Melatonin Attenuates Intervertebral Disk Degeneration via Maintaining Cartilaginous Endplate Integrity in Rats

ObjectiveThe aim of this study is to verify whether melatonin (Mel) could mitigate intervertebral disk degeneration (IVDD) in rats and to investigate the potential mechanism of it.MethodA rat acupuncture model of IVDD was established with intraperitoneal injection of Mel. The effect of Mel on IVDD was analyzed via radiologic and histological evaluations. The specific Mel receptors were investigated in both the nucleus pulposus (NP) and cartilaginous endplates (EPs). In vitro, EP cartilaginous cells (EPCs) were treated by different concentrations of Mel under lipopolysaccharide (LPS) and Luzindole conditions. In addition, LPS-induced inflammatory response and matrix degradation following nuclear factor kappa-B (NF-κB) pathway activation were investigated to confirm the potential mechanism of Mel on EPCs.ResultsThe percent disk height index (%DHI) and MRI signal decreased after initial puncture in the degeneration group compared with the control group, while Mel treatment protected disk height from decline and prevented the loss of water during the degeneration process. In the meantime, the histological staining of the Mel groups showed more integrity and well-ordered construction of the NP and EPs in both low and high concentration than that of the degeneration group. In addition, more deep-brown staining of type II collagen (Coll-II) was shown in the Mel groups compared with the degeneration group. Furthermore, in rat samples, immunohistochemical staining showed more positive cells of Mel receptors 1a and 1b in the EPs, instead of in the NP. Moreover, evident osteochondral lacuna formation was observed in rat EPs in the degeneration group; after Mel treatment, the osteochondral destruction alleviated accompanying fewer receptor activator for nuclear factor-κB ligand (RANKL) and tartrate-resistant acid phosphatase (TRAP)-stained positive cells expressed in the EPs. In vitro, Mel could promote the proliferation of EPCs, which protected EPCs from degeneration under LPS treatment. What is more, Mel downregulated the inflammatory response and matrix degradation of EPCs activated by NF-κB pathway through binding to its specific receptors.ConclusionThese results indicate that Mel protects the integrity of the EPs and attenuates IVDD by binding to the Mel receptors in the EPs. It may alleviate the inflammatory response and matrix degradation of EPCs activated by NF-κB pathway.

Outcome Study of Anterior Cervical Discectomy and Fusion with Lordotic Cage Insertion

Objective: This study retrospectively evaluated the clinical and radiographic outcomes following the use of a lordotic cage in anterior cervical discectomy and fusion (ACDF).Material and Methods: All patients who underwent ACDF, at Vajira Hospital; between May 2017 and May 2020, were included in this study. Radiographic images were used to evaluate the device-level Cobb angle (DLCA), segmental Cobb angle (SCA), global Cobb angle (GCA), sagittal vertical axis (SVA), sagittal alignment (SA), and intervertebral disk height. The visual analog scale (VAS) for neck pain, and the Japanese Orthopaedic Association (JOA) score were reviewed as part of the patient’s medical records. Preoperative DLCA, SCA, GCA, SVA, SA, and intervertebral disk height measurements were compared with postoperative measurements at 1 year.Results: A total of 51 patients (88 disks), having undergone ACDF with lordotic cage insertion were included in this study. The initial curvature of the cervical spine was diagnosed as kyphosis in 30 (58.8%) patients, and as lordosis in 21 (41.2%) patients. There was significant improvement in the VAS, JOA, DLCA, SCA, GCA, SVA, SA, and intervertebral disk height after ACDF (p-value<0.050). In patients with preoperative kyphosis, the greatest changes were observed in the GCA (p-value=0.004).Conclusion: The use of a lordotic cage in ACDF improved both the clinical and radiographic outcomes of all postoperative parameters, regardless of the patient’s preoperative cervical spine curvature; although, patients with preoperative kyphosis had greater improvement in GCA.

Disk height ratio impact in combined tool upon roughness of ground surface

The impact of the height ratio of fine-grain abrasive disks and coarse grinding ones included in a combined tool upon roughness of the surface ground is considered. There are drawn dependence diagrams of the arithmetic mean deviation of the ground surface profile in the function of independent factors of the process. On the basis of the multi-factor experiment carried out there is defined a ratio of heights of grinding disks mentioned ensuring a minimum value of the micro-geometry of the surface worked.

Constraining protoplanetary disk accretion and young planets using ALMA kinematic observations

Recent ALMA molecular line observations have revealed 3-D gas velocity structure in protoplanetary disks, shedding light on mechanisms of disk accretion and structure formation. 1) By carrying out viscous simulations, we confirm that the disk’s velocity structure differs dramatically using vertical stress profiles from different accretion mechanisms. Thus, kinematic observations tracing flows at different disk heights can potentially distinguish different accretion mechanisms. On the other hand, the disk surface density evolution is mostly determined by the vertically integrated stress. The sharp disk outer edge constrained by recent kinematic observations can be caused by a radially varying α in the disk. 2) We also study kinematic signatures of a young planet by carrying out 3-D planet-disk simulations. The relationship between the planet mass and the ‘kink’ velocity is derived, showing a linear relationship with little dependence on disk viscosity, but some dependence on disk height when the planet is massive (e.g. 10MJ). We predict the ‘kink’ velocities for the potential planets in DSHARP disks. At the gap edge, the azimuthally-averaged velocities at different disk heights deviate from the Keplerian velocity at similar amplitudes, and its relationship with the planet mass is consistent with that in 2-D simulations. After removing the planet, the azimuthally-averaged velocity barely changes within the viscous timescale, and thus the azimuthally-averaged velocity structure at the gap edge is due to the gap itself and not directly caused to the planet. Combining both axisymmetric kinematic observations and the residual ‘kink’ velocity is needed to probe young planets in protoplanetary disks.

Facet Joint Replacement: Intermediate- and Long-Term Outcome in a Large Case Series

Background The long-term outcome of facet joint replacement (FJR) still is to be proven. Methods We present a prospective case series of 26 (male-to-female ratio of 1:1; mean age: 61 years) patients undergoing FJR with a follow-up of at least 1 year (range: 12–112; mean: 67 months). Visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and the 12-Item Short Form Health Survey (SF-12) were applied pre- and postoperatively (after 3, 6, and 12 months) as well as at the last follow-up (N = 24). Using X-rays of the lumbar spine (N = 20), the range of motion (ROM) and disk height in the indicator and adjacent levels were assessed. Results FJR was performed at L3/L4 (N = 7), L4/L5 (N = 17), and L5/S1 (N = 2). Mean VAS (mm) for back pain decreased from 71 to 18, mean VAS for right leg pain from 61 to 7, and from 51 to 3 for the left leg. Mean ODI dropped from 51 to 22% (for all p < 0.01). Eighty seven percent of patients were satisfied and pretreatment activities were completely regained in 78.3% of patients. Disk height at the indicator and adjacent levels and ROM at the indicator segment and the entire lumbar spine were preserved. No loosening of implants was observed. Explantation of FJR and subsequent fusion had to be performed in four cases (15.4%). Conclusions In selected cases, long-term results of FJR show good outcome concerning pain, quality of life, preservation of lumbar spine motion, and protection of adjacent level.

Lumbar Interbody Fusion: Techniques, Pearls and Pitfalls

<p>Lumbar interbody fusion (LIF) is an effective and popular surgical procedure for the management of various spinal pathologies, especially degenerative diseases. Currently, LIF can be performed with posterior, transforaminal, anterior, and lateral approaches by open surgery or minimally invasive surgery (MIS). Each technique has its own advantages and disadvantages. In general, posterior LIF is a well-established procedure with good fusion rates and low complication rates but is limited by the possibility of iatrogenic injury to the neural structures and paraspinal muscles. Transforaminal LIF is frequently performed using an MIS technique and has an advantage of reducing these iatrogenic injuries. Anterior LIF (ALIF) can restore the disk height and sagittal alignment but has inherent approach-related challenges such as visceral and vascular complications. Lateral LIF and oblique LIF are performed using an MIS technique and have shown postoperative outcomes similar to ALIF; however, these approaches carry a risk of injury to psoas, lumbar plexus, and vascular structures. Herein, we provide a detailed description of the surgical procedures of each LIF technique. We shall then consider the pearls and pitfalls, as well as propose surgical indications and contraindications based on the available evidence in the literatures.</p>

Endoscopic transforaminal lumbar interbody fusion in the treatment of degenerative lumbar spondylolisthesis

Background Transforaminal lumbar interbody fusion (TLIF) has been widely accepted as a standard treatment option for the patients with lumbar spondylolisthesis with good clinical outcomes. However, some patients suffered from the back pain postoperatively. With the development of minimally invasive endoscopic methods in spine surgery, the current trend of evolution lumbar spinal surgery has been toward endoscopic procedures. Purpose The purpose of this study was to evaluate the clinical outcomes and efficacy of endoscopic transforaminal lumbar interbody fusion (ELIF) in the treatment of degenerative lumbar spondylolisthesis by compare to the standard transforaminal lumbar interbody fusion (TLIF). Methods A total of 93 patients with lumbar spondylolisthesis who had surgery from February 2016 to January 2018 were categorized into different groups depending on the procedure by ELIF or TLIF. The ELIF and TLIF procedures was performed, and the clinical outcomes of blood loss, operation times, hospital stay days, pain index, ODI score, the spondylolisthesis rate and reduction rate, and the disk height and intervertebral foramen height were recorded. Results In ends 86 cases had follow-up at least one year and seven cases lost, and the follow-up rate and followed time were no difference between two groups (P > 0.05). The operational time was longer in ELIF than TLIF (P < 0.01).The hospital days and blood loss were significant less in endoscopic group than TLIF (P < 0.01). The pain index and ODI score, the spondylolisthesis rate and reduction rate, and the disk height and intervertebral foramen height were better than preoperational (P < 0.01), and there were no difference between two groups (P > 0.05). All patients achieved spinal fusion with no cases of cage extrusion, and no infection, and no dural tear of cerebrospinal fluid leakage complication. There were one case of radiculitis (man) at endoscopic group. CT-myelogram revealed the radiculitis patients had normal radiologic findings, and the patient was recovered by neurotrophy drugs and functional exercises after 3 months. Conclusions Endoscopic lumbar decompression and interbody fusion procedures was an effective and safe measure in the treatment of the lumbar spondylolisthesis. Compare to open interbody fusion techniques, endoscopic lumbar interbody fusion was a minimally invasive surgery with less bold loss and earlier postoperative recovery.

Endoscopic transforaminal lumbar interbody fusion in the treatment of degenerative lumbar spondylolisthesis

Background There were no studies in literature of lumbar spondylolisthesis treated by endoscopic surgery. The purpose of this study was to evaluate the efficacy of endoscopic transforaminal lumbar interbody fusion (ELIF) in the treatment of degenerative lumbar spondylolisthesis by compare to the standard transforaminal lumbar interbody fusion (TLIF).Methods A total of 93 patients with lumbar spondylolisthesis who had surgery from February 2017 to January 2018 were categorized into different groups depending on the procedure by ELIF or TLIF. The ELIF and TLIF procedures was performed, and the clinical outcomes of blood loss, operation times, hospital stay days, pain index, ODI score, the spondylolisthesis rate and reduction rate, and the disk height and intervertebral foramen height were recorded.Results There was no intraoperative death in this series. In ends 86 cases had follow-up at least one year and 7 cases lost, and the follow-up rate and followed time were no difference between two groups (P > 0.05). The operational time was longer in ELIF than TLIF (P < 0.01).The hospital days and blood loss were significant less in endoscopic group than TLIF (P < 0.01). The pain index and ODI score, the spondylolisthesis rate and reduction rate, and the disk height and intervertebral foramen height were better than preoperational (P < 0.01), and there were no difference between two groups (P > 0.05). All patients achieved spinal fusion with no cases of cage extrusion, and no infection, and no dural tear of cerebrospinal fluid leakage complication. There were one case of radiculitis (man) at endoscopic group. CT-myelogram revealed the radiculitis patients had normal radiologic findings, and the patient was recovered by neurotrophy drugs and functional exercises after 3 months.Conclusions Endoscopic lumbar decompression and interbody fusion procedures was effective and safe measure in the treatment of the lumbar spondylolisthesis. Compare to open interbody fusion techniques, endoscopic lumbar interbody fusion was minimally invasive surgery with less bold loss and earlier postoperative recovery.