Time and skeptical opinion content erode the effects of science coverage on climate beliefs and attitudes.

Although experiments show that exposure to factual information can increase factual accuracy, the public remains stubbornly misinformed about many issues. Why do misperceptions persist even when factual interventions generally succeed at increasing the accuracy of people's beliefs? We seek to answer this question by testing the role of information exposure and decay effects in a four-wave panel experiment (n = 2,898 at wave 4) in which we randomize the media content that people in the United States see about climate change. Our results indicate that science coverage of climate change increases belief accuracy and support for government action immediately after exposure, including among Republicans and people who reject anthropogenic climate change. However, both effects decay over time and can be attenuated by exposure to skeptical opinion content (but not issue coverage featuring partisan conflict). These findings demonstrate that the increases in belief accuracy generated by science coverage are short lived and can be neutralized by skeptical opinion content.

The global effectiveness of fact-checking: Evidence from simultaneous experiments in Argentina, Nigeria, South Africa, and the United Kingdom.

The spread of misinformation is a global phenomenon, with implications for elections, state-sanctioned violence, and health outcomes. Yet, even though scholars have investigated the capacity of fact-checking to reduce belief in misinformation, little evidence exists on the global effectiveness of this approach. We describe fact-checking experiments conducted simultaneously in Argentina, Nigeria, South Africa, and the United Kingdom, in which we studied whether fact-checking can durably reduce belief in misinformation. In total, we evaluated 22 fact-checks, including two that were tested in all four countries. Fact-checking reduced belief in misinformation, with most effects still apparent more than 2 wk later. A meta-analytic procedure indicates that fact-checks reduced belief in misinformation by at least 0.59 points on a 5-point scale. Exposure to misinformation, however, only increased false beliefs by less than 0.07 points on the same scale. Across continents, fact-checks reduce belief in misinformation, often durably so.

Elite rhetoric can undermine democratic norms.

Democratic stability depends on citizens on the losing side accepting election outcomes. Can rhetoric by political leaders undermine this norm? Using a panel survey experiment, we evaluate the effects of exposure to multiple statements from former president Donald Trump attacking the legitimacy of the 2020 US presidential election. Although exposure to these statements does not measurably affect general support for political violence or belief in democracy, it erodes trust and confidence in elections and increases belief that the election is rigged among people who approve of Trump's job performance. These results suggest that rhetoric from political elites can undermine respect for critical democratic norms among their supporters.

Limited introgression from non-native commercial strains and signatures of adaptation in the key pollinator Bombus terrestris.

Insect pollination is fundamental for natural ecosystems and agricultural crops. The bumblebee species Bombus terrestris has become a popular choice for commercial crop pollination worldwide due to its effectiveness and ease of mass rearing. Bumblebee colonies are mass produced for the pollination of more than 20 crops and imported into over 50 countries including countries outside their native ranges, and the risk of invasion by commercial non-native bumblebees is considered an emerging issue for global conservation and biological diversity. Here, we use genome-wide data from seven wild populations close to and far from farms using commercial colonies, as well as commercial populations, to investigate the implications of utilizing commercial bumblebee subspecies in the UK. We find evidence for generally low levels of introgression between commercial and wild bees, with higher admixture proportions in the bees occurring close to farms. We identify genomic regions putatively involved in local and global adaptation, and genes in locally adaptive regions were found to be enriched for functions related to taste receptor activity, oxidoreductase activity, fatty acid and lipid biosynthetic processes. Despite more than 30 years of bumblebee colony importation into the UK, we observe low impact on the genetic integrity of local B. terrestris populations, but we highlight that even limited introgression might negatively affect locally adapted populations.

Routine use of antibiotic-laden bone cement in total knee arthroplasty is a cost-effective practice in the single-payer healthcare system.

PURPOSE: The purpose of this study was to determine the cost-effectiveness of antibiotic-laden bone cement (ALBC) in primary total knee arthroplasty (TKA) from the perspective of a single-payer healthcare system. METHODS: A cost-utility analysis (CUA) was performed over a 2-year time horizon comparing primary TKA with either ALBC or regular bone cement (RBC) from the perspective of the single-payer Canadian healthcare system. All costs were in 2020 Canadian dollars. Health utilities were in the form of quality-adjusted life years (QALYs). Model inputs for cost, utilities and probabilities were derived from the literature as well as regional and national databases. One-way deterministic sensitivity analysis was performed. RESULTS: Primary TKA with ALBC was found to be more cost-effective compared to primary TKA with RBC with an incremental cost-effectiveness ratio (ICER) of -3,637.79 CAD/QALY. The use of routine ALBC remained cost-effective even with cost increases of up to 50% per bag of ALBC. TKA with ALBC was no longer cost-effective if the rate of PJI following this practice increased 52%, or the rate of PJI following the use of RBC decreased 27%. CONCLUSIONS: The routine use of ALBC in TKA is a cost-effective practice in the single-payer Canadian healthcare system. This remains to be the case even with a 50% increase in the cost of ALBC. Policy makers and hospital administrators of single-payer healthcare systems can leverage this model to inform their local funding policies. Future prospective reviews and randomized controlled trials from the perspective of various healthcare models can further shed light on this issue. LEVEL OF EVIDENCE: III.

Marginalization Influences Access, Outcomes, and Discharge Destination Following Total Joint Arthroplasty in Canada's Universal Healthcare System.

BACKGROUND: The influence of socioeconomic status on outcomes following total joint arthroplasty (TJA) in the Canadian single-payer healthcare system is yet to be elucidated. The objective of the present study was to evaluate the impact of socioeconomic status on TJA outcomes. METHODS: This was a retrospective review of 7,304 consecutive TJA (4,456 knees and 2,848 hips) performed between January 1, 2001 and December 31, 2019. The primary independent variable was the average census marginalization index. The primary dependent variable was functional outcome scores. RESULTS: The most marginalized patients in both the hip and knee cohorts had significantly worse preoperative and postoperative functional scores. Patients in the most marginalized quintile (V) showed a decreased odds of achieving a minimal important difference in functional scores at 1-year follow-up (odds ratio [OR] 0.44; 95% confidence interval [CI] [0.20, 0.97], P = .043). Patients in the knee cohort in the most marginalized quintiles (IV and V) had increased odds of being discharged to an inpatient facility with an OR of 2.07 (95% CI [1.06, 4.04], P = .033) and OR of 2.57 (95% CI [1.26, 5.22], P = .009), respectively. Patients in the hip cohort in V quintile (most marginalized) had increased odds of being discharged to an inpatient facility with an OR of 2.24 (95% CI [1.02, 4.96], P = .046). CONCLUSION: Despite being a part of the Canadian universal single-payer healthcare system, the most marginalized patients had worse preoperative and postoperative function, and had increased odds of being discharged to another inpatient facility. LEVEL OF EVIDENCE: IV.

The quality of diagnostic studies used for the diagnostic criteria of periprosthetic joint infections.

BACKGROUND: Although periprosthetic joint infection (PJI) is a serious complication following a total joint arthroplasty procedure, there remains uncertainty regarding the diagnosis of PJI due to the lack of a globally accepted, standardized definition. The goal of this review is to critically analyze the quality of the evidence used for the novel 2018 MSIS PJI definition and identify gaps and limitations with using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. METHODS: References from the modified 2018 MSIS definition for PJI by Parvizi et al. were retrieved and manually reviewed. A total of 11 studies were assessed using a validated QUADAS-2 tool. RESULTS: Many included studies had an unclear or high risk of bias for the Index Test domain due to a lack of blinding and lack of prespecified thresholds. A majority of studies utilized Youden's J statistic to optimize the thresholds which may diminish external validity. Likewise, several studies were assessed to have an unclear and high risk of bias for the Flow and Timing domain primarily due to a lack of reporting and a large number of exclusions. Overall, there was a low risk of bias for the choice of reference standard, its conduct and interpretation, as well as for the Patient Selection domain. CONCLUSION: Although the literature used for the MSIS 2018 PJI definition is fraught with potential sources of bias, there may be a trend toward an improvement in the quality of evidence when compared to the earlier definition of PJI.

Are Functional Outcomes of a Total Hip Arthroplasty Predictive of a Contralateral Total Hip Arthroplasty: A Retrospective Cohort Study.

BACKGROUND: Current literature suggests that 8%-35% of patients undergoing total hip arthroplasty (THA) undergo a subsequent contralateral THA. This study aims to determine if functional outcomes after primary THA predict outcomes in the subsequent primary THA of the contralateral side. METHODS: A retrospective cohort of patients undergoing staged bilateral primary THA was reviewed. The Oxford Hip Score (OHS) was utilized as the functional outcome measurement tool and was assessed preoperatively and at one year postoperatively. The minimal clinically important difference (MCID) was assessed. Based on the first-side THA one-year outcomes, the odds of maintaining an MCID, or not, for the second-side THA were determined. RESULTS: The study cohort consisted of 551 patients and 1102 primary THAs. The average postoperative OHSs were similar after the first and second THA. Patients achieving the MCID with the first-side surgery were 2.6 times (95% confidence interval 1.0 to 6.64, P = .04) more likely to achieve the MCID for the second-side surgery than patients failing to reach the MCID for their first-side surgery. After the first THA, 29 (5.3%) patients failed to reach the predefined MCID for the OHS compared with 54 (9.8%) patients undergoing their second THA (odds ratio: 1.96 [95% confidence interval: 1.23 to 3.1], χ2 = 8.14, P = .005). CONCLUSIONS: Functional outcomes after the first THA are predictive of functional outcomes of the second THA. Patients are more likely to achieve a clinically significant improvement after their first THA related to higher preoperative OHSs before the second THA.

Phenology and flowering overlap drive specialisation in plant-pollinator networks.

Variation in dietary specialisation stems from fundamental interactions between species and their environment. Consequently, understanding the drivers of this variation is key to understanding ecological and evolutionary processes. Dietary specialisation in wild bees has received attention due to their close mutualistic dependence on plants, and because both groups are threatened by biodiversity loss. Many principles governing pollinator specialisation have been identified, but they remain largely unvalidated. Organismal phenology has the potential to structure realised specialisation by determining concurrent resource availability and pollinator foraging activity. We evaluate this principle using mechanistic models of adaptive foraging in pollinators within plant-pollinator networks. While temporal resource overlap has little impact on specialisation in pollinators with extended flight periods, reduced overlap increases specialisation as pollinator flight periods decrease. These results are corroborated empirically using pollen load data taken from bees with shorter and longer flight periods across environments with high and low temporal resource overlap.

Global patterns in bumble bee pollen collection show phylogenetic conservation of diet.

Bumble bees (Bombus) are a group of eusocial bees with a strongly generalised feeding pattern, collecting pollen from many different botanical families. Though predominantly generalists, some bumble bee species seem to have restricted dietary choices. It is unclear whether restricted diets in bumble bees are inherent or a function of local conditions due to a lack of data for many species across different regions. The objective of this study was to determine whether bumble bee species displayed specific patterns of pollen collection, and whether patterns were influenced by phylogenetic relatedness or tongue length, a trait known to be associated with structuring floral visitation. Bumble bee pollen collection patterns were quantified from 4,132 pollen loads taken from 58 bumble bee species, representing 24% of the pollen-collecting diversity of this genus. Phylogenetic trait mapping showed a conserved pattern of dietary dissimilarity across species, but not for dietary breadth. Dietary dissimilarity was driven by collection of Fabaceae, with the most similar species collecting around 50%-60% of their diet from this botanical family. The proportion of the diet collected from Fabaceae also showed a conserved phylogenetic signal. Greater collection of Fabaceae was associated with longer tongue lengths, with shorter tongued species focusing on alternative botanical families. However, this result was largely driven by phylogenetic relatedness, not tongue length per se. These results demonstrate that, though generalists, bumble bees are still subject to dietary restrictions that constrain their foraging choices. These dietary constraints have implications for their persistence should their core resources decline in abundance.

Compositional flexibility in Li-N-H materials: implications for ammonia catalysis and hydrogen storage.

Li-N-H materials, particularly lithium amide and lithium imide, have been explored for use in a variety of energy storage applications in recent years. Compositional variation within the parent lithium imide, anti-fluorite crystal structure has been related to both its facile storage of hydrogen and impressive catalytic performance for the decomposition of ammonia. Here, we explore the controlled solid-state synthesis of Li-N-H solid-solution anti-fluorite structures ranging from amide-dominated (Li4/3(NH2)2/3(NH)1/3 or Li1.333NH1.667) through lithium imide to majority incorporation of lithium nitride-hydride (Li3.167(NH)0.416N0.584H0.584 or Li3.167NH). Formation of these solid solutions is demonstrated to cause significant changes to the thermal stability and ammonia reactivity of the samples, highlighting the potential use of compositional variation to control the properties of the material in gas storage and catalytic applications.

Postoperative Outcomes Following Total Hip and Knee Arthroplasty in Patients with Pain Catastrophizing, Anxiety, or Depression.

BACKGROUND: The relationship among pain catastrophizing, emotional disorders, and total joint arthroplasty (TJA) outcomes is an emerging area of study. The purpose of this study is to examine the association of these factors with 1-year postoperative pain and functional outcomes. METHODS: A prospective cohort study of preoperative TJA patients using the Pain Catastrophizing Scale and Hospital Anxiety and Depression Scale (HADS-A/HADS-D) was conducted. Postoperative outcomes included Visual Analog Scale (VAS) pain, Oxford, Harris Hip (HHS) and Knee Society (KSS) scores. Median regression was used to assess the pattern of relationship among preoperative clinically relevant catastrophizing (CRC) pain, abnormal HADS, and 1-year postoperative outcomes. RESULTS: We recruited 463 TJA patients, all of which completed 1-year follow-up. At 1 year, CRC-rumination (adjusted median difference 1; 95% confidence interval [CI] 0.31-1.69, P = .005) and abnormal HADS-A (adjusted median difference 1; 95% CI 0.36-1.64, P = .002) were predictors of VAS pain, CRC magnification a predictor of HHS/KSS (adjusted median difference 1.3; 95% CI 5.23-0.11, P = .041), and abnormal HADS-A a predictor of Oxford (adjusted median difference 3.68; 95% CI 1.38-5.99, P = .002). CRC patients demonstrated inferior VAS pain (P = .001), Oxford (P < .0001), and HHS/KSS (P = .025). Abnormal HADS patients demonstrated inferior postoperative VAS (HADS-A, P = .025; HADS-D, P = .030) and Oxford (HADS-A, P = .001; HADS-D, P = .030). However, patients with CRC experienced significant improvement in VAS, Oxford, and HHS/KSS (P < .05) from preoperative to 1 year. Similarly, patients with abnormal HADS showed significant improvement in VAS pain and HHS/KSS (P < .05). CONCLUSION: TJA patients who are anxious, depressed, or pain catastrophizing have inferior preoperative and postoperative pain and function. However, as compared to their preoperative status, clinically significant improvement can be expected following hip/knee arthroplasty.

Quantifying the Level of Evidence of Podium Presentations at the American Association of Hip and Knee Surgeons From 2015 to 2019.

BACKGROUND: The American Association of Hip and Knee Surgeons (AAHKS) Annual Scientific Meeting is a leading forum for the presentation and dissemination of research regarding the management of hip and knee pathology making research presented at these meetings a representation of the current literature in the field. The purpose of this study was to quantify the level of evidence of podium presentations presented at the AAHKS annual meeting from 2015 to 2019. METHODS: Two reviewers evaluated the abstracts for the available presentations. Basic science and biomechanical studies were excluded from the review. Economic studies that were not able to be evaluated based on the American Academy of Orthopedic Surgeon guidelines were also excluded. The two reviewers then independently evaluated each abstract and assigned a level of evidence (level I-V) based on the American Academy of Orthopedic Surgeon classification scheme. RESULTS: A total of 258 podium presentations were included. In total, 17 (7%) abstracts were graded level I evidence, 57 (22%) were graded level II, 85 (33%) were graded level III, and 98 (38%) were graded level IV (Table 1). There was a significant change in the distribution of the level of evidence of podium presentations over time (χ2 = 24.6, P = .02). The proportion of level I studies has increased between 2015 and 2019 (from 3.9% to 11.8%) with a concomitant decrease in level IV studies (from 42.3% to 21.6%) over that time period. CONCLUSIONS: There has been a significant improvement in the levels of evidence of podium presentations at the AAHKS Annual Meeting from 2015 to 2019.

The Changing Characteristics of Arthroplasty Patients: A Retrospective Cohort Study.

BACKGROUND: Total joint arthroplasty (TJA) is among the most common operations performed worldwide, with global volumes on the rise. It is important to understand if the characteristics of this patient population are changing over time for resource allocation and surgical planning. The purpose of this study is to examine how this patient population has changed between 2003 and 2017. METHODS: A retrospective review of a prospective TJA database was conducted. Age, gender, body mass index, comorbidities, American Society of Anesthesiologists class, responsible diagnoses, and comorbidities were compared over 5-year intervals between 2003 and 2017. All patients undergoing primary, elective TJA were included. RESULTS: Overall, 17,138 TJAs were included. Mean body mass index increased over the study period for total hip arthroplasty (THA; 29.4-30.4 kg/m2, P < .0001) and total knee arthroplasty (TKA; 32.0-3.1 kg/m2, P < .0001) patients. THA patients were significantly younger in more recent years (68.0-66.8 years old, P = .0026); this trend was not observed among TKA patients. Over the study period, a significantly higher proportion of patients were American Society of Anesthesiologists class III/IV for THA (50.5%-72.3%) and TKA (57.5%-80.7%) (P < .00001). Prevalence of common comorbidities did not change significantly. CONCLUSION: The key findings of this retrospective analysis of a large prospective database are that patients undergoing TJA are becoming younger and more obese. It is unclear whether patients are becoming more medically complex. These trends paint a concerning picture of a population that is increasingly complex, and may require a greater allocation of resources in the future. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Randomized Controlled Trial of Sensor-Guided Knee Balancing Compared to Standard Balancing Technique in Total Knee Arthroplasty.

BACKGROUND: Despite advances in total knee arthroplasty (TKA) technology, up to 1 in 5 patients remain dissatisfied. This study sought to evaluate if sensor-guided knee balancing improves postoperative clinical outcomes and patient satisfaction compared to a conventional gap balancing technique. METHODS: We undertook a prospective double-blind randomized controlled trial of patients presenting for elective primary TKA to determine a difference in TKA soft tissue balance between a standard gap balancing (tensiometer) approach compared to augmenting the balance using a sensor-guided device. The sensor-guided experimental group had adjustments made to achieve a balanced knee to within 15 pounds of intercompartmental pressure difference. Secondary outcomes included differences in clinical outcome scores at 6 months and 1 year postoperative, including the Oxford Knee Score and Knee Society Score and patient satisfaction. RESULTS: The sample comprised of 152 patients, 76 controls and 76 experimental sensor-guided cases. Within the control group, 36% (27/76) of knees were unbalanced based on an average coronal plane intercompartmental difference >15 pounds, compared to only 5.3% (4/76) within the experimental group (P < .0001). There were no significant differences in 1-year postoperative flexion, Knee Society Score, or Oxford scores. Overall, TKA patient satisfaction at 1 year was comparable, with 81% of controls and experimental cases reporting they were very satisfied (P = .992). CONCLUSION: Despite the use of the sensor-guided knee balancer device to provide additional quantitative feedback in the evaluation of the soft tissue envelope during TKA, we were unable to demonstrate improved clinical outcomes or patient satisfaction compared to our conventional gap balancing technique.

Local antibiotics in primary hip and knee arthroplasty: a systematic review and meta-analysis.

BACKGROUND: Infection is a truly devastating complication of total joint arthroplasty, causing most patients to undergo a revision surgery, and to bear significant psychological and financial burden. The purpose of this study is to systematically evaluate the literature to determine the efficacy and complication profile of local antibiotic application in primary total joint arthroplasty. METHODS: All studies of primary total joint arthroplasty which assessed local antibiotics in any form other than antibiotic-impregnated cement as an intervention were included. Studies that reported at least one outcome related to infection and were available in full text in English were eligible for inclusion. Studies which included both primary and revision cases but did not report the stratified data for each type of surgery and studies on fracture populations were excluded. RESULTS: A total of 9 studies involving 3,714 cases were included. The pooled deep infection rate was 1.6% in the intervention groups and 3.5% in the control groups. Meta-analysis revealed a RR of 0.53 (95%CI: 0.35-0.79, p = 0.002) with no heterogeneity (I2 = 0%) for infection in the intervention groups. Meta-analysis revealed a non-significant reduction in superficial infection rates in the intervention groups; however, there was a significant increase in aseptic wound complications in the intervention groups. CONCLUSION: Local antibiotic application results in a moderate reduction in deep infection rates in primary total joint arthroplasty, with no significant impact on superficial infection rates. However, local antibiotic application may be associated with a moderate increase in aseptic wound complications.

Mismatched outcomes for biodiversity and ecosystem services: testing the responses of crop pollinators and wild bee biodiversity to habitat enhancement.

Supporting ecosystem services and conserving biodiversity may be compatible goals, but there is concern that service-focused interventions mostly benefit a few common species. We use a spatially replicated, multiyear experiment in four agricultural settings to test if enhancing habitat adjacent to crops increases wild bee diversity and abundance on and off crops. We found that enhanced field edges harbored more taxonomically and functionally abundant, diverse, and compositionally different bee communities compared to control edges. Enhancements did not increase the abundance or diversity of bees visiting crops, indicating that the supply of pollination services was unchanged following enhancement. We find that actions to promote crop pollination improve multiple dimensions of biodiversity, underscoring their conservation value, but these benefits may not be spilling over to crops. More work is needed to identify the conditions that promote effective co-management of biodiversity and ecosystem services.

Nuisance Symptoms in Total Joint Arthroplasty: Prevalence and Impact on Patient Satisfaction.

BACKGROUND: While hip and knee total joint arthroplasty (TJA) patients experience marked improvement in pain relief and function, many patients experience nuisance symptoms, which may cause discomfort and dissatisfaction. METHODS: A prospective survey study to determine type and prevalence of hip/knee TJA nuisance symptoms and impact on patient satisfaction at 1 year postoperative was conducted. The survey determined occurrence of common nuisance symptoms (eg, localized pain, swelling, instability, stiffness) and impact on overall satisfaction rated on a 10-point visual analog scale (VAS). Survey responses were analyzed using descriptive statistics. RESULTS: The sample comprised 545 TJA patients who completed the survey: 335 knees (61%) and 210 hips (39%). Among knees, the most commonly reported nuisance symptoms and associated impact on satisfaction included difficulty kneeling (78.2%; VAS, 4.3; SD, 3.3), limited ability to run/jump (71.6%; VAS, 3.3; SD, 3.3), and numbness around incision (46.3%; VAS, 3.8; SD, 3.3). Overall, 94% of knee patients experienced at least 1 nuisance symptom at 1 year, reporting mean satisfaction of 9/10 (SD, 1.7). Among hips, the most commonly reported nuisance symptoms and associated impact on satisfaction were limited ability to run/jump (68.6%; VAS, 3.4; SD, 3.4), thigh muscle pain (44.8%; VAS, 3; SD, 2.7), and limp when walking (37.6%; VAS, 4.1; SD, 3.2). Overall, 88% of hip patients experienced at least 1 self-reported nuisance symptom at 1 year, reporting mean satisfaction of 8.9/10 (SD, 1.7). CONCLUSION: Nuisance symptoms after hip/knee TJA are very common. Despite the high prevalence, impact on overall satisfaction is minimal and patient satisfaction remains high. Careful preoperative counseling regarding prevalence is prudent and will help establish realistic expectations following TJA.

Preoperative Patient Factors Affecting Length of Stay following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Total knee arthroplasty (TKA) yields substantial improvements in quality of life for patients with severe osteoarthritis. Previous research has shown that TKA outcomes are inferior in patients with certain demographic and clinical factors. Length of stay (LOS) following TKA is a major component of costs incurred by healthcare providers. It is hypothesized that patient-related factors may influence LOS following TKA. The purpose of this systematic review and meta-analysis is to investigate these factors. METHODS: Three databases (PubMed, Embase, and OVID Medline) were searched using variants of the terms "total knee arthroplasty" and "length of stay". Studies were screened and data abstracted in duplicate. The primary outcome was the effect of prognostic variables on LOS following TKA. Meta-analysis was performed using the Review Manager (RevMan) software (version 5.3. Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014). RESULTS: A total of 68 studies met all inclusion criteria for this review. These studies comprised 21,494,459 patients undergoing TKA with mean age 66.82 years (range, 15-95 years) and 63.8% (12,165,160 of 19,060,572 reported) females. The mean MINORS score was 7, suggesting that studies had a low quality of evidence. Mean LOS following TKA has steadily decreased over the past 4 decades, partially because of the implementation of fast-track programs. Demographic factors associated with increased LOS were age >70 years (mean difference [MD] = 0.81; 95% confidence interval [CI] = 0.38-1.24), female gender (MD = 0.32; 95% CI = 0.29-0.48), body mass index >30 (MD = 0.09; 95% CI = 0.01-0.16), and non-White race (MD = 0.20; 95% CI = 0.10-0.29). Clinical factors associated with increased LOS were American Society of Anesthesiologists score 3-4 vs 1-2 (MD = 1.12; 95% CI = 0.58 to 1.66), Charlson Comorbidity Index > 0 vs 0 (MD = 0.77; 95% CI = 0.32 to 1.22), and preoperative hemoglobin < 130 g/L (MD = 0.66; 95% CI = 0.34 to 0.98). CONCLUSION: This systematic review and meta-analysis showed that increased age, female gender, body mass index ≥ 30, non-White race, American Society of Anesthesiologists > 2, Charlson Comorbidity Index > 0, and preoperative hemoglobin < 130 g/L were predictors of increased LOS. Mean LOS has steadily decreased over the past decades with the implementation of perioperative "fast-track" programs. Future research should investigate the benefits of preoperative risk factor modification on LOS, in addition to novel surgical approaches, anesthetic adjuvants, and physiotherapy modifications. LEVEL OF EVIDENCE: IV, systematic review, and meta-analysis of level III and IV evidence.

Use of the Corail stem for revision total hip arthroplasty: evaluation of clinical outcomes and cost

Background: With the growing number of total hip arthroplasty (THA) procedures performed, revision surgery is also proportionately increasing, resulting in greater health care expenditures. The purpose of this study was to assess clinical outcomes and cost when using a collared, fully hydroxyapatite-coated primary femoral stem for revision THA compared to commonly used revision femoral stems. Methods: We retrospectively identified patients who underwent revision THA with a primary stem between 2011 and 2016 and matched them on demographic variables and reason for revision to a similar cohort who underwent revision THA. We extracted operative data and information on in-hospital resource use from the patients' charts to calculate average cost per procedure. Patient-reported outcomes were recorded preoperatively and 1 year postoperatively. Results: We included 20 patients in our analysis, of whom 10 received a primary stem and 10, a typical revision stem. There were no significant between-group differences in mean Western Ontario and McMaster Universities Osteoarthritis Index score, Harris Hip Score, 12-Item Short Form Health Survey (SF-12) Mental Composite Scale score or Physical Composite Scale score at 1 year. Operative time was significantly shorter and total cost was significantly lower (mean difference ­3707.64, 95% confidence interval ­5532.85 to ­1882.43) with a primary stem than with other revision femoral stems. Conclusion: We found similar clinical outcomes and significant institutional cost savings with a primary femoral stem in revision THA. This suggests a role for a primary femoral stem such as a collared, fully hydroxyapatite-coated stem for revision THA.

Contexte: Avec le nombre croissant d'interventions pour prothèse de hanche (PTH) effectuées, la chirurgie de révision est aussi proportionnellement en hausse, ce qui entraîne des coûts supérieurs pour le système de santé. Le but de cette étude était d'évaluer les résultats cliniques et le coût associés à l'emploi d'une prothèse fémorale primaire à collerette entièrement recouverte d'hydroxyapatite pour la révision de PTH, comparativement à d'autres prothèses d'usage courant utilisées pour les révisions. Méthodes: Nous avons identifié rétrospectivement les patients ayant subi une révision de PTH avec une prothèse primaire entre 2011 et 2016 et nous les avons assortis selon les caractéristiques démographiques et le motif de la révision à une cohorte similaire soumise à une révision de PTH. Nous avons extrait les données sur l'opération et sur l'utilisation des ressources hospitalières à partir des dossiers des patients pour calculer le coût par intervention. Les résultats déclarés par les patients ont été notés avant l'intervention et 1 an après. Résultats: Nous avons inclus 20 patients dans notre analyse, dont 10 ont reçu une prothèse primaire et 10, une révision de prothèse typique. On n'a noté aucune différence significative entre les groupes pour ce qui est du score WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) moyen pour l'arthrose, du score de Harris pour la hanche, ou des sous-échelles santé mentale ou santé physique à 1 an du questionnaire SF-12 (12-Item Short Form Health Survey). L'intervention a duré significativement moins longtemps et le coût a été significativement moindre (différence moyenne ­3707,64, intervalle de confiance de 95 % ­5532,85 à ­1882,43) avec une prothèse primaire qu'avec les autres prothèses de révision. Conclusion: Nous avons observé des résultats cliniques similaires et des économies significatives pour l'établissement avec la prothèse primaire utilisée pour la révision de PTH. Cela donne à penser que la prothèse fémorale primaire, par exemple, à collerette et entièrement recouverte d'hydroxyapatite, aurait un rôle à jouer pour la révision de PTH.