 ± 0.03, 0.39 ± 0.05, 0.62 ± 0.07, 0.72 ± 0.10) were significantly improved compared with those before surgery (Endo-ULBD: 44.56 ± 1.32, 0.33 ± 0.07; PLIF: 43.79 ± 1.91, 0.31 ± 0.09, respectively), with statistically significant differences (P < 0.05); however, there was no significant difference between the two groups at the last follow-up (P > 0.05). At the last follow-up, the excellent and good efficacy rate was 90.3% (28/31) in the Endo-ULBD group and 89.4% (34/38) in the PILF group (χ² = 0.089, P = 0.993). No mortality, irreversible nerve injury, or even paralysis occurred in either group. Endo-ULBD for lumbar spinal stenosis has the advantages of less trauma, a shortened operation time, and rapid recovery and is an effective alternative for the treatment of lumbar spinal stenosis. Strict surgical indications, reasonable surgical plans, and experienced surgeons are important factors to ensure safety and satisfactory postoperative efficacy.

Full-endoscopic decompression for thoracic myelopathy caused by ossification of the ligamentum flavum: patient series

BACKGROUND

This study aimed to describe the least invasive surgical technique of endoscopic decompression for thoracic myelopathy caused by ossification of the ligamentum flavum (OLF) and to review the literature available on the diagnosis and treatment of OLF.

OBSERVATIONS

The mean age of the patients was 51.2 (range, 40–62) years, and the mean preoperative, 2-week postoperative, and last follow-up modified Japanese Orthopaedic Association scores were 6.6 (range, 4–10), 9.6 (range, 7–11), and 13 (range, 10–14), respectively. All patients were discharged within 48 hours after the surgery. The mean follow-up period was 13.2 (range, 7–18) months. No complication was found perioperatively, and none of the patients had postoperative instability during the follow-up period.

LESSONS

Based on this clinical case series and literature review, the authors conclude that endoscopic decompression surgery is feasible and effective for managing thoracic myelopathy caused by OLF while minimizing surrounding tissue damage. Additionally, it enables shorter periods of hospital stay.

Full endoscopic surgery for thoracic pathology: an assessment of supportive evidence

In the last five years, surgeons have applied endoscopic transforaminal surgical techniques mastered in the lumbar spine to the treatment of thoracic pathology.

The aim of this systematic review was to collate the available literature to determine the place and efficacy of full endoscopic approaches used in the treatment of thoracic disc prolapse and stenosis.

An electronic literature search of PubMed, Embase, the Cochrane database and Google Scholar was performed as suggested by the Preferred Reporting Items for Systematic Review and Meta-analysis statements. Included were any full-text articles referring to full endoscopic thoracic surgical procedures in any language.

We identified 17 patient series, one cohort study and 13 case reports with single or of up to three patients.

Although the majority included disc pathology, 11 papers related cord compression in a proportion of cases to ossification of the ligamentum flavum or posterior longitudinal ligament. Two studies described the treatment of discitis and one reported the use of endoscopy for tumour resection.

Where reported, excellent or good outcomes were achieved for full endoscopic procedures in a mean of 81% of patients (range 46–100%) with a complication rate of 8% (range 0–15%), comparing favourably with rates reported after open discectomy (anterior, posterolateral and thoracoscopic) or by endoscopic tubular assisted approaches. Twenty-one of the 31 author groups reported use of local anaesthesia plus sedation rather than general anaesthesia, providing ‘self-neuromonitoring’ by allowing patients to respond to cord and/or nerve stimuli.

Cite this article: EFORT Open Rev 2021;6:50-60. DOI: 10.1302/2058-5241.6.200080

Microendoscopic Posterior Decompression for Treating Thoracic Myelopathy Caused by Ossification of the Ligamentum Flavum: Case Series

Background and Objectives: Ossification of the ligamentum flavum (OLF) is a relatively common cause of thoracic myelopathy. Surgical treatment is recommended for patients with myelopathy. Generally, open posterior decompression, with or without fusion, is selected to treat OLF. We performed minimally invasive posterior decompression using a microendoscope and investigated the efficacy of this approach in treating limited type of thoracic OLF. Materials and Methods: Microendoscopic posterior decompression was performed for 19 patients (15 men and four women) with thoracic OLF with myelopathy aged between 35 to 81 years (mean age, 61.9 years). Neurological examination and preoperative magnetic resonance imaging (MRI) and computed tomography (CT) were used to identify the location and morphology of OLF. The surgery was performed using a midline approach or a unilateral paramedian approach depending on whether the surgeon used a combination of a tubular retractor and endoscope. The numerical rating scale (NRS) and modified Japanese Orthopedic Association (mJOA) scores were compared pre- and postoperatively. Perioperative complications and the presence of other spine surgeries before and after thoracic OLF surgery were also investigated. Results: Four midline and 15 unilateral paramedian approaches were performed. The average operative time per level was 99 min, with minor blood loss. Nine patients had a history of cervical or lumbar spine surgery before or after thoracic spine surgery. The mean pre- and postoperative NRS scores were 6.6 and 5.3, respectively. The mean recovery rate as per the mJOA score was 33.1% (mean follow-up period, 17.8 months), the recovery rates were significantly different between patients who underwent thoracic spine surgery alone (50.5%) and patients who underwent additional spine surgeries (13.7%). Regarding adverse events, one patient experienced dural tear, another experienced postoperative hematoma, and one other underwent reoperation for adjacent thoracic stenosis. Conclusion: Microendoscopic posterior decompression was applicable in limited type of thoracic OLF surgery including beak-shaped type and multi vertebral levels. However, whole spine evaluation is important to avoid missing other combined stenoses that may affect outcomes.

Full-endoscopic decompression for thoracic ossification of ligamentum flavum: surgical techniques and clinical outcomes: A retrospective clinical study

BACKGROUND

Many complications are associated with thoracic open decompression surgery, such as dural tears and neurological deficits. The clinical outcomes are also not satisfactory. Full-endoscopic decompression of the lumbar spinal canal has achieved satisfactory results for the treatment of lumbar spinal stenosis. This surgery may be used for the treatment of thoracic ossification of the ligamentum flavum (OLF) under local anesthesia. The aim of our study is to introduce the surgical techniques used for full-endoscopic decompression for thoracic OLF and to evaluate its safety and efficacy.

METHODS

Fourteen patients with thoracic OLF (4 combined with dural ossification) underwent full-endoscopic decompression surgery. An interlaminar approach was performed. The anchoring method was used to establish the working passage. Spinal cord exposure began at a space between the ossification and the spinal cord, and dorsal and contralateral decompression were performed with the "Over the Top" technique. The modified Japanese Orthopedic Association score (11 points) was used to evaluate the efficacy during follow-up. At the same time, the visual analogue scale score for assessing back pain before and after the operation was evaluated.

RESULTS

The average operation time was 159.73 ± 62.09 minutes, and the hospitalization time was 7.43 ± 1.79 days. The follow-up period ranged from 8 to 22 months. Neurological function was improved. There were no serious complications. Dural tears occurred in 5 patients, intraoperative neurological deterioration occurred in 1 patient, and intraoperative headache and neck pain occurred in 1 patient.

CONCLUSION

Full-endoscopic decompression is an effective, safe surgical technique for thoracic OLF even the cases combined with dural ossification.

The Evolution of Transforaminal Endoscopic Spine Surgery

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

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

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

Full-Endoscopic Spine Surgery for the Treatment of Lumbar Ossification of the Ligamentum Flavum: Technical Report

BACKGROUND

Ossification of the ligamentum flavum (OLF) is a relatively common disease in East Asia. Although surgical decompression using a posterior approach is commonly used to treat OLF, there are several different treatment strategies. The purpose of this study is to clarify the technically important points for the treatment of OLF using full-endoscopic spine surgery (FESS).

METHODS

FESS was performed on 7 patients with lumbar OLF. Patients had a mean age of 62.3 years and single-level involvement. Computed tomography and magnetic resonance imaging were used to classify the OLF. Two different types of spinal endoscope were used for posterior decompression. Interlaminal and translaminal approaches were performed in 6 and 1 patient, respectively. Preoperative and postoperative pain was evaluated using the numeric rating scale score.

RESULTS

The mean operation time was 84.1 minutes. Unilateral round-type OLF was treated using a 4.1-mm working channel endoscope. The bilateral type was treated using a 6.4-mm working channel endoscope. A dural tear occurred in 1 patient with beak-type OLF, but no symptoms resulting from the tear were observed. The mean preoperative and postoperative numeric rating scale scores were 7.7 and 1.6, respectively.

CONCLUSIONS

Posterior decompression using FESS can be used to treat patients with lumbar OLF. Unilateral round-type OLF with ipsilateral radiculopathy can be treated using a 4.1-mm working channel endoscope. Bilateral-type OLF with cauda equina symptoms should be treated using a 6.4-mm working channel endoscope.

Ossification of the ligamentum flavum in the upper cervical spine: A report of two cases and literature review

Ossification of the ligamentum flavum (OLF) is rarely observed in the cervical spine, particularly not in the upper cervical spine. The present report describes two cases of OLF combined with cervical myelopathy and provides a literature review with a comparative analysis of previous studies and the present cases. Pre-operative CT, MRI and histological examination were performed to confirm the diagnosis of these patients (A 37-year-old female and 63-year-old male). In both cases, histological examination of surgical specimens revealed OLF. The symptoms of the two patients significantly improved after surgery and no recurrence was observed at 13 months after surgery. Furthermore, the clinical outcomes were satisfactory and the internal fixation was solid in the two cases. Review of the literature suggested that further research is required to reveal the optimal treatment methods for upper cervical OLF.

Surgical results and prognostic factors following percutaneous full endoscopic posterior decompression for thoracic myelopathy caused by ossification of the ligamentum flavum

Minimally invasive surgery (MIS) has shown satisfactory surgical results for the treatment of thoracic myelopathy (TM) caused by ossification of the ligamentum flavum (OLF). This study investigated the prognostic factors following MIS and was based on the retrospective analysis of OLF patients who underwent percutaneous full endoscopic posterior decompression (PEPD). Thirty single-segment OLF patients with an average age of 60.4 years were treated with PEPD under local anaesthesia. Clinical data were collected from the medical and operative records. The surgical results were assessed by the recovery rate (RR) calculated from the modified Japanese Orthopaedic Association (mJOA) score. Correlations between the RR and various factors were analysed. Patients’ neurological status improved from a preoperative mJOA score of 6.0 ± 1.3 to a postoperative mJOA score of 8.5 ± 2.0 (P < 0.001) at an average follow-up of 21.3 months. The average RR was 53.8%. Dural tears in two patients (6.7%, 2/30) were the only observed complications. Multiple linear regression analysis showed that a longer duration of preoperative symptoms and the presence of a high intramedullary signal on T2-weighted MRI (T2HIS) were significantly associated with poor surgical results. PEPD is feasible for the treatment of TM patients with a particular type of OLF. Patients without T2HIS could achieve a good recovery if they received PEPD early.