UNASSIGNED: Gout is the most prevalent form of inflammatory arthritis in the world. Total hip arthroplasty (THA) has emerged as a widely sought-after and highly effective surgical procedure for advanced hip diseases. However, there is a lack of research on the impact of gout on primary THA outcomes in large cohorts. This study aimed to address this gap by primarily investigating complications following THA in patients with or without gout.
UNASSIGNED: Patients with records of gout in the 2 years leading up to their primary THA and who also have at least 2 years of follow-up were identified using a national insurance database and compared to a 5:1 matched control. A total of 32,466 patients with gout and 161,514 patients without gout undergoing THA were identified. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. In addition, 90-day emergency department (ED) visits and inpatient readmission were also documented.
UNASSIGNED: Patients with gout demonstrated higher rates of medical complications including deep vein thrombosis, transfusion, acute kidney injury, and urinary tract infection than non-gout patients (p < 0.001). Gout patients also showed higher rates of pulmonary embolism (p = 0.017). Increased incidences of surgical complications were identified in gout patients, specifically wound complications and periprosthetic joint infection (p < 0.001). There was an increased risk of revision for gout patients up to 90 days (p = 0.003), 1 year (p = 0.027), and 2 years (p = 0.039). There was also an increased risk of dislocation for gout patients up to 90 days (p = 0.022) and 1 year (p = 0.047), but not at 2 years. No significant difference was observed in aseptic loosening or periprosthetic fracture. Additionally, gout patients also demonstrated a higher likelihood of 90-day ED visits and readmission (p < 0.001).
UNASSIGNED: Primary THA in gout patients is associated with increased risks of multiple medical and surgical complications. Our findings provide insights into the planning and expectation of THA for patients with gout. These insights have the potential to benefit the decision-making process for gout patients considering THA.

Cycling stands as one of the most widely embraced leisure activities and serves purposes such as exercise, rehabilitation, and commuting. This study aimed to assess the feasibility of assisting three unimpaired participants (age: 34.0 ± 7.9 years, height: 1.86 ± 0.02 m, weight: 75.7 ± 12.7 kg) using the GuroX hip exoskeleton, originally designed for walking assistance, during cycling against a resistance of 1 W/kg. The performance evaluation employed a sweep protocol that manipulated the timing of the exoskeleton\'s peak extension and flexion torque in addition to human-in-the-loop optimization to enhance these timings based on metabolic cost. Our findings indicate that with a peak assistance torque of approximately 10.3 Nm for extension and flexion, the GuroX substantially reduced the net metabolic cost of cycling by 31.4 ± 8.1% and 26.4 ± 14.1% compared to transparent and without exoskeleton conditions, respectively. This demonstrates the significant potential of a hip exoskeleton developed for walking assistance to profoundly benefit cycling. Additionally, customizing the assistance strategy proves beneficial in maximizing assistance. While we attribute the average motor power to be a major contributor to the reduced cycling effort, participant feedback suggests that user comfort and synchronization between the user and exoskeleton may have played integral roles. Further research should validate our initial findings by employing a larger participant pool in real-world conditions. Incorporating a more diverse set of parameters for the human-in-the-loop optimization could enhance individualized assistance strategies.

This study investigated the effects of plyometric training on lower-limb muscle strength and knee biomechanical characteristics during the landing phase. Twenty-four male subjects were recruited for this study with a randomised controlled design. They were randomly divided into a plyometric training group and a traditional training group and underwent training for 16 weeks. Each subject was evaluated every 8 weeks for knee and hip isokinetic muscle strength as well as knee kinematics and kinetics during landing. The results indicated significant group and time interaction effects for knee extension strength (F = 74.942 and p = 0.001), hip extension strength (F = 99.763 and p = 0.000) and hip flexion strength (F = 182.922 and p = 0.000). For landing kinematics, there were significant group main effects for knee flexion angle range (F = 4.429 and p = 0.047), significant time main effects for valgus angle (F = 6.502 and p = 0.011) and significant group and time interaction effects for internal rotation angle range (F = 5.475 and p = 0.008). The group main effect for maximum knee flexion angle was significant (F = 7.534 and p = 0.012), and the group and time interaction effect for maximum internal rotation angle was significant (F = 15.737 and p = 0.001). For landing kinetics, the group main effect of the loading rate was significant (F = 4.576 and p = 0.044). Significant group and time interaction effects were observed for knee extension moment at the moment of maximum vertical ground reaction force (F = 5.095 and p = 0.010) and for abduction moment (F = 8.250 and p = 0.001). These findings suggest that plyometric training leads to greater improvements in hip and knee muscle strength and beneficial changes in knee biomechanics during landing compared to traditional training.

BACKGROUND: Femoral neck fracture (FNF) accounts for approximately 3.58% of all fractures in the entire body, exhibiting an increasing trend each year. According to a survey, in 1990, the total number of hip fractures in men and women worldwide was approximately 338,000 and 917,000, respectively. In China, FNFs account for 48.22% of hip fractures. Currently, many studies have been conducted on postdischarge mortality and mortality risk in patients with FNF. However, there have been no definitive studies on in-hospital mortality or its influencing factors in patients with severe FNF admitted to the intensive care unit.
OBJECTIVE: In this paper, 3 machine learning methods were used to construct a nosocomial death prediction model for patients admitted to intensive care units to assist clinicians in early clinical decision-making.
METHODS: A retrospective analysis was conducted using information of a patient with FNF from the Medical Information Mart for Intensive Care III. After balancing the data set using the Synthetic Minority Oversampling Technique algorithm, patients were randomly separated into a 70% training set and a 30% testing set for the development and validation, respectively, of the prediction model. Random forest, extreme gradient boosting, and backpropagation neural network prediction models were constructed with nosocomial death as the outcome. Model performance was assessed using the area under the receiver operating characteristic curve, accuracy, precision, sensitivity, and specificity. The predictive value of the models was verified in comparison to the traditional logistic model.
RESULTS: A total of 366 patients with FNFs were selected, including 48 cases (13.1%) of in-hospital death. Data from 636 patients were obtained by balancing the data set with the in-hospital death group to survival group as 1:1. The 3 machine learning models exhibited high predictive accuracy, and the area under the receiver operating characteristic curve of the random forest, extreme gradient boosting, and backpropagation neural network were 0.98, 0.97, and 0.95, respectively, all with higher predictive performance than the traditional logistic regression model. Ranking the importance of the feature variables, the top 10 feature variables that were meaningful for predicting the risk of in-hospital death of patients were the Simplified Acute Physiology Score II, lactate, creatinine, gender, vitamin D, calcium, creatine kinase, creatine kinase isoenzyme, white blood cell, and age.
CONCLUSIONS: Death risk assessment models constructed using machine learning have positive significance for predicting the in-hospital mortality of patients with severe disease and provide a valid basis for reducing in-hospital mortality and improving patient prognosis.

UNASSIGNED: While it is known that patients with end-stage renal disease (ESRD) are at an increased risk of complications following total hip arthroplasty (THA), there is a gap in the literature in comparing patients with ESRD to patients who undergo renal transplant (RT) before or after THA. This study is to address this gap by analyzing outcomes of THA in ESRD patients, RT patients, and RT candidates.
UNASSIGNED: Using the PearlDiver Mariner database, ESRD patients, RT patients, and RT candidates undergoing primary THA were identified and compared. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications up to 2 years. Ninety-day emergency department (ED) visits and inpatient readmission were also documented.
UNASSIGNED: A total of 7,868 patients were included: 5,092 had ESRD, 2,520 had RT before THA, and 256 were candidates for RT. Compared to patients with ESRD, RT patients demonstrated lower rates of medical complications such as pneumonia (3.61% vs. 5.99%, p = 0.039) and transfusion (4.60% vs. 7.66%, p < 0.001). Additionally, RT patients displayed decreased rates of surgical complications, including wound complications (2.70% vs. 4.22%, p = 0.001), periprosthetic joint infection (PJI) at 1 year (2.30% vs. 4.81%, p < 0.001) and 2 years (2.58% vs. 5.42%, p < 0.001), and aseptic loosening at 2 years (0.79% vs. 1.43%, p = 0.006). Similarly, when compared to RT candidates, RT patients demonstrated a lower incidence of postoperative complications, including 1-year PJI (2.30% vs. 5.08%, p = 0.013), 2-year PJI (2.58% vs. 5.08%, p = 0.028), 1-year aseptic loosening (0.56% vs. 2.73%, p < 0.001), and 2-year aseptic loosening (0.79% vs. 2.73%, p = 0.005). RT patients also had lower rates of ED visits and hospital readmissions.
UNASSIGNED: Compared to ESRD patients and RT candidates, patients with RT have a significantly lower likelihood of medical complications, PJI, aseptic hardware loosening, ED visits, and hospital readmission. Patients with ESRD on the RT waiting list should delay THA until after RT surgery. For those not eligible for RT, it is vital to take extra precautions to reduce the risk of complications.

OBJECTIVE: To develop an AI-assisted MRI model to identify surgical target areas in pediatric hip and periarticular infections.
METHODS: A retrospective study was conducted on the pediatric patients with hip and periarticular infections who underwent Magnetic Resonance Imaging(MRI)examinations from January 2010 to January 2023 in three hospitals in China. A total of 7970 axial Short Tau Inversion Recovery (STIR) images were selected, and the corresponding regions of osteomyelitis (label 1) and abscess (label 2) were labeled using the Labelme software. The images were randomly divided into training group, validation group, and test group at a ratio of 7:2:1. A Mask R-CNN model was constructed and optimized, and the performance of identifying label 1 and label 2 was evaluated using receiver operating characteristic (ROC) curves. Calculation of the average time it took for the model and specialists to process an image in the test group. Comparison of the accuracy of the model in the interpretation of MRI images with four orthopaedic surgeons, with statistical significance set at P < 0.05.
RESULTS: A total of 275 patients were enrolled, comprising 197 males and 78 females, with an average age of 7.10 ± 3.59 years, ranging from 0.00 to 14.00 years. The area under curve (AUC), accuracy, sensitivity, specificity, precision, and F1 score for the model to identify label 1 were 0.810, 0.976, 0.995, 0.969, 0.922, and 0.957, respectively. The AUC, accuracy, sensitivity, specificity, precision, and F1 score for the model to identify label 2 were 0.890, 0.957, 0.969, 0.915, 0.976, and 0.972, respectively. The model demonstrated a significant speed advantage, taking only 0.2 s to process an image compared to average 10 s required by the specialists. The model identified osteomyelitis with an accuracy of 0.976 and abscess with an accuracy of 0.957, both statistically better than the four orthopaedic surgeons, P < 0.05.
CONCLUSIONS: The Mask R-CNN model is reliable for identifying surgical target areas in pediatric hip and periarticular infections, offering a more convenient and rapid option. It can assist unexperienced physicians in pre-treatment assessments, reducing the risk of missed and misdiagnosis.

BACKGROUND: Controversy remains over whether different surgical approaches exert an impact on the component positioning in total hip arthroplasty. We conducted a retrospective study to reveal the long-term position of prostheses in the first group of patients in China who underwent direct anterior hip arthroplasty.
METHODS: Collected were data from 350 patients who underwent direct anterior hip arthroplasty between 2008 and 2013, including demographic information, imaging data, Harris hip scores, and surgical complications. Variables, measured radiographically or by CT, included hip offset, leg length discrepancy, component position, and stability within one week after surgery and at the last follow-up. The data were subjected to statistical analysis by using paired t-tests and Pearson chi-square tests.
RESULTS: Data were harvested by follow-up and self-reported questionnaires. The postoperative follow-up lasted for 13.1 years on average (minimum, 10 years; maximum, 15 years), and the overall survival rate of hip prostheses was 96.3%. The mean Harris score at the final follow-up was 91.8 points. After excluding patients with significant preoperative hip deformities, the incidence of postoperative limb inequality (> 5 mm) was 4.9% at the last follow-up, and the incidence of hip offset discrepancy (> 5 mm) was 14.6%. The overall proportion of the acetabular components located in the Lewinnek safe zone was 77.7%, whereas the proportion of femoral prostheses in the safe zone (< 3° inclination) was 94.0%. Based on the revised data and the last follow-up imaging, the total proportion of acetabular and femoral prostheses with a radiolucence of > 2 mm was 5.1%.
CONCLUSIONS: Direct anterior approach hip arthroplasty could achieve excellent component positioning and long-term prosthesis survival in patients without severe hip deformities.

OBJECTIVE: Periprosthetic femoral fractures (PPFs) around the hip are challenging complications in orthopaedic surgery, particularly Vancouver type B2 (VTB2) fractures. The surgical management of these fractures is crucial and depends on various factors. Cementless short taper stem with plate osteosynthesis is an alternative surgical technique. This study aims to compare the outcomes of this surgical technique with revision arthroplasty (RA) with long stem in the treatment of VTB2 PPFs.
METHODS: This retrospective study was conducted in a single medical institute from February 2010 to May 2019. Patients who had received either total hip arthroplasty or bipolar hemiarthroplasty and subsequently developed a VTB2 PPF were included; patients who sustained intra-operative fractures or received a cemented stem previously were excluded from the analysis. The patients were divided into two groups: group I received RA with cementless long stem, while group II underwent RA with cementless short taper stem with plate osteosynthesis. Demographic data, radiographic and functional outcomes, and complications were analyzed between the two groups.
RESULTS: A total of 85 patients diagnosed with VTB2 PPFs were included in the study. There were no significant differences between the two groups in terms of demographic data, including age, gender, mean follow-up times, estimated blood loss, and operative times. The radiographic results showed that there was no significant difference in the incidence of subsidence and implant stability between the two groups. However, group II tended to have less subsidence and periprosthetic osteolysis. Patients in group II had significantly better functional scores (mean Harris hip score: post-operative: 60.2 in group I and 66.7 in group ii; last follow-up: 77.4 in group 1 and 83.2 in group II (both p < 0.05)). There were no significant differences in the overall complication rate, including infection, dislocation, re-fracture, and revision surgery, between the two groups.
CONCLUSIONS: Both surgical techniques, cementless long stem and cementless short taper stem with plate osteosynthesis, are effective in the treatment of Vancouver B2 PPFs, with no significant differences in outcomes or complications. However, patients in cementless short taper stem with plate osteosynthesis had better functional scores at both post-operative and the last follow-up.

OBJECTIVE: Preoperative anemia increases postoperative morbidity, mortality, and the risk of allogeneic transfusion. However, the incidence of preoperative anemia in patients undergoing total hip arthroplasty and total knee arthroplasty (TKA) and its relationship to postoperative outcomes has not been previously reported.
METHODS: We conducted a comprehensive literature search through PubMed, Cochrane Library, Web of Sincien, and Embase from inception to July 2023 to investigate the prevalence of preoperative anemia in patients undergoing Total Joint Arthroplasty, comorbidities between anemic and non-anemicpatients before surgery, and postoperative outcomes. postoperative outcomes were analyzed. Overall prevalence was calculated using a random-effects model, and heterogeneity between studies was examined by Cochran\'s Q test and quantified by the I2 statistic. Subgroup analyses and meta-regression analyses were performed to identify sources of heterogeneity. Publication bias was assessed by funnel plots and validated by Egger\'s test.
RESULTS: A total of 21 studies with 369,101 samples were included, all of which were retrospective cohort studies. 3 studies were of high quality and 18 studies were of moderate quality. The results showed that the prevalence of preoperative anemia was 22% in patients awaiting arthroplasty; subgroup analyses revealed that the prevalence of preoperative anemia was highest in patients awaiting revision of total knee arthroplasty; the highest prevalence of preoperative anemia was found in the Americas; preoperative anemia was more prevalent in the female than in the male population; and preoperative anemia with a history of preoperative anemia was more common in the female than in the male population. patients with a history of preoperative anemia; patients with joint replacement who had a history of preoperative anemia had an increased risk of infection, postoperative blood transfusion rate, postoperative blood transfusion, Deep vein thrombosis of the lower limbs, days in hospital, readmission within three months, and mortality compared with patients who did not have preoperative anemia.
CONCLUSIONS: The prevalence of preoperative anemia in patients awaiting total joint arthroplasty is 22%, and is higher in TKA and female patients undergoing revision, while preoperative anemia is detrimental to the patient\'s postoperative recovery and will increase the risk of postoperative complications, transfusion rates, days in the hospital, readmission rates, and mortality.

Biphasic models have been widely used to simulate the time-dependent biomechanical response of soft tissues. Modelling techniques of joints with biphasic weight-bearing soft tissues have been markedly improved over the last decade, enhancing our understanding of the function, degenerative mechanism and outcomes of interventions of joints. This paper reviews the recent advances, challenges and opportunities in computational models of joints with biphasic weight-bearing soft tissues. The review begins with an introduction of the function and degeneration of joints from a biomechanical aspect. Different constitutive models of articular cartilage, in particular biphasic materials, are illustrated in the context of the study of contact mechanics in joints. Approaches, advances and major findings of biphasic models of the hip and knee are presented, followed by a discussion of the challenges awaiting to be addressed, including the convergence issue, high computational cost and inadequate validation. Finally, opportunities and clinical insights in the areas of subject-specific modeling and tissue engineering are provided and discussed.