Sporadic inclusion body myositis-derived myotube culture revealed muscle cell-autonomous expression profiles.

Sporadic inclusion body myositis (sIBM) is a muscle disease in older people and is characterized by inflammatory cell invasion into intact muscle fibers and rimmed vacuoles. The pathomechanism of sIBM is not fully elucidated yet, and controversy exists as to whether sIBM is a primary autoimmune disease or a degenerative muscle disease with secondary inflammation. Previously, we established a method of collecting CD56-positive myoblasts from human skeletal muscle biopsy samples. We hypothesized that the myoblasts derived from these patients are useful to see the cell-autonomous pathomechanism of sIBM. With these resources, myoblasts were differentiated into myotubes, and the expression profiles of cell-autonomous pathology of sIBM were analyzed. Myoblasts from three sIBM cases and six controls were differentiated into myotubes. In the RNA-sequencing analysis of these "myotube" samples, 104 differentially expressed genes (DEGs) were found to be significantly upregulated by more than twofold in sIBM, and 13 DEGs were downregulated by less than twofold. For muscle biopsy samples, a comparative analysis was conducted to determine the extent to which "biopsy" and "myotube" samples differed. Fifty-three DEGs were extracted of which 32 (60%) had opposite directions of expression change (e.g., increased in biopsy vs decreased in myotube). Apolipoprotein E (apoE) and transmembrane protein 8C (TMEM8C or MYMK) were commonly upregulated in muscle biopsies and myotubes from sIBM. ApoE and myogenin protein levels were upregulated in sIBM. Given that enrichment analysis also captured changes in muscle contraction and development, the triggering of muscle atrophy signaling and abnormal muscle differentiation via MYMK or myogenin may be involved in the pathogenesis of sIBM. The presence of DEGs in sIBM suggests that the myotubes formed from sIBM-derived myoblasts revealed the existence of muscle cell-autonomous degeneration in sIBM. The catalog of DEGs will be an important resource for future studies on the pathogenesis of sIBM focusing on primary muscle degeneration.

RSPO3 is a novel contraction-inducible factor identified in an "in vitro exercise model" using primary human myotubes.

The physiological significance of skeletal muscle as a secretory organ is now well known but we can only speculate as to the existence of as-yet-unidentified myokines, especially those upregulated in response to muscle contractile activity. We first attempted to establish an "insert-chamber based in vitro exercise model" allowing the miniature but high cell-density culture state enabling highly developed contractile human myotubes to be readily obtained by applying electric pulse stimulation (EPS). By employing this in vitro exercise model, we identified R-spondin 3 (RSPO3) as a novel contraction-inducible myokine produced by cultured human myotubes. Contraction-dependent muscular RSPO3 mRNA upregulation was confirmed in skeletal muscles of mice subjected to sciatic nerve mediated in situ contraction as well as those of mice after 2 h of running. Pharmacological in vitro experiments demonstrated a relatively high concentration of metformin (millimolar range) to suppress the contraction-inducible mRNA upregulation of human myokines including RSPO3, interleukin (IL)-6, IL-8 and CXCL1. Our data also suggest human RSPO3 to be a paracrine factor that may positively participate in the myogenesis processes of myoblasts and satellite cells. Thus, the "insert chamber-based in vitro exercise model" is a potentially valuable research tool for investigating contraction-inducible biological responses of human myotubes usually exhibiting poorer contractility development even in the setting of EPS treatment.

Contracted joint capsule affects labral and chondral lesions in patients with frozen shoulder.

PURPOSE: Intra-articular pathologies, such as labral and chondral lesions, are common in patients with frozen shoulder. This study evaluated the correlations between the range of motion and labral and chondral lesions in patients with frozen shoulder and investigated their pathophysiologies. METHODS: In total, 125 individuals (53 men and 72 women) who underwent arthroscopic pan-capsular release between 2014 and 2020 were included in the study. The range of motion was measured using scapular fixation and true glenohumeral motion under general anaesthesia. The American Shoulder and Elbow Surgeons Shoulder score and the Shoulder Rating Scale score of the University of California, Los Angeles were used to compare intra-articular pathologies. RESULTS: More than 80% of patients with frozen shoulder had labral pathologies, and nearly half of them had chondral pathologies. Labral lesions extending to the anterior rim of the glenoid had a greater range of motion and the greatest total American Shoulder and Elbow Surgeons Shoulder score. More severe chondral lesions had a lesser range of motion, but presented the greatest function scores and the lowest strength scores according to the Shoulder Rating Scale of the University of California, Los Angeles. The pain scores of the American Shoulder and Elbow Surgeons Shoulder score and the Shoulder Rating Scale of the University of California, Los Angeles were not correlated with the degree of these pathologies. The traction force affected the labrum during true range of motion, and the compression force occurred on the articular cartilage during internal rotation at 90° of forward flexion during diagnostic arthroscopy. CONCLUSION: Labral and chondral lesions are common in patients with frozen shoulder. Adherence to the capsulolabral complex induced a limited range of motion and labral and chondral pathologies. Diagnostic arthroscopy with motion is an important method of reproducing the pathogenesis of intra-articular structures for patients with frozen shoulder. LEVEL OF EVIDENCE: Level III.

Mitochondrial dysfunction underlying sporadic inclusion body myositis is ameliorated by the mitochondrial homing drug MA-5.

Sporadic inclusion body myositis (sIBM) is the most common idiopathic inflammatory myopathy, and several reports have suggested that mitochondrial abnormalities are involved in its etiology. We recruited 9 sIBM patients and found significant histological changes and an elevation of growth differential factor 15 (GDF15), a marker of mitochondrial disease, strongly suggesting the involvement of mitochondrial dysfunction. Bioenergetic analysis of sIBM patient myoblasts revealed impaired mitochondrial function. Decreased ATP production, reduced mitochondrial size and reduced mitochondrial dynamics were also observed in sIBM myoblasts. Cell vulnerability to oxidative stress also suggested the existence of mitochondrial dysfunction. Mitochonic acid-5 (MA-5) increased the cellular ATP level, reduced mitochondrial ROS, and provided protection against sIBM myoblast death. MA-5 also improved the survival of sIBM skin fibroblasts as well as mitochondrial morphology and dynamics in these cells. The reduction in the gene expression levels of Opa1 and Drp1 was also reversed by MA-5, suggesting the modification of the fusion/fission process. These data suggest that MA-5 may provide an alternative therapeutic strategy for treating not only mitochondrial diseases but also sIBM.

Effects of arthroscopic pancapsular release for proximal humeral fractures treated with intramedullary nailing: a retrospective study.

BACKGROUND: Proximal humeral fractures are one of the most common fractures in adults. Some patients treated operatively have restriction in range of motion (ROM) after surgery. This study aimed to evaluate arthroscopic pancapsular release in patients with severe stiffness after treatment with intramedullary nailing for proximal humeral fractures. METHODS: This study included 12 patients (7 women and 5 men) who underwent arthroscopic pancapsular release in the beach-chair position between May 2015 and February 2018. Intraoperative findings were recorded, and ordinary (with scapulothoracic motion) and true (without scapulothoracic motion) glenohumeral ROMs were measured with a goniometer. The American Shoulder and Elbow Surgeons shoulder score, Shoulder Rating Scale score of the University of California, Los Angeles scoring system, and Constant score were compared before and after the release. The Wilcoxon signed rank and Mann-Whitney U tests were used to analyze data. RESULTS: The average age of the patients was 65.1 years (standard deviation, 9.5 years), and the mean follow-up period after the release was 30.6 months (standard deviation, 11.7 months). All ROMs on the affected side after surgery were significantly greater than those before surgery in all directions. However, ROMs in forward flexion, lateral elevation, and external rotation with the arm at the side and at 90° of forward flexion on the affected side postoperatively were significantly lower than those on the unaffected side. All scores were significantly greater after surgery than before surgery. CONCLUSION: Arthroscopic pancapsular release is effective for patients with proximal humeral fractures treated with intramedullary nailing.

Effects of joint capsular release on range of motion in patients with frozen shoulder.

BACKGROUND: A thickened joint capsule is believed to be one of the most specific manifestations of and the primary restraint against range of motion (ROM) in frozen shoulders. The purpose of this study was to evaluate the relationship among ROMs under general anesthesia before surgery and the effects of each joint capsular release on ROM. METHODS: ROM was measured using a goniometer with scapular fixation. Arthroscopic pan-capsular release was performed with the patient in the beach-chair position in the following order: (1) rotator interval, (2) coracohumeral ligament, (3) superior capsule, (4) middle glenohumeral ligament, (5) anterior inferior glenohumeral ligament, and (6) posterior inferior glenohumeral ligament. ROMs in forward flexion (FF), lateral elevation (LE), external rotation with the arm at the side (ER1), external rotation at 90° of LE (ER2), internal rotation at 90° of LE (IR2), horizontal flexion, external rotation at 90° of FF (ER3), and internal rotation at 90° of FF (IR3) were evaluated before and after each release. RESULTS: A total of 32 consecutive shoulders were included. After each capsular release, the ROM recovered; the final ROM was significantly greater on the affected side than on the unaffected side. Significant correlations were found between FF and LE, FF and ER1, ER1 and ER2, ER1 and ER3, ER2 and ER3, and IR2 and IR3 on both sides, regardless of surgery. CONCLUSION: Each segment of the joint capsule affected ROM in all directions, supporting the need for whole-joint capsular release; ROM was significantly greater on the affected side than on the unaffected side after surgery.

RAGE-dependent NF-kB inflammation processes in the capsule of frozen shoulders.

BACKGROUND: The etiology of frozen shoulder (FS) remains uncertain. Advanced glycation end-products (AGEs) cause the cross-linking and stabilization of collagen and are increased in FS. The purpose of this study was to elucidate the pathogenesis of FS by evaluating the receptor of AGE (RAGE)-dependent pathways. METHODS: Tissue samples of the coracohumeral ligament (CHL) and anterior inferior glenohumeral ligament (IGHL) were collected from 33 patients with FS, with severe stiffness, and 25 with rotator cuff tears (RCTs) as controls. Gene expression levels of RAGE, high-mobility group box 1 (HMGB1), Toll-like receptor 2 (TLR2), TLR4, nuclear factor-kappa B (NF-kB), and cytokines were evaluated using a quantitative real-time polymerase chain reaction. The immunoreactivities of carboxymethyllysine (CML), pentosidine, and RAGE were also evaluated. CML and pentosidine were further evaluated using high-performance liquid chromatography. RESULTS: Gene expression levels of RAGE, HMGB1, TLR2, TLR4, and NF-kB were significantly greater in the CHLs and IGHLs from the FS group than in those from the RCT group. Immunoreactivities of RAGE and CML were stronger in the CHLs and IGHLs from the FS group than in those from the RCT group. Pentosidine was weakly immunostained in the CHLs and IGHLs from the FS group. CML using high-performance liquid chromatography was significantly greater in the CHLs and IGHLs from the FS group than in those from the RCT group. CONCLUSIONS: AGEs and HMGB1 might play important roles in the pathogenesis of FS by binding to RAGE and activating NF-kB signaling pathways. Suppression of these pathways could be a treatment option for FS.

Parents' Own Experience of Verbal Abuse Is Associated with their Acceptance of Abuse towards Children from Youth Sports Coaches.

Verbal or physical abuse from coaches has negative effects on young athletes, and the parents of athletes also have an influence on the sports environment. It is therefore important to understand parents' attitudes towards abuse against their children from the coaches. This study aimed to elucidate the characteristics of parents who accept the infliction of verbal or physical abuse on their children from coaches of youth sports teams. A cross-sectional study using self-report questionnaires was conducted with parents of young athletes (n = 6,493). Multivariate logistic regression models were used to assess the factors associated with parents' acceptability of verbal or physical abuse against their children. The proportion of parents who were accepting of verbal or physical abuse was 21.5%. Acceptability of verbal or physical abuse was significantly associated with male (odds ratio: 1.67, 95% confidence interval: 1.43-1.95), younger age (1.24, 1.09-1.41), lower educational attainment (1.32, 1.17-1.50), smoking habits (1.42, 1.23-1.63), experience of playing on a team with high levels of competition during their junior or high school days (1.31, 1.15-1.50), and experience of verbal and physical abuse by their own former coaches (3.59, 3.03-4.26 and 1.17, 1.02-1.35). About 58% and 28% of parents had experienced verbal and physical abuse from their own former coaches, and parents who had experienced verbal abuse themselves were most likely to be accepting of verbal or physical abuse towards their children. Educating parents is considered to be important for preventing and eradicating abuse against young athletes.

In vitro exercise model using contractile human and mouse hybrid myotubes.

Contraction of cultured myotubes with application of electric pulse stimulation (EPS) has been utilized for investigating cellular responses associated with actual contractile activity. However, cultured myotubes derived from human subjects often exhibit relatively poor EPS-evoked contractile activity, resulting in minimal contraction-inducible responses (i.e. myokine secretion). We herein describe an "in vitro exercise model", using hybrid myotubes comprised of human myoblasts and murine C2C12 myoblasts, exhibiting vigorous contractile activity in response to EPS. Species-specific analyses including RT-PCR and the BioPlex assay allowed us to separately evaluate contraction-inducible gene expressions and myokine secretions from human and mouse constituents of hybrid myotubes. The hybrid myotubes, half of which had arisen from primary human satellite cells obtained from biopsy samples, exhibited remarkable increases in the secretions of human cytokines (myokines) including interleukins (IL-6, IL-8, IL-10, and IL16), CXC chemokines (CXCL1, CXCL2, CXCL5, CXCL6, CXCL10), CC chemokines (CCL1, CCL2, CCL7, CCL8, CCL11, CCL13, CCL16, CCL17, CCL19, CCL20, CCL21, CCL22, CCL25, CCL27), and IFN-γ in response to EPS-evoked contractile activity. Together, these results indicate that inadequacies arising from human muscle cells are effectively overcome by fusing them with murine C2C12 cells, thereby supporting the development of contractility and the resulting cellular responses of human-origin muscle cells. Our approach, using hybrid myotubes, further expands the usefulness of the "in vitro exercise model".

The characteristics of coaches that verbally and physically abuse young baseball players using a self-reported questionnaire.

BACKGROUND: Because the relationship between coaches and athletes is unequal, verbal and physical abuse remains a common problem among sports coaches. We aimed to elucidate the characteristics of baseball coaches who verbally/physically abuse young baseball players. METHODS: A cross-sectional study was conducted on youth sports team coaches in Miyagi prefecture, Japan (n = 380), using a self-reported questionnaire. Multivariate logistic regression models were used for the analyses, evaluating the following variables: sex, age, educational level, smoking habits, years of coaching, level of baseball-playing experience, personal experience with verbal/physical abuse by former coaches, satisfaction with athletes' attitudes, number of athletes on the team, team competition level, awareness of the recommendations of the Japanese Society of Clinical Sports Medicine, limitations in the total pitch count, difficulty in coaching in other positions, number of games per year, and acceptance of former verbal/physical abuse. RESULTS: The prevalence of verbal/physical abuse toward young athletes was 74.5% (n = 283) and 6.6% (n = 25), respectively. Verbal abuse was significantly associated with personal experience of verbal abuse by former coaches (odds ratio [OR]: 2.00, 95% confidence interval [95% CI]: 1.04-3.85), and acceptance of verbal/physical abuse (OR: 2.61, 95% CI: 1.34-5.10). Physical abuse was significantly associated with greater than 10 years of coaching experience (OR: 7.16, 95% CI: 1.36-37.78), personal experience with physical abuse by former coaches (OR: 4.25, 95% CI: 1.23-14.70), and acceptance of verbal/physical abuse (OR: 3.85, 95% CI: 1.51-9.84). CONCLUSIONS: Coaches' experiences with verbal/physical abuse by former coaches negatively affected young athletes. Breaking this cycle is necessary to keep athletes active and interested in playing baseball. LEVEL OF EVIDENCE: Level III.

Knee pain is associated with lower back pain in young baseball players: a cross-sectional study.

PURPOSE: Considerable research has focused on shoulder and elbow injuries among baseball players; however, although lumbar spine and knee injuries are commonly experienced, they are less frequently studied. During common motions in baseball, such as throwing, hitting, and running, energy is transferred from the lower extremities through the lower back to the upper body. Lower extremity pain, as well as lower back pain (LBP), can disrupt the kinematic chain, and it is important to understand the association between lower extremity complaints and LBP. The purpose of this study was to elucidate the association between knee pain and LBP among young baseball players. METHODS: A cross-sectional study was conducted with young baseball players (aged 6-15 years, n = 1,609) using a self-reported questionnaire. Multivariate logistic regression models were used for analyses. Variables considered in the models were sex, age, body mass index, team levels, number of days of training per week, number of hours in practice per day on weekdays and weekend, frequency of participation in games, practice intensity, and player position. RESULTS: The point prevalence of LBP and knee pain was 8.4% and 13.1%, respectively. Knee pain was significantly associated with LBP. Using the absence of knee pain as a reference, the adjusted odds ratio (95% confidence interval) for LBP was 5.83 (3.93-8.65) (p < 0.001) in the presence of knee pain. CONCLUSIONS: Knee pain was associated with LBP among young baseball players. Clinicians should pay attention to knee complaints to prevent and treat LBP among young baseball players. LEVEL OF EVIDENCE: III.

Comparative proteome analysis of the capsule from patients with frozen shoulder.

BACKGROUND: The etiology of frozen shoulder (FS) is unclear. Accordingly, this study used a label-free quantitative shotgun proteomic approach to elucidate the pathogenesis of FS based on protein expression levels. METHODS: Tissue samples from the rotator interval (RI), middle glenohumeral ligament (MGHL), and anterior-inferior glenohumeral ligament (IGHL) were collected from 12 FSs with severe stiffness and 7 shoulders with a rotator cuff tear (RCT) as controls. Protein mixtures were digested and analyzed by nano-liquid chromatography/electrospray ionization-tandem mass spectrometry. Relative protein expression levels were calculated by the signal intensity of identified peptide ions on mass spectra. Differentially expressed proteins between FS and RCT samples were evaluated by a gene enrichment analysis using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. RESULTS: We identified 1594 proteins, 1358 of which were expressed in all 6 tissue groups. We detected more upregulated proteins in the upper (RI and MGHL) FS groups and the lower (IGHL) RCT group than in the comparative groups, respectively. Various proteins with functions in tissue repair, collagen metabolism and fibrillation, cell-cell and cell-matrix adhesion, blood coagulation, and the immune response were expressed more highly in the RI and MGHL FS groups than in the RCT group. Proteins with functions in phagocytosis, glutathione metabolism, retinoid metabolism, and cholesterol metabolism were expressed more highly in the IGHL RCT group than in the FS group. CONCLUSIONS: The pathophysiology of FS differs between the upper and lower parts of the joint capsule. Different treatment strategies for FS may be appropriate, depending on the location.

Neutrophils Provide a Favorable IL-1-Mediated Immunometabolic Niche that Primes GLUT4 Translocation and Performance in Skeletal Muscles.

Metabolic immunomodulation involving IL-1 has been investigated for unfavorable metabolic effects, including obesity, but a potentially favorable role for IL-1 remains unclear. Here, we find mechanistic interactions between working skeletal muscles and locally recruited neutrophils expressing IL-1ß, which supports muscle performance through priming exercise-dependent GLUT4 translocation. Thus, during exercise, both IL-1α/ß-deficient and neutrophil-depleted mice similarly exhibit increased fatigability associated with impaired muscle glucose homeostasis due to GLUT4 dysregulation. Deficiency of IL-1-producing neutrophils results in intrinsic abnormalities represented by aberrant Rac1 signaling and irregular GLUT4-storage vesicles, suggesting that these properties are maintained by local IL-1 produced by recruited neutrophils upon exercise, possibly on a daily basis. We propose that neutrophils are highly engaged in skeletal muscle performance via IL-1 regulation, which coordinates favorable inflammatory microenvironments supporting muscle glucose metabolism.

Effects of Low-Intensity Pulsed Ultrasound for Preventing Joint Stiffness in Immobilized Knee Model in Rats.

The purpose of this study was to examine the effect of low-intensity pulsed ultrasound (LIPUS) in preventing joint stiffness. Unilateral knee joints were immobilized in two groups of rats (n = 6/period/group). Under general anesthesia, the immobilized knee joints were exposed to LIPUS for 20 min/d, 5 d/wk, using an existing LIPUS device (LIPUS group, 1.5-MHz frequency, 1.0-kHz repetition cycle, 200-µs burst width and 30-mW/cm2 power output) until endpoints (2, 4 or 6 wk). In the control group, general anesthesia alone was administered in the same manner as in the other group. The variables compared between the groups included joint angles; histologic, histomorphometric and immunohistochemical analyses; quantitative reverse transcription polymerase chain reactions; and tissue elasticity. LIPUS had a preventive effect on joint stiffness, resulting in decreased adhesion, fibrosis and inflammation and hypoxic response after joint immobilization.

Retained Myogenic Potency of Human Satellite Cells from Torn Rotator Cuff Muscles Despite Fatty Infiltration.

Rotator cuff tears (RCTs) are a common shoulder problem in the elderly that can lead to both muscle atrophy and fatty infiltration due to less physical load. Satellite cells, quiescent cells under the basal lamina of skeletal muscle fibers, play a major role in muscle regeneration. However, the myogenic potency of human satellite cells in muscles with fatty infiltration is unclear due to the difficulty in isolating from small samples, and the mechanism of the progression of fatty infiltration has not been elucidated. The purpose of this study was to analyze the population of myogenic and adipogenic cells in disused supraspinatus (SSP) and intact subscapularis (SSC) muscles of the RCTs from the same patients using fluorescence-activated cell sorting. The microstructure of the muscle with fatty infiltration was observed as a whole mount condition under multi-photon microscopy. Myogenic differentiation potential and gene expression were evaluated in satellite cells. The results showed that the SSP muscle with greater fatty infiltration surrounded by collagen fibers compared with the SSC muscle under multi-photon microscopy. A positive correlation was observed between the ratio of muscle volume to fat volume and the ratio of myogenic precursor to adipogenic precursor. Although no difference was observed in the myogenic potential between the two groups in cell culture, satellite cells in the disused SSP muscle showed higher intrinsic myogenic gene expression than those in the intact SSC muscle. Our results indicate that satellite cells from the disused SSP retain sufficient potential of muscle growth despite the fatty infiltration.

Youth baseball players with elbow and shoulder pain have both low back and knee pain: a cross-sectional study.

PURPOSE: Serious arm injuries in youth baseball players have been increasing. Though a breakage in the kinetic chain could affect arm injuries, an association between arm injuries and insufficient support of the trunk and lower extremities is not well understood. The purpose of this study was to investigate the association of low back and knee pain with elbow and/or shoulder complaints among youth baseball players. METHODS: A self-administered questionnaire and document informed consent were mailed to youth athletes belonging to the Miyagi Amateur Sports Association. Multiple logistic regression analysis was used to examine the association of low back and knee pain with elbow and/or shoulder pain at the time of the questionnaire. Variables considered in the models were as follows: sex, age, BMI, years of athletic experience, position, team level, the amount of practice, participating day in team practice and game per week, frequency of participation in games, and practice intensity. RESULTS: The final study population was comprised 1582 youth baseball players (aged 6-15 years old, male 95.6 %) who had responded to the questionnaire. A total of 24.8 % (n = 381) had elbow and/or shoulder pain, whereas 8.5 % (n = 130) had low back pain and 13.1 % (n = 201) had knee pain. The prevalence of elbow and/or shoulder pain with concomitant low back and knee pain was 61.2 % (n = 82) and 51.9 % (n = 108) (p < 0.001), respectively. The presence of low back and knee pain was significantly associated with the prevalence of elbow and/or shoulder pain among youth baseball players [adjusted odds ratio (ORs): 4.31, 95 % confidence interval (95 % CI): 2.86-6.51, p < 0.001, and ORs: 2.92, 95 % CI: 2.09-4.09, p < 0.001, respectively]. For other variables, older age (10- and 11-year old: ORs: 1.73, 95 % CI 1.10-2.73, p = 0.018; 12-15 year old: ORs: 1.62, 95 % CI: 1.18-2.58, p = 0.006), pitcher (ORs: 1.46, 95 % CI: 1.10-1.94, p = 0.009), catcher (ORs: 1.69, 95 % CI: 1.24-2.31, p = 0.001,), and practice intensity (ORs: 1.58, 95 % CI: 1.22-2.06, p = 0.001) were significantly associated with elbow and/or shoulder pain. CONCLUSION: Both low back and knee pain were significantly associated with elbow and/or shoulder pain in youth baseball players. Clinicians should check the complaints of the trunk and lower extremities as well as those of the elbow and shoulder for preventing severe injuries in youth baseball players. Level of Evidence III.

Living status, economic hardship and sleep disturbance were associated with subjective shoulder pain in survivors of the Great East Japan Earthquake: A cross sectional study.

BACKGROUND: The Great East Japan Earthquake and devastating Tsunami hit hard everything on the northeastern coast of Japan. This study aimed to determine socio-psychological factors for "subjective shoulder pain" of the survivors at 2 years evaluated by a self-report questionnaire. METHODS: Between November 2012 to February 2013, survivors replied to the self-report questionnaire, and 2275 people consented to join this study. Living status was divided into 5 categories (1. same house as before the earthquake (reference group), 2. temporary small house, 3. apartment, 4. house of relatives or acquaintance, 5. new house) and economic hardship was divided into 4 categories (1. normal (reference group), 2. a little bit hard, 3. hard, 4. very hard). Gender, age, body mass index, living areas, smoking and drinking habits, complications of diabetes mellitus and cerebral stroke, working status, and walking time were considered as the confounding factors. Kessler Psychological Distress Scale of ≥10/24 and Athens Insomnia Scale of ≥6/24 points were defined as a presence of psychological distress and sleep disturbance, respectively. We used multiple logistic regression analysis to examine the association of shoulder pain with living environment, economic hardship, psychological distress, and sleep disturbance at 2 years after the earthquake. RESULTS: There were significant differences in the risk of having shoulder pain in those with "apartment" (OR = 1.74, 95% CI = 1.03-2.96), "house of relatives or acquaintance" (OR = 2.98, 95% CI = 1.42-6.25), economic hardship of "hard" (OR = 1.71, 95% CI = 1.08-2.7) and "very hard" (OR = 2.51, 95% CI = 1.47-4.29), and sleep disturbance (OR = 2.96, 95% CI = 2.05-4.27). CONCLUSIONS: Living status of "apartment" and "house of relatives or acquaintance", economic hardship of "hard" and "very hard", and "sleep disturbance" were significantly associated with shoulder pain.

Magnetic resonance imaging classification of haemodialysis-related amyloidosis of the shoulder: risk factors and arthroscopic treatment.

PURPOSE: This study proposed new magnetic resonance imaging (MRI) of haemodialysis shoulders (HDS) focusing on the changes of the rotator cuff, and rotator interval and risk factors for the development of HDS were examined. METHODS: Eighty-five shoulders in 72 patients with a chief complaint of shoulder pain during haemodialysis and at least 10 years of haemodialysis were included. They were classified into 5 groups based on the thickness of the rotator cuff and conditions of rotator interval. Clinical and radiological findings in each grade were examined, and risk factors for the development of HDS were evaluated. Arthroscopic surgeries were performed on 22 shoulders in 20 patients, and arthroscopic findings were also evaluated. RESULTS: Positive correlations for the development of HDS were observed in duration of haemodialysis, positive hepatitis C virus (HCV) infection, and previous haemodialysis-related orthopaedic surgery (P < 0.001, respectively). Strong correlations were observed between positive HCV and the progression of HDS (odds ratio 24.8, 95 % confidence interval 5.7-107.6). Arthroscopically, progression of the surrounding soft tissue degeneration was observed, and operative times were lengthened depending on the progression of MRI grading. CONCLUSION: A new MRI classification of HDS which may be helpful when considering arthroscopic surgeries has been proposed. Positive HCV infection was strongly associated with the progression of HDS on MRI. Conditions of the rotator interval and the rotator cuff based on the MRI classification should be examined when treating HDS patients. LEVEL OF EVIDENCE: III.