Periostin increased by mechanical stress upregulates interleukin-6 expression in the ligamentum flavum.

Ligamentum flavum (LF) hypertrophy is a major cause of lumbar spinal canal stenosis. Although mechanical stress is thought to be a major factor involved in LF hypertrophy, the exact mechanism by which it causes hypertrophy has not yet been fully elucidated. Here, changes in gene expression due to long-term mechanical stress were analyzed using RNA-seq in a rabbit LF hypertrophy model. In combination with previously reported analysis results, periostin was identified as a molecule whose expression fluctuates due to mechanical stress. The expression and function of periostin were further investigated using human LF tissues and primary LF cell cultures. Periostin was abundantly expressed in human hypertrophied LF tissues, and periostin gene expression was significantly correlated with LF thickness. In vitro, mechanical stress increased gene expressions of periostin, transforming growth factor-ß1, α-smooth muscle actin, collagen type 1 alpha 1, and interleukin-6 (IL-6) in LF cells. Periostin blockade suppressed the mechanical stress-induced gene expression of IL-6 while periostin treatment increased IL-6 gene expression. Our results suggest that periostin is upregulated by mechanical stress and promotes inflammation by upregulating IL-6 expression, which leads to LF degeneration and hypertrophy. Periostin may be a pivotal molecule for LF hypertrophy and a promising therapeutic target for lumbar spinal stenosis.

Discovery of novel indole derivatives as potent and selective inhibitors of proMMP-9 activation.

Matrix metalloproteinase-9 (MMP-9) is a secreted zinc-dependent endopeptidase that degrades the extracellular matrix and basement membrane of neurons, and then contributes to synaptic plasticity by remodeling the extracellular matrix. Inhibition of MMP-9 activity has therapeutic potential for neurodegenerative diseases such as fragile X syndrome. This paper reports the molecular design, synthesis, and in vitro studies of novel indole derivatives as inhibitors of proMMP-9 activation. High-throughput screening (HTS) of our internal compound library and subsequent merging of hit compounds 1 and 2 provided compound 4 as a bona-fide lead. X-ray structure-based design and subsequent lead optimization led to the discovery of compound 33, a highly potent and selective inhibitor of proMMP-9 activation.

Lower preoperative Hounsfield unit values as a risk factor for poor 5-year clinical outcomes after lumbar spine surgery.

OBJECTIVE: Hounsfield Unit (HU) value has been associated with future osteoporotic fractures and postoperative complications. However, no studies on the impact of low HU values on mid-term clinical outcomes following lumbar spine surgery have been reported. We aimed to evaluate the usefulness of preoperative HU values for 5-year clinical outcomes following lumbar spine surgery. METHODS: We enrolled 200 patients who underwent lumbar surgery (≤ 3-disc levels) for lumbar spinal stenosis. HU values were assessed using preoperative lumbar computed tomography as part of routine preoperative planning for lumbar surgery. Patients were divided into two groups based on the cutoff value of the HU values obtained from the receiver operating characteristic curve for the incidence of vertebral fractures within five years postoperatively. Clinical scores preoperatively and 1, 2, and 5 years postoperatively, including Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Short Form-36 (SF-36), were compared using a mixed-effects model. RESULTS: Comparative analysis indicated that all domains of JOABPEQ, except for lumbar function, and the physical component summary of the SF-36 were significantly worse in the low HU group than in the high HU group. Using multiple regression analysis, low HU values were significantly correlated with worse 5-year postoperative scores in all domains of JOABPEQ and SF-36. CONCLUSION: Low preoperative HU values are a risk factor for poor 5-year clinical outcomes after lumbar spine surgery. HU values are not only a valuable tool for analyzing bone mineral density but also may be a valuable poor prognostic factor of postoperative clinical outcomes.

Recovery of phosphorus, magnesium, and potassium from surplus activated sludge using existing sludge treatment facilities and thickened primary sludge.

The separation of P, K, and Mg from surplus activated sludge (SAS) was investigated using existing sludge treatment facilities and the thickened primary sludge (TPS). The addition of the TPS to the SAS storage tank accelerated the anaerobic release of the three elements from SAS with maximum efficiencies of about 60%. The efficiency of P release showed a significant correlation with the oxidation-reduction potential. Increasing the total solid concentration increased the release of elements. The released elements could be transferred to a separate liquid (SL) from a screw-press thickener, and maximum concentrations of P, K, and Mg were about 200, 60, and 35 mg/L, respectively. The addition of CaCl2 and NaOH solutions to SL precipitated P as hydroxyapatite. However, no precipitation of K and Mg occurred simultaneously with P, even when the pH of SL was increased to 9. These findings suggest that about 60% of P, K, and Mg can be separated from SAS into SL using existing sludge treatment facilities and TPS; however, a method other than precipitation would be needed to recover P and K from SL simultaneously.

Prediction of Slow-Flow Phenomenon After Stent Implantation Using Near-Infrared Spectroscopy in Patients With Acute and Chronic Coronary Syndrome.

BACKGROUND: The slow-flow phenomenon is associated with worse clinical outcomes after percutaneous coronary intervention (PCI), so our goal for this study was to see how predictive how near-infrared spectroscopy (NIRS) could be.Methods and Results: We enrolled 179 lesions from 152 patients who had de novo coronary stent implantation guided by NIRS-intravascular ultrasound (IVUS) (male: 69.1%, mean age: 74.3±11.5 years, acute coronary syndrome: 65.1%, diabetes: 42.1%). NIRS automatically determined the maximum 4-mm lipid core burden index (maxLCBI4 mm) value at pre- and post-PCI procedures. The slow-flow phenomenon was defined as the deterioration of TIMI (Thrombolysis in Myocardial Infarction) flows on angiography during the PCI procedure in the absence of mechanical obstruction. The slow-flow phenomenon occurred in 13 (7.3%) lesions, and the slow-flow phenomenon group had a significantly higher maxLCBI4 mm(740±147 vs. 471±223, P<0.001). The best maxLCBI4 mmcutoff point in both acute and chronic coronary syndrome was 578 and 480, with sensitivity of 100%, for predicting the slow-flow phenomenon. In the receiver-operating characteristics analysis, the area under the curve for acute and chronic coronary syndrome was 0.849 and 0.851, respectively. CONCLUSIONS: The results of this study support the utility of NIRS-IVUS-guided PCI for the prediction of the slow-flow phenomenon.

Less-invasive decompression procedures can reduce risk of reoperation for lumbar spinal stenosis with diffuse idiopathic skeletal hyperostosis extended to the lumbar segment: analysis of two retrospective cohorts.

PURPOSE: Clinical outcomes after decompression procedures are reportedly worse for lumbar spinal stenosis (LSS) with diffuse idiopathic skeletal hyperostosis (DISH), especially DISH extended to the lumbar segment (L-DISH). However, no studies have compared the effect of less-invasive surgery versus conventional decompression techniques for LSS with DISH. The purpose of this study was to compare the long-term risk of reoperation after decompression surgery focusing on LSS with L-DISH. METHODS: This study compared open procedure cohort (open conventional fenestration) and less-invasive procedure cohort (bilateral decompression via a unilateral approach) with ≥ 5 years of follow-up. After stratified analysis by L-DISH, patients with L-DISH were propensity score-matched by age and sex. RESULTS: There were 57 patients with L-DISH among 489 patients in the open procedure cohort and 41 patients with L-DISH among 297 patients in the less-invasive procedure cohort. The reoperation rates in L-DISH were higher in the open than less-invasive procedure cohort for overall reoperations (25% and 7%, p = 0.026) and reoperations at index levels (18% and 5%, p = 0.059). Propensity score-matched analysis in L-DISH demonstrated that open procedures were significantly associated with increased overall reoperations (hazard ratio [HR], 6.18; 95% confidence interval [CI], 1.37-27.93) and reoperations at index levels (HR, 4.80; 95% CI, 1.04-22.23); there was no difference in reoperation at other lumbar levels. CONCLUSIONS: Less-invasive procedures had a lower risk of reoperation, especially at index levels for LSS with L-DISH. Preserving midline-lumbar posterior elements could be desirable as a decompression procedure for LSS with L-DISH.

Relationship between body mass index and spinal pathology in community-dwelling older adults.

PURPOSE: To clarify the relationship between body mass index (BMI) and spinal pathologies including spinal sagittal balance, back extensor strength (BES), paraspinal muscle mass, prevalent vertebral fracture, disc degeneration, Modic changes, low back pain, and quality of life (QOL) in community-dwelling older adults. METHODS: This study included 380 participants (age: ≥ 65 years, male/female: 152/228) from the Shiraniwa Study. Multivariate nonlinear regression analysis was used to investigate the relationship between BMI and sagittal vertical axis (SVA), BES, paraspinal muscle mass, visual analog scale (VAS) for low back pain, Oswestry Disability Index (ODI), and EuroQoL-5 Dimension (EQ5D) score after adjusting for sex, age, Hospital Anxiety and Depression Scale score, and Charlson Comorbidity Index. In addition, multiple logistic regression analysis was used to investigate the association between BMI and prevalent vertebral fracture, disc degeneration, and Modic changes. RESULTS: BMI was significantly correlated with SVA, BES, paraspinal muscle mass, VAS, ODI, and EQ5D score. The increase in BMI was associated with the deterioration of all outcomes, which accelerated when the BMI increased from approximately 22-23 kg/m2. Moreover, overweight/obesity was significantly correlated with disc degeneration and Modic changes. CONCLUSION: Increased BMI is significantly associated with spinal pathologies such as SVA, BES, paraspinal muscle mass, VAS, QOL, disc degeneration, and Modic changes. The findings suggest that measures for controlling overweight and obesity among older adults can play an important role in the prevention and treatment of spinal pathologies.

Machine-learning-based approach for nonunion prediction following osteoporotic vertebral fractures.

PURPOSE: An osteoporotic vertebral fracture (OVF) is a common disease that causes disabilities in elderly patients. In particular, patients with nonunion following an OVF often experience severe back pain and require surgical intervention. However, nonunion diagnosis generally takes more than six months. Although several studies have advocated the use of magnetic resonance imaging (MRI) observations as predictive factors, they exhibit insufficient accuracy. The purpose of this study was to create a predictive model for OVF nonunion using machine learning (ML). METHODS: We used datasets from two prospective cohort studies for OVF nonunion prediction based on conservative treatment. Among 573 patients with acute OVFs exceeding 65 years in age enrolled in this study, 505 were analyzed. The demographic data, fracture type, and MRI observations of both studies were analyzed using ML. The ML architecture utilized in this study included a logistic regression model, decision tree, extreme gradient boosting (XGBoost), and random forest (RF). The datasets were processed using Python. RESULTS: The two ML algorithms, XGBoost and RF, exhibited higher area under the receiver operating characteristic curves (AUCs) than the logistic regression and decision tree models (AUC = 0.860 and 0.845 for RF and XGBoost, respectively). The present study found that MRI findings, anterior height ratio, kyphotic angle, BMI, VAS, age, posterior wall injury, fracture level, and smoking habit ranked as important features in the ML algorithms. CONCLUSION: ML-based algorithms might be more effective than conventional methods for nonunion prediction following OVFs.

Bone Marrow-Derived Fibrin Clots Stimulate Healing of a Knee Meniscal Defect in a Rabbit Model.

PURPOSE: To determine the in vivo effectiveness of bone marrow aspirate-derived (BMA) fibrin clots for avascular meniscal defect healing in a rabbit model. METHODS: In 42 Japanese white rabbits, a 2.0-mm cylindrical defect was introduced into the avascular zone of the anterior part of the medial meniscus in the bilateral knees. The rabbits were grouped according to implantation of a BMA fibrin clot (BMA group) or a peripheral blood (PB)-derived clot (PB group) into the defect and nonimplantation (control group). Macroscopic and histological assessments were performed using a scoring system at 4 and 12 weeks after surgery. At 12 weeks after surgery, compressive stress was analyzed biomechanically. RESULTS: The meniscal score in the BMA group (12.1) was greater than that in the PB group (5.5; P = .031) and control group (4.4; P = .013) at 4 weeks. The meniscal score in the BMA group (13.1) was greater than that in the control group (6.4; BMA = 13.1; P = .0046) at 12 weeks. In the biomechanical analysis, the BMA group demonstrated significantly higher compressive strength than the PB group (6.6 MPa) (BMA = 15.4 MPa; P = .0201) and control group (3.6 MPa; BMA = 15.4 MPa; P = .007). CONCLUSIONS: Implantation of BMA fibrin clots into the meniscal defect of the avascular zone in a rabbit model improved the meniscal score at 4 weeks and strengthened the reparative meniscal tissue at 12 weeks compared with the implantation of PB fibrin clots. CLINICAL RELEVANCE: Healing in the avascular zone of the meniscus can be problematic. Approaches to improving this healing response have had variable results. This study provides additional information that may help improve the outcomes in patients with these injuries.

Maternal cardiopulmonary resuscitation.

The perinatal resuscitation history in Japan is short, with the earliest efforts in the field of neonatology. In contrast, the standardization and dissemination of maternal resuscitation is lagging. With the establishment of the Maternal Death Reporting Project and the Maternal Death Case Review and Evaluation Committee in 2010, with the aim of reducing maternal deaths, the true situation of maternal deaths came to light. Subsequently, in 2015, the Japan Council for the Dissemination of Maternal Emergency Life Support Systems (J-CIMELS) was established to educate and disseminate simulations in maternal emergency care; training sessions on maternal resuscitation are now conducted in all prefectures. Since the launch of the project and council, the maternal mortality rate in Japan (especially due to obstetric critical hemorrhage) has gradually decreased. This has been probably achieved due to the tireless efforts of medical personnel involved in perinatal care, as well as the various activities conducted so far. However, there are no standardized guidelines for maternal resuscitation yet. Therefore, a committee was set up within the Japan Resuscitation Council to develop a maternal resuscitation protocol, and the Guidelines for Maternal Resuscitation 2020 was created in 2021. These guidelines are expected to make the use of high-quality resuscitation methods more widespread than ever before. This presentation will provide an overview of the Guidelines for Maternal Resuscitation 2020.

Artificial intelligence model to identify elderly patients with locomotive syndrome: A cross-section study.

BACKGROUND: Identifying elderly individuals with locomotive syndrome is important to prevent disability in this population. Although screening tools for locomotive syndrome are available, these require time commitment and are limited by an individual's ability to complete questionnaires independently. To improve on this limitation, we developed a screening tool that uses information on the distribution of pressure on the plantar surface of the foot with an artificial intelligence (AI)-based decision system to identify patients with locomotor syndrome. Herein, we describe our AI-based system and evaluate its performance. METHODS: This was a cross-sectional study of 409 participants (mean age, 73.5 years). A foot scan pressure system was used to record the planter pressure distribution during gait. In the image processing step, we developed a convolutional neural network (CNN) to return the logit of the probability of locomotive syndrome based on foot pressure images. In the logistic regression step of the AI model, we estimated the predictor coefficients, including age, sex, height, weight, and the output of the CNN, based on foot pressure images. RESULTS: The AI model improved the identification of locomotive syndrome among elderly individuals compared to clinical data, with an area under curve of 0.84 (95% confidence interval, 0.79-0.88) for the AI model compared to 0.80 (95% confidence interval, 0.75-0.85) for the clinical model. Including the footprint force distribution image significantly improved the prediction algorithm (the net reclassification improvement was 0.675 [95% confidence interval, 0.45-0.90] P < 0.01; the integrated discrimination improvement was 0.059 [95% confidence interval, 0.039-0.088] P < 0.01). CONCLUSIONS: The AI system, which includes force distribution over the plantar surface of the foot during gait, is an effective tool to screen for locomotive syndrome.

Development of locomotive syndrome in elderly population after COVID-19 outbreak: A population-based cross-sectional study with over 12,000 participants.

BACKGROUND: Restrictions during the coronavirus disease 2019 (COVID-19) pandemic have decreased physical activity levels, which may result in locomotive syndrome. This study evaluated the change in locomotive syndrome prevalence and associated risk factors among an elderly population before and after a coronavirus outbreak. METHODS: This written self-administered cross-sectional survey was conducted in conjunction with the coronavirus disease vaccination program in Habikino City, Japan. Participants who were aged ≥65 years completed the five-question Geriatric Locomotive Function Scale before and during the pandemic. The diagnosis of locomotive syndrome and its stage was based on the Geriatric Locomotive Function Scale score: stage 1 (2-3 points), 2 (4-5 points), and 3 (≥6 points). Data on lifestyle changes, including regular exercise, during the pandemic were collected. RESULTS: This study included 12,197 participants (36.7% of the city's total elderly residents). The prevalence of locomotive syndrome increased from 41.3% to 47.1% after the outbreak. In total, 765 (6.3% of overall population) and 295 (9.5% of the participants who had stages 1-2 before the pandemic) participants developed locomotive syndrome and stage 3 locomotive syndrome, respectively. The multivariate logistic regression analysis indicated that a decrease in exercise was significantly associated with the onset of locomotive syndrome (all stages) (odds ratio = 2.5, p < 0.001) and locomotive syndrome stage 3 (odds ratio = 2.6, p < 0.001). CONCLUSIONS: Extrapolation of the study's findings to the entire population of Japan suggests that approximately 2 million elderly individuals might develop locomotive syndrome after the coronavirus outbreak. Additionally, 10% of the participants with mild-moderate locomotive syndrome before the pandemic may develop severe locomotive syndrome after the outbreak. The greatest risk factor for new-onset or worsening locomotive syndrome was a decrease in daily exercise. Thus, there is an urgent need for adequate exercise guidelines during the coronavirus pandemic, especially for the elderly population.

Risk Factors for Vulnerable Plaque Detected Using Near-Infrared Spectroscopy in Patients Receiving Statin Therapy with No History of Coronary Artery Disease.

Residual risk of atherosclerosis remains high despite the use of lipid-lowering therapy with statins. Near-infrared spectroscopy intravascular ultrasound imaging (NIRS-IVUS) can identify vulnerable plaque via the detection of lipid-rich plaque. This study aimed to reveal the clinical characteristics of patients with vulnerable plaque despite statin therapy.NIRS-IVUS was used to determine the maximum 4 mm Lipid Core Burden Index (MaxLCBI4 mm) values of 38 de novo culprit lesions from 32 patients with acute coronary syndrome (53%) (mean age: 73.1 ± 13.1 years) who underwent percutaneous coronary intervention after a minimum 6 months of statin therapy for primary prevention. A patient with vulnerable plaque was defined as an individual presenting at least 1 target lesion with a vulnerable plaque (MaxLCBI4 mm > 400). Overall, the average low-density lipoprotein cholesterol (LDL-C) level was 95.5 ± 27.2 mg/dL. Patients in the vulnerable plaque group were younger and had higher LDL-C, triglycerides, and non-high-density lipoprotein cholesterol (HDL-C) levels than those in the non-vulnerable plaque group. The MaxLCBI4 mm was positively correlated with LDL-C (P = 0.0002), triglycerides (P = 0.0003), and non-HDL-C (P = 0.0001). In multivariate analysis, all 3 treatable lipid components failed to show an independent relationship with the patients with vulnerable plaque. Using receiver-operating characteristics curve analysis, the cutoff points for LDL-C, triglycerides, and non-HDL-C were determined to be 78 mg/dL, 108 mg/dL, and 111 mg/dL, respectively, at MaxLCBI4 mm > 400. In conclusion, this study supports a more comprehensive and aggressive lipid-lowering therapy for the primary prevention of coronary artery disease.

Neck pain and related factors in patients with rheumatoid arthritis.

OBJECTIVES: In rheumatoid arthritis, neck pain can be caused by inflammatory reactions or cervical lesions, but the prevalence and associated factors have not been well studied. This study aimed to investigate the prevalence of neck pain in patients with rheumatoid arthritis and elucidate the related factors. METHODS: This study included 146 patients with rheumatoid arthritis. Neck pain, quality of life, and levels of anxiety and depression were evaluated using a questionnaire. Cervical lesions and spinal alignment were evaluated using plain radiograph and magnetic resonance imaging. Factors associated with neck pain were analysed using a logistic regression model. RESULTS: Fifty-six per cent of the patients had neck pain, and the quality of life scores were significantly worse in these patients. Multivariate analysis revealed age, C7 sagittal vertical axis, upper cervical lesion, and endplate erosion as factors associated with neck pain in patients with rheumatoid arthritis. CONCLUSIONS: More than half the patients with rheumatoid arthritis suffer from neck pain, and neck pain affects the quality of life and activities of daily living. Neck pain was associated with upper cervical lesion and endplate erosion suggesting the importance of radiological examination in patients with rheumatoid arthritis and neck pain.

Incidence of and risk factors for spondylolisthesis, scoliosis, and vertebral fracture in rheumatoid arthritis.

INTRODUCTION: Although lumbar lesions such as spondylolisthesis, scoliosis, and vertebral fracture are not specific to rheumatoid arthritis (RA), the prevalence is high in RA patients. However, no longitudinal study has evaluated lumbar lesions in RA. This study aimed to investigate the incidence of and risk factors for lumbar lesions in RA by a prospective longitudinal cohort study. MATERIALS AND METHODS: The study cohort comprised 110 patients with RA from the 'analysis of factors for RA spinal disorders (AFFORD)' study who completed the secondary survey at a single orthopaedic outpatient RA clinic. Radiological examination included standing radiographs and magnetic resonance imaging (MRI) of the lumbar spine. New development of spondylolisthesis, scoliosis, and vertebral fracture were assessed between baseline and secondary survey. RESULTS: The incidences of spondylolisthesis, scoliosis, and vertebral fracture were 42%, 16%, and 12%, respectively, during a mean follow-up of 7 years. The independent risk factor for de novo scoliosis was poor control of RA (adjusted odds ratio [aOR] 4.81, p = 0.011), while the independent risk factors for new vertebral fracture was use of glucocorticoid at secondary survey (aOR 14.87, p = 0.012). Patients with de novo scoliosis exhibited more severe low back pain and lower quality of life than those without. CONCLUSION: The incidence of scoliosis was related in patients with poor control of RA, while new vertebral fracture was more common in patients with use of glucocorticoid. Control of disease activity might be important in preventing radiological lumbar disorders in RA.

Decreased daily exercise since the COVID-19 pandemic and the deterioration of health-related quality of life in the elderly population: a population-based cross-sectional study.

BACKGROUNDS: The current prolonging state of the coronavirus disease (COVID-19), could affect many aspects of people's lives, especially the elderly population who experience a decrease in regular exercise. However, whether this decrease in regular exercise affects health-related quality of life (HRQOL) of the elderly population, remains unclear. METHODS: The current population-based cross-sectional survey aimed to identify the relationship between the decrease in regular exercise since the COVID-19 pandemic and any changes in the HRQOL in the general elderly Japanese population. This study was conducted as a part of the COVID-19 vaccination program in Habikino city in Japan, between June and July 2021 using printed questionnaires. The participants included residents of the city who were aged ≥ 65 years, and were being vaccinated for COVID-19 at the city's center. The EuroQoL 5-dimension 5-level (EQ-5D-5L) was assessed at two different time points (pre-pandemic and current). Data on lifestyle changes, including their regular exercise routine since the pandemic, were collected. RESULTS: Finally, 14,494 participants (45.3% of the city's total elderly residents) were enrolled. Among them, 4321 participants (29.8%) had experienced a decrease in regular exercise since the pandemic. These participants showed a significantly higher rate of deterioration in all the EQ-5D-5L domains than the participants who did not experience a decrease in regular exercise. In the multivariate logistic regression analysis, participants with a decrease in regular exercise were significantly related to the EQ-5D-5L index deterioration compared to those with an unchanged regular exercise routine (p < 0.001, adjusted odds ratio = 5.60) independent of age, sex, body mass index (BMI), and the existence of back pain, joint pain, and/or numbness of extremities. CONCLUSION: The current survey that included 45% of the elderly people living in a city revealed that up to 30% of them had experienced a decrease in the regular exercise since the COVID-19 pandemic. This decrease was significantly related to HRQOL deterioration independent of age, sex, BMI, baseline activities of daily living status, and musculoskeletal symptoms. Our data could be useful for understanding the current problem and provide a strong basis for the creation of exercise guidelines for the post-COVID-19 era.

Delayed aortic injury after thoracic corrective osteotomy: a case report.

PURPOSE: To present a case of delayed aortic perforation due to a nondisplaced fracture of the 9th rib after vertebral osteotomy for degenerative kyphoscoliosis in patients with osteoporosis. METHODS: A 78-year-old female patient with osteoporosis had undergone T9-iliac correction surgery for degenerative kyphoscoliosis. After 2 years, the patient underwent T10 pedicle subtraction osteotomy for a T10 vertebral fracture and progression of kyphosis. Postoperatively, the patient had been doing well for 3 weeks; however, just before the day of discharge, she died following a cardiopulmonary arrest. An autopsy was performed with the consent of her family. RESULTS: Autopsy revealed a large amount of blood and a clot in the left thoracic cavity. Aortic perforation was found just in front of a nondisplaced fracture of the left 9th rib. CONCLUSION: This report describes a new critical complication after spinal correction surgery. Even without pedicle screw malposition, aortic injuries can happen to patients with osteoporosis after corrective osteotomy for degenerative kyphoscoliosis due to positional change of aorta and fragility of the ribs. The spine surgeon should be aware of this type of complication, and rib fractures around the aorta after vertebral osteotomy should not be neglected even when there is no displacement.

Decreased muscle mass and strength affected spinal sagittal malalignment.

PURPOSE: Correction surgeries for spinal malalignment showed good clinical outcomes; however, there were concerns including increased invasiveness, complications, and impact on medico-economics. Ideally, an early intervention is needed. To better understand the patho-mechanism and natural course of spinal alignment, the effect of factors such as muscle mass and strength on spinal sagittal imbalance were determined in a multicenter cross-sectional study. METHODS: After excluding metal implant recipients, 1823 of 2551 patients (mean age: 69.2 ± 13.8 years; men 768, women 1055) were enrolled. Age, sex, past medical history (Charlson comorbidity index), body mass index (BMI), grip strength (GS), and trunk muscle mass (TM) were reviewed. Spinal sagittal imbalance was determined by the SRS-Schwab classification. Multiple comparison analysis among four groups (Normal, Mild, Moderate, Severe) and multinomial logistic regression analysis were performed. RESULTS: On multiple comparison analysis, with progressing spinal malalignment, age in both sexes tended to be higher; further, TM in women and GS in both sexes tended to be low. On multinomial logistic regression analysis, age and BMI were positively associated with spinal sagittal malalignment in Mild, Moderate, and Severe groups. TM in Moderate and Severe groups and GS in the Moderate group were negatively associated with spinal sagittal malalignment. CONCLUSION: Aging, obesity, low TM, and low GS are potential risk factors for spinal sagittal malalignment. Especially, low TM and low GS are potentially associated with more progressed spinal sagittal malalignment. Thus, early intervention for muscles, such as exercise therapy, is needed, while the spinal sagittal alignment is normal or mildly affected.

Comparison of new and old all-inside suture devices in meniscal cyst formation rates after meniscal repair.

PURPOSE: We compared the magnetic resonance imaging (MRI)-confirmed cyst formation rate after meniscal tear repair using a new all-inside suture device (N group) versus the older all-inside suture device (O group). METHODS: Between October 2008 and July 2017, 94 consecutive menisci of 89 patients were diagnosed with meniscal tears and underwent arthroscopic meniscal repair using the all-inside suture device. Five of these patients were lost to follow-up within 12 months and were excluded from the study. The remaining 89 menisci were followed up for at least 12 months and were included in this retrospective cohort study. Older all-inside suture devices (FasT-Fix, Ultra FasT-Fix) were used until December 2012, while the new all-inside suture device (FasT-Fix 360) was used from January 2013 onwards. Meniscal cysts were detected on T2-weighted fat-suppressed MRI at 12 months postoperatively. Multiple logistic regression analysis was used to identify demographic and clinical factors associated with the use of the new all-inside suture device and cyst formation. RESULTS: In total, 36 and 53 menisci were included in the N and O groups, respectively. The incidence of meniscal cysts was significantly greater in the O group (14 out of 53, 26.4%) than in the N group (two out of 36, 5.56%) (P = 0.012). Two patients in the O group had symptomatic cysts that required removal. Multivariate logistic analyses showed that the cyst formation risk significantly decreased after using the new all-inside suture device than the older all-inside suture devices (odds ratio = 0.139; P = 0.04). CONCLUSIONS: The MRI-confirmed cyst formation rate after meniscal tear repair was significantly lower using the new than the older all-inside suture devices, indicating that the use of a low-profile device may decrease the cyst formation rate.

The health-related quality of life of patients with musculoskeletal disorders after the COVID-19 pandemic.

PURPOSE: To verify changes in the health-related quality of life (HRQOL) of patients with musculoskeletal disorders after the coronavirus disease 2019 (COVID-19) pandemic and to assess the relationship between the patients' change in several activities of daily living and in the HRQOL to discover factors related to the deterioration in HRQOL. METHODS: A multi-centre cross-sectional questionnaire survey was administered between November 1, 2020, and December 31, 2020, in Japan. The participants included those who visited the orthopaedics clinic within the survey period and had experienced the first and second waves of COVID-19 in Japan and the first stay-at-home order issued by the government. Patients' HRQOL at the two different time points (pre-outbreak and post-second wave of COVID-19) was assessed with the EuroQoL-5 dimensions 5-level (EQ-5D). RESULTS: The survey was completed by 1254 patients (average age: 52.5 ± 21.9 years; 644 women). Among them, 431 patients (34.3%) reported a decrease in the EQ-5D index after the pandemic. The largest decrease was in the pain domain followed by the mobility domain. Multivariate logistic regression analysis revealed that the patients with decreased regular exercise habits were significantly related to deterioration in HRQOL compared with those with stable regular exercise (adjusted odds ratio = 1.76, p < 0.001) independently from age, sex, and change of symptoms. CONCLUSIONS: Up to 35% of patients with musculoskeletal disorders reported deterioration of HRQOL after the COVID-19 pandemic. Pain and mobility rather than anxiety were the two leading factors of the HRQOL decrease. The decrease in regular exercise was related to the HRQOL decrease.