We aimed to investigate operating conditions, postoperative pain, and overall satisfaction of surgeons using deep neuromuscular blockade (NMB) vs. no NMB in patients undergoing lumbar spinal surgery under general anesthesia. Eighty-three patients undergoing lumbar fusion were randomly assigned to receive deep NMB (n = 43) or no NMB (n = 40). In the deep-NMB group, rocuronium was administered to maintain deep NMB (train-of-four count 0, post-tetanic count 1–2) until the end of surgery. In the no-NMB group, sugammadex 4 mg/kg at train-of-four (TOF) count 0–1 or sugammadex 2 mg/kg at TOF count ≥2 was administered to reverse the NMB 10 min after placing the patient prone. Peak inspiratory airway pressure, plateau airway pressure, lumbar retractor pressure significantly were lower in the deep-NMB group. Degree of surgical field bleeding (0–5), muscle tone (1–3), and satisfaction (1–10) rated by the surgeon were all superior in the deep-NMB group. Pain scores, rescue fentanyl consumption in post-anesthesia care unit (PACU), and postoperative patient-controlled analgesia consumption were significantly lower in the deep-NMB group, and this group had a shorter length of stay in PACU. Compared to no NMB, deep NMB provides better operating conditions, reduced postoperative pain and higher overall satisfaction in lumbar spinal surgery.

The angiogenic capacity of ECs was significantly inhibited by NCs under hypoxia via a VEGF-related pathway. Our results suggest that NCs may play a key role in the development of IVDs by inhibiting vascular growth within the disc, and this may be a promising novel therapeutic strategy for targeting vascular ingrowth in symptomatic DDD.

Intervertebral disc (IVD) degeneration is the main source of intractable lower back pain, and symptomatic IVD degeneration could be due to different degeneration mechanisms. In this article, we describe the molecular basis of symptomatic IVD degenerative disc diseases (DDDs), emphasizing the role of degeneration, inflammation, angiogenesis, and extracellular matrix (ECM) regulation during this process. In symptomatic DDD, pro-inflammatory mediators modulate catabolic reactions, resulting in changes in ECM homeostasis and, finally, neural/vascular ingrowth-related chronic intractable discogenic pain. In ECM homeostasis, anabolic protein-regulating genes show reduced expression and changes in ECM production, while matrix metalloproteinase gene expression increases and results in aggressive ECM degradation. The resultant loss of normal IVD viscoelasticity and a concomitant change in ECM composition are key mechanisms in DDDs. During inflammation, a macrophage-related cascade is represented by the secretion of high levels of pro-inflammatory cytokines, which induce inflammation. Aberrant angiogenesis is considered a key initiative pathologic step in symptomatic DDD. In reflection of angiogenesis, vascular endothelial growth factor expression is regulated by hypoxia-inducible factor-1 in the hypoxic conditions of IVDs. Furthermore, IVD cells undergoing degeneration potentially enhance neovascularization by secreting large amounts of angiogenic cytokines, which penetrate the IVD from the outer annulus fibrosus, extending deep into the outer part of the nucleus pulposus. Based on current knowledge, a multi-disciplinary approach is needed in all aspects of spinal research, starting from basic research to clinical applications, as this will provide information regarding treatments for DDDs and discogenic pain.

Objective : Classification systems for cervical ossification of the posterior longitudinal ligament (OPLL) have traditionally focused on the morphological characteristics of ossification. Although the classification describes many clinical features associated with the shape of the ossification, including the concept of spondylosis seems necessary because of the similarity in age distribution. Methods : Patients diagnosed with OPLL who presented with increase signal intensity (ISI) on magnetic resonance imaging were surgically treated in our department. The patients were divided into two groups (pure versus degenerative) according to the presence of disc degeneration. Results : Of 141 patients enrolled in this study, more than half (61%) were classified into the degenerative group. The pure group showed a profound male predominance, early presentation of myelopathy, and a different predilection for ISI compared to the degenerative group. The mean canal compromise ratio (CC) of the ISI was 47% in the degenerative group versus 61% in the pure group (p<0.0000). On the contrary, the global and segment motions were significantly larger in the degenerative group (p<0.0000 and p=0.003, respectively). The canal diameters and global angles did not differ between groups. Conclusion : Classifying cervical OPLL based on the presence of combined disc degeneration is beneficial for understanding the disorder's behavior. CC appears to be the main factor in the development of myelopathy in the pure group, whereas additional dynamic factors appear to affect its development in the degenerative group.

BACKGROUND:Sagittal spinopelvic alignment (SSPA) parameters are essential for the diagnosis of adult spinal deformities (ASDs) and their progression. Certain clinical symptoms that occur in patients with lumbar spinal stenosis (LSS) and herniated nucleus pulposus (HNP) may distort the SSPA and mimic ASD.OBJECTIVE:To differentiate SSPA in symptomatic patients from asymptomatic patients within 10 minutes in the standing position.METHODS:This retrospective cohort study evaluated changes in SSPA after simple lumbar decompression surgery in patients with LSS and HNP. Relative sagittal alignment (RSA), relative pelvic version, relative lumbar lordosis (RLL), Lordosis Distribution Index (LDI), and global alignment and proportion (GAP) values were calculated using the conventional Schwab classification method. First, the preoperative and postoperative SSPA parameters were compared. Second, patients were subgrouped into symptomatic within 10 minutes of standing (SP group) and other symptoms of LSS and HNP as controls. Changes in SSPA parameters after symptom relief after simple lumbar decompression surgery were compared between the two groups.RESULTS:Overall, all SSPA parameters improved after surgery. However, after subgrouping, patients in the control group did not show significant SSPA alterations, except for LDI, whereas patients in the SP group significantly improved in terms of their RSA, RLL, LDI, and GAP values after symptom relief after surgery.CONCLUSION:Patients with pain on standing within 10 minutes showed significant correction in RSA, RLL, and GAP values after simple lumbar decompression. Therefore, it is important to observe such clinical symptoms to avoid misdiagnosis of ASD.

Objective: Interlaminar endoscopic spine surgery has been introduced and utilized for lumbar lateral recess decompression. We modified this technique and utilized it for bilateral lateral recess stenoses without significant central stenosis. Here we present the surgical details and clinical outcome of ligamentum flavum sparing unilateral laminotomy for bilateral recess decompression (ULBRD).Methods: Prospectively collected registry for full-endoscopic surgeries was reviewed retrospectively. One hundred eighty-two consecutive cases from a single center between September 2015 and March 2021 were reviewed and 57 of them whom underwent ULBRD were enrolled for analysis. Basic patient demographic data, perioperative details, surgeryrelated complications, and clinical outcome were reviewed. The detailed surgical technique is presented as well.Results: Among the 57 patients enrolled, 37 were males while the other 20 were females. The mean age was 58.53 ± 14.51 years, and a bimodal age distribution at the age of mid-fifties and mid-sixties or older was noted. The later age-peak was related to coexistence of degenerative scoliosis. The average operative time per lamina was 70.34 ± 20.51 minutes and mean length of stay was 0.56 ± 0.85 days. Four perioperative complications were reported (7.0%) and the overall reoperation rate at the index level within 1 year was 8.8%. The preoperative back/leg visual analogue scale scores and functional outcome scales including EuroQol-5 dimension questionnaire, Oswestry Disability Index presented significant improvement immediately after surgery and were maintained until final follow-up.Conclusion: ULBRD for bilateral lateral recess stenoses without significant central stenosis resulted in good clinical outcomes with acceptably low perioperative complications rates. Sufficient decompression was achieved with the central ligamentum flavum being preserved.

Intervertebral disc (IVD) degeneration is a major cause of low back pain (LBP) in the lumbar spine. This phenomenon is caused by several processes, including matrix degradation in IVD tissues, which is mediated by matrix metalloproteinases (MMPs) and inflammatory responses, which can be mediated by interactions among immune cells, such as macrophages and IVD cells. In particular, interleukin (IL)-1 beta (β), which is a master regulator secreted by macrophages, mediates the inflammatory response in nucleus pulposus cells (NP) and plays a significant role in the development or progression of diseases. In this study, we developed a custom electrical stimulation (ES) platform that can apply low-constant-current stimulation (LCCS) signals to microfluidic chips. Using this platform, we examined the effects of LCCS on IL-1β-mediated inflammatory NP cells, administered at various currents (5, 10, 20, 50, and 100 μA at 200 Hz). Our results showed that the inflammatory response, induced by IL-1β in human NP cells, was successfully established. Furthermore, 5, 10, 20, and 100 μA LCCS positively modulated inflamed human NP cells’ morphological phenotype and kinetic properties. LCCS could affect the treatment of degenerative diseases, revealing the applicability of the LCCS platform for basic research of electroceuticals.

Ligamentum flavum hypertrophy (LFH) is a known contributor to lumbar spinal canal stenosis (LSCS). However, the clinical significance and quantitative role of LFH compared to other components, such as disc bulging and facet hypertrophy, have not yet been examined. We investigated the correlation between the quantitative radiological factors, clinical symptoms, and outcomes in patients with LSCS. In total, 163 patients diagnosed with single-level (L4-L5) stenosis were included. The patients were divided into 2 groups according to claudication severity: >100 m for mild (n = 92) and < 100 m for severe (n = 71). The visual analog scale (VAS) was used to quantify back and leg pain, and the Oswestry Disability Index (ODI) and Short form-36 (SF-36) physical component summary (PCS) scores, and Macnab criteria were evaluated as clinical factors 6 months after treatment. We measured the baseline canal cross-sectional area, ligamentum flavum (LF) area, disc herniation area, dural sac area, fat area, and LF thickness using MRI. A comparative analysis was performed to evaluate the association between radiologic and clinical factors. Additionally, further comparative analyses between the types of surgeries were performed. Among various radiologic factors, the baseline LF thickness (odds ratio [OR] 1.73; 95% confidence interval [CI] 1.25-2.41) was the only major contributing factor to the severity of claudication in the multivariate logistic regression analysis. The types of surgery (decompression alone vs fusion) did not significantly differ in terms of their clinical outcomes, including back and leg VAS, ODI, SF-36 PCS, and satisfaction with the MacNab classification. LF thickness is a major factor contributing to claudication severity.