Derivation and comprehensive analysis of ageing-related genes in intervertebral disc degeneration for prediction and immunology

Intervertebral disc degeneration (IDD) is triggered primarily by ageing, a process characterized by intrinsic, multifaceted and progressive characteristics. Regarding the crucial senescence genes and underlying regulatory mechanisms leading to the etiology of IDD, there is still some uncertainty. In this study, we used gene expression patterns from the GEO database to create a diagnostic model of IDD using differential ageing-related genes (DARG). We examine the relative dynamics of immune cells by single-sample gene set. On the basis of transcription factor (TF) miRNA and miRNA-mRNA pairs, the regulatory network for transcription and post-transcriptional processes was built. The active therapeutic components and Chinese herbal remedies of the main ageing genes were investigated using a network pharmacology approach. 20 DARGs were combined to create a diagnostic model, and both the training and validation sets had an area under the ROC curve of 1. We found alterations in many cell types in IDD tissue, but mainly in activated dendritic cells, type 17 T helper cells, and mast cells. We identified a regulatory axis for STAT1/miR-4306/PPARA based on the correlations between gene expression and targeting. Active substances (Naringenin and Quercetin) and herbs (Aurantii fructus and Eucommiae cortex) targeting PPARA for the treatment of IDD were discovered through network pharmacology. These results provide a theoretical framework for identifying and treating IDD. For the first time, we were able to diagnose IDD patients using 20 ageing-related indicators. At the same time, TF-miRNA-mRNA in conjunction with network pharmacology enabled the identification of prospective therapeutic targets and pharmacological processes.

Postoperative Upper-limb Palsy After Posterior Percutaneous Endoscopic Cervical Foraminotomy and Discectomy

BACKGROUND

Postoperative upper-limb palsy (ULP) is a serious complication after cervical spine surgery. ULP after posterior percutaneous endoscopic cervical foraminotomy and discectomy (PPCED) has not yet been reported.

OBJECTIVE

To introduce cases of postoperative ULP after PPCED and associated risk factors.

STUDY DESIGN

A single-center, retrospective, observational study.

SETTING

Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China.

METHODS

From January 2016 through January 2022, PPCED involving a total of 663 segments was performed in 610 patients with radiculopathy who were diagnosed with cervical radiculopathy or mixed cervical spondylosis caused by foraminal stenosis or posterolateral disc herniation.

RESULTS

PPCED was successfully completed in 610 patients, 6 of whom (0.98%) developed ULP. Two patients were diagnosed with double-segment cervical nerve root canal stenosis (C4/5/6, C5/6/7) and 2 with migrated cervical disc soft herniation (a magnetic resonance image of one showed a migrated disc herniation downward from C4/5 in the sagittal plane; another showed this upward from C5/6); one patient was diagnosed with C5/6 intervertebral foraminal stenosis, and one had simple C4/5 lateral disc herniation. Postoperative ULP rates for C4/5 (2/30, 6.67%) and C5/6 (2/177, 1.13%) were much higher than those for the other levels. Anatomically, the width of the intervertebral foramen on computed tomography was 2.3 ± 1.12 mm in ULP cases, which was significantly lower than that in non-ULP cases (3.4 ± 1.83, P < 0.05). This suggests that preoperative foramen width correlates highly negatively with postoperative ULP incidence.

LIMITATIONS

This was a single-center, retrospective, nonrandomized study with a low level of evidence.

CONCLUSIONS

PPCED is a good treatment for cervical radiculopathy. The rate of postoperative ULP after PPCED is much lower than that after posterior cervical foraminotomy. Perturbation to the C5 (or C6) nerve root, thermal injury due to burr use or the radiofrequency applied, and marked foraminal stenosis are possible relevant factors associated with postoperative ULP.

Effect of species, concentration and volume of local anesthetics on intervertebral disk degeneration in rats with discoblock

PURPOSE

Discoblock is effective in relieving discogenic low back pain, but it can also cause intervertebral disk degeneration (IDD). The effect of species, concentration and volume of local anesthetics on IDD with discoblock have not been reported. The purpose was to study the effect of species, concentration and volume of local anesthetics on IDD in rats undergoing discoblock.

METHODS

The effects of local anesthetics on nucleus pulposus cell (NPC) viability in vitro were studied. NPCs were exposed to lidocaine, bupivacaine and ropivacaine at different concentrations. NPC viability was measured. The least cytotoxic local anesthetic was used in vivo. The concentration and volume of local anesthetics on IDD in rat with discoblocks were tested in vivo. Detection indicators included X-ray, MRI, water content of the disk and histological changes.

RESULTS

The toxicity of local anesthetics to NPCs was dose and time dependent, and the cytotoxicity of different local anesthetics was different. Among the three local anesthetics, ropivacaine was the least toxic to NPCs. The effect of ropivacaine concentration on IDD was not significant, as detected by X-ray, MRI, disk water content and histology (P < 0.05). The volume of ropivacaine has a significant effect on IDD, as supported by X-ray, MRI, disk water content and histology (P < 0.05). Acupuncture itself significantly increased IDD, as detected by MRI, disk water content and histology (P < 0.05).

CONCLUSION

Ropivacaine should be selected for its low cytotoxicity. A lower volume and slow injection speed should be used to reduce IDD during discoblock.

Oblique lateral interbody fusion stand-alone vs. combined with percutaneous pedicle screw fixation in the treatment of discogenic low back pain

Objective

Oblique lateral interbody fusion (OLIF) has unique advantages in the treatment of discogenic low back pain (DBP). However, there are few studies in this area, and no established standard for additional posterior internal fixation. The purpose of this study was to investigate the efficacy of OLIF stand-alone vs. combined with percutaneous pedicle screw fixation (PPSF) in the treatment of DBP.

Methods

This retrospective case-control study included forty patients. All patients were diagnosed with DBP by discography and discoblock. Perioperative parameters (surgery duration, blood loss, and muscle damage), complications, Visual analog scale (VAS), and Oswestry Disability Index (ODI) were assessed. Imaging data including cage subsidence, cage retropulsion, fusion rate, and adjacent spondylosis degeneration (ASD) were analyzed.

Results

There were 23 patients in the OLIF stand-alone group and 17 patients in the OLIF + PPSF group. The mean surgery duration, blood loss, and muscle damage in the OLIF stand-alone group were significantly better than those in the OLIF + PPSF group (P < 0.05). However, there was no significant difference in the average hospitalization time between the two groups (P > 0.05). There was no significant difference in the VAS and ODI scores between the two groups before surgery (P > 0.05), and VAS and ODI scores significantly improved after surgery (P < 0.05). The VAS and ODI scores in the OLIF stand-alone group were significantly better than those in the OLIF + PPSF group at 1 month (P < 0.05), While there was no significant difference between the two groups at 12 months and last follow up (P > 0.05). At the last follow-up, there was no significant difference in cage subsidence, fusion rate, ASD and complication rate between the two groups (P > 0.05).

Conclusion

OLIF stand-alone and OLIF + PPSF are both safe and effective in the treatment of DBP, and there is no significant difference in the long-term clinical and radiological outcomes. OLIF stand-alone has the advantages of surgery duration, blood loss, muscle damage, and early clinical effect. More clinical data are needed to confirm the effect of OLIF stand-alone on cage subsidence and ASD. This study provides a basis for the clinical application of standard DBP treatment with OLIF.

Clinical Outcomes of Percutaneous Endoscopic Lumbar Discectomy Assisted With Sequential SNRB in Treating Lumbosacral Contiguous Double-Level Disc Herniation

BACKGROUND

For patients with lumbosacral contiguous double-level disc herniation, there has been no consensus on which level(s) should be treated. Selective nerve root block (SNRB) can identify the pain-generating nerve root; however, its diagnostic accuracy remains controversial due to potential spread of the injectate. Sequential SNRB from S1 to L5 may improve the diagnostic specificity.

OBJECTIVES

To examine the clinical and radiographic outcomes of percutaneous endoscopic lumbar discectomy (PELD) assisted with sequential SNRB from S1 to L5 in patients who had lumbosacral contiguous double-level disc herniation.

STUDY DESIGN

A retrospective design was used.

SETTING

This study was conducted in a university-affiliated tertiary hospital in Shanghai, China.

METHODS

Fifty-eight consecutive patients with lumbosacral contiguous double-level disc herniation were included (January 2018 to January 2021). Sequential SNRB from S1 to L5 was performed to identify the symptomatic level(s), followed by PELD based on the results of sequential SNRB. Clinical outcomes were assessed by the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and modified Macnab criteria. Pre- and post-operation radiologic and clinical parameters were evaluated. Demographics were retrieved from medical records.

RESULTS

Patients were followed-up with an average duration of 18.6 months. Among the 58 patients, 21 received surgical treatment at L4/L5 level, 25 at L5/S1 level, and 12 at both levels based on the results of sequential SNRB from S1 to L5. Compared with preoperative values, mean VAS scores for leg and back pain, as well as the ODI score, improved significantly after the surgery. There were no significant differences in the clinical outcomes between patients receiving surgical treatment at L4/L5, L5/S1, or both levels. According to the Macnab criteria, 49 patients (84.5%) had excellent or good results.

LIMITATIONS

This study used a retrospective design with relatively small sample size and medium follow-up duration.

CONCLUSIONS

Sequential SNRB from S1 to L5 was an effective approach to guide PELD treatment for patients with lumbosacral contiguous double-level disc herniation. Health care providers may consider using this approach to facilitate future clinical practice.

METTL3-Mediated m6A Modification of lncRNA MALAT1 Facilitates Prostate Cancer Growth by Activation of PI3K/AKT Signaling

Accumulating data show that N6-methyladenosine (m⁶A) methyltransferase METTL3 and long noncoding RNA MALAT1 act pivotal roles in multiple malignancies including prostate cancer (PCa). However, the role and molecular mechanism underlying METTL3-mediated m⁶A modification of MALAT1 in PCa remain undocumented. The association of METTL3 and MALAT1 expression with clinicopathological characteristics and prognosis in patients with PCa was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and public The Cancer Genome Atlas (TCGA) dataset. The in vitro and in vivo experiments were executed to investigate the role of METTL3 in PCa. m⁶A dot blot, methylated RNA immunoprecipitation (MeRIP), RIP, and qRT-PCR assays were employed to observe METTL3-mediated m⁶A modification of MALAT1. The effects of METTL3 on MALAT1-mediated PI3K/AKT pathway were assessed by Western blot analysis. As a result, we found that METTL3 was significantly upregulated in PCa tissues and high expression of METTL3 was associated with Gleason score and tumor recurrence in patients with PCa. Knockdown of METTL3 markedly repressed growth and invasion of PCa cells in vitro and in vivo, whereas ectopic expression of METTL3 showed the opposite effects. Moreover, knockdown of METTL3 decreased the total m⁶A levels of PCa cells as well as the MALAT1 m⁶A levels, leading to reduced MALAT1 expression. Overexpression of MALAT1 reversed METTL3 knockdown-induced antitumor effects and PI3K/AKT signaling inactivation. MALAT1 harbored a positive correlation with METTL3 expression and tumor recurrence in PCa. In conclusion, our findings demonstrate that METTL3-mediated m⁶A modification of lncRNA MALAT1 promotes growth and invasion of PCa cells by activating PI3K/AKT signaling.

Chronic Intermittent Hypoxia Reduces the Effects of Glucosteroid in Asthma via Activating the p38 MAPK Signaling Pathway

Aims

Obstructive sleep apnea (OSA) is a risk factor for steroid-resistant (SR) asthma. However, the underlying mechanism is not well defined. This study aimed to investigate how chronic intermittent hypoxia (CIH), the main pathophysiology of OSA, influenced the effects of glucocorticoids (GCs) on asthma.

Main Methods

The effects of dexamethasone (Dex) were determined using the ovalbumin (OVA)-challenged mouse model of asthma and transforming growth factor (TGF)-β treated airway smooth muscle cells (ASMCs), with or without CIH. The p38 MAPK signaling pathway activity was then detected in the mouse (n = 6) and ASMCs models (n = 6), which were both treated with the p38 MAPK inhibitor SB239063.

Key Findings

Under CIH, mouse pulmonary resistance value, inflammatory cells in bronchoalveolar lavage fluid (BALF), and inflammation scores increased in OVA-challenged combined with CIH exposure mice compared with OVA-challenged mice (p < 0.05). These indicators were similarly raised in the OVA + CIH + Dex group compared with the OVA + Dex group (P < 0.05). CIH exposure enhanced the activation of the p38 MAPK pathway, oxidative stress injury, and the expression of NF-κB both in lung tissue and ASMCs, which were reversed by treatment with Dex and SB239063. In the in vitro study, treatment with Dex and SB239063 decreased ASMCs proliferation induced by TGF-β combined with CIH and suppressed activation of the p38 MAPK pathway, oxidative stress injury, and NF-κB nuclear transcription (p < 0.05).

Significance

These results indicated that CIH decreased GC sensitivity by activating the p38 MAPK signaling pathway.

Clinical and radiological outcomes of endoscopic foraminoplasty and decompression assisted with preoperative planning software for lumbar foraminal stenosis

PURPOSE

To assess the clinical and radiological outcomes of using endoscopic foraminoplasty and decompression assisted with a preoperative planning software in the treatment of lumbar foraminal stenosis.

METHODS

This retrospective study included 43 patients with lumbar foraminal stenosis (Jan 2018 and June 2019). These patients were divided into two groups. Patients in the conventional group (group A) underwent endoscopic lumbar foraminoplasty and decompression. Patients in the experimental group (group B) underwent the same surgery assisted with a preoperative software. The total operation time, puncture-channel establishment time, and the number of intraoperative fluoroscopic images taken were recorded. The Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were administered preoperatively and postoperatively (at 1-month, 3-month, and 12-month follow-up). The modified MacNab criteria were used to assess the global outcome at 12-month follow-up.

RESULTS

Patients in group B had shorter operation time, puncture-channel establishment time, and less number of intraoperative fluoroscopic images taken, as compared with group A. The VAS and ODI scores were significantly lower than pre-operation for both groups at all follow-ups. No significant difference was observed between these two groups. Based on the modified MacNab criteria, the excellent-to-good rate was 86.4% in group A and 90.5% in group B, respectively. After the operation, no patients had residual osteophytes in group B, while two patients still had residual osteophytes and foraminal stenosis in group A.

CONCLUSION

For endoscopic surgery treating lumbar foraminal stenosis, using preoperative planning software could reduce the puncture-channel establishment time, operation time, and the number of intraoperative fluoroscopic images taken without affecting the clinical outcomes.

Clinical Outcomes of Posterior Percutaneous Endoscopic Cervical Foraminotomy and Discectomy Assisted with SNRB in Treating Cervical Radiculopathy with Diagnostic Uncertainty

BACKGROUND

Selective nerve root block (SNRB) has been used to facilitate the diagnostic process when radiologic abnormalities are not correlated with clinical symptomatology in patients with cervical radiculopathy. Meanwhile, minimally invasive posterior percutaneous endoscopic cervical foraminotomy and discectomy (PPECFD) has been widely used to treat cervical radiculopathy because of its advantages. However, combination of these 2 procedures in the treatment of cervical radiculopathy with diagnostic uncertainty has not been reported.

OBJECTIVES

To examine the clinical outcomes of PPECFD assisted with SNRB in patients who had cervical radiculopathy with diagnostic uncertainty.

STUDY DESIGN

A retrospective design was used.

SETTING

This study was conducted in a university-affiliated tertiary hospital in Shanghai, China.

METHODS

Thirty consecutive patients with cervical radicular pain who had diagnostic uncertainty were included (January 2018 to January 2019). Diagnostic SNRB was performed to identify the responsible nerve root(s). PPECFD was selected as the treatment when the SNRB result was positive. Clinical outcomes were assessed by the Visual Analog Scale (VAS), Neck Disability Index (NDI), and modified Macnab criteria. Pre- and post-operative radiologic and clinical parameters were evaluated. Other information was retrieved from the electronic records.

RESULTS

All patients had successful SNRB procedures. Four were excluded from the analysis because of the negative results of the SNRB. Among the remaining 26 patients who underwent the subsequent PPECFD surgery, the mean follow-up was 14 months. Compared with preoperative values, the mean VAS scores for radicular arm pain and neck pain, as well as the NDI score, improved significantly. According to the Macnab criteria, 22 patients (84.6%) had excellent or good results. No major peri- and postoperative complications were observed.

LIMITATIONS

This study used a retrospective design with relatively small sample size and medium follow-up duration.

CONCLUSIONS

Diagnostic SNRB may be a helpful tool to identify the origin of cervical radicular pain for patients with diagnostic uncertainty. With the guidance of SNRB, PPECFD is likely to be an effective and safe option for the treatment of cervical radiculopathy with diagnostic uncertainty.

Circular RNA_PDHX Promotes the Proliferation and Invasion of Prostate Cancer by Sponging MiR-378a-3p

The dysregulation of circular RNAs (circRNAs) is implicated in the pathogenesis of prostate cancer (PCa). However, the underlying mechanisms by which hsa_circ_0003768 (circPDHX) contributes to PCa remain elusive. The differentially expressed circRNAs between PCa and normal tissues were identified by Gene Expression Omnibus dataset. The association of circPDHX and miR-378a-3p expression with the clinicopathological parameters and prognosis in patients with PCa was analyzed by fluorescence in situ hybridization and The Cancer Genome Atlas dataset. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays as well as a xenograft tumor model were used to assess the role of circPDHX in PCa cells. circPDHX-specific binding with miR-378a-3p was validated by bioinformatic analysis, luciferase gene reporter, and RNA immunoprecipitation assays. As a result, we found that increased expression of circPDHX was associated with Gleason score (P = 0.001) and pathogenic T stage (P = 0.01) and acted as an independent prognostic factor of poor survival (P = 0.036) in patients with PCa. Knockdown of circPDHX inhibited cell proliferation and invasion in vitro and in vivo, but ectopic expression of circPDHX reversed these effects. Furthermore, circPDHX could sponge miR-378a-3p to promote cell proliferation, but miR-378a-3p counteracted circPDHX-induced cell proliferation and insulin-like growth factor 1 receptor (IGF1R) expression in PCa cells. In conclusion, our findings demonstrated that circPDHX facilitated the proliferation and invasion of PCa cells by sponging miR-378a-3p.

ESM1/HIF‑1α pathway modulates chronic intermittent hypoxia‑induced non‑small‑cell lung cancer proliferation, stemness and epithelial‑mesenchymal transition

Obstructive sleep apnea (OSA) is a sleep‑related disorder characterized by chronic intermittent hypoxia (CIH). Previous studies have found that intermittent hypoxia promotes drug resistance, cell proliferation, migration and invasion in non‑small cell lung cancer (NSCLC). Endothelial cell‑specific molecule‑1 (ESM1) is a molecule shown to be overexpressed in several types of tumors. The purpose of this study was to investigate the correlation between CIH and ESM1 and their potential roles in the progression of NSCLC. Tumorspheres, cell viability and colony formation assays were used to evaluate cell proliferation. The expression levels of cancer stem cell (CSC) markers CD44, CD133, OCT4 and SOX2 were measured with western blotting and/or RT‑qPCR. Transwell assays were applied to assess cell migration and invasion. Changes in the expression levels of epithelial‑mesenchymal transition (EMT)‑associated proteins were also detected by western blotting. The results indicated that CIH enhanced lung cancer stem cell (LCSC) NSCLC progression by promoting stemness, drug resistance, cell proliferation, migration and invasion via the ESM1/HIF‑1α pathway. Unexpectedly, inhibition of ESM1 reversed the CIH‑involved negative effects on LCSCs and in a mouse model. ESM1 therefore appears to be crucial mediator of CIH‑mediated lung cancer progression.

Deep learning-based lumbosacral reconstruction for difficulty prediction of percutaneous endoscopic transforaminal discectomy at L5/S1 level: A retrospective cohort study

BACKGROUND

Deep learning has been validated as a promising technique for automatic segmentation and rapid three-dimensional (3D) reconstruction of lumbosacral structures on CT. Simulated foraminoplasty of percutaneous endoscopic transforaminal discectomy (PETD) through the Kambin triangle may benefit viability assessment of PETD at L5/S1 level.

MATERIAL AND METHODS

Medical records and radiographic data of patients with L5/S1 lumbar disc herniation (LDH) who received a single-level PETD from March 2013 to February 2018 were retrospectively collected and analyzed. Deep learning was adopted to achieve semantic segmentation of lumbosacral structures (nerve, bone, disc) on CT, and the segmented masks on reconstructed 3D models. Two observers measured the area of the Kambin triangle on 6 selected deep learning-derived 3D (DL-3D) models and ground truth-derived 3D (GT-3D) models, and intraclass correlation coefficient (ICC) was calculated to assess the test-retest and interobserver reliability. Foraminoplasty of PETD was simulated on L5/S1 lumbosacral 3D models. Patients with extended foraminoplasty or stuck canula occurs on simulations were predicted as PETD-difficult cases (Group A). The remaining patients were regarded as PETD-normal cases (Group B). Clinical information and outcomes were compared between the two groups.

RESULTS

Deep learning-derived 3D models of lumbosacral structures (nerves, bones, and disc) from thin-layer CT were reliable. The area of the Kambin triangle was 161.27 ± 40.10 mm² on DL-3D models and 153.57 ± 32.37 mm² on GT-3D models (p = 0.206). Reliability test revealed strong test-retest reliability (ICC between 0.947 and 0.971) and interobserver reliability of multiple measurements (ICC between 0.866 and 0.961). The average operation time was 99.62 ± 17.39 min in Group A and 88.93 ± 21.87 min in Group B (P = 0.025). No significant differences in patient-reported outcomes or complications were observed between the two groups (P > 0.05).

CONCLUSION

Deep learning achieved accurate and rapid segmentations of lumbosacral structures on CT, and deep learning-based 3D reconstructions were efficacious and reliable. Foraminoplasty simulation with deep learning-based lumbosacral reconstructions may benefit surgical difficulty prediction of PETD at L5/S1 level.

Is selective nerve root block necessary for learning percutaneous endoscopic lumbar discectomy: a comparative study using a cumulative summation test for learning curve

PURPOSE

The aim of this study was to investigate the effect of lumbar spine selective nerve root block (SNRB) experience on the learning efficiency of percutaneous endoscopic lumbar discectomy (PELD) for junior trainees.

METHODS

A total of 480 patients undergoing single-level PELD performed by eight junior trainees were included. The trainees were divided into two groups based on whether they had previous SNRB experience (group A, yes; group B, no). Surgical proficiency was defined as total operation time less than 65 minutes and cumulative radiation exposure time no more than 40 seconds. The learning curve was analyzed by cumulative summation (CUSUM) test. Clinical evaluations included Macnab classification, visual analog scale (VAS)-low back score, VAS-leg score, and Oswestry Disability Index (ODI). Follow-up information at 12 months was also obtained.

RESULTS

Integral number of cases before achieving an acceptable surgical level in group A (47.75 ± 2.50 cases) was significantly smaller than that in group B (56.50 ± 1.29 cases, p < 0.05), along with less accumulated failure (18.75 ± 0.96 cases vs. 25.50 ± 1.75 cases, p < 0.05). The two groups were comparable in clinical outcomes. Forty-seven cases of complications were observed, with 17 in group A and 30 in group B (p < 0.05).

CONCLUSION

Previous experience of SNRB improved the performance of PELD with shorter operation time and less radiation exposure. SNRB practice may reduce the complication rate without a significant effect on the recurrence of symptoms and reoperation.

Two-level percutaneous endoscopic lumbar discectomy for highly migrated upper lumbar disc herniation: A case report

BACKGROUND

The technique of percutaneous endoscopic lumbar discectomy (PELD) as a transforaminal approach has been used to treat highly migrated lower lumbar disc herniations. However, due to the different anatomic characteristics of the upper lumbar spine, conventional transforaminal PELD may fail to remove the highly migrated upper lumbar disc nucleus pulposus. Therefore, the purpose of this study was to describe a novel surgical technique, two-level PELD, for the treatment of highly migrated upper lumbar disc herniations and to report its related clinical outcomes.

CASE SUMMARY

A 60-year-old male presented with a complaint of pain at his lower back and right lower limb. The patient received 3 mo of conservative treatments but the symptoms were not alleviated. Physical examination revealed a positive femoral nerve stretch test and a negative straight leg raise test for the right leg, and preoperative visual analog scale (VAS) score for the lower back was 6 points and for the right leg was 8 points. Magnetic resonance imaging (MRI) demonstrated L2-L3 disc herniation on the right side and the herniated nucleus pulposus migrated to the upper margin of L2 vertebral body. According to physical examination and imaging findings, surgery was the primary consideration. Therefore, the patient underwent surgical treatment with two-level PELD. The pain symptom was relieved and the VAS score for back and thigh pain was one point postoperatively. The patient was asymptomatic and follow-up MRI scan 1 year after operation revealed no residual nucleus pulposus.

CONCLUSION

Two-level PELD as a transforaminal approach can be a safe and effective procedure for highly migrated upper lumbar disc herniation.

Comparison of Clinical Outcomes of Two-Level PELD and Foraminoplasty PELD for Highly Migrated Disc Herniations: A Comparative Study

Objective

The aim of this study is to compare the clinical outcomes of two-level percutaneous endoscopic lumbar discectomy (PELD) and foraminoplasty PELD in treating highly migrated lumbar disc herniations.

Methods

Patients with highly migrated lumbar disc herniations were enrolled from May 2014 to June 2016. Low back pain and leg pain were evaluated by the Visual Analog Scale (VAS), and functional outcomes were assessed with the Oswestry Disability Index (ODI). The satisfaction rate of clinical outcomes was assessed according to the modified MacNab criteria. In addition, the intraoperative duration and postoperative complications were also recorded.

Results

Forty patients, 14 cases in two-level PELD group and 26 cases in foraminoplasty PELD group, were included. The VAS scores of low back pain (P=0.67) and leg pain (P=0.86), as well as the ODI scores (P=0.87), were comparative between two-level PELD and foraminoplasty PELD groups. The satisfaction rate of clinical outcomes based on the modified MacNab criteria in the two-level PELD group was equivalent to that in foraminoplasty PELD group (92.9% versus 92.3%, P=0.92). In addition, the intraoperative duration of two-level PELD group was longer than that of foraminoplasty PELD group (80.2 ± 6.6 min versus 64.1 ± 7.3 min, P < 0.01). The postoperative complications in the two-level PELD group (postoperative dysesthesia: N = 1) were relatively fewer as compared to those in the foraminoplasty PELD group (postoperative dysesthesia: N = 1; recurrence: N = 1; nucleus pulposus residues: N = 1).

Conclusions

Both two-level PELD and foraminoplasty PELD are safe and effective surgical procedures for the patients with highly migrated lumbar disc herniations. Moreover, the two-level PELD technique has merits in reducing the incidence of postoperative nucleus pulposus residue.

Feasibility of Virtual Reality Combined with Isocentric Navigation in Transforaminal Percutaneous Endoscopic Discectomy: A Cadaver Study

Objectives

Transforaminal percutaneous endoscopic discectomy (TPED) is one of the most commonly used minimally invasive spine surgeries around the world. However, conventional surgical planning and intraoperative procedures for TPED have relied on surgeons’ experience, which limits its standardization and popularization. Virtual reality (VR) is a novel technology for pre‐surgical planning in various fields of medicine, while isocentric navigation can guide intraoperative procedures for TPED. The present study aimed to explore the feasibility of applying VR combined with isocentric navigation in TPED on cadavers.

Methods

The surgical levels were L₃/L₄ and L₄/L₅ as well as L₅/S₁ of both sides of each cadaver specimen. First, the surgeon manually conducted the above procedures on the left side of every specimen without preoperative simulation and isocentric navigation (Group A). Then the same surgeon conducted the VR simulation for surgical planning of the right side (Group B). After VR simulation, the same surgeon made the percutaneous punctures and placed the working channel on the right side of the specimen at all levels.

Results

At the L₃/L₄ level, the puncture‐channel time was 11.36 ± 2.13 min in Group A and 11.29 ± 2.23 min in Group B (t = 0.097, P = 0.938). The exposure time was 17.21 ± 2.91 s in Group A and 14.64 ± 1.60 s in Group B (t = 2.534, P = 0.025). At the L₄/L₅ level, the puncture‐channel time was 13.86 ± 3.90 min in Group A and 11.93 ± 2.95 min in Group B (t = 2.291, P = 0.039). Exposure time was 20.64 ± 3.84 s in Group A and 16.43 ± 2.47 s in Group B (t = 6.118, P < 0.01). There were 7 patients undergoing foraminotomy in Group A and 3 patients undergoing foraminotomy in Group B (t = 2.280, P = 0.236). At the L₅/S₁ level, the puncture‐channel time was 18.21 ± 1.85 min in Group A and 15.71 ± 3.20 min in Group B (t = 2.476, P = 0.028). Exposure time was 26.07 ± 3.17 s in Group A and 22.50 ± 2.68 s in Group B (t = 2.980, P = 0.011). There were 14 patients receiving foraminotomy in Group A and 13 patients receiving foraminotomy in Group B (t = 1.000, P = 1.000).

Conclusions

Virtual reality combined with isocentric navigation is feasible in TPED. It enables precise surgical planning and improves intraoperative procedures, and has the potential for application in clinical practice.

Neighboring Pt Atom Sites in an Ultrathin FePt Nanosheet for the Efficient and Highly CO-Tolerant Oxygen Reduction Reaction

Single atom catalyst and ultrathin two-dimensional (2D) nanostructures exhibit improved properties because of the improved exposure of more active atomic sites and optimized electronic structures. However, the oxygen reduction reaction (ORR) in fuel cells via a fast four-electron path usually uses at least two Pt atoms, which cannot be realized in highly isolated single Pt atoms. The synthesis of a densely dispersed single atom catalyst with adjacent atoms accessible at the same time on a matrix with a high surface area provides a feasible way and, however, is challenging. Here, we synthesize ultrathin FePt nanosheets (NSs) with 6.7 wt % neighboring dispersed Pt atoms. Different from the reported isolated Pt single atom catalysts, these ultrathin wrinkled FePt NSs with neighboring Pt sites adopt a four-electron reduction pathway, a high electrochemical active surface area (ECSA) of 545.54 m² g_Pt^-1, and an improved mass activity 7 times as high as Pt/C in the ORR. The improved performance results from the optimal use of neighboring Pt atoms dispersed in a more packed spacing and exposed on the surface of ultrathin sheets. The Pt atoms can interact synergistically to catalyze a fast ORR process. Furthermore, both the experiment and density functional theory (DFT) calculation indicated an outstanding CO-tolerance performance of this catalyst in the ORR.

Epidural versus intravenous steroids application following percutaneous endoscopic lumbar discectomy

Retrospectively study.The purpose of this study was to compare the effects of intraoperative epidural steroids and single dose intravenous steroids following a percutaneous endoscopic lumbar discectomy (PELD).Inflammatory irritation of dorsal root ganglia or sensory nerve roots may cause postoperative pain. Epidural steroids have been applied after a lumbar discectomy for more than 20 years. Epidural steroid application after a PELD is easier to perform and safer because the operations are under observation of the scope.We retrospectively reviewed the medical records of patients with lumbar intervertebral disc herniation who had undergone transforaminal PELD at our department. There are 60 patients in epidural steroid group, intravenous steroid group, and control group, respectively. Visual analog scores (VAS) and the Oswestry Disability Index (ODI) were collected. Successful pain control is defined as 50% or more reduction in back and leg pain (VAS scores).VAS scores (back and leg) and ODI showed a significant decrease in all groups when comparing pre- and postoperatively. Epidural steroid group had a significant improvement in successful pain control compared with the control group at 2 weeks of follow-up. VAS scores (leg) in the epidural steroid group showed a significant decrease compared with the intravenous steroids group at 1, 3, and 7 days after the surgery, but this difference had no statistical significance at 1, 6, and 12 months of follow-up. All groups did not show a significant difference in ODI at 1, 6, and 12 months follow-up.Epidural application of steroid has a better effect on controlling the postoperative pain of PELD in the short term. The epidural application of steroid did not show a tendency to cause infection.

The effect of preoperative administration of morphine in alleviating intraoperative pain of percutaneous transforaminal endoscopic discectomy under local anesthesia: A STROBE compliant study

Local anesthesia is routinely recommended for percutaneous transforaminal endoscopic discectomy (PTED). However, the intense intraoperative pain remains a serious problem. The purpose of the current study is to find a safe and effective method to alleviate the intense pain during PTED for lumbar disc herniation (LDH) under local anesthesia.This study retrospectively analyzed 63 LDH patients who accepted PTED under local anesthesia. Thirty-one patients received intramuscular injection of morphine before PTED, while the other 32 were not. The 10 points visual analogue scale (VAS) was used to assess the patients' maximum leg and back pain. Patients were asked to grade their experiences of surgery and anesthesia on a 5-point Likert-type scale after the surgery. Modified Mac Nab Criteria were used to evaluate the surgical outcomes after 3-month follow-up.The intraoperative VAS scores of patients who accepted preoperative intervention decreased significantly. The postoperative VAS scores of both groups showed no significance. Patients who received preoperative intervention reported a higher subjective satisfaction rate with the surgery experience. According to the Modified Mac Nab criteria, the surgical outcomes of both groups were similar through the 3-month follow-up. After injection of morphine, 4 patients complained nausea and 2 patients experienced vomiting.Preoperative intramuscular injection of morphine could reduce the patients' pain during the PTED surgery and improve the patients' satisfaction without affecting the surgical outcome. Except for a higher incidence of nausea and vomiting, this method is relatively safe and convenient.

Radiation reduction of minimally invasive transforaminal lumbar interbody fusion with localisation system in overweight patients: practical technique

AIMS

Minimally invasive transforaminal lumbar interbody fusion (MITLIF) has been well validated in overweight and obese patients who are consequently subject to a higher radiation exposure. This prospective multicentre study aimed to investigate the efficacy of a novel lumbar localisation system for MITLIF in overweight patients.

PATIENTS AND METHODS

The initial study group consisted of 175 patients. After excluding 49 patients for various reasons, 126 patients were divided into two groups. Those in Group A were treated using the localisation system while those in Group B were treated by conventional means. The primary outcomes were the effective radiation dosage to the surgeon and the exposure time.

RESULTS

There were 62 patients in Group A and 64 in Group B. The mean effective dosage was 0.0217 mSv (standard deviation (sd) 0.0079) in Group A and 0.0383 mSv (sd 0.0104) in Group B (p < 0.001). The mean fluoroscopy exposure time was 26.42 seconds (sd 5.91) in Group A and 40.67 seconds (sd 8.18) in Group B (p < 0.001). The operating time was 175.56 minutes (sd 32.23) and 206.08 minutes (sd 30.15) (p < 0.001), respectively. The mean pre-operative localisation time was 4.73 minutes (sd 0.84) in Group A and 7.03 minutes (sd 1.51) in Group B (p < 0.001). The mean screw placement time was 47.37 minutes (sd 10.43) in Group A and 67.86 minutes (sd 14.15) in Group B (p < 0.001). The pedicle screw violation rate was 0.35% (one out of 283) in Group A and 2.79% (eight out of 287) in Group B (p = 0.020).

CONCLUSION

The study shows that the localisation system can effectively reduce radiation exposure, exposure time, operating time, pre-operative localisation time, and screw placement time in overweight patients undergoing MITLIF. Cite this article: Bone Joint J 2017;99-B:944-50.

Clinical Outcome and Postoperative CT Measurements of Microendoscopic Decompression for Lumbar Spinal Stenosis

STUDY DESIGN

This was a retrospective case series.

OBJECTIVE

To retrospectively evaluate the clinical outcome of microendoscopic decompression for lumbar spinal stenosis (LSS) including an evaluation of the extent of decompression using computed tomography.

SUMMARY OF BACKGROUND DATA

Microendoscopic decompression has been a widely applied procedure to treat LSS with satisfactory outcomes and comparatively fewer complications and revision. However, few reports showed computed tomography (CT) measurements of the lumbar spine to assess the postoperative decompression.

METHODS

This study included 103 patients (55 males and 48 females; mean age, 69 y) who underwent microendoscopic decompression for treatment of LSS between January 2009 and January 2011. All patients underwent preoperative CT and postoperative CT at 6 months and 2 years of follow-up to measure the vertebral canal area and the sagittal diameter of the lateral recess at the outer rim. The Japanese Orthopedic Association (JOA) scale, Oswestry Disability Index, and Visual Analogue Scale were used to evaluate clinical efficacy.

RESULTS

The mean vertebral canal area and sagittal diameter of the lateral recess were significantly larger at 6 months and 2 years after surgery compared with 1 day before surgery (P<0.001). The mean JOA scale scores were significantly higher at 6 and 24 months following surgery compared with before surgery (P<0.001). The mean Oswestry Disability Index scores and Visual Analogue Scale scores at 6 months and 2 years after surgery were significantly lower compared with before surgery (both P<0.001). The mean JOA recovery rates at 6 months and 2 years of follow-up were 61% and 64.3%, respectively.

CONCLUSIONS

The results confirm that microendoscopic decompression for LSS is safe and effective. This study is one of the first to obtain CT measurements of the lumbar spine to assess the postoperative decompression of this procedure.

Learning curves of percutaneous endoscopic lumbar discectomy in transforaminal approach at the L4/5 and L5/S1 levels: a comparative study

OBJECTIVES

This study aimed to compare the learning curves of percutaneous endoscopic lumbar discectomy (PELD) in a transforaminal approach at the L4/5 and L5/S1 levels.

METHODS

We retrospectively reviewed the first 60 cases at the L4/5 level (Group I) and the first 60 cases at the L5/S1 level (Group II) of PELD performed by one spine surgeon. The patients were divided into subgroups A, B, and C (Group I: A cases 1-20, B cases 21-40, C cases 41-60; Group II: A cases 1-20, B cases 21-40, C cases 41-60). Operation time was thoroughly analyzed.

RESULTS

Compared with the L4/5 level, the learning curve of transforaminal PELD at the L5/S1 level was flatter. The mean operation times of Groups IA, IB, and IC were (88.75±17.02), (67.75±6.16), and (64.85±7.82) min, respectively. There was a significant difference between Groups A and B (P<0.05), but no significant difference between Groups B and C (P=0.20). The mean operation times of Groups IIA, IIB, and IIC were (117.25±13.62), (109.50±11.20), and (92.15±11.94) min, respectively. There was no significant difference between Groups A and B (P=0.06), but there was a significant difference between Groups B and C (P<0.05). There were 6 cases of postoperative dysesthesia (POD) in Group I and 2 cases in Group IIA (P=0.27). There were 2 cases of residual disc in Group I, and 4 cases in Group II (P=0.67). There were 3 cases of recurrence in Group I, and 2 cases in Group II (P>0.05).

CONCLUSIONS

Compared with the L5/S1 level, the learning curve of PELD in a transforaminal approach at the L4/5 level was steeper, suggesting that the L4/5 level might be easier to master after short-term professional training.

Guide wire breakage during posterolateral endoscopic lumbar discectomy procedure: A case report

OBJECTIVE

To present a unique case of guide wire breakage as a rare complication during posterolateral endoscopic lumbar discectomy.

BACKGROUND

Posterolateral endoscopic lumbar discectomy (PELD) has become a routinely performed minimally invasive spinal procedure. However, several complications of PELD have attracted our concerns, including the intraoperative injury to neural and vascular structures and failure of the surgery. We have countered a rare intraoperative complication of guidewire breakage during a PELD procedure, as far as we know, this has not been reported previously, and we wish to draw attention to this hazard.

METHODS

The medical records, operative reports, and radiographical imaging studies of a single patient were retrospectively reviewed.

RESULTS

A 28-year-old man presented with right posterior sciatica for 3 months was admitted to the hospital. Unsatisfactory improvement was observed under supervised conservative treatment. Preoperative magnetic resonance imaging (MRI) showed a disc herniation at the L4-L5 level. After preoperative evaluation, a PELD procedure was performed with local anesthesia. After advancement of guide wire and discography, the guiding rod was found not in the vicinity of the extruding disc fragment. Therefore, the operator tried to redirect the guiding rod. However, after several attempts, the guide wire was broken in the disc fragment under imaging. With the patient's permit, the operator inserted the working cannula to the broken end of guide wire and retrieved it using straightened grasping forceps. Then foraminotomy and fragmentectomy were accomplished under endoscope. The patient made uneventful recovery and was free of symptoms for the following 6 months.

CONCLUSIONS

In conclusion, the guide wire breakage during PELD procedures is a rare but a serious complication. An appropriate manner and operation is very important to prevent this complication. Once it does occur, the remnant of the guide wire can possibly be retrieved under endoscope with great experience. However, as for the beginners, a transfer to open operation is suggested to prevent new complications.