Full-Endoscopic Foraminal Decompression for Foraminal Stenosis Following Osteoporotic Vertebral Fracture in an Elderly Woman Under Local Anesthesia:A Case Report.

Osteoporotic vertebral fracture (OVF) is common in the elderly population. In this report, we describe a case with radiculopathy due to foraminal stenosis caused by OVF in a very elderly patient that was treated successfully by full-endoscopic foraminotomy under local anesthesia. The patient was an 89-year-old woman who presented with a chief complaint of left leg pain for 5 years. She visited a couple of hospitals and finally consulted us to determine the exact cause of the pain. Computed tomography scans were obtained and selective nerve root block at L3 was performed. The diagnosis was radiculopathy at L3 due to foraminal stenosis following OVF. The patient had severe heart disease, so we decided to avoid surgery under general anesthesia and planned full-endoscopic spine surgery under local anesthesia. We performed transforaminal full-endoscopic lumbar foraminotomy at L3-L4 to decompress the L3 nerve root. The leg pain disappeared completely immediately after surgery. Postoperative computed tomography confirmed appropriate bone resection. The leg pain did not recur during a year of postoperative follow-up. OVF may cause lumbar radiculopathy as a result of foraminal stenosis, and transforaminal full-endoscopic lumbar foraminotomy under local anesthesia would be the best option in an elderly patient with poor general condition. J. Med. Invest. 71 : 179-183, February, 2024.

Mismatch between Augmented Reality Navigation Images and Actual Location of a Cauda Equina Tumor:A Case Report.

BACKGROUND: Augmented reality navigation is the one of the navigation technologies that allows computer-generated virtual images to be projected onto a real-world environment. Augmented reality navigation can be used in spinal tumor surgery. However, it is unknown if there are any pitfalls when using this technique. CASE PRESENTATION: The patient in this report underwent complete resection of a cauda equina tumor at the L2-L3 level using microscope-based augmented reality navigation. Although the registration error of navigation was <1 mm, we found a discrepancy between the augmented reality navigation images and the actual location of the tumor, which we have called "navigation mismatch". This mismatch, which was caused by the mobility of the spinal tumor in the dura mater, seems to be one of the pitfalls of augmented reality navigation for spinal tumors. CONCLUSIONS: Combined use of intraoperative ultrasound and augmented reality navigation seems advisable in such cases. J. Med. Invest. 71 : 174-176, February, 2024.

Robotic-assisted minimally invasive repair surgery for progressive spondylolysis in a young athlete: a technical note.

Presently, the invasiveness of direct repair surgery for lumbar spondylolysis is relatively high. Thus, high school and junior high school students who play sports often cannot return to sports before graduation because of the invasiveness. The use of a robotic system enabled an accurate and minimally invasive procedure. Robotic-assisted minimally invasive direct pars repair surgery is useful for young patients with progressive spondylolysis.

Return-to-play outcomes after full-endoscopic spine surgery under local anesthesia in professional baseball players: Comparison by timing of surgery.

BACKGROUND: Full-endoscopic spine surgery via a transforaminal approach (TF-FESS) is minimally invasive and could help athletes quickly return to play. When treating professional athletes, we have to consider their season schedule. In this study, we investigated the characteristics of Japanese professional baseball players who underwent TF-FESS and examine how the timing of surgery influenced their postoperative course. METHODS: Ten players who underwent TF-FESS (discectomy, foraminoplasty, or thermal annuloplasty according to their diagnosis) under local anesthesia were analyzed. Multilevel surgeries were performed at the same time in patients with lesions at multiple levels. The patients were divided into three groups according to timing of surgery (pre/during/post-season). Time to complete return to play and duration of official game loss were compared between the three groups. RESULTS: All players (100 %) could return to their original level of professional play after FESS surgery. Seven of the 10 patients underwent two-level surgery. The mean time until complete return to play was 4.6 months (range, 2-8 months) and the mean duration of game loss was 1.5 months (range, 0-4 months). The mean duration of game loss was shorter in the post-season group than in the other groups (0.9 vs 2,4 months), and 4 of 6 patients in the post-season group did not miss any games. CONCLUSIONS: TF-FESS is a good technique for achieving a quick return to play in professional baseball players. In particular, surgery performed during the post-season could allow players to return to play after adequate rehabilitation with no game loss.

Morphological Evaluation of Lumbar Facet Joints in Professional Baseball Players.

Background: Many professional baseball players experience low back pain, a major cause of which is lumbar facet joint arthropathy. Purpose: To evaluate the relationship between the dominant hand side and facet joint morphology in baseball movement. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Participants were 25 Japanese professional baseball players (11 pitchers and 14 fielders) with low back pain and lower limb symptoms. Player age, hand dominance, and length of professional playing experience were recorded, and the lateral diameter of all lumbar facet joints was determined from the axial computed tomography scans. We defined the facet joints ipsilateral and contralateral to the dominant hand as dominant and nondominant, respectively. The nondominant-to-dominant (N/D) ratio of the lateral diameter was calculated, and differences between the pitchers and fielders were analyzed using the unpaired t test. Results: The average player age and length of professional playing experience were 26.9 years (range, 19-37 years) and 7.2 years (range, 1-15 years), respectively. The right hand was dominant in 9 pitchers and 5 fielders, while the left hand was dominant in 2 pitchers and 9 fielders. In pitchers, the average lateral facet joint diameter on the nondominant side was significantly larger than on the dominant side at all vertebral levels except L1 to L2 (P < .05 for all). The N/D ratio for each facet joint was 1.06 (L1-L2), 1.11 (L2-L3), 1.10 (L3-L4), 1.12 (L4-L5), and 1.12 (L5-S1). In fielders, the average lateral facet joint diameter on the dominant side was significantly larger than on the nondominant side at L3 to L4 (P < .05), with N/D ratios of 0.98 (L1-L2), 0.96 (L2-L3), 0.94 (L3-L4), 0.97 (L4-L5), and 0.98 (L5-S1). The N/D ratio was significantly larger in pitchers than in fielders at all levels (P < .05 for all). Conclusion: The facet joints of professional baseball players were enlarged asymmetrically, with different tendencies observed between pitchers and fielders. Although pitching and batting are movements that transmit the rotation from the lower limbs to the upper limbs, the effects of rotation and lateral flexion were associated significantly with facet joint hypertrophy.

Clinical Outcome of Full Endoscopic Trans Kambin's Triangle Lumbar Interbody Fusion: A Systematic Review.

Full-endoscopic (FE) lumbar interbody fusion (LIF) is now a widely used type of minimally invasive surgery (MIS). Although FE-LIF includes LIF with foraminoplasty via a Kambin's triangle approach (FE-KLIF) and LIF with foraminotomy via an interlaminar approach, these techniques are rarely discussed separately. This review evaluates the outcomes and complications of FE-KLIF reported in the literature. The PubMed, Medline, Embase, Web of Science, and Cochrane Library databases were searched for studies reporting the outcomes of FE-KLIF. Of 464 publications assessed, 11 met our inclusion criteria. Although the most frequently treated level was L4/5, L5/S1 was also treated. FE-KLIF was performed under local anesthesia and sedation or under epidural anesthesia without general anesthesia. Visual analog scale and Oswestry Disability Index scores were improved postoperatively in all uncontrolled studies; however, there was no significant difference in these scores in studies that compared FE-KLIF with posterior LIF (PLIF) or MIS-transforaminal LIF (TLIF). There was also no significant difference in the fusion rate between FE-KLIF and PLIF or MIS-TLIF. In terms of complications, although there were no reports of hematoma, dural tear and surgical site infection were reported in 1 paper each, with transient nerve disorders reported in 5 studies (frequency, 1.8%-23.5%). This review indicates that FE-KLIF is a feasible and viable surgical option for lumbar degenerative disease. However, the amount and level of evidence is low for the studies included in this review, and the data on long-term outcomes remain limited.

Advantages of Full-endoscopic Trans-Kambin's Triangle Lumbar Interbody Fusion for Degenerative Spondylolisthesis: Illustrative Cases.

Various approaches to lumbar interbody fusion have been described. The usefulness of full-endoscopic trans-Kambin's triangle lumbar interbody fusion has recently been reported. This technique has several advantages in patients with degenerative spondylolisthesis, including the ability to improve symptoms without decompression surgery. Moreover, given that the entire procedure is performed percutaneously, it can be performed without increasing the operation time or surgical invasiveness, even in obese patients. In this article, we discuss these advantages and illustrate them with representative cases.

Spatiotemporal changes of tissue glycans depending on localization in cardiac aging.

Heart failure is caused by various factors, making the underlying pathogenic mechanisms difficult to identify. Since cardiovascular disease tends to worsen over time, early diagnosis is key for treatment. In addition, understanding the qualitative changes in the heart associated with aging, where information on the direct influences of aging on cardiovascular disease is limited, would also be useful for treatment and diagnosis. To fill these research gaps, the focus of our study was to detect the structural and functional molecular changes associated with the heart over time, with a focus on glycans, which reflect the type and state of cells. METHODS: We investigated glycan localization in the cardiac tissue of normal mice and their alterations during aging, using evanescent-field fluorescence-assisted lectin microarray, a technique based on lectin-glycan interaction, and lectin staining. RESULTS: The glycan profiles in the left ventricle showed differences between the luminal side (medial) and wall side (lateral) regions. The medial region was characterized by the presence of sialic acid residues. Moreover, age-related changes in glycan profiles were observed at a younger age in the medial region. The difference in the age-related decrease in the level of α-galactose stained with Griffonia simplicifolia lectin-IB4 in different regions of the left ventricle suggests spatiotemporal changes in the number of microvessels. CONCLUSIONS: The glycan profile, which retains diverse glycan structures, is supported by many cell populations, and maintains cardiac function. With further research, glycan localization and changes have the potential to be developed as a marker of the signs of heart failure.

Hemangioblastoma of the Cauda Equina†:†A Case Report and Review of the Literature.

Introduction : Hemangioblastoma in the spine mainly occurs at the cervical and thoracic levels and is often associated with von Hippel-Lindau (VHL) syndrome. Here, we reported a quite rare case of spinal sporadic hemangioblastoma arising from the cauda equina. Case presentation : A 66-year-old woman presented with a 5-year history of low back and leg pain. Imaging revealed a hypervascular intradural extramedullary tumor in the lumbar region. Preoperative angiography helped to identify the feeding arteries and draining vein, and so facilitated subsequent tumor resection. The pain was dramatically improved but weakness of the left tibialis anterior and left extensor hallucis longus muscles persisted. Discussion : We reported a rare case of spinal hemangioblastoma arising from the cauda equina. Preoperative angiography may be useful for diagnosis and understanding of the anatomy of feeding veins. J. Med. Invest. 69 : 312-315, August, 2022.

Transforaminal Full-endoscopic Discectomy for Gas-containing Herniated Nucleus Pulposus at L5-S1 Under Local Anesthesia†:†A Case Report.

The vacuum phenomenon is often observed in degenerative disc disease, whereas gas-containing disc herniation is relatively rare. Full-endoscopic discectomy at the lumbar spine level via a transforaminal approach, which was established and subsequently refined over the last two decades, requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles. Foraminoplasty, performed with a high-speed drill, is a useful technique to enlarge the foramen, especially when applied at the L5-S1 level, where the trajectory is limited because of anatomical structures such as the iliac crest. Here, we report a case of gas-containing lumbar disc herniation at L5-S1 that was successfully treated by transforaminal full-endoscopic discectomy. The patient was a 62-year-old man with low back pain and pain in the plantar aspect of the right great toe. Magnetic resonance and computed tomography scans demonstrated gas-containing lumbar disc herniation at L5-S1 on the right. Following foraminoplasty, transforaminal full-endoscopic lumbar discectomy was successfully performed under local anesthesia. The patient's symptoms improved immediately after the surgery. Transforaminal full-endoscopic surgery can be effective and minimally invasive even when performed for gas-containing disc herniation. J. Med. Invest. 69 : 328-331, August, 2022.

Low Back Pain and Lumbar Degeneration in Japanese Professional Baseball Players.

Background: Baseball is one of the most popular sports in Asia. It is known that baseball can easily lead to back pain. However, there has been no survey of low back pain (LBP) and lumbar disc degeneration in Japanese professional baseball players to date. Purpose: To investigate the cause of LBP and lumbar degeneration in professional Japanese baseball players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We retrospectively reviewed the medical records of Japanese professional baseball players with LBP who visited our hospital. Data were collected from July 2018 to April 2021. We also investigated whether the results differed between players in their 20s and 30s or between pitchers and fielders. Data analysis was performed using the chi-square test. Results: We surveyed 32 professional baseball players. The most frequent causes of LBP among players in their 20s (n = 21) were lumbar disc herniation (LDH; 57%) and spondylolysis (24%). Of the players with spondylolysis, 50% had adult-onset spondylolysis. Players in their 30s (n = 11) most commonly had discogenic pain (55%) as well as LDH and facet joint arthritis (each 18%). The incidence of lumbar intervertebral disc degeneration was significantly higher in players in their 30s (91%) than those in their 20s (14%), as was the incidence of Schmorl nodes and Modic type 1 changes. There was no significant difference in the cause of LBP or the incidence of lumbar intervertebral disc degeneration between pitchers and fielders (P = .59). Conclusion: Among professional baseball players in their 20s, lumbar degeneration was less common, and they most frequently developed diseases less related to degeneration, such as LDH. However, among players in their 30s, lumbar degeneration was more advanced, and degenerative diseases such as discogenic pain occurred more frequently. Research on training methods could lead to the prevention of LBP. Our data may be applicable to other professional athletes and will contribute to diagnosis and treatment.

Additional effects of simultaneous treatment with C14-Cblin and celastrol on the clinorotation-induced rat L6 myotube atrophy.

Two novel reagents, N-myristoylated Cbl-b inhibitory peptide (C14-Cblin) and celastrol, a quinone methide triterpene, are reported to be effective in preventing myotube atrophy. The combined effects of C14-Cblin and celastrol on rat L6 myotubes atrophy induced by 3D-clinorotation, a simulated microgravity model, was investigated in the present study. We first examined their effects on expression in atrogenes. Increase in MAFbx1/atrogin-1 and MuRF-1 by 3D-clinorotation was significantly suppressed by treatment with C14-Cblin or celastrol, but there was no additive effect of simultaneous treatment. However, celastrol significantly suppressed the upregulation of Cbl-b and HSP70 by 3D-clinorotation. Whereas 3D-clinorotation decreased the protein level of IRS-1 in L6 myotubes, C14-Cblin and celastrol inhibited the degradation of IRS-1. C14-Cblin and celastrol promoted the phosphorylation of FOXO3a even in microgravity condition. Simultaneous administration of C14-Cblin and celastrol had shown little additive effect in reversing the impairment of IGF-1 signaling by 3D-clinorotation. While 3D-clinorotation-induced marked oxidative stress in L6 myotubes, celastrol suppressed 3D-clinorotation-induced ROS production. Finally, the C14-Cblin and celastrol-treated groups were inhibited decrease in L6 myotube diameter and increased the protein content of slow-twitch MyHC cultured under 3D-clinorotation. The simultaneous treatment of C14-Cblin and celastrol additively prevented 3D-clinorotation-induced myotube atrophy than single treatment. J. Med. Invest. 69 : 127-134, February, 2022.

Association of spinal anomalies with spondylolysis and spina bifida occulta.

PURPOSE: To investigate the association of spinal anomalies with lumbar spondylolysis and spina bifida occulta (SBO). METHODS: A total of 1190 patients with thoracic, abdominal, and pelvic computed tomography scans available were categorized according to the number of presacral (thoracic and lumbar) mobile vertebrae and the presence or absence of lumbosacral transitional vertebrae (LSTV). The prevalence of spondylolysis and SBO and the association of spinal anomalies with these disorders were evaluated. RESULTS: Normal morphology (17 mobile vertebra with no LSTV) was found in 607 men (86.5%) and 419 women (85.9%) and about 14% of patients had anomalies. Spondylolysis was found in 74 patients (6.2%), comprising 54 men (7.7%) and 20 women (4.1%). SBO involving the lumbar spine was found in 9 men (1.3%) and 2 women (0.4%). Spondylolysis was significantly more common in men with 18 vertebrae without LSTV (21.1%) than in those with 17 vertebrae without LSTV (7.2%) (p = 0.002). The prevalence of spinal anomalies was 55.6% in men and 50.0% in women with SBO that included a lumbar level was significantly higher than in both men (13.5%, p < 0.001) and women (4.8%, p = 0.003) without SBO. CONCLUSION: These findings indicate that there is a relationship between spinal anomalies and both spondylolysis and SBO, which may lead to elucidation of the mechanism of onset of spondylolysis and improve its treatment and prognosis. Awareness that patients with SBO involving the lumbar spine have an increased likelihood of a spinal anomaly may help to prevent level errors during spinal surgery.

MuRF1 deficiency prevents age-related fat weight gain, possibly through accumulation of PDK4 in skeletal muscle mitochondria in older mice.

Recent studies show that muscle mass and metabolic function are interlinked. Muscle RING finger 1 (MuRF1) is a critical muscle-specific ubiquitin ligase associated with muscle atrophy. Yet, the molecular target of MuRF1 in atrophy and aging remains unclear. We examined the role of MuRF1 in aging, using MuRF1-deficient (MuRF1-/- ) mice in vivo, and MuRF1-overexpressing cell in vitro. MuRF1 deficiency partially prevents age-induced skeletal muscle loss in mice. Interestingly, body weight and fat mass of more than 7-month-old MuRF1-/- mice were lower than in MuRF1+/+ mice. Serum and muscle metabolic parameters and results of indirect calorimetry suggest significantly higher energy expenditure and enhanced lipid metabolism in 3-month-old MuRF1-/- mice than in MuRF1+/+ mice, resulting in suppressed adipose tissue gain during aging. Pyruvate dehydrogenase kinase 4 (PDK4) is crucial for a switch from glucose to lipid metabolism, and the interaction between MuRF1 and PDK4 was examined. PDK4 protein levels were elevated in mitochondria from the skeletal muscle in MuRF1-/- mice. In vitro, MuRF1 interacted with PDK4 but did not induce degradation through ubiquitination. Instead, SUMO posttranscriptional modification (SUMOylation) of PDK4 was detected in MuRF1-overexpressing cells, in contrast to cells without the RING domain of MuRF1. MuRF1 deficiency enhances lipid metabolism possibly by upregulating PDK4 localization into mitochondrial through prevention of SUMOylation. Inhibition of MuRF1-mediated PDK4 SUMOylation is a potential therapeutic target for age-related dysfunction of lipid metabolism and muscle atrophy.

Full-Endoscopic Trans-Kambin Triangle Lumbar Interbody Fusion: Surgical Technique and Nomenclature.

BACKGROUND: Full-endoscopic lumbar surgery is used for decompression of lumbar spinal canal stenosis. Now, a cage can be inserted through Kambin's triangle for lumbar interbody fusion (LIF). We have been performing full-endoscopic trans-Kambin triangle LIF (KLIF) at our institution since 2018. In this article, we describe this technique and present our results. METHODS: We performed full-endoscopic one-level KLIF in 10 patients. The procedure is as follows. First, percutaneous pedicle screws are inserted. Listhesis is reduced if necessary. The endoscope is inserted in Kambin's triangle. Next, the superior articular process is partially removed, enlarging Kambin's triangle to allow safe insertion of the cage. A cannula is inserted into the disk to avoid damaging the exiting nerve. The disk material is shaved and curetted. Finally, the harvested bone is packed in a cage and inserted into the disk space. We analyze the complications, visual analog scores (VAS), and MacNab's criteria. RESULTS: One patient had an irritation in the exiting nerve at L4-L5. The VAS for back pain and leg pain decreased from 69 to 9 and from 60 to 9, respectively. The clinical outcome was considered excellent in eight and good in two patients. CONCLUSIONS: Kambin's triangle lies immediately behind the psoas major. Therefore, we consider KLIF as a lateral LIF procedure comparable with oblique or extreme LIF. However, unlike oblique or extreme LIF, there are no major vessels and organs in the surgical field; therefore, KLIF is the safest type of lateral LIF. Furthermore, using the endoscope, we can perform decompression directly using the facetectomy technique.

Transitional vertebrae and numerical variants of the spine : prevalence and relationship to low back pain or degenerative spondylolisthesis.

AIMS: Although lumbosacral transitional vertebrae (LSTV) are well-documented, few large-scale studies have investigated thoracolumbar transitional vertebrae (TLTV) and spinal numerical variants. This study sought to establish the prevalence of numerical variants and to evaluate their relationship with clinical problems. METHODS: A total of 1,179 patients who had undergone thoracic, abdominal, and pelvic CT scanning were divided into groups according to the number of thoracic and lumbar vertebrae, and the presence or absence of TLTV or LSTV. The prevalence of spinal anomalies was noted. The relationship of spinal anomalies to clinical symptoms (low back pain, Japanese Orthopaedic Association score, Roland-Morris Disability Questionnaire) and degenerative spondylolisthesis (DS) was also investigated. RESULTS: Normal vertebral morphology (12 thoracic and five lumbar vertebrae without TLTV and LSTV) was present in 531 male (76.7%) and 369 female patients (75.8%). Thoracolumbar transitional vertebrae were present in 15.8% of males and 16.0% of females. LSTV were present in 7.1% of males and 9.0% of females. The prevalence of the anomaly of 16 presacral mobile vertebrae (total number of thoracolumbar vertebrae and TLTV) without LSTV was 1.0% in males and 4.1% in females, and that of the anomaly of 18 vertebrae without LSTV was 5.3% in males and 1.2% in females. The prevalence of DS was significantly higher in females with a total of 16 vertebrae than in those with normal morphology. There was no significant correlation between a spinal anomaly and clinical symptoms. CONCLUSION: Overall, 24% of subjects had anomalies in the thoracolumbar region: the type of anomaly differed between males and females, which could have significant implications for spinal surgery. A decreased number of vertebrae was associated with DS: numerical variants may potentially be a clinical problem. Cite this article: Bone Joint J 2021;103-B(7):1301-1308.

Role of growth plate (apophyseal ring fracture) in causing modic type changes in pediatric low back pain patients.

PURPOSE: We investigated the prevalence of Modic changes (MCs) and associated pathologies in pediatric patients. METHODS: A total of 368 MRI obtained for 240 male and 128 female patients under the age of 18 years with complaints of low back/leg pain were retrospectively examined. All changes in signal intensity in the vertebral endplate and subchondral bone on MRI were defined as MCs. We investigated the relationship between MCs and underlying diseases, including lumbar spondylolysis/spondylolisthesis, and conditions of the growth plate in cases with MCs. The degree of disc degeneration in patients with MCs was evaluated using the Pfirrmann grading system. RESULTS: MCs were identified in six patients (1.6%). In five of the six patients, the signal intensity changes were localized to the anterosuperior endplate of the affected vertebra; the MCs were associated with anterior apophyseal ring fracture and an open growth plate in all these cases. Disc degeneration was classified as Pfirrmann grade I in three patients and grade II and III in one patient each. One patient had type I changes associated with grade IV disc degeneration and herniation and no sign of an open growth plate. CONCLUSION: The prevalence of MCs in pediatrics patients was much lower than the rates reported in adults. Most MCs were associated with an anterior apophyseal ring fracture. If Modic type changes are seen in immature vertebrae of pediatric patients, growth plate lesions such as apophyseal ring fractures should be considered. LEVEL OF EVIDENCE: Diagnostic: individual l cross-sectional studies with consistently applied reference standard and blinding.

A new surgical strategy for the intractable chronic low back pain due to type 1 Modic change using transforaminal full-endoscopic disc cleaning (FEDC) surgery under the local anesthesia†:†A case report and literature review.

It has been reported that Modic change of the lumbar spine endplate includes three types: i.e. . edema or inflammation for type 1, fatty marrow change for type 2 and sclerotic change for type 3. Basically, type 1 Modic change may be related to the chronic low back pain. There are two kinds of the treatment for the type 1 Modic change to heal the pain : the anti-inflammatory drugs, and intra-discal injection of steroid. When the inflammatory change would be intractable, surgical intervention is needed. The gold standard for the surgical intervention is the segmental fusion of the affected level. The fusion surgery may cause the adjacent degeneration ; thus, motion preservation surgery is better, if possible. Our department started the motion preservation full-endoscopic intradiscal debridement surgery for this pathology, since some of the type 1 Modic change may be chronic discitis by P. Acnes. In this paper, we describe the first patient of type 1 Modic change who was successfully treated by the full-endoscopic intra-discal debridement and drainage under the local anesthesia. We named this procedure as transforaminal full-endoscopic disc cleaning surgery (FEDC). Finally, pathology, conservative and surgical intervention of Modic change was discussed. J. Med. Invest. 68 : 1-5, February, 2021.

Extraosseous Signal Changes on Magnetic Resonance Imaging in Pediatric Patients with Early-Stage Lumbar Spondylolysis.

Purpose : To analyze extraosseous signal changes (ESCs) on magnetic resonance imaging (MRI) in pediatric patients with stress fractures occurring in the lamina. Methods : This study was a retrospective review of 69 consecutive pediatric patients with stress fractures occurring in the lamina. We analyzed MRI scans obtained at the first presentation. Results : We used mainly axial short tau inversion recovery images acquired through the pedicle of these 84 fracture sites to identify the ESCs. These were then divided into three groups: "invisible" when no ESC was detected, "periosteal" for ESC seen on only the dorsal side of the lamina, and "perimuscular" for ESC distinctly spread around / in the paravertebral muscles. In total, 78 (92.9%) fracture sites showed ESCs on the dorsal side of the lamina among which 72 ESCs were located on only the "dorsal" side, while 6 ESCs were on the ventral side against the transverse process. Conclusion : ESCs on MRI were detected in more than 90% of patients before stress fracture became apparent in the lamina, which was considered similar to findings of periosteal thickening / edema detected at the onset of stress fracture in long bone. J. Med. Invest. 68 : 136-139, February, 2021.

Morin attenuates dexamethasone-mediated oxidative stress and atrophy in mouse C2C12 skeletal myotubes.

Glucocorticoids are the drugs most commonly used to manage inflammatory diseases. However, they are prone to inducing muscle atrophy by increasing muscle proteolysis and decreasing protein synthesis. Various studies have demonstrated that antioxidants can mitigate glucocorticoid-induced skeletal muscle atrophy. Here, we investigated the effect of a potent antioxidative natural flavonoid, morin, on the muscle atrophy and oxidative stress induced by dexamethasone (Dex) using mouse C2C12 skeletal myotubes. Dex (10 µM) enhanced the production of reactive oxygen species (ROS) in C2C12 myotubes via glucocorticoid receptor. Moreover, Dex administration reduced the diameter and expression levels of the myosin heavy chain protein in C2C12 myotubes, together with the upregulation of muscle atrophy-associated ubiquitin ligases, such as muscle atrophy F-box protein 1/atrogin-1, muscle ring finger protein-1, and casitas B-lineage lymphoma proto-oncogene-b. Dex also significantly decreased phosphorylated Foxo3a and increased total Foxo3a expression. Interestingly, Dex-induced ROS accumulation and Foxo3a expression were inhibited by morin (10 µM) pretreatment. Morin also prevented the Dex-induced reduction of myotube thickness, together with muscle protein degradation and suppression of the upregulation of atrophy-associated ubiquitin ligases. In conclusion, our results suggest that morin effectively prevents glucocorticoid-induced muscle atrophy by reducing oxidative stress.