Application of machine learning models on predicting the length of hospital stay in fragility fracture patients.

BACKGROUND: The rate of geriatric hip fracture in Hong Kong is increasing steadily and associated mortality in fragility fracture is high. Moreover, fragility fracture patients increase the pressure on hospital bed demand. Hence, this study aims to develop a predictive model on the length of hospital stay (LOS) of geriatric fragility fracture patients using machine learning (ML) techniques. METHODS: In this study, we use the basic information, such as gender, age, residence type, etc., and medical parameters of patients, such as the modified functional ambulation classification score (MFAC), elderly mobility scale (EMS), modified Barthel index (MBI) etc, to predict whether the length of stay would exceed 21 days or not. RESULTS: Our results are promising despite the relatively small sample size of 8000 data. We develop various models with three approaches, namely (1) regularizing gradient boosting frameworks, (2) custom-built artificial neural network and (3) Google's Wide & Deep Learning technique. Our best results resulted from our Wide & Deep model with an accuracy of 0.79, with a precision of 0.73, with an area under the receiver operating characteristic curve (AUC-ROC) of 0.84. Feature importance analysis indicates (1) the type of hospital the patient is admitted to, (2) the mental state of the patient and (3) the length of stay at the acute hospital all have a relatively strong impact on the length of stay at palliative care. CONCLUSIONS: Applying ML techniques to improve the quality and efficiency in the healthcare sector is becoming popular in Hong Kong and around the globe, but there has not yet been research related to fragility fracture. The integration of machine learning may be useful for health-care professionals to better identify fragility fracture patients at risk of prolonged hospital stays. These findings underline the usefulness of machine learning techniques in optimizing resource allocation by identifying high risk individuals and providing appropriate management to improve treatment outcome.

The imminent risk of a fracture-existing worldwide data: a systematic review and meta-analysis.

The overall incidence of imminent fracture after a prior fragility fracture was 7.58% in the first year and 11.58% in the first 2 years. Approximately half of re-fractures occurred in the first 2 years after a fragility fracture. Older patients that have suffered from a fragility fracture should be treated promptly, with immediate care and a secondary fracture prevention to prevent the high imminent risk of a fracture. INTRODUCTION: Imminent fractures refer to the fractures that occur within 2 years of an initial fracture. It is well known that the risk of a subsequent fracture is not constant with time and occurs shortly after the initial one. This systematic review and meta-analysis aimed to present the existing data on imminent fracture worldwide. METHODS: Literature search was conducted in Pubmed, Embase, and Web of Science databases until 26 October 2021 for studies reporting the incidence of imminent osteoporotic fractures among people aged 50 years or older. The overall incidence of imminent fracture was pooled and subgroup analyses of index fracture sites and regions on incidence of imminent fracture were performed, with the 95% confidence interval (CI) being calculated. Percentage of imminent fracture occurring in follow-up period was calculated and pooled by meta-analysis. Hazard ratio (HR) was used to estimate the gender differences on the imminent risk of fracture. RESULTS: A total of 1446 articles were identified. Nineteen observational studies were eligible for our systematic review, in which 18 were used for quantitative analysis. Pooled overall incidence of imminent fracture in the first year after an osteoporotic fracture was 7.58% (95% CI 5.84 to 9.31%) and cumulative incidence in the first 2 years was 11.58% (95% CI 8.94 to 14.21%). Subgroup analysis showed that in the first 2 years, the pooled incidence in Asia was 7.30% (95% CI 3.42 to 11.18%), whilst incidence in Europe/North America was 13.17% (95% CI 10.14 to 16.20%). In included studies with follow-up period of more than 5 years, pooled imminent fracture percentage in the first 2 years was 47.24% (95% CI 26.18 to 68.30%). Hazard ratio (HR) on gender showed that women had an overall slight increase in risk of imminent fractures (HR 1.18, 95% CI 1.11 to 1.25). CONCLUSION: The incidence of imminent fracture is high globally at 11.58%. Approximately half of all refractures occur in the first 2 years after an index fragility fracture. Older patients that have suffered from a fragility fracture should be treated promptly. Also, immediate care and secondary fracture prevention are necessary to prevent the high imminent risk of a fracture, especially within the first 2 years.

Gait Synergy Analysis and Modeling on Amputees and Stroke Patients for Lower Limb Assistive Devices.

The concept of synergy has drawn attention and been applied to lower limb assistive devices such as exoskeletons and prostheses for improving human-machine interaction. A better understanding of the influence of gait kinematics on synergies and a better synergy-modeling method are important for device design and improvement. To this end, gait data from healthy, amputee, and stroke subjects were collected. First, continuous relative phase (CRP) was used to quantify their synergies and explore the influence of kinematics. Second, long short-term memory (LSTM) and principal component analysis (PCA) were adopted to model interlimb synergy and intralimb synergy, respectively. The results indicate that the limited hip and knee range of motions (RoMs) in stroke patients and amputees significantly influence their synergies in different ways. In interlimb synergy modeling, LSTM (RMSE: 0.798° (hip) and 1.963° (knee)) has lower errors than PCA (RMSE: 5.050° (hip) and 10.353° (knee)), which is frequently used in the literature. Further, in intralimb synergy modeling, LSTM (RMSE: 3.894°) enables better synergy modeling than PCA (RMSE: 10.312°). In conclusion, stroke patients and amputees perform different compensatory mechanisms to adapt to new interlimb and intralimb synergies different from healthy people. LSTM has better synergy modeling and shows a promise for generating trajectories in line with the wearer's motion for lower limb assistive devices.

Use of mobile app to enhance functional outcomes and adherence of home-based rehabilitation program for elderly with hip fracture: A randomized controlled trial.

Background: Mobile app has been used to improve exercise adherence and outcomes in populations with different health conditions. However, the effectiveness of mobile app in delivering home-based rehabilitation program to elderly patients with hip fracture is unclear. Objective: The aim of this study was to test the effectiveness of mobile app in delivering home-based rehabilitation program for improving functional outcomes and reducing caregiver stress with enhancing adherence among the elderly patients with hip fracture. Methods: A randomized controlled trial with an intervention period of two months was performed. Eligible participants were randomized into either experimental group with home-based rehabilitation program using a mobile app or control group with home-based rehabilitation program using an exercise pamphlet. Primary outcomes were Modified Functional Ambulatory Category (MFAC), Elderly Mobility Scale (EMS) and Lower Extremity Functional Scale (LEFS). Secondary outcomes were exercise adherence and Modified Caregiver Strain Index (M-CSI). The outcomes were collected at pre-discharge training session, one month and two months after hospital discharge. Results: A total of 50 participants were enrolled, with 19 participants in the experimental group and 20 participants in the control group. Eleven participants had withdrawn from the study. The experimental group showed higher exercise adherence than the control group in first month (p=0.03). There were no between-group differences in MFAC, EMS, LEFS and M-CSI at the first month and second month. Conclusion: Use of the mobile app improved exercise adherence, yet it did not improve physical performance, self-efficacy and reduce caregiver stress when compared to a standard home rehabilitation program for elderly patients with hip fracture. Further studies to investigate the benefits of mobile apps are required. (ClinicalTrials.gov ID: NCT04053348.).

Global sagittal alignment of the spine, pelvis, lower limb after vertebral compression fracture and its effect on quality of life.

BACKGROUND: Vertebral compression fractures (VCFs) are the most common among all osteoporotic fractures. The body may compensate to the kyphosis from vertebral compression fractures with lordosis of the adjacent spinal segments, rotation of the pelvis, knee flexion and ankle dorsiflexion. However, the detailed degree of body compensation, especially the lower limb, remains uncertain. Herein, the aim of this study is to investigate the values of global sagittal alignments (GSA) parameters, including the spine, pelvis and lower limbs, in patients with and without VCFs, as well as to evaluate the effect of VCFs on various quality of life (QoL) parameters. METHODS: A cross-sectional study was conducted from May 2015 to June 2018. A total of 142 patients with VCFs aged over 60 years old and 108 age-matched asymptomatic controls were recruited. Whole body sagittal alignment including thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), T1-pelvic angle (TPA), knee-flex angle (KA) and ankle-flex angle (AA) were measured. In addition, lower back pain and quality of life were assessed using self-reported questionnaires. RESULTS: Compared to asymptomatic controls, patients with VCF showed significantly greater TK (33.4o ± 16.4o vs 28.4o ± 11.4o; p < 0.01), PT (25.4o ± 10.5o vs 16.6o ± 8.9o; p < 0.001), PI (54.6o ± 11.8o vs 45.8o ± 12.0o; p < 0.001), SVA (49.1 mm ± 39.6 mm vs 31.5 mm ± 29.3 mm; p < 0.01), and TPA (28.6o ± 10.8o vs 14.8o ± 8.6o; p < 0.001). Whereas for lower limb alignment, patients with VCF showed significantly higher KA (10.1o ± 7.8o vs 6.0o ± 6.4o; p < 0.001) and AA (7.0o ± 3.9o vs 4.8o ± 3.6o; p < 0.001) than controls. The number of VCF significantly correlated with lower limb alignments (KA and AA) and global sagittal balance (TPA). VCF patients showed poorer quality of life assessment scores in terms of SF-12 (30.0 ± 8.3 vs 72.4 ± 16.9; p < 0.001), ODI (37.8 ± 24.0 vs 18.7 ± 16.6; p < 0.001) and VAS (3.8 ± 2.8 vs 1.9 ± 2.2; p < 0.001). CONCLUSION: This is the first study to illustrate the abnormal lower limb alignment exhibited in patients with VCF. Patients with VCF showed an overall worse global sagittal alignment and decreased quality of life. Poorer global sagittal alignment of VCF patients also imply worse quality of life and more severe VCF.

Does additional weekend and holiday physiotherapy benefit geriatric patients with hip fracture? - A case-historical control study.

OBJECTIVE: To evaluate the new service model of additional weekend and holiday physiotherapy (PT) by comparing functional outcomes and hospital length of stay between a group of geriatric patients with hip fracture receiving daily PT training and a group of geriatric patients with hip fracture receiving weekdays PT training. METHODS: A retrospective case-historical control chart review was conducted and a total of 355 patients were identified. Between-group comparisons were done on functional outcomes including Modified Functional Ambulation Classification (MFAC), Elderly Mobility Scale (EMS), Modified Barthel Index (MBI) and process outcome in terms of length of stay (LOS) in hospitals. RESULTS: With similar characteristics, patients who received weekend and holiday PT training had a significant higher percentage of MFAC Category III and a significant lower percentage of MFAC Category II ( p = 0 . 015 ) and significant higher MBI scores ( mean ± standard deviation, median; Study group: 47 . 4 ± 19 . 6 points, 51 points; Control group: 43 . 0 ± 20 . 0 points, 43 points; p = 0 . 042 ) upon admission to rehabilitation hospital. A similar trend in EMS scores (Study group: 8 . 2 ± 5 . 5 points, 7 points; Control group: 8 . 4 ± 6 . 1 points, 6 points; p = 0 . 998 ) and MBI scores (Study group: 63 . 0 ± 23 . 4 points, 68 points; Control group: 61 . 2 ± 26 . 1 points, 64 points; p = 0 . 743 ) were observed upon discharge from the rehabilitation hospital. The average LOS in acute hospitals remained static (Study group: 7 . 7 ± 3 . 9 days, 7 days; Control group: 7 . 4 ± 5 . 0 days, 6 days; p = 0 . 192 ). The average LOS in rehabilitation hospital (Study group: 20 . 0 ± 5 . 5 days, 20 days; Control group: 24 . 3 ± 9 . 9 days, 23 days; p < 0 . 001 ) and total in-patient LOS (Study group: 26 . 7 ± 6 . 4 days, 26 days; Control group: 30 . 7 ± 11 . 2 days, 28 days; p < 0 . 001 ) were significantly reduced. A higher percentage of days having PT training during hospitalization in rehabilitation hospital was shown with the implementation of new service (Study group: 89.1%; Control group: 65.9%, p < 0 . 001 ). CONCLUSION: Additional weekend and holiday PT training in post-operative acute and rehabilitation hospitalization benefits geriatric patients with hip fracture in terms of improved training efficiency, where hospital LOS was shortened with more PT sessions, without any significant impacts on functional outcome.

Changes in dural sac caliber with standing MRI improve correlation with symptoms of lumbar spinal stenosis.

PURPOSE: Weight bearing does alter the dimension of lumbar spinal canal, but no study has analyzed its clinical correlation. This study aims to evaluate whether the changes in dural sac cross-sectional area (DSCA) and sagittal anteroposterior (AP) diameter on standing magnetic resonance imaging (MRI) correlate better with clinical symptoms of lumbar spinal stenosis. METHODS: Seventy consecutive patients with neurogenic claudication were prospectively recruited to undergo a 0.25-T MRI examination performed in supine and standing positions. Clinical symptoms including the walking distance, Visual Analogue Score of leg pain, Chinese Oswestry Disability Index, and short form-12 were assessed. DSCA and sagittal AP diameter at the most constricted spinal level on supine and standing positions were measured and correlated with each clinical symptom by Pearson correlation coefficients (r). RESULTS: DSCA and AP diameter on standing MRI and their % changes from supine to standing showed significant (r = 0.55, 0.53, -0.44, -0.43; p < 0.001) and better correlations than those on supine MRI (r = 0.39, 0.42; p < 0.001) with walking distance. Significant correlations were also found between dural sac calibers on standing MRI and leg pain scores (r = -0.20, r = -0.25; p < 0.05). Patients walking ≤500 m had a significantly smaller DSCA, narrower AP diameter and greater % change in dural sac calibers (p < 0.01) than those walking >500 m. A >30% reduction of DSCA and AP diameter was observed in patients with worse claudication distance (p < 0.05). CONCLUSION: DSCA and sagittal AP diameter on standing MRI correlate significantly and better than findings on supine MRI with claudication symptoms. Standing MRI demonstrates dynamic changes of dural sac and provides an additional value to supine MRI in correlating clinical symptoms of lumbar spinal stenosis.

Integrative Western and Traditional Chinese Medicine service model for low back pain.

OBJECTIVE: Low back pain (LBP) is a common, costly, and debilitating condition that creates a heavy socioeconomic burden on the global health care systems. In Western Medicine (WM), the treatment goals are to relieve pain, reduce disability, and enhance rehabilitation. In Traditional Chinese Medicine (TCM), acupuncture is frequently used to rebalance the vital energy "Qi". Whilst numerous literatures are available from WM and TCM in the management of LBP, the value of an integrative WMTCM therapy remains unknown. This article aims to introduce an integrative WM-TCM service model for LBP, which is now available at the Hong Kong Institute of Integrative Medicine, the Chinese University of Hong Kong.

Effects of physical exercise on neuromuscular junction degeneration during ageing: A systematic review.

The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies. Moreover, there is still lack of strong consensus on the specific effects of exercise on improving the morphology and function of the ageing NMJ. Consequently, the purpose of this study was to conduct a systematic review to elucidate the effects of exercise training on NMJ compartments in the elderly. We conducted a systematic review using PubMed, Embase, and Web of Science databases, employing relevant keywords. Two independent reviewers selected studies that detailed NMJ changes during exercise in ageing, written in English, and available in full text. In total, 20 papers were included. We examined the altered adaptation of the NMJ to exercise, focusing on presynaptic and postsynaptic structures and myofibers in older animals or humans. Our findings indicated that aged NMJs exhibited different adaptive responses to physical exercise compared to younger counterparts. Endurance training, compared with resistance and voluntary exercise regimens, was found to have a more pronounced effect on NMJ structural remodeling, particularly in fast twitch muscle fibers. Physical exercise was observed to promote the formation and maintenance of acetylcholine receptor (AChR) clusters by increasing the recombinant docking protein 7 (Dok7) expression and stabilizing Agrin and lipoprotein receptor-related protein 4 (LRP4). These insights suggest that research on exercise-related therapies could potentially attenuate the progression of neuromuscular degeneration. Translational potential of this article: This systematic review provides a detailed overview of the effects of different types of physical exercise on improving NMJ in the elderly, providing scientific support for the timely intervention of muscle degeneration in the elderly by physical exercise, and providing help for the development of new therapeutic interventions in the future.

Biophysical and nutritional combination treatment for myosteatosis in patients with sarcopenia: a study protocol for single-blinded randomised controlled trial.

INTRODUCTION: Sarcopenia is characterised by age-related loss of skeletal muscle and function and is associated with risks of adverse outcomes. The prevalence of sarcopenia increases due to ageing population and effective interventions is in need. Previous studies showed that ß-hydroxy ß-methylbutyrate (HMB) supplement and vibration treatment (VT) enhanced muscle quality, while the coapplication of the two interventions had further improved muscle mass and function in sarcopenic mice model. This study aims to investigate the efficacy of this combination treatment in combating sarcopenia in older people. The findings of this study will demonstrate the effect of combination treatment as an alternative for managing sarcopenia. METHODS AND ANALYSIS: In this single-blinded randomised controlled trial, subjects will be screened based on the Asian Working Group for Sarcopenia (AWGS) 2019 definition. 200 subjects who are aged 65 or above and identified sarcopenic according to the AWGS algorithm will be recruited. They will be randomised to one of the following four groups: (1) Control+ONS; (2) HMB+ONS; (3) VT+ONS and (4) HMB+VT + ONS, where ONS stands for oral nutritional supplement. ONS will be taken in the form of protein formular once/day; HMB supplements will be 3 g/day; VT (35 Hz, 0.3 g, where g=gravitational acceleration) will be received for 20 mins/day and at least 3 days/week. The primary outcome assessments are muscle strength and function. Subjects will be assessed at baseline, 3-month and 6-month post treatment. ETHICS AND DISSEMINATION: This study was approved by Joint CUHK-NTEC (The Chinese University of Hong Kong and New Territories East Cluster) Clinical Research Management Office (Ref: CRE-2022.223-T) and conformed to the Declaration of Helsinki. Trial results will be published in peer-reviewed journals and disseminated at academic conferences. TRIAL REGISTRATION NUMBER: NCT05525039.

Deep Learning-Based Prediction Model for the Cobb Angle in Adolescent Idiopathic Scoliosis Patients.

Scoliosis, characterized by spine deformity, is most common in adolescent idiopathic scoliosis (AIS). Manual Cobb angle measurement limitations underscore the need for automated tools. This study employed a vertebral landmark extraction method and Feedforward Neural Network (FNN) to predict scoliosis progression in 79 AIS patients. The novel intervertebral angles matrix format showcased results. The mean absolute error for the intervertebral angle progression was 1.5 degrees, while the Pearson correlation of the predicted Cobb angles was 0.86. The accuracy in classifying Cobb angles (<15°, 15-25°, 25-35°, 35-45°, >45°) was 0.85, with 0.65 sensitivity and 0.91 specificity. The FNN demonstrated superior accuracy, sensitivity, and specificity, aiding in tailored treatments for potential scoliosis progression. Addressing FNNs' over-fitting issue through strategies like "dropout" or regularization could further enhance their performance. This study presents a promising step towards automated scoliosis diagnosis and prognosis.

Application of image recognition-based tracker-less augmented reality navigation system in a series of sawbone trials.

BACKGROUND: This study introduced an Augmented Reality (AR) navigation system to address limitations in conventional high tibial osteotomy (HTO). The objective was to enhance precision and efficiency in HTO procedures, overcoming challenges such as inconsistent postoperative alignment and potential neurovascular damage. METHODS: The AR-MR (Mixed Reality) navigation system, comprising HoloLens, Unity Engine, and Vuforia software, was employed for pre-clinical trials using tibial sawbone models. CT images generated 3D anatomical models, projected via HoloLens, allowing surgeons to interact through intuitive hand gestures. The critical procedure of target tracking, essential for aligning virtual and real objects, was facilitated by Vuforia's feature detection algorithm. RESULTS: In trials, the AR-MR system demonstrated significant reductions in both preoperative planning and intraoperative times compared to conventional navigation and metal 3D-printed surgical guides. The AR system, while exhibiting lower accuracy, exhibited efficiency, making it a promising option for HTO procedures. The preoperative planning time for the AR system was notably shorter (4 min) compared to conventional navigation (30.5 min) and metal guides (75.5 min). Intraoperative time for AR lasted 8.5 min, considerably faster than that of conventional navigation (31.5 min) and metal guides (10.5 min). CONCLUSIONS: The AR navigation system presents a transformative approach to HTO, offering a trade-off between accuracy and efficiency. Ongoing improvements, such as the incorporation of two-stage registration and pointing devices, could further enhance precision. While the system may be less accurate, its efficiency renders it a potential breakthrough in orthopedic surgery, particularly for reducing unnecessary harm and streamlining surgical procedures.

The predictive validity of OMPQ on the rehabilitation outcomes for patients with acute and subacute non-specific LBP in a Chinese population.

INTRODUCTION: Early screening of physical and psychosocial risk factors has been advocated as a way to identify low back pain (LBP) patients who may develop chronic disability. This study evaluated the predictive validity of a Chinese version of the Orebro Musculoskeletal Pain Questionnaire (OMPQ) in identifying LBP patients at risk of developing poor return-to-work (RTW) outcomes. METHODS: Altogether 241 patients with acute or subacute non-specific LBP agreed to participate, and they were screened at baseline with OMPQ, and evaluated after discharge from physiotherapy (n = 173) with outcome measures including the Roland-Morris Disability Questionnaire (RMDQ), numerical pain score (0-10) and global recovery (0-10). At 1-year follow-up, information on RTW status as well as sick leave duration were obtained. RESULTS: At baseline the OMPQ had a mean score of 112.0 (SD = 26.5). The receiver operator characteristic (ROC) curves of OMPQ scores at 1-year follow-up recorded values of area under the curve of 0.693 for RTW and 0.714 for sick leave duration, which are comparable to those reported in European studies. OMPQ was the only factor that could significantly predict the RTW outcomes, compared to other variables such as the RMDQ scores. CONCLUSION: The results confirmed the predictive validity of the Chinese version of OMPQ in screening LBP patients at risk of developing poor occupational outcomes, and appropriate interventions can be arranged for these high-risk individuals in the rehabilitation process.

The effectiveness of robotic-assisted upper limb rehabilitation to improve upper limb function in patients with cervical spinal cord injuries: a systematic literature review.

Background: Spinal Cord Injury (SCI) damages corticospinal tracts and descending motor pathways responsible for transmitting signals from the brain to the spinal cord, leading to temporary or permanent changes in sensation, motor function, strength, and body function below the site of injury. Cervical SCI (cSCI), which leads to tetraplegia, causes severe functional upper limb (UL) impairments that increase falls risk, limits independence, and leads to difficulties with activities of daily living (ADLs). Robotic therapy (RT) has been developed in recent decades as a new treatment approach for people with cervical spinal cord injuries (cSCI). The present review aimed to explore current available evidence and studies regarding the effectiveness of RT for individuals with cSCI in improving UL function, identify current research gaps and future research directions. Method: This review was conducted by searching PubMed, CINAHL, Medline, Embase, and APA PsycInfo for relevant studies published from January 2010 to January 2022. Selected studies were analyzed with a focus on the patients' self-perception of limited UL function and level of independence in activities of daily living. In addition, the JBI Critical Appraisal checklist was used to assess study quality. Results: A total of 7 articles involving 87 patients (74 males and 13 females) were included in the analysis, with four studies utilizing exoskeleton and three studies utilizing end-effector robotic devices, respectively. The quality of these studies varied between JBI Critical Appraisal scores of 4 to 8. Several studies lacked blinding and a control group which affected internal validity. Nevertheless, four out of seven studies demonstrated statistically significant improvements in outcome measurements on UL function and strength after RT. Conclusion: This review provided mixed evidence regarding the effectiveness of RT as a promising intervention approach to improve upper limb function in participants with cSCI. Although RT was shown to be safe, feasible, and reduces active therapist time, further research on the long-term effects of UL RT is still needed. Nevertheless, this review serves as a useful reference for researchers to further develop exoskeletons with practical and plausible applications toward geriatric orthopaedics.

Does exercise influence skeletal muscle by modulating mitochondrial functions via regulating MicroRNAs? A systematic review.

BACKGROUND: Sarcopenia is the accelerated loss of muscle mass, strength and function. Mitochondrial dysfunction was related to the progression of sarcopenia; meanwhile, microRNAs were regarded as core roles in regulating mitochondrial function. Physical exercise is a well-accepted approach to attenuate sarcopenia, yet very few studies depict the molecular mechanisms. The aim of this systematic review is to explore the potential relationships among physical exercise, mitochondrial function, and microRNAs, which may give new insight for retarding sarcopenia. METHODS: A systematic literature search was performed in PubMed, Embase and Web of Science. The keywords were combined as "(microRNA OR miR) AND mitochondri* AND muscle AND exercise" and searched in all fields. PRISMA guidelines were followed. Information was extracted from the included studies for review. RESULTS: In this review, 18 preclinical studies and 5 clinical studies were included. Most of the included studies suggested that effective physical exercise had positive effects on mitochondrial functions by regulating microRNAs. The results showed that 12 microRNAs improved mitochondrial functions, while 18 microRNAs suppressed them. Meanwhile, the results showed that 5 microRNAs improved muscle performance. CONCLUSIONS: This systematic review provides an up-to-date sequential overview and highlights the potential relationship among exercise, mitochondrial function, and microRNAs in muscle. Meanwhile, evidence revealed that physical exercise can improve muscle performance by up-regulating mitochondrial functions, especially mitochondrial biogenesis, through modulating microRNAs.

The role of obesity in sarcopenia and the optimal body composition to prevent against sarcopenia and obesity.

Background: Elderly people with low lean and high fat mass, are diagnosed with sarcopenic obesity (SO), and often have poor clinical outcomes. This study aimed to explore the relationship between obesity and sarcopenia, and the optimal proportion of fat and muscle for old individuals. Methods: Participants aged 60 years or above were instructed to perform bioelectrical impedance analysis to obtain the muscle and fat indicators, and handgrip strength was also performed. Sarcopenia was diagnosed according to predicted appendicular skeletal muscle mass and function. Body mass index (BMI) and body fat percentage (BF%) were used to define obesity. The association of muscle and fat indicators were analyzed by Pearson's correlation coefficient. Pearson Chi-Square test was utilized to estimate odds ratios (OR) and 95% confidence intervals (CI) on the risk of sarcopenia according to obesity status. Results: 1637 old subjects (74.8 ± 7.8 years) participated in this study. Not only fat mass, but also muscle indicators were positively correlated to BMI and body weight (p < 0.05). Absolute muscle and fat mass in different positions had positive associations (p < 0.05). Muscle mass and strength were negatively related to appendicular fat mass percentage (p < 0.05). When defined by BMI (OR = 0.69, 95% CI [0.56, 0.86]; p = 0.001), obesity was a protective factor for sarcopenia, whilst it was a risk factor when using BF% (OR = 1.38, 95% CI [1.13, 1.69]; p = 0.002) as the definition. The risk of sarcopenia reduced with the increase of BMI in both genders. It was increased with raised BF% in males but displayed a U-shaped curve for females. BF% 26.0-34.6% in old females and lower than 23.9% in old males are recommended for sarcopenia and obesity prevention. Conclusion: Skeletal muscle mass had strong positive relationship with absolute fat mass but negative associations with the percentage of appendicular fat mass. Obesity was a risk factor of sarcopenia when defined by BF% instead of BMI. The management of BF% can accurately help elderly people prevent against both sarcopenia and obesity.

Deciphering the "obesity paradox" in the elderly: A systematic review and meta-analysis of sarcopenic obesity.

Aging and obesity are two global concerns in public health. Sarcopenic obesity (SO), defined as the combination of age-related sarcopenia and obesity, has become a pressing issue. This systematic review and meta-analysis summarize the current clinical evidence relevant to SO. PubMed, Embase, and Web of Science were searched, and 106 clinical studies with 167,151 elderlies were included. The estimated prevalence of SO was 9% in both men and women. Obesity was associated with 34% reduced risk of sarcopenia (odds ratio [OR] 0.66, 95% CI 0.48-0.91; p < 0.001). The pooled hazard ratio (HR) of all-cause mortality was 1.51 (95% CI 1.14-2.02; p < 0.001) for people with SO compared with healthy individuals. SO was associated with increased risk of cardiovascular disease and related mortality, metabolic disorders, cognitive impairment, arthritis, functional limitation, and lung diseases (all ORs > 1.0, p < 0.05). The attenuated risk of sarcopenia in elderlies with obesity ("obesity paradox") was dependent on higher muscle mass and strength. Apart from unifying the diagnosis of SO, more research is needed to subphenotype people with obesity and sarcopenia for individualized treatment. Meanwhile, the maintenance of proper body composition of muscle and fat may delay or attenuate the adverse outcomes of aging.

Regulation of mitochondrial dynamic equilibrium by physical exercise in sarcopenia: A systematic review.

Background: Sarcopenia is a hallmark of the ageing process, which is characterized by the decline in muscle mass and strength. Growing evidence indicates that mitochondria dysfunction play core roles in this process. Meanwhile, physical exercise is regarded as one of the efficiency therapies to attenuate sarcopenia via regulating mitochondrial function during ageing. However, the specific mechanisms among exercise, mitochondrial function and sarcopenia are still unclear. The aim of this systematic review is to delineate the effects of physical exercise on mitochondria during ageing in order to explore potential target for rescuing sarcopenia. Methods: A systematic literature search was performed in PubMed, Embase and Web of Science. Information was extracted from the included studies for review. Results: In this review, 16 pre-clinical studies were included and 105 clinical studies that were not mechanistic research were excluded. 16 pre-clinical studies provided evidence that physical exercise could affect mitochondrial quality control to attenuate sarcopenia. Most of the included studies described the important role of mitochondrial dynamic equilibrium in sarcopenia and showed that effective physical exercise could influence mitochondrial biogenesis, fusion, fission and mitophagy to attenuate sarcopenia in aged animal. Conclusions: This systematic review provides an up-to-date sequential overview and highlights the link in the potential mitochondria-related target and physical exercise in aged animal. Translation of this article: Currently, there is no standard treatment method for sarcopenia. This systematic review revealed the underlying mechanisms for how physical exercise improved muscle performance via regulating mitochondrial dynamic equilibrium, which could provide scientific support for using exercise as a timely intervention for sarcopenia. Additionally, this systematic review allows a better understanding of mitochondrial dynamic equilibrium and exercise for future development of new therapeutic interventions to attenuate sarcopenia.

A novel image-based machine learning model with superior accuracy and predictability for knee arthroplasty loosening detection and clinical decision making.

Background: Loosening is the leading cause of total knee arthroplasty (TKA) revision. This is a heavy burden toward the healthcare system owing to the difficulty in diagnosis and complications occurring from the delay management. Based on automatic analytical model building, machine learning, may potentially help to automatically recognize the risk of loosening based on radiographs alone. The aim of this study was to build an image-based machine-learning model for detecting TKA loosening. Methods: Image-based machine-learning model was developed based on ImageNet, Xception model and a TKA patient X-ray image dataset. Based on a dataset with TKA patient clinical parameters, another system was then created for developing the clinical-information-based machine learning model with random forest classifier. In addition, the Xception Model was pre-trained on the ImageNet database with python and TensorFlow deep learning library for the prediction of loosening. Class activation maps were also used to interpret the prediction decision made by model. Two senior orthopaedic specialists were invited to assess loosening from X-ray images for 3 attempts in setting up comparison benchmark. Result: In the image-based machine learning loosening model, the precision rate and recall rate were 0.92 and 0.96, respectively. While for the accuracy rate, 96.3% for visualization classification was observed. However, the addition of clinical-information-based model, with precision rate of 0.71 and recall rate of 0.20, did not further showed improvement on the accuracy. Moreover, as class activation maps showed corresponding signals over bone-implant interface that is loosened radiographically, this confirms that the current model utilized a similar image recognition pattern as that of inspection by clinical specialists. Conclusion: The image-based machine learning model developed demonstrated high accuracy and predictability of knee arthroplasty loosening. And the class activation heatmap matched well with the radiographic features used clinically to detect loosening, which highlighting its potential role in assisting clinicians in their daily practice. However, addition of clinical-information-based machine-learning model did not offer further improvement in detection. As far as we know, this is the first report of pure image-based machine learning model with high detection accuracy. Importantly, this is also the first model to show relevant class activation heatmap corresponding to loosening location. Translational potential: The finding in this study indicated image-based machine learning model can detect knee arthroplasty loosening with high accuracy and predictability, which the class activation heatmap can potentially assist surgeons to identify the sites of loosening.