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Oral Surgery, Oral Medicine, Oral... Jun 2023This study compared magnetic resonance imaging (MRI) findings and fractal dimension (FD) values in the temporomandibular joints (TMJs) of study patients with disk...
OBJECTIVE
This study compared magnetic resonance imaging (MRI) findings and fractal dimension (FD) values in the temporomandibular joints (TMJs) of study patients with disk perforation vs control patients.
STUDY DESIGN
Of 75 TMJs examined with MRI for characteristics of the disk and condyle, 45 were included in the study group and 30 in the control group. MRI findings and FD values were compared for significance of differences between the groups. The frequency of subclassifications was analyzed for differences between the two forms of disk configuration and grades of effusion. Mean FD values were analyzed for differences among subclassifications of MRI findings and between groups.
RESULTS
Examination of MRI variables revealed that the study group had significantly greater frequencies of flattened disks, disk displacement, flattening and combined defects in condylar morphology, and grade 2 effusion (P = .001) Joints with perforated disks had a large percentage of normal disk-condyle relationships (73.3%). Significant differences were discovered between biconcave and flattened disk configuration in the frequencies of internal disk status and condylar morphology. FD values of all patients varied significantly among the subclassifications of disk configuration, internal disk status, and effusion. Mean FD values were significantly lower in the study group with perforated disks (1.07) compared with the control group (1.20, P = .001).
CONCLUSIONS
MRI variables and FD can be useful in investigating intra-articular TMJ status.
Topics: Humans; Temporomandibular Joint Disc; Fractals; Temporomandibular Joint Disorders; Temporomandibular Joint; Magnetic Resonance Imaging; Joint Dislocations; Mandibular Condyle
PubMed: 36890079
DOI: 10.1016/j.oooo.2023.01.001 -
Acta Neurochirurgica. Supplement 2023Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease....
Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease. The aim of the study was to perform a systematic literature review on long-term clinical and radiological outcomes after Bryan cervical disk arthroplasty.Material and Methodsː A systematic literature review was performed according to PRISMA guidelines via PubMed and Embase, Scopus, and the Cochrane Library database by using the following keywords: "Bryan prosthesis"; "cervical disk arthroplasty"; "outcomes"; and "long-term follow-up." Eight articles with at least 10 years of follow-up were considered for eligibility.Resultsː In total, 481 patients were enrolled in the studies. Because of the occurrence of multiple treated levels, 588 arthroplasties were performed, divided as follows: 12 C3/4 cervical disk arthroplasties (2.01%), 63 C4/5 (10.71%), 325 C5/6 (55.27%), and 188 C6/7 (31.97%). The mean preoperative cervical lordosis was 13.6 ± 9.3°, whereas the last follow-up value was 12.8 ± 8.7°. In the last follow-up, the mean segmental range of motion was 8.2 ± 3.3°.Discussion: Recent studies have suggested that cervical disk arthroplasty should be safely performed in healthy young patients with disk degeneration who may need future revision surgery. The results suggest that this procedure preserves native cervical spinal biomechanics at long-term follow-up with acceptable adjacent segments disease and periprosthetic ossifications.Conclusionsː Cervical disk arthroplasty has good long-term device survival, motility, adjacent segment degeneration, and clinical outcomes. Therefore, it represents a valid alternative for the treatment of cervical spine degenerative pathologies, especially in young patients.
Topics: Animals; Humans; Arthroplasty; Biomechanical Phenomena; Databases, Factual; Intervertebral Disc Degeneration; Intervertebral Disc Displacement
PubMed: 38153488
DOI: 10.1007/978-3-031-36084-8_49 -
Global Spine Journal Jul 2021This is an experimental study using an animal model.
STUDY DESIGN
This is an experimental study using an animal model.
OBJECTIVES
Disk degeneration is a common cause of low back pain. However, few attempts have been made to proffer a medical solution. The aim of this study was to investigate the effect of aloe vera gel (AVG) on the histomorphometric changes in the intervertebral disk of annular-punctured rabbits.
METHODS
A total of 25 rabbits weighing 1.0 to 3.5 kg were used for this study; 20 rabbits were subjected to annular puncture of the L3/L4, L4/L5, and L5/L6 disks using an 18G needle. Five rabbits were randomly assigned to 5 groups (A, B, C, D, and E) of 5 animals per group. Group A was not punctured. Group B was punctured. Groups C, D, and E were punctured and given 600 400, and 200 (mg/kg) of AVG orally, respectively. The disk histology and nucleus pulposus cell count were done 6 weeks after the puncture procedure.
RESULTS
The results revealed a gradual reversal of degenerative changes in the treated groups compared with the nontreated groups ( < .05). The observed changes in the organization of the elastic and collagen content, increase in fibrochondrocyte-like cells of the nucleus pulposus and annulus fibrosus ( = .0027), and the degree of degeneration of the disk ( = .0001) in the treated groups compared with the nontreated groups were statistically significant.
CONCLUSION
Administration of AVG halted and reversed disk degeneration in an annular puncture-induced disk degeneration rabbit model.
PubMed: 32677517
DOI: 10.1177/2192568220927712 -
Journal of Biomechanical Engineering May 2019Aging and degeneration of the intervertebral disk are noted by changes in tissue composition and geometry, including a decrease in nucleus pulposus (NP) area. The NP...
Aging and degeneration of the intervertebral disk are noted by changes in tissue composition and geometry, including a decrease in nucleus pulposus (NP) area. The NP centroid is positioned slightly posterior of the disk's centroid, but the effect of NP size and location on disk joint mechanics is not well understood. We evaluated the effect of NP size and centroid location on disk joint mechanics under dual-loading modalities (i.e., compression in combination with axial rotation or bending). A finite element model (FEM) was developed to vary the relative NP area (NP:Disk area ratio range = 0.21-0.60). We also evaluated the effect of NP position by shifting the NP centroid anteriorly and posteriorly. Our results showed that compressive stiffness and average first principal strains increased with NP size. Under axial compression, stresses are distributed from the NP to the annulus, and stresses were redistributed toward the NP with axial rotation. Moreover, peak stresses were greater for disks with a smaller NP area. NP centroid location had a greater impact on intradiscal pressure during flexion and extension, where peak pressures in the posterior annulus under extension was greater for disks with a more posteriorly situated NP. In conclusion, the findings from this study highlight the importance of closely mimicking NP size and location in computational models that aim to understand stress/strain distribution during complex loading and for developing repair strategies that aim to recapitulate the mechanical behavior of healthy disks.
PubMed: 30835267
DOI: 10.1115/1.4043029 -
Retina (Philadelphia, Pa.) May 2018To examine parapapillary zones gamma and delta in highly myopic eyes. (Observational Study)
Observational Study
PURPOSE
To examine parapapillary zones gamma and delta in highly myopic eyes.
METHODS
The retrospective observational study included patients attending the Tokyo high myopia clinics. Fundus photographs were morphometrically examined.
RESULTS
The study population included 600 eyes (304 individuals) with a mean age of 62.7 ± 14.3 years (range: 13-90 years) and mean axial length of 29.6 ± 2.2 mm (range: 23.2-35.4 mm). In multivariate analysis (regression coefficient r:0.90), larger horizontal gamma zone diameter was correlated with wider delta zone diameter (P < 0.001; standardized regression coefficient beta: 0.81), higher ratio of vertical-to-horizontal disk diameter (P < 0.001; beta: 0.10), shorter fovea-outer gamma zone border distance (P < 0.001; beta: -0.19), longer disk-fovea distance (P < 0.001; beta: 0.18), and higher count of chorioretinal atrophic lesions (P < 0.001; beta: 0.07). Longer horizontal delta zone width was correlated with longer horizontal gamma zone diameter (P < 0.001; beta: 1.00), longer horizontal disk diameter (P < 0.001; beta: 0.15), shorter disk-fovea distance (P < 0.001; beta: -0.19), longer fovea-outer gamma zone border distance (P < 0.001; beta: 0.19), and smaller diameter of the largest chorioretinal lesion (P = 0.03; beta: -0.04). Longer width of both zones together was associated with longer horizontal disk diameter (P < 0.001; beta: 0.31), higher ratio of vertical-to-horizontal disk diameter (P = 0.001; beta: 0.18), longer disk-fovea distance (P < 0.001; beta: 0.19), shorter fovea-outer gamma zone border distance (P < 0.001; beta: -0.18), higher number of chorioretinal lesions (P < 0.001; beta: 0.30), and longer vertical distance between the superior and inferior temporal arterial arcade (P = 0.001; beta: 0.13).
CONCLUSION
Larger gamma and delta zones were correlated with larger optic disk and more marked vertical optic disk rotation, longer disk-fovea distance, higher number of chorioretinal lesions, and longer temporal vascular arcade diameter. Parapapillary gamma and delta zones may develop before chorioretinal lesions develop and enlarge.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Fovea Centralis; Fundus Oculi; Humans; Male; Middle Aged; Multivariate Analysis; Myopia, Degenerative; Optic Atrophy; Optic Disk; Retrospective Studies; Young Adult
PubMed: 28426626
DOI: 10.1097/IAE.0000000000001650 -
Materials (Basel, Switzerland) Oct 2022Titanium dioxide (TiO), by its tribological behavior, is known as a solid lubricant. TiO as a solid lubricant, together with tungsten disulfide (WS) and molybdenum...
Titanium dioxide (TiO), by its tribological behavior, is known as a solid lubricant. TiO as a solid lubricant, together with tungsten disulfide (WS) and molybdenum disulfide (MoS) decreases friction and excessive wear. By compacting TiO powder, pellets are formed. Studies and research on the solid lubricant coatings were conducted with success on a tribometer with the possibility of making two simultaneous contacts, pellet/disk, and slider pad/disk. On the disk of a tribometer, we studied the lubrication characteristics of the TiO powder particles as the third body by intentionally transferring. Results show that the TiO pellet behaved like an effective oil-free lubricant by self-repairing and self-replenishing. In experiments, a TiO pellet is intentionally sheared against the surface of the disk, while the slider pad slips loaded on the lubricated surface until the deposited powder film is exhausted. A theoretical model control volume fractional coverage (CVFC) was used to estimate both the wear rate for the lubricated pellet/disk sliding contact and the friction coefficient at the pad/disk separation surface. According to materials properties, disk velocity, pellet and slider pad load, the pellet wear rate, and slider pad friction coefficient, using the CVFC model, can establish the pellet wear rate, and slider pad friction coefficient. The fractional coverage represents a parameter of the CVFC model that varies with time, and it is useful for estimating the film amount from the third body that covers the disk asperities. Model results well enough describe the tribological behavior of the sliding contacts in experiments, both qualitatively and quantitatively. In addition, the theoretical results obtained by modeling and the experimental those obtained in the process of friction, are compared.
PubMed: 36295214
DOI: 10.3390/ma15207145 -
Frontiers in Neurology 2023Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of...
INTRODUCTION
Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of the annulus fibrosus (AF) may be an important contributor to back pain symptoms. However, the types and origins of sensory nerve terminals in the mouse lumbar disks have not been widely studied. Using disk microinjection and nerve retrograde tracing methods, the current study aimed to characterize the nerve types and neuropathway of the lumbar 5/6 (L5/6) disk in mice.
METHODS
Using an anterior peritoneal approach, the L5/6 disk of adult C57BL/6 mice (males, 8-12 weeks) disk microinjection was performed. Fluorogold (FG) was injected into the L5/6 disk using the Hamilton syringe with a homemade glass needle driven by a pressure microinjector. The lumbar spine and bilateral thoracic 13 (Th13) to L6 DRGs were harvested at 10 days after injection. The number of FG neurons among different levels was counted and analyzed. Different nerve markers, including anti-neurofilament 160/200 (NF160/200), anti-calcitonin gene-related peptide (CGRP), anti-parvalbumin (PV), and anti-tyrosine hydroxylase (TH), were used to identify different types of nerve terminals in AF and their origins in DRG neurons.
RESULTS
There were at least three types of nerve terminals at the outer layer of L5/6 AF in mice, including NF160/200 (indicating Aβ fibers), CGRP (Aδ and C fibers), and PV (proprioceptive fibers). No TH fibers (sympathetic nerve fibers and some C-low threshold mechanoreceptors) were noticed in either. Using retrograde tracing methods, we found that nerve terminals in the L5/6 disk were multi-segmentally from Th13-L6 DRGs, with L1 and L5 predominately. An immunofluorescence analysis revealed that FG neurons in DRGs were co-localized with NF160/200, CGRP, and PV, but not TH.
CONCLUSION
Intervertebral disks were innervated by multiple types of nerve fibers in mice, including Aβ, Aδ, C, and proprioceptive fibers. No sympathetic nerve fibers were found in AF. The nerve network of the L5/6 disk in mice was multi-segmentally innervated by the Th13-L6 DRGs (mainly L1 and L5 DRGs). Our results may serve as a reference for preclinical studies of discogenic pain in mice.
PubMed: 37077575
DOI: 10.3389/fneur.2023.1084209 -
Frontiers in Veterinary Science 2015This review discusses terminology, pathological, clinical, and magnetic resonance imaging (MRI) findings, treatment, outcome, and prognostic factors of... (Review)
Review
This review discusses terminology, pathological, clinical, and magnetic resonance imaging (MRI) findings, treatment, outcome, and prognostic factors of fibrocartilaginous embolic myelopathy (FCEM), acute non-compressive nucleus pulposus extrusion (ANNPE), and intradural/intramedullary intervertebral disk extrusion (IIVDE). FCEM, ANNPE, and IIVDE have a similar clinical presentation characterized by peracute onset of neurological dysfunction that is generally non-progressive after the initial 24-48 h. Differentiating between these conditions can be challenging, however, certain clinical and imaging findings can help. FCEM can occur in both adult and immature animals, whereas ANNPE or IIVDE have been reported only in animals older than 1 year. In dogs, ANNPE and IIVDE most commonly occur in the intervertebral disk spaces between T12 and L2, whereas FCEM has not such site predilection. In cats, FCEM occurs more frequently in the cervical spinal cord than in other locations. Data on cats with ANNPE and IIVDE are limited. Optimal MRI definition and experience in neuroimaging can help identify the findings that allow differentiation between FCEM, ANNPE, and IIVDE. In animals with ANNPE and IIVDE, the affected intervertebral disk space is often narrowed and the focal area of intramedullary hyperintensity on T2-weighted images is located above the affected intervertebral disk space. In dogs with ANNPE signal changes associated with the extruded nucleus pulposus and epidural fat disruption can be identified in the epidural space dorsal to the affected intervertebral disk. Identification of a linear tract (predominantly hyperintense on T2-weighted images, iso to hypointense on T1-weighted images and hypointense on T2*-weighted gradient recall echo images) extending from the intervertebral disk into the spinal cord parenchyma is highly suggestive of IIVDE. Treatment of FCEM and ANNPE is conservative. Dogs reported with IIVDE have been managed either conservatively or surgically. Prognostic factors include degree of neurological dysfunction (particularly loss of nociception) and disease-specific MRI variables.
PubMed: 26664953
DOI: 10.3389/fvets.2015.00024 -
Ophthalmology Apr 2023
Topics: Humans; Optic Disk Drusen; Optic Disk; Retinal Hemorrhage
PubMed: 36737346
DOI: 10.1016/j.ophtha.2022.12.024 -
Journal of Chiropractic Medicine Mar 2018The purpose of this narrative literature review is to discuss the literature regarding the potential role that cytokines play in degenerative disk disease. (Review)
Review
OBJECTIVE
The purpose of this narrative literature review is to discuss the literature regarding the potential role that cytokines play in degenerative disk disease.
METHODS
The inclusion criteria were studies that used inflammatory mediators in advancing disk disease processes. Research studies were limited to the last 3 decades that had free full-text available online in English. Exclusion criteria were review articles and articles pertaining to temporomandibular joints and other joints of the body other than the intervertebral disk. The following databases were searched: PubMed, EBSCOhost, and Google Scholar through March 13, 2017.
RESULTS
A total of 82 studies were included in this review. The papers were reviewed for complex mechanisms behind the degenerative cascade, emphasizing the role of proinflammatory cytokines, which may be instrumental in processes of inflammation, neurologic pain, and disk degeneration. Interleukin-1β and tumor necrosis factor α were among the more notable cytokines involved in this cascade. Because monocyte chemoattractant protein-1 stimulates and activates macrophages in the event of infiltration, additional proinflammatory cytokines are released to act on molecules to promote blood and nerve ingrowth, resulting in pain signaling and tissue degradation. Excessive inflammation and/or tissue damage initiates a pathologic imbalance between anabolic and catabolic processes.
CONCLUSIONS
This literature review describes how inflammatory and biochemical changes may trigger disk degeneration. Proinflammatory cytokines stimulate microvascular blood and nerve ingrowth, resulting in pain signaling and tissue degradation. This may sensitize a person to chemical and/or mechanical stimuli, contributing to severe low back pain.
PubMed: 29628809
DOI: 10.1016/j.jcm.2017.09.003