ProDisc-C versus anterior cervical discectomy and fusion for the surgical treatment of symptomatic cervical disc disease: two-year outcomes of Asian prospective randomized controlled multicentre study.

PURPOSE: Our study aimed to evaluate non-inferiority of ProDisc-C to anterior cervical discectomy and fusion (ACDF) in terms of clinical outcomes and incidence of adjacent segment disease (ASD) at 24-months post-surgery in Asian patients with symptomatic cervical disc disease (SCDD). METHODS: This multicentre, prospective, randomized controlled trial was initiated after ethics committee approval at nine centres (China/Hong Kong/Korea/Singapore/Taiwan). Patients with single-level SCDD involving C3-C7-vertebral segments were randomized (2:1) into: group-A treated with ProDisc-C and group-B with ACDF. Assessments were conducted at baseline, 6-weeks, 3/6/12/18/24-months post-surgery and annually thereafter till 84-months. Primary endpoint was overall success at 24-months, defined as composite of: (1) ≥ 20% improvement in neck disability index (NDI); (2) maintained/improved neurologic parameters; (3) no implant removal/revision/re-operation at index level; and (4) no adverse/severe/life-threatening events. RESULTS: Of 120 patients (80ProDisc-C,40ACDF), 76 and 37 were treated as per protocol (PP). Overall success (PP) was 76.5% in group-A and 81.8% in group-B at 24-months (p = 0.12), indicating no clear non-inferiority of ProDisc-C to ACDF. Secondary outcomes improved for both groups with no significant inter-group differences. Occurrence of ASD was higher in group-B with no significant between-group differences. Range of motion (ROM) was sustained with ProDisc-C but lost with ACDF at 24-months. CONCLUSION: Cervical TDR with ProDisc-C is feasible, safe, and effective for treatment of SCDD in Asians. No clear non-inferiority was demonstrated between ProDisc-C and ACDF. However, patients treated with ProDisc-C demonstrated significant improvement in NDI, neurologic success, pain scores, and 36-item-short-form survey, along with ROM preservation at 24-months. Enrolment difficulties resulted in inability to achieve pre-planned sample size to prove non-inferiority. Future Asian-focused, large-scale studies are needed to establish unbiased efficacy of ProDisc-C to ACDF.

Unilateral approach with two-cage insertion for full endoscopic transforaminal lumbar interbody fusion: technical report.

BACKGROUND: The advantages of performing a transforaminal lumbar interbody fusion (TLIF) with two cages rather than a single cage include a larger cage-bone contact area and higher interbody stability. METHODS: A customized cage guide is docked in the disc space created after a total facet resection. The first cage is inserted deeply into the contralateral disc space. The second cage is then inserted using the cage guide device while protecting the exiting and traversing nerve roots. CONCLUSION: We successfully inserted two cages from unilateral side during full endoscopic TLIF. This technique is recommended for L4-L5 and L5-S1 levels.

Full-endoscopic versus microscopic unilateral laminotomy for bilateral decompression of lumbar spinal stenosis at L4-L5: comparative study.

PURPOSE: Full-endoscopic spine surgery for degenerative lumbar diseases is growing in popularity and has shown favourable outcomes. Lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) has been used to treat lumbar spinal stenosis (LSS). However, studies comparing LE-ULBD to microscopic ULBD are lacking. This study compared the clinical efficacy and radiological outcomes between the LE-ULBD and microscopic ULBD. METHODS: The study retrospectively enrolled patients undergoing either LE-ULBD or microscopic ULBD for spinal stenosis at the L4-L5 level. The demographic data, operative details, radiological images, clinical outcomes, and complications of patients from the two groups were compared through matched-pairs analysis. The minimum follow-up duration was 24 months. RESULTS: There were 93 patients undergoing either LE-ULBD (n = 42) or microscopic ULBD (n = 51). The patient demographics were similar between the two groups. The LE-ULBD group had significantly less estimated blood loss, less analgesic use, and shorter hospitalization duration (P < .05). The endoscopic group had a significantly lower visual analog scale for back pain at all follow-up intervals compared with the microscopic group (P < .05). There were no significant differences in leg pain or Oswestry Disability Index. The cross-section area of the spinal canal was significantly wider after microscopic ULBD. There were no significant differences in post-operative degenerative changes in disc height, translational motion, or facet preservation rate. CONCLUSIONS: LE-ULBD is comparable in clinical and radiological outcomes with enhanced recovery for single-level LSS. The endoscopic approach might further minimize tissue injury and enhance post-operative recovery.

Biportal endoscopic unilateral laminotomy with bilateral decompression for the treatment of cervical spondylotic myelopathy.

BACKGROUND: The advantages of biportal endoscopic approaches over conventional open surgery include the preservation of the normal structures, less intraoperative bleeding, fast postoperative recovery, and preservation of the motion segments. METHOD: We attempted the posterior biportal endoscopic approach for cervical stenosis at the C5-C6-C7 levels. Biportal endoscopic right ipsilateral hemilaminectomy with bilateral decompression at the C5-C6-C7 levels and right foraminotomy at the C6-C7 level were performed under general anesthesia. CONCLUSIONS: We successfully performed neural decompression at the C5-C6-C7 levels using biportal endoscopic surgery. The biportal endoscopic posterior cervical approach may be an alternative surgical method for treating cervical myelopathy.

Comparative analysis of three types of minimally invasive decompressive surgery for lumbar central stenosis: biportal endoscopy, uniportal endoscopy, and microsurgery.

OBJECTIVERecently, minimally invasive unilateral laminotomy with bilateral decompression (ULBD) has been performed for lumbar stenosis using endoscopic approaches. The object of this retrospective study was to compare the clinical and radiological outcomes of three types of minimally invasive decompressive surgery: microsurgery, percutaneous uniportal endoscopic surgery, and percutaneous biportal endoscopic surgery.METHODSIn the period from March 2016 to December 2017, minimally invasive ULBD was performed using microscopy, a uniportal endoscopic approach, or a biportal endoscopic approach to treat lumbar canal stenosis. Patients were classified into three groups based on the surgery they had undergone. The angle of medial facetectomy area and postoperative dural expansion were measured using MR images. The visual analog scale (VAS) score for leg and back pain, Oswestry Disability Index (ODI), operation time, and complications were assessed. Clinical and radiological parameters were compared among the three groups.RESULTSThere were 33 patients in the microscopy group, 37 in the biportal endoscopy group, and 27 in the uniportal endoscopy group. Preoperatively stenotic dural areas were significantly expanded in each of the three groups after surgery (p < 0.05). Mean dural expansion in the uniportal endoscopy group was significantly lower than that in the microscopy or biportal endoscopy group (p < 0.05). The mean angle of the facetectomy in the biportal endoscopic group was significantly lower than that in the microscopic group or uniportal endoscopic group (p < 0.05). On the 1st day after surgery, the VAS score for back pain was significantly higher in the microscopic group than in the uniportal or biportal endoscopic group (p < 0.05). However, there were no significant differences in the VAS score for back pain, VAS score for leg pain, or ODI at the final follow-up among the three groups (p > 0.05).CONCLUSIONSAlthough radiological results were different among the three groups of patients, postoperative clinical outcomes were significantly improved after each type of surgery. The percutaneous biportal or uniportal endoscopic approach offers the advantage of reduced immediate postoperative pain. A percutaneous uniportal or biportal endoscopic lumbar approach may be effective for the treatment of lumbar central stenosis and an alternative to conventional microsurgical decompression.

Percutaneous endoscopic lumbar discectomy: minimally invasive technique for multiple episodes of lumbar disc herniation.

BACKGROUNDS: Although open lumbar discectomy is a gold standard surgical technique for lumbar disc herniation (LDH), surgery-induced tissue injury may actually become a source of postsurgical pain. Percutaneous endoscopic lumbar discectomy (PELD) is introduced as a minimal invasive spinal technique for LDH. The PELD has gained popularity and shown successful results. The authors report the clinical usefulness of the PELD technique in two patients with the serial multilevel LDHs. CASE PRESENTATIONS: A 32-year-old man suffered from radicular pain at the L5 dermatome due to the down migrated soft LDH at the L4-5 level. The PELD was performed to remove the ruptured fragments, yielding a complete decompression of the L5 nerve root. Four years later, he visited the clinic because of right leg radiating pain along the S1 dermatome. An MRI scan revealed the LDH at the L5-S1 level. The PELD with foraminoplasty was also performed successfully at the L5-S1 level. Two months after the second PELD, he visited the clinic again because of severe pain along the left L4 dermatome; consequently, the PELD was also performed at the L3-4 level without any complications. A 34-year-old man presented with radiating pain in the back and both legs at the L5 dermatome. The MR images show a disc extrusion at the L4-5. The patient underwent the PELD at the L4-5 via the left approach. After the PELD, the back and leg pain both improved. One year later, the patient suffered from severe pain in the back and the left anterior thigh. The MR images show a left paramedian LDH at the L2-3. After the PELD was performed at the L2-3, the pain was relieved. The final MR images show no signs of any aggravated degeneration of the intervertebral discs or the facet joints at all of the treated levels. CONCLUSION: When multiple episodes of LDH occur in a patient's life span, PELD could be considered as an alternative good technique to treat LDH in each step by preserving normal anatomic structures.

Bone loss of vertebral bodies at the operative segment after cervical arthroplasty: a potential complication?

OBJECTIVE Bony overgrowth and spontaneous fusion are complications of cervical arthroplasty. In contrast, bone loss or bone remodeling of vertebral bodies at the operation segment after cervical arthroplasty has also been observed. The purpose of this study is to investigate a potential complication-bone loss of the anterior portion of the vertebral bodies at the surgically treated segment after cervical total disc replacement (TDR)-and discuss the clinical significance. METHODS All enrolled patients underwent follow-up for more than 24 months after cervical arthroplasty using the Baguera C disc. Clinical evaluations included recording demographic data and measuring the visual analog scale and Neck Disability Index scores. Radiographic evaluations included measurements of the functional spinal unit's range of motion and changes such as bone loss and bone remodeling. The grading of the bone loss of the operative segment was classified as follows: Grade 1, disappearance of the anterior osteophyte or small minor bone loss; Grade 2, bone loss of the anterior portion of the vertebral bodies at the operation segment without exposure of the artificial disc; or Grade 3, significant bone loss with exposure of the anterior portion of the artificial disc. RESULTS Forty-eight patients were enrolled in this study. Among them, bone loss developed in 29 patients (Grade 1 in 15 patients, Grade 2 in 6 patients, and Grade 3 in 8 patients). Grade 3 bone loss was significantly associated with postoperative neck pain (p < 0.05). Bone loss was related to the motion preservation effect of the operative segment after cervical arthroplasty in contrast to heterotopic ossification. CONCLUSIONS Bone loss may be a potential complication of cervical TDR and affect early postoperative neck pain. However, it did not affect mid- to long-term clinical outcomes or prosthetic failure at the last follow-up. Also, this phenomenon may result in the motion preservation effect in the operative segment after cervical TDR.

Clinical and radiological results of posterior cervical foraminotomy at two or three levels: a 3-year follow-up.

BACKGROUND: Single-level unilateral posterior cervical foraminotomy is regarded as a safe method. However, the outcomes of posterior cervical foraminotomy performed on two or three levels are uncertain and debated. We aimed to analyze the long-term clinical and radiological outcomes of posterior cervical foraminotomy at two or three levels. METHODS: From September 2008 to December 2011, a total of 42 patients who underwent a posterior cervical foraminotomy at two or three levels and were followed for at least 3 years were analyzed with retrospective cohort study. Clinical assessments were performed using the visual analog scale (VAS), neck disability index (NDI) and modified MacNab criteria. Radiological evaluation included the assessment of static and dynamic lateral radiographs to identify instability, postlaminectomy kyphotic deformity, adjacent segmental degeneration (ASD), and focal degeneration. RESULTS: The mean VAS improved from preoperative score 8.5 ± 0.3 to postoperative score 1.8 ± 0.5 significantly. The mean presenting NDI score was 32.9 ± 2.0 and the mean postoperative NDI score was 14.2 ± 1.3. Improvement of radiculopathy was displayed in 39 patients (92.9%). During radiological evaluation, no significant change in disc height related to ASD and focal degeneration was noted. However, we confirmed one patient with radiological instability and one patient with radiological postlaminectomy kyphotic deformity. CONCLUSIONS: Posterior cervical foraminotomy at two or three levels is fairly effective for treating patients with cervical radiculopathy, and results in long-lasting pain relief and improved quality of life in nearly all patients. However, further studies of three levels that include more patients are needed.

Unusual solvent-dependent photophysical and self-assembly properties of NO2 substituted T-shaped phenazines.

This paper investigates the importance of substituent placement when designing low-molecular mass π-organogelators. The electron-deficient NO2 substituent was systematically added to novel T-shaped phenazines to examine electronic as well as assembly properties. This T-shaped molecular platform promotes selective electronic tuning, which can be theoretically analyzed by examining the system's frontier molecular orbitals. Electronic properties were characterized by UV-vis spectroscopy and cyclic voltammetry, and comparisons were made based on number and placement of the NO2 group. Computational chemistry (B3LYP/6-31G*) was employed for geometry optimizations, and to generate molecular orbital diagrams for all systems. The most noticeable influence of NO2 position was found for two molecules with four NO2 groups placed at different locations about the molecule (T-34dNT and T-35dNT). A 0.13 eV difference in ELUMO was observed while EHOMO was not significantly impacted by this change only in NO2 placement. Interestingly and unexpectedly, the photophysical properties and solvent-dependent gelation properties were considerably different for T-34dNT and T-35dNT. T-34dNT exhibited a unique fluorescence (FL) solvatochromism, with FL intensity and maxima dependent on solvent polarity. This result is indicative of intramolecular charge transfer. In addition, long tailing at the solid-state absorption of T-34dNT suggests the presence of intermolecular charge transfer. The gelation of T-34dNT produced chromism ranging from red to orange to yellow when the solvents changed from acetonitrile to ethyl acetate to cyclohexane, respectively. T-35dNT gels in these solvents did not exhibit any of the same properties. Xerogel morphology characterizations were carried out using three different solvents for both T-34dNT and T-35dNT. In the case of T-34dNT, striking differences in the morphology were detected by field-emission scanning electron microscopy (FE-SEM). We conclude that numbers of substituents are not the only consideration in effective molecular design for organogelators, but that substituent position plays a critical role in certain fundamental properties of these systems.

Analysis of Risk Factors Causing New Symptomatic Vertebral Compression Fractures After Percutaneous Vertebroplasty for Painful Osteoporotic Vertebral Compression Fractures: A 4-year Follow-up.

STUDY DESIGN: A retrospective cohort study. OBJECTIVE: New vertebral compression fracture (NVCF) is a highly potential risk after percutaneous vertebroplasty (PVP). The study aimed at analyzing the incidence and risk factors of NVCF and preventing its development. SUMMARY OF BACKGROUND DATA: PVP is widely used and highly effective technique for reducing pain caused by an osteoporotic vertebral compression fracture. However, there is a great deal of debate about whether PVP is associated with NVCF, and many risk factors of NVCF have been hypothesized. METHODS: From January to December 2008, a total of 198 patients (176 women, 22 men; mean age, 76.6±0.5 y) who underwent PVP at 270 levels for painful osteoporotic VCF were retrospectively analyzed during a 4-year follow-up. The following parameters were evaluated: NVCF incidence and average time, body mass index (BMI), smoking history, the existence of trauma, and bone mineral density (BMD) before and after PVP. Cement location, intradiscal leakage, distribution pattern, kyphotic angle, sagittal index, compression ratio, injected cement volume, and numbers of fractures and thoracolumbar junction fractures were analyzed. RESULTS: During follow-up, 34 patients (17.2%) sustained symptomatic NVCF for 4-year follow-up. All 34 patients with NVCF had lower BMD than that before initial PVP. For adjacent VCF, multivariable analysis showed that a higher risk of NVCF after vertebroplasty was associated with a larger number of VCF (P=0.025) and lower BMI (P=0.045), whereas for remote VCF, the risk of NVCF was higher in patients who had not experienced trauma and lower BMD (P=0.045). None of the radiographic evaluation values were related to the occurrence of NVCF. CONCLUSIONS: The most important elements related to reducing NVCF were treating osteoporosis and improving BMD and BMI. More aggressive BMD and BMI correction is more important than the vertebroplasty technique.

Monitoring Redox Processes in Lithium-Ion Batteries by Laboratory-Scale Operando X-ray Emission Spectroscopy.

Tracking changes in the chemical state of transition metals in alkali-ion batteries is crucial to understanding the redox chemistry during operation. X-ray absorption spectroscopy (XAS) is often used to follow the chemistry through observed changes in the chemical state and local atomic structure as a function of the state-of-charge (SoC) in batteries. In this study, we utilize an operando X-ray emission spectroscopy (XES) method to observe changes in the chemical state of active elements in batteries during operation. Operando XES and XAS were compared by using a laboratory-scale setup for four different battery systems: LiCoO2 (LCO), Li[Ni1/3Co1/3Mn1/3]O2 (NMC111), Li[Ni0.8Co0.1Mn0.1]O2 (NMC811), and LiFePO4 (LFP) under a constant current charging the battery in 10 h (C/10 charge rate). We show that XES, despite narrower chemical shifts in comparison to XAS, allows us to fingerprint the battery SOC in real time. We further demonstrate that XES can be used to track the change in net spin of the probed atoms by analyzing changes in the emission peak shape. As a test case, the connection between net spin and the local chemical and structural environment was investigated by using XES and XAS in the case of electrochemically delithiated LCO in the range of 2-10% lithium removal.

Side group dependent room temperature crystallization-induced phosphorescence of benzil based all organic phosphors.

In this work, we report alkoxy substituted benzil based all organic room temperature phosphors which showed crystallization induced phosphorescence (CIP). Nine title compounds were prepared with various alkyl lengths (OCnH2n+1: n = 8-16) and the effect of alkyl side group length on the phosphorescence performance was investigated, as compared to p-anisil. It was found that both phosphorescence quantum yield and lifetime increased concomitantly as the alkyl length increased up to nonyloxy (BZL-OC9). Further increase in the carbon number caused the phosphorescence performance to deteriorate due to greater conformational freedom of the side groups. An incredible quantum yield of 70% was achieved for BZL-OC9. A promising finding is that the increased quantum yield was accompanied by the increase in the lifetime relative to p-anisil, which has been historically challenging. Single crystallography coupled with UV-Vis spectroscopy revealed that a higher level of intermolecular π-π interactions was observed from p-anisil while more alkyl interactions with less intermolecular π-orbital overlap were found for BZL-OC8. As a result, molecular rigidification with less phosphorescence quenching was achieved for BZL-OC8 leading to enhanced performance. A precipitation study on a dichloromethane solution as a function of the content of MeOH (poor solvent) proved that the emission of the BZL-OCn system is truly aggregation-induced. The current work demonstrates that strategic side group engineering could be a promising approach to developing high-performance all organic phosphors as well as improving the properties of existing phosphors.

Controlling the electron-deficiency of self-assembling pyrazine-acenes: a collaborative experimental and theoretical investigation.

This paper reports novel pyrazine-acenes containing electron-deficient heteroaromatic π-extenders, such as pyridine, pyrazine, and benzothiadiazole, directly fused with pyrazine. Electronic properties of these systems were characterized by UV-Vis, fluorescence spectroscopy, and cyclic voltammetry. Computational electronic property evaluation of all experimentally synthesized compounds is provided, and is coupled with electronic calculations of closely related compounds that were not synthetically feasible. Our theoretical results provide insight into the overall analysis and interpretation of the experimentally observed trends. In this study, we found a systematic decrease in the LUMO energy (E(LUMO)) with an increasing number of imine functions in the π-extender. Additionally, when comparing the pyrazine-acene containing pyrazine π-extender to a reference compound with C≡N peripheral substituents, we found that the imine function is comparable to the C≡N substituent in lowering E(LUMO). The most dramatic E(LUMO) lowering was experimentally observed using dibromobenzothiadiazole as a π-extender. In all cases, the HOMO energy (EHOMO) was negligibly affected, thus we found options for electronic property control based solely on E(LUMO) manipulation. This is computationally validated by an examination of the molecular orbitals in which the LUMO orbital was found predominantly on the π-extender section of the molecules, while the HOMO orbital was localized away from the π-extender. Interestingly, the self-assembly of all the experimentally synthesized compounds showed excellent one-dimensional fiber formation in spite of their large π-core framework. These fibers were characterized by atomic force microscopy and UV-Vis spectroscopy.

Design optimization of a flexure spring used in small-sized ultra-precise optical instrument.

Small-sized ultra-precise optical devices require compact compliant ortho-planar springs (COPS) aka. flexure springs, for precise, frictionless linear motion which depends highly on the design. A self-developed arm-hinge-linked design, named "Panto-style" flexure spring was optimized by selecting 5 design parameters (thickness: t, hinge width: W, arm length 1 and 2: L1 and L2, arm angle: Ó¨) and constructing sets of design of experiments (DOEs). Signal-to-noise ratio (SNR) and response surface model (RSM) regression were obtained in terms of axial deformation. The highest response from the main effects plot was the thickness (t), followed by hinge width (W). The angle of the arm (Ó¨), was considered a non-relevant parameter. The parameters optimization was implemented with constraint input and output. Kinetostatic performances (axial/radial deformations, and stress) were predicted, validated, and compared (RSM, KNN, FE simulations, and experiments) using the optimized design. The average value of KNN and RSM (KNN + RSM) increased the accuracy of axial deformation value compared to RSM alone. To conclude, RSM design parameter optimization followed by KNN + RSM has successfully predicted the output results (axial/radial deformation and stress) confirmed both numerically and experimentally.

Biportal Endoscopic Posterior Thoracic Laminectomy for Thoracic Spondylotic Myelopathy Caused by Ossification of the Ligamentum Flavum: Technical Developments and Outcomes.

OBJECTIVE: Advanced biportal endoscopic surgery techniques can be used to treat thoracic myelopathy secondary to ossification of the ligamentum flavum (OLF). This case series elaborates on a feasible biportal endoscopic technique for thoracic OLF removal and evaluates clinical and radiological outcomes. METHODS: A biportal endoscopic posterior thoracic laminectomy was performed to remove the thoracic OLF. Surgical techniques have evolved from inside-out piecemeal removal methods to outside-in en bloc removal methods. Preoperative computed tomography was performed to analyze dural ossification and OLF types. Intraoperative videos were reviewed to observe dural ossification and to determine the surgical method. Neurological outcomes were assessed using the Japanese Orthopaedic Association (JOA) score. RESULTS: Clinical symptoms and neurological function improved markedly after surgery (JOA score, preoperative: 12.6 ± 1.0, final follow-up: 15.6 ± 1.2). The mean operation time per segment was not short (106.6 ± 38 minutes). At early experience stages, inside-out piecemeal decompression was used and it caused intraoperative spinal cord injury. However, outside-in en bloc decompression technique did not induce neural complications. Postoperative segmental instability and correlated mechanical back pain were not observed. CONCLUSION: The biportal endoscopic posterior thoracic approach is an attractive surgical option to treat thoracic spondylotic myelopathy secondary to OLF. Piecemeal inside-out decompression can induce irreversible spinal cord injury, especially in the early experience stages. Outside-in decompression is more efficient and safer than inside-out pattern procedures by minimizing dural manipulation. Nonetheless, this technique is technically demanding and should only be performed in selected patients after acquiring abundant experience with endoscopic spine surgeries.

Saving Stabilizing Structure Treatment With Bilateral-Contralateral Decompression for Spinal Stenosis in Degenerative Spondylolisthesis Using Unilateral Biportal Endoscopy.

OBJECTIVE: This study aimed to evaluate the treatment of spinal stenosis with spondylolisthesis using bilateral-contralateral unilateral biportal endoscopic (UBE) decompression to minimize facet joint damage. METHODS: We retrospectively evaluated 42 patients with grade 1 spondylolisthesis who underwent bilateral-contralateral UBE decompression between July 2018 and September 2019. To identify segmental instability, static and dynamic images from preoperative and postoperative procedures and final follow-up radiographs were reviewed. Lateral radiograph slippage ratio, sagittal motion, and facet joint preservation were evaluated. Clinical assessments were conducted using the visual analogue scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria. RESULTS: The average final follow-up period was 26.5 ± 1.3 months. The average preoperative slip percentage was 15.70% ± 5.25%, which worsened to 18.80% ± 5.41% at the final follow-up (p < 0.005). The facet joint preservation rate was 95.6% ± 4.1% on the contralateral side. Improvements in the VAS scores (leg pain: from 7.9 ± 2.2 to 3.1 ± 0.7; p < 0.005; back pain: from 7.2 ± 3.0 to 2.8 ± 1.0; p < 0.005) were observed at the final follow-up. The mean preoperative ODI was 26.19 ± 3.42, which improved to 9.6 ± 1.0 (p < 0.005). Thirteen patients exhibited delayed focal segmental instability following decompression. Despite the absence of symptoms or improvement with conservative treatment in the majority of patients with delayed instability, two patients required fusion surgery to address the instability. Additionally, 2 patients developed facet synovial cysts, while 2 experienced spinous process fractures. CONCLUSION: Bilateral decompression with a contralateral UBE approach could be an effective and alternative treatment method to reduce instability in spinal stenosis with grade 1 spondylolisthesis.

Widespread 8-oxoguanine modifications of miRNA seeds differentially regulate redox-dependent cancer development.

Oxidative stress contributes to tumourigenesis by altering gene expression. One accompanying modification, 8-oxoguanine (o8G) can change RNA-RNA interactions via o8G•A base pairing, but its regulatory roles remain elusive. Here, on the basis of o8G-induced guanine-to-thymine (o8G > T) variations featured in sequencing, we discovered widespread position-specific o8Gs in tumour microRNAs, preferentially oxidized towards 5' end seed regions (positions 2-8) with clustered sequence patterns and clinically associated with patients in lower-grade gliomas and liver hepatocellular carcinoma. We validated that o8G at position 4 of miR-124 (4o8G-miR-124) and 4o8G-let-7 suppress lower-grade gliomas, whereas 3o8G-miR-122 and 4o8G-let-7 promote malignancy of liver hepatocellular carcinoma by redirecting the target transcriptome to oncogenic regulatory pathways. Stepwise oxidation from tumour-promoting 3o8G-miR-122 to tumour-suppressing 2,3o8G-miR-122 occurs and its specific modulation in mouse liver effectively attenuates diethylnitrosamine-induced hepatocarcinogenesis. These findings provide resources and insights into epitranscriptional o8G regulation of microRNA functions, reprogrammed by redox changes, implicating its control for cancer treatment.

Evaluation of the efficacy and safety of conventional and interlaminar full-endoscopic decompressive laminectomy to treat lumbar spinal stenosis (ENDO-F trial): Protocol for a prospective, randomized, multicenter trial.

Lumbar spinal stenosis is a common spinal degenerative condition. Minimally invasive interlaminar full-endoscopic decompressive laminectomy provides greater patient satisfaction and faster recovery than open decompressive laminectomy. The aim of our randomized controlled trial will be to compare the safety and efficacy of interlaminar full-endoscopic laminectomy and open decompressive laminectomy. Our trial will include 120 participants (60 per group) who will undergo surgical treatment for lumbar spinal stenosis. The primary outcome will be the Oswestry Disability Index measured at 12 months postoperatively. Secondary patient-reported outcomes will include back and radicular leg pain measured via a visual analog scale; the Oswestry Disability Index; the Euro-QOL-5 Dimensions score measured at 2 weeks and at 3, 6, and 12 months postoperatively; and patient satisfaction. The functional measures will include time to return to daily activities postoperatively and walking distance/time. The surgical outcomes will include postoperative drainage, operation time, duration of hospital stay, postoperative creatine kinase (an indicator of muscle injury) level, and postoperative surgical scarring. Magnetic resonance and computed tomography images and simple radiographs will be obtained for all patients. The safety outcomes will include surgery-related complications and adverse effects. All evaluations will be performed by a single assessor at each participating hospital who will be blinded to group allocation. The evaluations will be conducted preoperatively and at 2 weeks and 3, 6, and 12 months postoperatively. The randomized, multicenter design of the trial, blinding, and justification of the sample size will reduce the risk of bias in our trial. The results of the trial will provide data regarding the use of interlaminar full-endoscopic laminectomy as an alternative to open decompressive laminectomy that results in similar surgical findings with less invasiveness. Trial registration: This trial is registered at cris.nih.go.kr. (KCT0006198; protocol version 1; 27 May 2021).

Surgical Removal of Cervical Extradural Cysts Using the Biportal Endoscopic Approach.

BACKGROUND: Symptomatic intraspinal extradural cysts of the cervical spine are uncommon; however, they are usually treated using conventional posterior decompression. Biportal endoscopic surgery is widely used to treat degenerative cervical pathological conditions. This study presented an optimized surgical technique for a biportal endoscopic posterior approach for removal of cervical intraspinal extradural cysts that caused cervical radiculomyelopathy. METHODS: A broad laminotomy was performed, which was wider than the outer contour of the cysts. The ligamentum flavum was detached from the bony margin and removed after an epidural dissection, and a dense adhesive tissue entrapped the extradural cysts. A spinal endoscope was placed close to the dissection plane and offered a high-resolution magnified view. The cyst capsule was safely dissected from the dura and removed en bloc without dural injury. RESULTS: Postoperatively, neurological deficits, including cervical myelopathy, radiating arm pain, and upper back pain improved in both patients. CONCLUSIONS: We successfully removed an extradural cervical cystic mass lesion by using a biportal endoscopic posterior cervical approach without complications. The biportal endoscopic approach may have advantages, such as minimizing trauma to the normal structures of the posterior cervical region, magnified endoscopic view, and early recovery after the surgery. Biportal endoscopy may be used as an alternative surgical treatment for symptomatic cervical intraspinal extradural cystic lesions.

Comparative Analysis With Modified Inclined Technique for Posterior Endoscopic Cervical Foraminotomy in Treating Cervical Osseous Foraminal Stenosis: Radiological and Midterm Clinical Outcomes.

OBJECTIVE: We compared the midterm clinical and radiological outcomes between 2 types of full endoscopic posterior cervical foraminotomy, including conventional posterior endoscopic cervical foraminotomy (PECF) and modified inclined technique for PECF. METHODS: One of the 2 types of PECF surgery was performed for defined cervical foraminal stenosis. The foraminal expansion ratio and facet resection rate and foraminal stenosis grade were measured using magnetic resonance imaging. Visual analogue scale (VAS) scores for neck and arm pain, neck disability index, MacNab criteria, operation time, hospital stay, and complications, including postoperative dysesthesia, were assessed. Clinical and radiological parameters were compared between the 2 surgical groups. RESULTS: There were 49 and 46 patients in the PECF and modified-PECF groups, respectively. The modified-PECF group showed significantly higher expansion of distal foraminal diameter and foraminal height, and a lower facet resection rate compared to PECF group (in all, p < 0.001). The modified-PECF group displayed significantly lower VAS score for neck pain at 1 day and 1 week after surgery and lower arm pain VAS score after 6-month follow-up (p = 0.002, p = 0.001, p = 0.002, respectively). CONCLUSION: Compared with the PECF, the modified inclined technique has radiologic benefits, including enhanced facet joint preservation, restoration of the natural course of nerve roots, and prevention of restenosis by expanding the superior articular process base, especially in grade 2 foraminal stenosis. Furthermore, the modified inclined technique significantly improved the postoperative VAS score for neck pain within the 1-week follow-up and that of arm pain after 6-month follow-up.