CXCR2/Snail-1-Induced Epithelial-Mesenchymal Transition in the Formation and Progression of RCC with Inferior Vena Cava Tumour Thrombus.

BACKGROUND: Renal cell carcinoma (RCC), a common and highly invasive malignant tumour, presents clinical challenges due to its propensity for easy metastasis. Inferior vena cava tumour thrombus is a common RCC complication significantly impacting patient prognosis. This study investigates C-X-C chemokine receptor type 2 (CXCR2)/Snail-1-induced epithelial-mesenchymal transition (EMT) in RCC with inferior vena cava tumour thrombus. METHODS: Tissues from 51 RCC patients were analysed for CXCR2 and Snail-1 Messenger Ribonucleic Acid (mRNA) levels using Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Elevated levels of both were observed in tumour and inferior vena cava tumour thrombus tissues. Using Short Hairpin RNA (shRNA) technology, we inhibited CXCR2 and Snail-1 expression to investigate their impact on EMT, invasiveness, and metastatic potential in RCC cells. RESULTS: Compared with that in the Short Hairpin RNA-Negative Control (ShNC) group, inhibition of CXCR2 and Snail-1 suppressed the degree of EMT, invasiveness, and metastatic ability of RCC cells (p < 0.01). Further mechanistic studies showed that CXCR2/Snail-1 participated in the formation and progression of RCC by regulating the extracellular signal-regulated kinase 1/2 (ERK1/2) signalling pathways. Additionally, compared with that in the ShNC group, knockdown of CXCR2 and Snail-1 significantly inhibited the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9; p < 0.01), thereby regulating the metastasis of RCC. CONCLUSIONS: Our findings suggest that CXCR2/Snail-1-induced EMT plays an important role in the formation and progression of RCC with inferior vena cava tumour thrombus. CXCR2/Snail-1 participates in the invasion and metastasis of RCC by regulating the expression of multiple signalling pathways and related genes. These results provide new insights and directions for the treatment of RCC.

The Association of Dental Caries or Dental Implant Placement Within One Year of Primary Total Hip Arthroplasty on Medical and Implant Complications.

BACKGROUND: Total hip arthroplasty (THA) adverse events among patients who have dental diagnoses remain unclear. We sought to determine if dental caries or dental implant placements increased (1) 90-day medical complications, (2) 90-day readmissions, and (3) 2-year implant-related complications, including periprosthetic joint infections (PJIs) after THA. METHODS: A nationwide database for primary THAs from 2010 to 2021 was queried to compare 3 patient cohorts. Patients who had a history of dental implants or caries within 12 months prior to THA (n = 1,179) or 12 months after THA (n = 1,218) were case-matched to patients who did not have dental history (n = 6,090) by age and comorbidities. Outcomes included 90-day complications, 90-day readmissions, and 2-year implant-related complications. Logistic regression models computed the odds ratios (ORs) of complications and readmissions. P values less than .006 were significant. RESULTS: Patients who had dental caries or implant placement 12 months before or after THA experienced 1.6-fold greater odds of 90-day medical complications compared to case-matched patients. Readmissions within 90 days increased for patients who had a dental history before (11.7% versus 8.3%; OR: 1.49, P < .0001) and after (14.2% versus 8.3%; OR: 1.84, P < .0001) THA compared to case-matched patients. A dental caries diagnosis or dental implant placement within 12 months following THA increased 2-year implant complications compared to case-matched patients (15.2% versus 9.3%; OR: 1.69, P < .0001), including PJIs (5.3% versus 2.8%; OR: 1.98, P < .0001), dislocations (4.4% versus 2.7%; OR: 1.63, P = .002), and THA revisions (3.9% versus 2.5%; OR: 1.61, P = .005). CONCLUSIONS: Dental diagnoses within 12 months of THA are associated with increased medical complications. Dental diagnoses occurring 12 months after THA are associated with greater implant-related complications, including PJIs. Delaying invasive dental procedures for 12 months after THA may be advisable.

Standardised Measurements for Monitoring and Comparing Multiphoton Microscope Systems.

The goal of this protocol is to enable better characterisation of multiphoton microscopy hardware across a large user base. The scope of this protocol is purposefully limited to focus on hardware, touching on software and data analysis routines only where relevant. The intended audiences are scientists using and building multiphoton microscopes in their laboratories. The goal is that any scientist, not only those with optical expertise, can test whether their multiphoton microscope is performing well and producing consistent data over the lifetime of their system.

Market resilience of orthopaedic hip/knee arthroplasty sales during COVID-19.

INTRODUCTION: The coronavirus 2019 (COVID-19) pandemic led to a marked decrease in elective surgical volume and orthopaedic device sales. The aim of this paper was to quantify this decrease and the related financial impact on the largest hip/knee arthroplasty companies by: (1) tracking individual hip/knee company valuations; (2) calculating aggregate changes in overall hip/knee arthroplasty market valuations; and (3) quantifying quarterly hip/knee revenues relative to prior years. MATERIALS AND METHODS: Financial data on the top five hip/knee arthroplasty companies by size between January 1, 2019, and October 1, 2020, was collected from a Wall Street financial database, S&P Capital IQ. Changes in valuation of these companies were compared against benchmark market indices, the S&P500 and Vanguard Healthcare ETF. U.S. hip/knee arthroplasty-specific revenue for Q1 and Q2 of 2019 and 2020 was collected from Securities Exchange Commission 10-Q forms. Quarterly revenue changes were calculated using 1-2Q19 revenues as baselines and aggregate to approximate the overall hip/knee arthroplasty market. RESULTS: The top five hip/knee companies lost $179.2 billion (32.7% loss) in market value from pre COVID-19 market highs to COVID-19 market lows (March 2020), while S&P500 and Vanguard Healthcare ETF decreased 36.1 and 33.2%, respectively. From market lows to October 2020, arthroplasty companies rallied 38.6% while the S&P500 and Vanguard Healthcare ETF regained 43.5 and 56.4% respectively. Notably, this occurred while aggregate 1Q/2Q20 revenue lagged 7.1/41.8% relative to 2019, with an overall decrease of $1.58B (24.8%). CONCLUSIONS: Similar to the overall market and healthcare sector, the top five hip/knee arthroplasty companies have recovered from their COVID market lows. Our results reveal that the valuations of hip/knee companies remained robust during COVID, even as revenues fell, likely due to strong investor confidence in the industry outlook and the greater overall healthcare system utilization.

The Cousa objective: a long-working distance air objective for multiphoton imaging in vivo.

Multiphoton microscopy can resolve fluorescent structures and dynamics deep in scattering tissue and has transformed neural imaging, but applying this technique in vivo can be limited by the mechanical and optical constraints of conventional objectives. Short working distance objectives can collide with compact surgical windows or other instrumentation and preclude imaging. Here we present an ultra-long working distance (20 mm) air objective called the Cousa objective. It is optimized for performance across multiphoton imaging wavelengths, offers a more than 4 mm2 field of view with submicrometer lateral resolution and is compatible with commonly used multiphoton imaging systems. A novel mechanical design, wider than typical microscope objectives, enabled this combination of specifications. We share the full optical prescription, and report performance including in vivo two-photon and three-photon imaging in an array of species and preparations, including nonhuman primates. The Cousa objective can enable a range of experiments in neuroscience and beyond.

Crohn's disease is associated with higher rates of implant-related complications following primary total knee arthroplasty.

INTRODUCTION: In Western countries, there has been a rise in the prevalence of Crohn's Disease (CD) and primary total knee arthroplasty (TKA). This study delves deeper into the effects of CD on TKA patients by examining (1) the length of in-hospital stay (LOS); (2) the rates of readmission; (3) complications related to implants; and (4) the costs associated with care. METHODS: A retrospective analysis using the PearlDiver database was conducted, encompassing the time frame between January 1st, 2005 and March 31st, 2014, focusing on patients who underwent TKA and were either diagnosed with CD or not. Patients with CD were paired with control subjects at a 1:5 ratio based on age, gender, and medical comorbidities. The analysis comprised a total of 96,229 patients (CD = 16,039; non-CD = 80,190). RESULTS: Patients with CD had a notably longer hospital stay (3 v. 2 days, p < 0.0001) and faced significantly higher rates of 90-day readmissions and complications (19.80% v. 14.91%, OR: 1.40, p < 0.0001; 6.88% v. 4.88%, OR: 1.43, p < 0.0001 respectively). Additionally, CD patients incurred greater expenses on the surgery day ($18,365.98 v. $16,192.00) and within 90 days post-surgery ($21,337.46 v. $19,101.42). CONCLUSION: This study demonstrates longer in-hospital LOS, higher rates of readmissions, implant-related complications, and costs of care among CD patients following primary TKA.

The Association of Inflammatory Bowel Disease with Postoperative Complications, Re-admissions and Emergency Department Visits Following Primary Total Hip Arthroplasty.

BACKGROUND: Inflammatory bowel disease (IBD) is a systemic inflammatory disorder of the gut. Few studies have evaluated whether patients with a history of IBD have worse outcomes following primary total hip arthroplasty (THA). Therefore, the purpose of this study was to evaluate whether IBD is associated with increased: (1) medical complications; (2) readmissions; and (3) emergency department (ED) visits. METHODS: Using a nationwide claims database, patients with IBD undergoing primary THA were identified and matched to a comparison group according to age, sex and the Charlson Comorbidity Index. Outcomes assessed included the development of 90-day medical complications, 90-day re-admissions and 90-day ED visit rates. A p-value <0.0001 was considered statistically significant. RESULTS: Patients with IBD had a greater incidence and odds ratio of total medical complications (31.90% vs. 11.47%; OR 2.89; p < 0.0001) compared with matched controls. IBD patients had significantly higher incidence and odds ratio of developing acute kidney injury (5.46 vs. 1.46%; OR 3.92; p < 0.0001), cerebrovascular accident (1.32 vs. 0.35%; OR 3.79; p < 0.0001), pneumonia (4.02 vs. 1.30%; OR 3.19; p < 0.0001), respiratory failure (1.21 vs. 0.41%; OR 2.94; p < 0.0001), deep vein thrombosis (0.89% vs. 0.30%; OR 2.93; p < 0.0001), and other adverse events. IBD patients also had higher incidence and odds ratio of 90-day re-admissions (4.20% vs. 3.23%; OR 1.31; p < 0.0001) and ED visits (6.56% vs. 3.99%; OR 1.69; p < 0.0001). CONCLUSIONS: This study found that patients with IBD are at increased risk of 90-day medical complications, re-admissions, and ED visits. Due to its systemic nature, surgeons operating on these patients should be aware of the disease's extra-intestinal manifestations, and the potential postoperative risks in IBD patients. Providers should use this investigation when educating patients on potential risks of elective THA.

Inflammatory bowel disease patients undergoing total hip arthroplasty have higher odds of implant-related complications.

PURPOSE: This study evaluates whether IBD patients are at increased risk of implant-related complications after THA. MATERIALS AND METHODS: A retrospective study from 01 January 2010 to 31 October 31 2020 using an administrative claims database was performed. IBD patients undergoing THA (n = 11,025), without corticosteroid treatment, were propensity score matched to controls in a 1:5 ratio (n = 55,121) based on age, sex, and the Charlson Comorbidity Index (CCI). Outcomes evaluated included periprosthetic fracture, aseptic loosening, prosthetic joint infection, and THA revision within 2 years of index procedure. Chi-square analyses were used to compare the matched cohorts. The association of IBD and implant-related complications was evaluated using logistical regression to calculate odds ratios (ORs), 95% confidence intervals (95% CIs), and p-values. A p-value < 0.001 was used as the significance threshold. RESULTS: Patients with IBD had a greater incidence and odds of total implant complications (7.03% vs. 3.98%; OR 1.76; p < 0.001) compared with matched controls. IBD patients had significantly higher incidence and odds of developing periprosthetic fracture (0.50% vs. 0.20%; OR 2.46; p < 0.001), THA revisions (2.21% vs. 1.17%; OR 1.91; p < 0.001), aseptic loosening (1.45% vs. 0.84%; OR 1.75; p < 0.001), and prosthetic joint infection (2.87% vs. 1.77%; OR 1.64; p < 0.001). CONCLUSIONS: Patients with IBD who underwent primary THA had a significantly higher risk of implant-related complications compared to matched controls. Providers should use this study to appropriately assess post-complication risk factors for their patients with IBD.

Lack of chromokinesin Klp-19 creates a more rigid midzone and affects force transmission during anaphase in C. elegans.

Recent studies have highlighted the significance of the spindle midzone - the region positioned between chromosomes - in ensuring proper chromosome segregation. By combining advanced 3D electron tomography and cutting-edge light microscopy we have discovered a previously unknown role of the regulation of microtubule dynamics within the spindle midzone of C. elegans. Using Fluorescence recovery after photobleaching and a combination of second harmonic generation and two-photon fluorescence microscopy, we found that the length of the antiparallel microtubule overlap zone in the spindle midzone is constant throughout anaphase, and independent of cortical pulling forces as well as the presence of the microtubule bundling protein SPD-1. Further investigations of SPD-1 and the chromokinesin KLP-19 in C. elegans suggest that KLP-19 regulates the overlap length and functions independently of SPD-1. Our data shows that KLP-19 plays an active role in regulating the length and turn-over of microtubules within the midzone as well as the size of the antiparallel overlap region throughout mitosis. Depletion of KLP-19 in mitosis leads to an increase in microtubule length in the spindle midzone, which also leads to increased microtubule - microtubule interaction, thus building up a more robust microtubule network. The spindle is globally stiffer and more stable, which has implications for the transmission of forces within the spindle affecting chromosome segregation dynamics. Our data shows that by localizing KLP-19 to the spindle midzone in anaphase microtubule dynamics can be locally controlled allowing the formation of a functional midzone.

Sex-Specific Postoperative Outcomes of Primary Total Hip Replacements: The Performance of Total Hip Replacement Procedures Leads to Worse Outcomes in Men.

INTRODUCTION: The demand for primary total hip arthroplasty (THA) is expected to increase significantly in the coming years, and women are expected to account for the greatest proportion of this increased demand. The purpose of this study was to determine, using a national database, the effect of sex on 90-day outcomes in primary THA patients while matching for confounding variables. Specifically, we evaluated: (1) in-hospital lengths of stay; (2) 90-day readmission rates; (3) 90-day medical complications; (4) and total global 90-day episode-of-care (EOC) costs in men and women. MATERIALS AND METHODS: Using the 100% Medicare Standard Analytical Files (SAF), a query from January 1, 2005 to March 31, 2014 from a nationwide database was performed to analyze patients who received a primary THA. The series was divided into two cohorts: men (n=436,737) and women (n=436,737). Male and female patients were matched according to age and Elixhauser-Comorbidity Index (ECI). Uni- and multi-variable regression analyses were performed to analyze the effects of sex on in-hospital lengths of stay, 90-day readmission rates, 90-day medical complications, and total global 90-day EOC costs. RESULTS: Men had greater overall 90-day medical complications compared to women following primary THA (1.28 vs. 1.19%, p<0.001). Men were found to have higher rates of acute kidney failure (0.12 vs 0.05%, p<0.0001), acute pancreatitis (0.02 vs. 0.01%, p<0.0001), cerebrovascular accidents (0.03 vs. 0.01%, p<0.0001), deep vein thromboses (0.06 vs. 0.04%, p<0.0001), and myocardial infarctions (0.02 vs. 0.01%, p<0.0001). Women were found to have higher rates of acute post-hemorrhagic anemiae (0.31 vs. 0.30%, p<0.001) and urinary tract infections (UTI; 0.40 vs. 0.28%, p<0.0001) compared to men. Men had shorter in-hospital lengths of stay (LOS) (3.42 vs. 3.54 days, p<0.001) but greater 90-day readmission rates (7.67 vs. 6.39% p<0.0001). Both cohorts had similar total global 90-day EOC costs ($14,869.85 ± $12,333.50 vs. $14,957.34 ± $10,915.61, p=0.36). CONCLUSION: Men undergoing THA have a greater number of overall 90-day medical complications and readmission rates while women have higher incidence of UTI, post-hemorrhagic anemia, and longer LOS. Understanding sex-based differences in complication rates and outcomes can help surgeons with preoperative counseling and targeted preoperative optimization.

Postoperative Complications, Readmissions, Lengths of Stay, and Cost Analyses of Patients Who Have Atrial Septal Defects After Total Joint Arthroplasty.

BACKGROUND: Atrial septal defects (ASDs) are a common congenital heart defect. This study aimed to determine whether patients diagnosed with ASDs undergoing total joint arthroplasty have differences in 1) medical complications, 2) readmissions, 3) lengths of stay (LOS), and 4) costs. METHODS: Using an administrative claims data set, a retrospective query from 2010 to 2020 was performed. The ASD patients were 1:5 ratio matched with controls, yielding a total of 45,695 total knee arthroplasty (TKA) (ASD = 7,635, control = 38,060) and 18,407 total hip arthroplasty (THA) (ASD = 3,084, control = 15,323) patients. Outcomes included medical complications, readmissions, LOS, and costs. Logistical regressions were used to calculate odds ratios (ORs) and P values. P values < 0.001 were significant. RESULTS: The ASD patients had higher odds of medical complications after TKA (38.8 versus 21.0%; OR 2.09; P < .001) and THA (45.2 versus 23.5%; OR 2.1; P < .001), noticeably deep vein thromboses, strokes, and other thromboembolic complications. The ASD patients were not significantly more likely to be readmitted after TKA (5.3 versus 4.7%; OR 1.13; P = .033) or THA (6.0 versus 5.7%; OR 1.05; P = .531). Patient LOS was not significantly greater in ASD patients undergoing TKA (3.2 versus 3.2 days; P = .805) but was greater after THA (5.3 versus 3.76 days; P < .001). Same-day surgery costs were not significantly increased in ASD patients after TKA ($23,892.53 versus $23,453.40; P = .066) but were after THA ($23,981.93 versus $23,579.18; P < .001). Costs within 90 days were similar between cohorts. CONCLUSION: The ASD patients have greater 90-day complications following primary total joint arthroplasty. Providers may consider preoperative cardiac clearance or adjusting anticoagulation in this population to mitigate these risks. LEVEL OF EVIDENCE: III.

Numerical Study on Characteristics of Convection and Temperature Evolution in Microchannel of Thermal Flowmeter.

During practical usage, thermal flowmeters have a limited range of applications. The present work investigates the factors influencing thermal flowmeter measurements and observes the effects of buoyancy convection and forced convection on the flow rate measurement sensitivity. The results show that the gravity level, inclination angle, channel height, mass flow rate, and heating power affect the flow rate measurements by influencing the flow pattern and the temperature distribution. Gravity determines the generation of convective cells, while the inclination angle affects the location of the convective cells. Channel height affects the flow pattern and temperature distribution. Higher sensitivity can be achieved with smaller mass flow rates or higher heating power. According to the combined influence of the aforementioned parameters, the present work investigates the flow transition based on the Reynolds number and the Grashof number. When the Reynolds number is below the critical value corresponding to the Grashof number, convective cells emerge and affect the accuracy of flowmeter measurements. The research on influencing factors and flow transition presented in this paper has potential implications for the design and manufacture of thermal flowmeters under different working conditions.

Increasing trend toward joint-preserving procedures for hip osteonecrosis in the United States from 2010 to 2019.

INTRODUCTION: The incidence of osteonecrosis of the femoral head is estimated at about 10 to 20,000 patients annually, and, when left untreated, 80% or more of cases progress to femoral head collapse. A series of joint-preserving procedures have been developed to prevent/delay the need for hip arthroplasty. The aim of this study was to provide a five-year update: (1) evaluating temporal trends of arthroplasty vs. joint-preservation techniques such as core decompression, bone grafting, osteotomies, and arthroscopy; (2) determining proportions of procedures in patients aged less than vs. over 50 years; and (3) quantifying rates of specific operative techniques. METHODS: A total of 10,334 patients diagnosed with osteonecrosis of the femoral head and having received hip surgery were identified from a nationwide database between 1 January 2010 and 31 December 2019, by using the International Classification of Disease, the Ninth/Tenth revision (ICD-9/10) codes. The percentage of patients managed by each operative procedure was calculated annually. To identify trends, patients were grouped by age under/over 50 years and divided into a joint-preserving and a non-joint-preserving (arthroplasty) group. Chi-squared tests were performed to compare the total number of procedures per year. RESULTS: Rates of arthroplasty far exceeded those for joint-preserving procedures. However, from 2015 to 2019, significantly more joint-preserving procedures were performed than in 2010 to 2014 (4.3% vs. 3.0%, P < 0.001). Significantly more joint-preserving procedures were performed in patients aged < 50 years relative to those ≥ 50 years (7.56% vs. 1.86%, P < 0.001). Overall, total hip arthroplasty was the most common procedure (9,814; 94.97%) relative to core decompression (331; 3.20%), hemiarthroplasty/resurfacing (102; 0.99%), bone grafting (48; 0.46%), and osteotomy (5; 0.05%). CONCLUSION: Management of patients who have osteonecrosis of the femoral head continues to be predominantly arthroplasty procedures, specifically, total hip arthroplasty. Our findings suggest a small, but significant trend toward increased joint-preserving procedures, especially in patients under 50 years. In particular, the proportion of patients receiving core decompression has increased significantly from 2015 to 2019 relative to prior years.

Trends in Surgical Management of Osteonecrosis of the Femoral Head: A 2010 to 2020 Nationwide Study.

BACKGROUND: The incidence of osteonecrosis of the femoral head (ONFH) is estimated at more than 20,000 patients annually in the US. Our study aimed to provide a 10-year analysis: 1) evaluating total operative procedures with rates normalized to the population; 2) determining trends of arthroplasty versus joint-preserving procedures; and 3) quantifying specific operative techniques in patients <50 versus >50 years of age. METHODS: A total of 64,739 patients who were diagnosed with ONFH and underwent hip surgery were identified from a nationwide database between 2010 and 2020. The percentage of patients managed by each operative procedure was calculated and normalized to the overall population annually. Patients were grouped into joint-preserving versus non-joint-preserving (arthroplasty) procedures, and divided by age under/over 50 years. Linear regression modeling was performed to evaluate trends/differences in procedural volume by year. RESULTS: The number of operative procedures to treat ONFH has relatively declined from 2010 to 2020. The relative proportion of joint-preserving procedures increased (8.6% to 11.2%) during this time period. There were significantly more joint-preserving procedures in patients aged <50 years relative to >50 years (15.3% versus 2.7%, P < .001). Overall, THA was the most common procedure (57,033;88.1%) relative to hemiarthroplasty (3,875;6.0%), core decompression (2,730;4.2%), bone graft (467;0.7%), and osteotomy (257;0.4%). CONCLUSION: Surgical management of patients who have ONFH remains predominantly arthroplasty procedures (94% overall). Our findings suggest an increase in joint-preserving procedures, particularly core decompression, in patients <50 years (15.3%). Our findings provide insight into surgical management trends for ONFH, and suggest opportunities for joint-preserving procedures.

A comparative study based on performance and techno-economic analysis of different strategies for PV-Electrolyzer (green) hydrogen fueling incinerator system.

The integration of hydrogen in the primary energy mix requires a major technological shift in virtually every energy-related application. This study has attempted to investigate the techno-economic solar photovoltaic (PV) integrated water electrolysis and waste incineration system. Three different strategies, i.e., (i) PV + Battery(Hybrid mode with required batteries); (ii) auto-ignition (Direct coupling); and (iii) PV + Secondary-Electrolyzer(Direct coupling assisted with secondary electrolyzer), have been envisioned. The 'PV + Battery' consume 42.42 % and 15.07 % less energy than the auto-ignition and 'PV + Secondary-Electrolyzer' methods. However, the capital cost of 'PV + Battery' has been calculated to be 15.4 % and 11.8 % more than auto-ignition and 'PV + Secondary-Electrolyzer, respectively.The energy consumption relative to waste input, the 'PV + Battery' method used 80 % less energy, while auto-ignition and 'PV + Secondary-Electrolyzer' showed 70.5 % and 77.5 % less energy, respectively. Furthermore, these approaches showed a vast difference in cost-benefit for the longer run. 'PV + Battery' was forecasted to be 73.3 % and 23.3 % more expensive than auto-ignition and 'PV + Secondary-Electrolyzer' methods, respectively, for 30 years. Overall, this study can benefit from using either of these methods depending on the application, usage scale, and climatic conditions.

How to Create an Orthopaedic Arthroplasty Administrative Database Project: A Step-by-Step Guide Part I: Study Design.

BACKGROUND: Use of clinical and administrative databases in orthopaedic surgery research has grown substantially in recent years. It is estimated that approximately 10% of all published lower extremity arthroplasty research have been database studies. The aim of this review is to serve as a guide on how to (1) design, (2) execute, and (3) publish an orthopaedic administrative database arthroplasty project. METHODS: In part I, we discuss how to develop a research question and choose a database (when databases should/should not be used), detailing advantages/disadvantages of those most commonly used. To date, the most commonly published databases in orthopaedic research have been the National Inpatient Sample, Medicare, National Surgical Quality Improvement Program, and those provided by PearlDiver. General advantages of most database studies include accessibility, affordability compared to prospective research studies, ease of use, large sample sizes, and the ability to identify trends and aggregate outcomes of multiple health care systems/providers. RESULTS: Disadvantages of most databases include their retrospective observational nature, limitations of procedural/billing coding, relatively short follow-up, limited ability to control for confounding variables, and lack of functional/patient-reported outcomes. CONCLUSION: Although this study is not all-encompassing, we hope it will serve as a starting point for those interested in conducting and critically reviewing lower extremity arthroplasty database studies.

What are the Causes, Costs and Risk-Factors for Emergency Department Visits Following Primary Total Hip Arthroplasty? An Analysis of 1,018,772 Patients.

BACKGROUND: Well-powered studies analyzing the relationship and nature of emergency department (ED) visits following primary total hip arthroplasties (THAs) are limited. The aim of this study was to: 1) compare baseline demographics of patients with/without an ED visit; 2) determine leading causes of ED visits; 3) identify patient-related risk factors; and 4) quantify 90-day episode-of-care healthcare costs divided by final diagnosis. METHODS: Patients undergoing primary THA between January 1, 2010 and October 1, 2020 who presented to the ED within 90-days postoperatively were identified using the Mariner dataset of PearlDiver, yielding 1,018,772 patients. This included 3.9% (n = 39,439) patients who did and 96.1% (n = 979,333) who did not have an ED visit. Baseline demographics between the control/study cohorts, ED visit causes, risk-factors, and subsequent costs-of-care were analyzed. Using Bonferroni-correction, a P-value less than 0.002 was considered statistically significant. RESULTS: Patients who presented to the ED post-operatively were most often aged 65-74 years old (41.09%) or female sex (55.60%). Nonmusculoskeletal etiologies comprised 66.8% of all ED visits. Risk factors associated with increased ED visits included alcohol abuse, depressive disorders, congestive heart failure, coagulopathy, and electrolyte/fluid derangements (P < .001 for all). Pulmonary ($28,928.01) and cardiac ($28,574.69) visits attributed to the highest costs of care. CONCLUSION: Nonmusculoskeletal causes constituted the majority of ED visits. The top five risk factors associated with increased odds of ED visits were alcohol abuse, electrolyte/fluid derangements, congestive heart failure, coagulopathy, and depression. This study highlights potential areas of pre-operative medical optimization that may reduce ED visits following primary THA.

How to Create an Orthopaedic Arthroplasty Database Project: A Step-by-Step Guide Part II: Study Execution.

In recent years, the use of national databases in orthopaedic surgery research has grown substantially with database studies comprising an estimated ∼10% of all published lower extremity arthroplasty research. The aim of this review is to serve as a guide on how to: (1) design; (2) execute; and (3) publish an orthopaedic database arthroplasty project. In part II, we discuss how to collect data, propose a novel checklist/standards for presenting orthopaedic database information (SOPOD), discuss methods for appropriate data interpretation/analysis, and summarize how to convert findings to a manuscript (providing a previously published example study). Data collection can be divided into two stages: baseline patient demographics and primary/secondary outcomes of interest. Our proposed SOPOD is more orthopaedic-centered and builds upon previous standards for observational studies from the EQUATOR network. There are a host of statistical methods available to analyze data to compare baseline demographics, primary/secondary outcomes, and reduce type 1 errors seen in large datasets. When drafting a manuscript, it is important to consider and discuss the limitations of database studies, including their retrospective nature, issues with coding/billing, differences in statistical versus clinical significance (or relevance), lack of surgery details (approach, laterality, and implants), and limited sampling or follow-up. We hope this paper will serve as a starting point for those interested in conducting lower extremity arthroplasty database studies.