Association Between Periprosthetic Joint Infection and Mortality Following Primary Total Hip Arthroplasty.

BACKGROUND: Periprosthetic joint infection (PJI) remains a dreaded and unpredictable complication after total hip arthroplasty (THA). In addition to causing substantial morbidity, PJI may contribute to long-term mortality risk. Our objective was to determine the long-term mortality risk associated with PJI following THA. METHODS: This population-based, retrospective cohort study included adult patients (≥18 years old) in Ontario, Canada, who underwent their first primary elective THA for arthritis between April 1, 2002, and March 31, 2021. The primary outcome was death within 10 years after the index THA. Mortality was compared between propensity-score-matched groups (PJI within 1 year after surgery versus no PJI within 1 year after surgery) with use of survival analyses. Patients who died within 1 year after surgery were excluded to avoid immortal time bias. RESULTS: A total of 175,432 patients (95,883 [54.7%] women) with a mean age (and standard deviation) of 67 ± 11.4 years underwent primary THA during the study period. Of these, 868 patients (0.49%) underwent surgery for a PJI of the replaced joint within 1 year after the index procedure. After matching, patients with a PJI within the first year had a significantly higher 10-year mortality rate than their counterparts (11.4% [94 of 827 patients] versus 2.2% [18 of 827 patients]; absolute risk difference, 9.19% [95% confidence interval (CI), 6.81% to 11.6%]; hazard ratio, 5.49 [95% CI, 3.32 to 9.09]). CONCLUSIONS: PJI within 1 year after surgery is associated with over a fivefold increased risk of mortality within 10 years. The findings of this study underscore the importance of prioritizing efforts related to the prevention, diagnosis, and treatment of PJIs. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

MRI use leading up to total knee arthroplasty: a retrospective cohort study.

BACKGROUND: Demand for total knee arthroplasty (TKA) is increasing as it remains the gold-standard treatment for end-stage osteoarthritis (OA) of the knee. Magnetic resonance imaging (MRI) scans of the knee are not indicated for diagnosing knee OA and represent a possible delay to orthopaedic surgeon referral and unnecessary expenditure. The purpose of this study was to determine the proportion of patients who underwent an MRI in the two years prior to their primary TKA for OA and determine patient and physician associations with increased MRI usage. METHODS: This is a population-based cohort study using administrative data from Ontario, Canada. All patients over 40 years old who underwent their first primary TKA between April 1, 2008, and March 31, 2019, were included. Statistical analyses were performed using SAS and included the Cochran-Armitage test for trend of MRI prior to surgery. A predictive multivariable regression model was used to determine features correlated to receiving an MRI. RESULTS: There were 194,989 eligible first-time TKA recipients, of which 38,244 (19.6%) received an MRI in the two years prior to their surgery. The majority of these (69.6%) were ordered by primary care physicians. Patients who received an MRI were younger, had fewer comorbidities and were more affluent than patients who did not (p < 0.001). MRI use prior to TKA increased from 2008 to 2018 (p < 0.001). CONCLUSION: Despite MRIs rarely being indicated for the work-up of end-stage OA, nearly one in five patients have an MRI in the two years prior to their TKA. This may be increasing healthcare expenditure and surgical wait-times.

Association between immigration status and total knee arthroplasty outcomes in Ontario, Canada: a population-based matched cohort study.

BACKGROUND: Immigrants and refugees face unique challenges navigating the health care system to manage severe arthritis, because of unfamiliarity, lack of awareness of surgical options, or access. The purpose of this study was to assess total knee arthroplasty (TKA) uptake, surgical outcomes, and hospital utilization among immigrants and refugees compared with Canadian-born patients. METHODS: We included all adults undergoing primary TKA from January 2011 to December 2020 in Ontario. Cohorts were defined as Canadian-born or immigrants and refugees. We assessed change in yearly TKA utilization for trend. We compared differences in 1-year revision, infection rates, 30-day venous thromboembolism (VTE), presentation to emergency department, and hospital readmission between matched Canadian-born and immigrant and refugee groups. RESULTS: We included 158 031 TKA procedures. A total of 11 973 (7.6%) patients were in the immigrant and refugee group, and 146 058 (92.4%) patients were in the Canadian-born group. The proportion of TKAs in Ontario performed among immigrants and refugees nearly doubled over the 10-year study period (p < 0.001). After matching, immigrants were at relatively lower risk of 1-year revision (0.9% v. 1.6%, p < 0.001), infection (p < 0.001), death (p = 0.004), and surgical complications (p < 0.001). No differences were observed in rates of 30-day VTE or length of hospital stay. Immigrants were more likely to be discharged to rehabilitation (p < 0.001) and less likely to present to the emergency department (p < 0.001) than Canadian-born patients. CONCLUSION: Compared with Canadian-born patients, immigrants and refugees have favourable surgical outcomes and similar rates of resource utilization after TKA. We observed an underutilization of these procedures in Ontario relative to their proportion of the population. This may reflect differences in perceptions of chronic pain or barriers accessing arthroplasty.

Understanding the Influence of Single Payer Health Insurance on Socioeconomic Disparities in Total Hip Arthroplasty (THA) Utilization: A Transnational Analysis.

OBJECTIVE: Access to care varies between countries. It is theorized that income-based disparities in access may be reduced in countries with universal health insurance relative to the United States, but data are currently limited. We hypothesized that income-based differences in total hip arthroplasty (THA) utilization and outcomes would be larger in the United States than in Canada. METHODS: We retrospectively compared all patients undergoing THA from 2012 to 2018 in Pennsylvania, the United States, and Ontario, Canada. We compared age-standardized and sex-standardized per-capita THA utilization in the United States and Canada overall and across different income strata, where income strata were defined by neighborhood income quintile. We also examined income-based differences in rates of 1-year revision, 90-day mortality, and 90-day readmission. RESULTS: Overall THA utilization per 10,000 people per year was higher across all income groups in Pennsylvania compared with Ontario (15.1 versus 8.8, P < 0.001 in lowest-income quintile; 21.4 versus 12.6, P < 0.001 in highest-income quintile). Income-based differences in utilization in the highest-income vs lowest-income quintile groups were greater in Ontario (43.2%) than Pennsylvania (41.7%). The adjusted odds for the lowest-income group compared with the highest-income group of 1-year revision were greater in Ontario compared with Pennsylvania (P = 0.03), and risk of 90-day mortality and 90-day readmission was similar between the regions. CONCLUSION: Income-based differences in THA utilization were more notable in Ontario than in Pennsylvania. In addition, patients in low-income communities in Ontario were at equal or greater risk relative to high-income community patients for adverse outcomes compared with patients in Pennsylvania. Income-based disparities in THA utilization and outcomes were smaller in the United States than in Canada, in contrast to what might be expected. LEVEL OF EVIDENCE: III.

Hardware Removal and Conversion Hip Arthroplasty via a Single Interval Anterior Approach: Surgical Technique.

The supine 'off-table' anterior-based muscle-sparing (ABMS) approach is an established approach for primary total hip arthroplasty. The approach is performed with the patient positioned supine on a regular operating room table. It combines utilizing the Watson-Jones interval (without disrupting the abductor muscles) with principles of capsular management borrowed from the direct anterior approach. The approach may also be utilized for complex primary and revision hip arthroplasties. One clinical scenario the ABMS approach may be particularly well-suited to is conversion hip arthroplasty when retained hardware requires removal. The approach enables the surgeon to remove proximal femoral hardware and perform hip arthroplasty within the same muscle interval. This is in contrast to direct anterior approach, which entails separate windows being created on either side of the tensor fascia lata muscle to remove hardware and insert hip arthroplasty components, respectively. In this article, we describe our surgical technique for performing conversion total hip arthroplasty with hardware removal (sliding hip screw and plate in the discussed case) via a single interval with the supine off-table ABMS approach.

Virtual versus in-person physiotherapy following total knee arthroplasty: a comparative analysis.

PURPOSE: At our centre, we developed and implemented a video-based post-operative physiotherapy program for patients undergoing total knee arthroplasty (TKA). Our aims were to analyse and compare the outcomes of this program to in-person physiotherapy. METHODS: We reviewed the outcomes of 112 patients and captured range-of-motion (ROM) measurements and pain scores (P4 questionnaire). We compared the outcomes to a cohort of 175 patients undergoing in-person therapy. Comparative analysis was performed using a two-tailed Student's t-test. RESULTS: There was no significant difference between the two groups in age, sex, or initial post-operative knee ROM. On discharge from virtual physiotherapy, mean flexion was 122.6° (SD 7.6). There was no significant difference in improvement in knee flexion between the virtual and in-person groups (mean 30.6° vs 34.0°, p = 0.07). There was no significant difference in the proportion of patients achieving ≥ 120° of flexion (85.0% virtual vs 91.3% in-person, p = 0.11) or those achieving an extension deficit of ≤ 5° (96.0% vs 98.3%, p = 0.25). There was no difference in the number of PT visits to discharge (10.5 vs 11.1, p = 0.14) or final pain scores (12.4 vs 11.9, p = 0.61). CONCLUSION: Improvements in knee ROM measures are comparable between virtual and in-person physiotherapy with both groups achieving a good functional range. These findings have implications for the virtual delivery of healthcare, especially among remote populations and patients with mobility limitations.

Impact of the coronavirus disease 2019 pandemic on equity of access to hip and knee replacements: a population-level study.

PURPOSE: The COVID-19 pandemic had innumerable impacts on healthcare delivery. In Canada, this included limitations on inpatient capacity, which resulted in an increased focus on outpatient surgery for non-emergent cases such as joint replacements. The objective of this study was to assess whether the pandemic and the shift towards outpatient surgery had an impact on access to joint replacement for marginalized patients. METHODS: Data from Ontario's administrative healthcare databases were obtained for all patients undergoing an elective hip or knee replacement between January 1, 2018 and August 31, 2021. All surgeries performed before March 15, 2020 were classified as "pre-COVID," while all procedures performed after that date were classified as "post-COVID." The Ontario Marginalization Index domains were used to analyze proportion of marginalized patients undergoing surgery pre- and post-COVID. RESULTS: A total of 102,743 patients were included-42,812 hip replacements and 59,931 knee replacements. There was a significant shift towards outpatient surgery during the post-COVID period (1.1% of all cases pre-COVID to 13.2% post-COVID, p < 0.001). In the post-COVID cohort, there were significantly fewer patients from some marginalized groups, as well as fewer patients with certain co-morbidities, such as congestive heart failure and chronic obstructive pulmonary disease. CONCLUSION: The most important finding of this population-level database study is that, compared to before the COVID-19 pandemic, there has been a change in the profile of patients undergoing hip and knee replacements in Ontario, specifically across a range of indicators. Fewer marginalized patients are undergoing joint replacement surgery since the COVID-19 pandemic. Further monitoring of access to joint replacement surgery is required in order to ensure that surgery is provided to those who are most in need.

Variation in care for patients presenting with hip fracture in six high-income countries: A cross-sectional cohort study.

BACKGROUND: Hip fractures are costly and common in older adults, but there is limited understanding of how treatment patterns and outcomes might differ between countries. METHODS: We performed a retrospective serial cross-sectional cohort study of adults aged ≥66 years hospitalized with hip fracture between 2011 and 2018 in the US, Canada, England, the Netherlands, Taiwan, and Israel using population-representative administrative data. We examined mortality, hip fracture treatment approaches (total hip arthroplasty [THA], hemiarthroplasty [HA], internal fixation [IF], and nonoperative), and health system performance measures, including hospital length of stay (LOS), 30-day readmission rates, and time-to-surgery. RESULTS: The total number of hip fracture admissions between 2011 and 2018 ranged from 23,941 in Israel to 1,219,696 in the US. In 2018, 30-day mortality varied from 3% (16% at 1 year) in Taiwan to 10% (27%) in the Netherlands. With regards to processes of care, the proportion of hip fractures treated with HA (range 23%-45%) and THA (0.2%-10%) differed widely across countries. For example, in 2018, THA was used to treat approximately 9% of patients in England and Israel but less than 1% in Taiwan. Overall, IF was the most common surgery performed in all countries (40%-60% of patients). IF was used in approximately 60% of patients in the US and Israel, but only 40% in England. In 2018, rates of nonoperative management ranged from 5% of patients in Taiwan to nearly 10% in England. Mean hospital LOS in 2018 ranged from 6.4 days (US) to 18.7 days (England). The 30-day readmission rate in 2018 ranged from 8% (in Canada and the Netherlands) to nearly 18% in England. The mean days to surgery in 2018 ranged from 0.5 days (Israel) to 1.6 days (Canada). CONCLUSIONS: We observed substantial between-country variation in mortality, surgical approaches, and health system performance measures. These findings underscore the need for further research to inform evidence-based surgical approaches.

Patient appropriateness for total knee arthroplasty and predicted probability of a good outcome.

OBJECTIVES: One-fifth of total knee arthroplasty (TKA) recipients experience a suboptimal outcome. Incorporation of patients' preferences in TKA assessment may improve outcomes. We determined the discriminant ability of preoperative measures of TKA need, readiness/willingness and expectations for a good TKA outcome. METHODS: In patients with knee osteoarthritis (OA) undergoing primary TKA, we preoperatively assessed TKA need (Western Ontario-McMaster Universities OA Index (WOMAC) Pain Score and Knee injury and Osteoarthritis Outcome Score (KOOS) function, arthritis coping), health status, readiness (Patient Acceptable Symptom State, depressive symptoms), willingness (definitely yes-yes/no) and expectations (outcomes deemed 'very important'). A good outcome was defined as symptom improvement (met Outcome Measures in Rheumatology and Osteoarthritis Research Society International (OMERACT-OARSI) responder criteria) and satisfaction with results 1 year post TKA. Using logistic regression, we assessed independent outcome predictors, model discrimination (area under the receiver operating characteristic curve, AUC) and the predicted probability of a good outcome for different need, readiness/willingness and expectations scenarios. RESULTS: Of 1,053 TKA recipients (mean age 66.9 years (SD 8.8); 58.6% women), 78.1% achieved a good outcome. With TKA need alone (WOMAC pain subscale, KOOS physical function short-form), model discrimination was good (AUC 0.67, 95% CI 0.63 to 0.71). Inclusion of readiness/willingness, depressive symptoms and expectations regarding kneeling, stair climbing, well-being and performing recreational activities improved discrimination (p=0.01; optimism corrected AUC 0.70, 0.66-0.74). The predicted probability of a good outcome ranged from 44.4% (33.9-55.5) to 92.4% (88.4-95.1) depending on level of TKA need, readiness/willingness, depressive symptoms and surgical expectations. CONCLUSIONS: Although external validation is required, our findings suggest that incorporation of patients' TKA readiness, willingness and expectations in TKA decision-making may improve the proportion of recipients that experience a good outcome.

Improving Resource Utilization for Arthroplasty Care by Leveraging Machine Learning and Optimization: A Systematic Review.

Background: There is a growing demand for total joint arthroplasty (TJA) surgery. The applications of machine learning (ML), mathematical optimization, and computer simulation have the potential to improve efficiency of TJA care delivery through outcome prediction and surgical scheduling optimization, easing the burden on health-care systems. The purpose of this study was to evaluate strategies using advances in analytics and computational modeling that may improve planning and the overall efficiency of TJA care. Methods: A systematic review including MEDLINE, Embase, and IEEE Xplore databases was completed from inception to October 3, 2022, for identification of studies generating ML models for TJA length of stay, duration of surgery, and hospital readmission prediction. A scoping review of optimization strategies in elective surgical scheduling was also conducted. Results: Twenty studies were included for evaluating ML predictions and 17 in the scoping review of scheduling optimization. Among studies generating linear or logistic control models alongside ML models, only 1 found a control model to outperform its ML counterpart. Furthermore, neural networks performed superior to or at the same level as conventional ML models in all but 1 study. Implementation of mathematical and simulation strategies improved the optimization efficiency when compared to traditional scheduling methods at the operational level. Conclusions: High-performing predictive ML-based models have been developed for TJA, as have mathematical strategies for elective surgical scheduling optimization. By leveraging artificial intelligence for outcome prediction and surgical optimization, there exist greater opportunities for improved resource utilization and cost-savings in TJA than when using traditional modeling and scheduling methods.

Artificial Intelligence for Hip Fracture Detection and Outcome Prediction: A Systematic Review and Meta-analysis.

Importance: Artificial intelligence (AI) enables powerful models for establishment of clinical diagnostic and prognostic tools for hip fractures; however the performance and potential impact of these newly developed algorithms are currently unknown. Objective: To evaluate the performance of AI algorithms designed to diagnose hip fractures on radiographs and predict postoperative clinical outcomes following hip fracture surgery relative to current practices. Data Sources: A systematic review of the literature was performed using the MEDLINE, Embase, and Cochrane Library databases for all articles published from database inception to January 23, 2023. A manual reference search of included articles was also undertaken to identify any additional relevant articles. Study Selection: Studies developing machine learning (ML) models for the diagnosis of hip fractures from hip or pelvic radiographs or to predict any postoperative patient outcome following hip fracture surgery were included. Data Extraction and Synthesis: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses and was registered with PROSPERO. Eligible full-text articles were evaluated and relevant data extracted independently using a template data extraction form. For studies that predicted postoperative outcomes, the performance of traditional predictive statistical models, either multivariable logistic or linear regression, was recorded and compared with the performance of the best ML model on the same out-of-sample data set. Main Outcomes and Measures: Diagnostic accuracy of AI models was compared with the diagnostic accuracy of expert clinicians using odds ratios (ORs) with 95% CIs. Areas under the curve for postoperative outcome prediction between traditional statistical models (multivariable linear or logistic regression) and ML models were compared. Results: Of 39 studies that met all criteria and were included in this analysis, 18 (46.2%) used AI models to diagnose hip fractures on plain radiographs and 21 (53.8%) used AI models to predict patient outcomes following hip fracture surgery. A total of 39 598 plain radiographs and 714 939 hip fractures were used for training, validating, and testing ML models specific to diagnosis and postoperative outcome prediction, respectively. Mortality and length of hospital stay were the most predicted outcomes. On pooled data analysis, compared with clinicians, the OR for diagnostic error of ML models was 0.79 (95% CI, 0.48-1.31; P = .36; I2 = 60%) for hip fracture radiographs. For the ML models, the mean (SD) sensitivity was 89.3% (8.5%), specificity was 87.5% (9.9%), and F1 score was 0.90 (0.06). The mean area under the curve for mortality prediction was 0.84 with ML models compared with 0.79 for alternative controls (P = .09). Conclusions and Relevance: The findings of this systematic review and meta-analysis suggest that the potential applications of AI to aid with diagnosis from hip radiographs are promising. The performance of AI in diagnosing hip fractures was comparable with that of expert radiologists and surgeons. However, current implementations of AI for outcome prediction do not seem to provide substantial benefit over traditional multivariable predictive statistics.

Sex-specific differences in 30-day outcomes following primary total hip replacement in 86,684 patients.

INTRODUCTION: Although differential outcomes based on sex are widespread in medicine and surgery, evaluation of sex-specific differences in the field of orthopaedic surgery in general - and arthroplasty in particular - are lacking. We hypothesised that morbidly obese male and female patients would have differing risks of surgical complications following primary total hip replacement. METHODS: We reviewed data contained within the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database from 2015 through 2018, inclusive. A multivariable binary logistic regression model was used to determine the adjusted odds ratios (OR) of relevant variables on primary and secondary outcomes. RESULTS: A total of 86,684 patients undergoing THR were identified, of whom 9972 patients (4095 male and 5877 female) were morbidly obese. Among morbidly obese patients, odds of surgical site infection were higher in females than males within 30 days of surgery (adjusted OR 1.40; 95% CI, 1.10-1.79; p = 0.007). This comprised the odds of both superficial infection (1.8% vs. 1.1%, adjusted OR 1.67; 95% CI, 1.16-2.40; p = 0.006) and deep infection (1.9% vs. 1.4%, adjusted OR 1.22; 95% CI, 0.88-1.68; p = 0.24). Unexpected return to the operating room (i.e., reoperation) within 30 days of the surgical procedure was also higher among females than males (4.2% vs. 3.1%, adjusted OR 1.38, 95% CI, 1.10-1.71, p = 0.005). There were no differences between male and female patients in the non-obese cohort. CONCLUSIONS: Among patients with morbid obesity, the risk of surgical site infection and reoperation within the first 30 days is greater in women as compared to men. Future research must address whether this early increased risk among morbidly obese women persists in the longer term, and whether it results in compromised function or quality of life.

Association of age, sex and race with prescription of anti-osteoporosis medications following low-energy hip fracture in a retrospective registry cohort.

BACKGROUND: Initiation of anti-osteoporosis medications after hip fracture lowers the risk of subsequent fragility fractures. Historical biases of targeting secondary fracture prevention towards certain groups may result in treatment disparities. We examined associations of patient age, sex and race with anti-osteoporosis medication prescription following hip fracture. METHODS: A cohort of patients with a hip fracture between 2016-2018 was assembled from the American College of Surgeons National Surgical Quality Improvement Program registry. Patients on anti-osteoporosis medications prior to admission were excluded. Multivariable logistic regression was used to determine adjusted associations between patient age, sex and race and their interactions with prescription of anti-osteoporosis medications within 30 days of surgery. RESULTS: In total, 12,249 patients with a hip fracture were identified with a median age of 82 years (IQR: 73-87), and 67% were female (n = 8,218). Thirty days postoperatively, 26% (n = 3146) of patients had been prescribed anti-osteoporosis medication. A significant interaction between age and sex with medication prescription was observed (p = 0.04). Male patients in their 50s (OR:0.75, 95%CI:0.60-0.92), 60s (OR:0.81, 95%CI:0.70-0.94) and 70s (OR:0.89, 95%CI:0.81-0.97) were less likely to be prescribed anti-osteoporosis medication compared to female patients of the same age. Patients who belonged to minority racial groups were not less likely to receive anti-osteoporosis medications than patients of white race. INTERPRETATION: Only 26% of patients were prescribed anti-osteoporosis medications following hip fracture, despite consensus guidelines urging early initiation of secondary prevention treatments. Given that prescription varied by age and sex, strategies to prevent disparities in secondary fracture prevention are warranted.

Association between isolated abnormal coagulation profile on transfusion following major surgery: A NSQIP analysis of individuals without bleeding disorders.

INTRODUCTION: Preoperative coagulation screening for patients without bleeding disorders remains controversial. The combinatorial risk of INR, aPTT, and platelet count (PLT) abnormalities leading to bleeding requiring transfusion is not known in these patients. We examined the association between abnormal coagulation profile and the risk of transfusion following common elective surgery in patients without bleeding disorders. STUDY DESIGN AND METHODS: We utilized the National Surgical Quality Improvement Program (NSQIP) database from 2004 to 2018 to identify patients without a history of bleeding disorders undergoing common 23 major elective procedures across 10 specialties. Multivariable logistic regression was used to assess the association between coagulation profile and bleeding requiring packed red blood cell transfusion intra-/post-operatively. RESULTS: Of the 672,075 patients meeting inclusion criteria, 53.7% presented with normal coagulation profile preoperatively. Overall, 12.2% (n = 82,368) received transfusion. In the setting of normal aPTT/PLT, both Equivocal INR of 1.1-1.5 (aOR 1.41, 95% CI 1.38-1.44) and Abnormal INR of >1.5 (aOR 1.81, 95% CI 1.71-1.93) were significantly associated with an increased risk of transfusion. Equivocal (60-70) and Abnormal (>70) aPTT with normal INR/PLT did not demonstrate a comparable risk of transfusion. We observed a synergistic effect of combinatorial lab abnormalities on the risk of transfusion when both Abnormal INR/aPTT and Low PLT of <100,000 were present (aOR 5.18, 95% CI 3.04-8.84), compared to the effect of Abnormal INR/aPTT and normal/elevated PLT (aOR 1.90, 95% CI 1.48-2.45). DISCUSSION: The preoperative presence of abnormal findings in INR or PLT was significantly associated with the risk of bleeding requiring transfusion during intraoperative and postoperative periods.

Are Income-based Differences in TKA Use and Outcomes Reduced in a Single-payer System? A Large-database Comparison of the United States and Canada.

BACKGROUND: Income-based differences in the use of and outcomes in TKA have been studied; however, it is not known if different healthcare systems affect this relationship. Although Canada's single-payer healthcare system is assumed to attenuate the wealth-based differences in TKA use observed in the United States, empirical cross-border comparisons are lacking. QUESTIONS/PURPOSES: (1) Does TKA use differ between Pennsylvania, USA, and Ontario, Canada? (2) Are income-based disparities in TKA use larger in Pennsylvania or Ontario? (3) Are TKA outcomes (90-day mortality, 90-day readmission, and 1-year revision rates) different between Pennsylvania and Ontario? (4) Are income-based disparities in TKA outcomes larger in Pennsylvania or Ontario? METHODS: We identified all patients hospitalized for primary TKA in this cross-border retrospective analysis, using administrative data for 2012 to 2018, and we found a total of 161,244 primary TKAs in Ontario and 208,016 TKAs in Pennsylvania. We used data from the Pennsylvania Health Care Cost Containment Council, Harrisburg, PA, USA, and the ICES (formally the Institute for Clinical Evaluative Sciences), Toronto, Ontario, Canada. We linked patient-level data to the respective census data to determine community-level income using ZIP Code or postal code of residence and stratified patients into neighborhood income quintiles. We compared TKA use (age and gender, standardized per 10,000 population per year) for patients residing in the highest-income versus the lowest-income quintile neighborhoods. Similarly secondary outcomes 90-day mortality, 90-day readmission, and 1-year revision rates were compared between the two regions and analyzed by income groups. RESULTS: TKA use was higher in Pennsylvania than in Ontario overall and for all income quintiles (lowest income quartile: 31 versus 18 procedures per 10,000 population per year; p < 0.001; highest income quartile: 38 versus 23 procedures per 10,000 population per year; p < 0.001). The relative difference in use between the highest-income and lowest-income quintile was larger in Ontario (28% higher) than in Pennsylvania (23% higher); p < 0.001. Patients receiving TKA in Pennsylvania were more likely to be readmitted within 90 days and were more likely to undergo revision within the first year than patients in Ontario, but there was no difference in mortality at 1 year. When comparing income groups, there were no differences between the countries in 90-day mortality, readmission, or 1-year revision rates (p > 0.05). CONCLUSION: These results suggest that universal health insurance through a single-payer may not reduce the income-based differences in TKA access that are known to exist in the United States. Future studies are needed determine if our results are consistent across other geographic regions and other surgical procedures. LEVEL OF EVIDENCE: Level III, therapeutic study.

Access to hip arthroplasty and rates of complications in different socioeconomic groups : a review of 111,000 patients in a universal healthcare system.

AIMS: Total hip arthroplasty (THA) is one of the most successful surgical procedures. The objectives of this study were to define whether there is a correlation between socioeconomic status (SES) and surgical complications after elective primary unilateral THA, and investigate whether access to elective THA differs within SES groups. METHODS: We conducted a retrospective, population-based cohort study involving 202 hospitals in Ontario, Canada, over a 17-year period. Patients were divided into income quintiles based on postal codes as a proxy for personal economic status. Multivariable logistic regression models were then used to primarily assess the relationship between SES and surgical complications within one year of index THA. RESULTS: Of 111,359 patients who underwent elective primary THA, those in the lower SES groups had statistically significantly more comorbidities and statistically significantly more postoperative complications. While there was no increase in readmission rates within 90 days, there was a statistically significant difference in the primary and secondary outcomes including all revisions due (with a subset of deep wound infection and dislocation). Results showed that those in the higher SES groups had proportionally more cases performed than those in lower groups. Compared to the highest SES quintile, the lower groups had 61% of the number of hip arthroplasties performed. CONCLUSION: Patients in lower socioeconomic groups have more comorbidities, fewer absolute number of cases performed, have their procedures performed in lower-volume centres, and ultimately have higher rates of complications. This lack of access and higher rates of complications is a "double hit" to those in lower SES groups, and indicates that we should be concentrating efforts to improve access to surgeons and hospitals where arthroplasty is routinely performed in high numbers. Even in a universal healthcare system where there are no penalties for complications such as readmission, there seems to be an inequality in the access to THA. Cite this article: Bone Joint J 2022;104-B(5):589-597.

Do Adhesive Drapes Have an Effect on Infection Rates in Orthopaedic Surgery? A Systematic Review and Meta-Analysis.

BACKGROUND: Adhesive surgical drapes are purported to reduce the rates of surgical site infection. Despite that, international surgical guidelines generally recommend against the use of such drapes; however, this is primarily based on nonorthopaedic evidence. QUESTIONS/PURPOSES: (1) Does the use of adhesive drapes decrease the risk of wound contamination? (2) Does intraoperative drape peeling (intentional or inadvertent) increase the risk of wound contamination? (3) Does the use of adhesive drapes decrease the risk of surgical site infection? METHODS: A systematic review of the MEDLINE and Embase databases was performed according to the Cochrane Handbook methods for randomized controlled trials (RCTs) published since 2000 and comparing adhesive drapes with controls. All databases were searched from inception to March 1, 2021. A pooled meta-analysis was performed, where possible. The Cochrane Risk of Bias Assessment Tool was used to assess risk of bias among the included studies. From among 417 search results, five eligible RCTs were identified and included, all of which were published between 2018 and 2020. There were a total of 2266 patients, with 1129 (49.8%) in the adhesive drape groups, and 1137 (50.2%) in the control groups. The studies included hip and knee surgery trials (n = 3 trials; 1020 patients in intervention groups and 1032 patients in control groups) as well as trials on shoulder arthroscopy (n = 1 trial; 65 patients in the intervention group and 61 patients in the control group) and lumbar spine surgery (n = 1 trial; 44 patients in each group). The data for all three outcomes (wound contamination, impact of intraoperative peeling, and surgical site infection) revealed low heterogeneity based on random-effects models (I2 = 14%, 0%, and 0%, respectively). RESULTS: Based on data from pooled wound swab culture results from four studies, a reduction in wound contamination was associated with the use of adhesive drapes (odds ratio 0.49 [95% CI 0.34 to 0.72]; p < 0.001). The available evidence was inconclusive to determine whether intraoperative drape peeling (intentional or inadvertent) influenced the risk of wound contamination. Three studies did not report on this outcome, one study found an increased infection rate with drape peel back, and another study found a reduced treatment effect of adhesive drapes when peel back occurred in a subgroup analysis. The two studies that analyzed surgical site infections reported no infections in either arm; therefore, we could not answer the question of whether adhesive drapes affect risk of surgical site infection. CONCLUSION: The findings of this review suggest that adhesive drapes, including those with antimicrobial properties, decrease the risk of wound contamination during orthopaedic procedures. In circumstances where drape adhesion is compromised and peel back occurs at the wound edge, there is an increased risk of wound contamination with the use of adhesive drapes. The best currently available evidence is indeterminate as to the effect of adhesive drapes on the risk of surgical site infections; however, if used, care should be taken to avoid or minimize drape peel back. LEVEL OF EVIDENCE: Level I, therapeutic study.

Relationship Between Patient-Reported Readiness for Total Knee Arthroplasty and Likelihood of a Good Outcome at One-Year Follow-Up.

OBJECTIVE: To determine the relationship between patients' preoperative readiness for total knee arthroplasty (TKA) and surgical outcome at 1 year post-TKA. METHODS: This prospective cohort study recruited patients with knee osteoarthritis (OA) who were ≥30 years and were referred for TKA at 2 hip/knee surgery centers in Alberta, Canada. Those who underwent primary unilateral TKA completed questionnaires prior to TKA to assess pain using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), physical disability using the Knee Injury and Osteoarthritis Outcome Score physical function short form, perceived arthritis coping efficacy, general self-efficacy, depressed mood using the Patient Health Questionnaire 8, body mass index, comorbidities, and TKA readiness (patient acceptable symptom state; willingness to undergo TKA); these same individuals also completed the above questionnaires 1 year post-TKA to assess surgical outcomes. A good TKA outcome was defined as an individual having improved knee symptoms, measured using the Osteoarthritis Research Society International-Outcome Measures in Rheumatology responder criteria, and overall satisfaction with results of the TKA. Poisson regression with robust error estimation was used to estimate the relative risk (RR) of a good outcome for exposures, before and after controlling for covariates. RESULTS: Of 1,272 TKA recipients assessed at 1 year post-TKA, 1,053 with data for the outcome assessed in the study were included (mean ± SD age 66.9 ± 8.8 years; 58.6% female). Most patients (87.8%) were definitely willing to undergo TKA and had "unacceptable" knee symptoms (79.7%). Among patients who underwent TKA, 78.1% achieved a good outcome. Controlling for pre-TKA OA-related disability, arthritis coping efficacy, comorbid hip symptoms, and depressed mood, definite willingness to undergo TKA and unacceptable knee symptoms were associated with a greater likelihood of a good TKA outcome, with adjusted RRs of 1.18 (95% confidence interval [95% CI] 1.04-1.35) and 1.14 (95% CI 1.02-1.27), respectively. CONCLUSION: Among patients who underwent TKA for knee OA, patients' psychological readiness for TKA and willingness to undergo TKA were associated with a greater likelihood of a good outcome. Incorporation of these factors in TKA decision-making may enhance patient outcomes and appropriate the use of TKA.

Association of Surgeon-Patient Sex Concordance With Postoperative Outcomes.

Importance: Surgeon sex is associated with differential postoperative outcomes, though the mechanism remains unclear. Sex concordance of surgeons and patients may represent a potential mechanism, given prior associations with physician-patient relationships. Objective: To examine the association between surgeon-patient sex discordance and postoperative outcomes. Design, Setting, and Participants: In this population-based, retrospective cohort study, adult patients 18 years and older undergoing one of 21 common elective or emergent surgical procedures in Ontario, Canada, from 2007 to 2019 were analyzed. Data were analyzed from November 2020 to March 2021. Exposures: Surgeon-patient sex concordance (male surgeon with male patient, female surgeon with female patient) or discordance (male surgeon with female patient, female surgeon with male patient), operationalized as a binary (discordant vs concordant) and 4-level categorical variable. Main Outcomes and Measures: Adverse postoperative outcome, defined as death, readmission, or complication within 30-day following surgery. Secondary outcomes assessed each of these metrics individually. Generalized estimating equations with clustering at the level of the surgical procedure were used to account for differences between procedures, and subgroup analyses were performed according to procedure, patient, surgeon, and hospital characteristics. Results: Among 1 320 108 patients treated by 2937 surgeons, 602 560 patients were sex concordant with their surgeon (male surgeon with male patient, 509 634; female surgeon with female patient, 92 926) while 717 548 were sex discordant (male surgeon with female patient, 667 279; female surgeon with male patient, 50 269). A total of 189 390 patients (14.9%) experienced 1 or more adverse postoperative outcomes. Sex discordance between surgeon and patient was associated with a significant increased likelihood of composite adverse postoperative outcomes (adjusted odds ratio [aOR], 1.07; 95% CI, 1.04-1.09), as well as death (aOR, 1.07; 95% CI, 1.02-1.13), and complications (aOR, 1.09; 95% CI, 1.07-1.11) but not readmission (aOR, 1.02; 95% CI, 0.98-1.07). While associations were consistent across most subgroups, patient sex significantly modified this association, with worse outcomes for female patients treated by male surgeons (compared with female patients treated by female surgeons: aOR, 1.15; 95% CI, 1.10-1.20) but not male patients treated by female surgeons (compared with male patients treated by male surgeons: aOR, 0.99; 95% CI, 0.95-1.03) (P for interaction = .004). Conclusions and Relevance: In this study, sex discordance between surgeons and patients negatively affected outcomes following common procedures. Subgroup analyses demonstrate that this is driven by worse outcomes among female patients treated by male surgeons. Further work should seek to understand the underlying mechanism.

Machine learning using preoperative patient factors can predict duration of surgery and length of stay for total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most resource-intensive, high-volume surgical procedures. Two drivers of the cost of TKAs are duration of surgery (DOS) and postoperative inpatient length of stay (LOS). The ability to predict TKA DOS and LOS has substantial implications for hospital finances, scheduling, and resource allocation. The goal of this study was to predict DOS and LOS for elective unilateral TKAs using machine learning models (MLMs) based on preoperative factors. METHODS: The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for unilateral TKAs from 2014 to 2019. The dataset was split into training, validation, and testing based on year. Models (linear, tree-based, and multilayer perceptron (MLP)) were fitted to the training set in scikit-learn and PyTorch, with hyperparameters tuned on the validation set. The models were trained to minimize the mean squared error (MSE). Models with the best performance on the validation set were evaluated on the testing set according to 1) MSE, 2) buffer accuracy, and 3) classification accuracy, with results compared to a mean regressor. RESULTS: A total of 302,300 patients were included in this study. During validation, the PyTorch MLPs had the best MSEs for DOS (0.918) and LOS (0.715). During testing, the PyTorch MLPs similarly performed best based on MSEs for DOS (0.896) and LOS (0.690). While the scikit-learn MLP yielded the best 30-minute buffer accuracy for DOS (78.8%), the PyTorch MLP provided the best 1-day buffer accuracy for LOS (75.2%). Nearly all the ML models were more accurate than the mean regressors for both DOS and LOS. CONCLUSION: Conventional and deep learning models performed better than mean regressors for predicting DOS and LOS of unilateral elective TKA patients based on preoperative factors. Future work should include operational factors to improve overall predictions.