Cooperative Self-Assembly Process Involving Giant Toroidal Polyoxometalate as a Membrane Building Block in Nanoscale Vesicles.

The self-assembly of organic amphiphilic species into various aggregates such as spherical or elongated micelles and cylinders up to the formation of lyotropic hexagonal or lamellar phases results from cooperative processes orchestrated by the hydrophobic effect, while those involving ionic inorganic polynuclear entities and nonionic organic components are still intriguing. Herein, we report on the supramolecular behavior of giant toroidal molybdenum blue-type polyoxometalate, namely, the {Mo154} species in the presence of n-octyl-ß-glucoside (C8G1), widely used as a surfactant in biochemistry. Structural investigations were carried out using a set of complementary multiscale methods including single-crystal X-ray diffraction analysis supported by molecular modeling, small-angle X-ray scattering and cryo-TEM observations. In addition, liquid NMR, viscosimetry, surface tension measurement, and isothermal titration calorimetry provided further information to decipher the complex aggregation pathway. Elucidation of the assembly process reveals a rich scenario where the presence of the large {Mo154} anion disrupts the self-assembly of the C8G1, well-known to produce micelles, and induces striking successive phase transitions from fluid-to-gel and from gel-to-fluid. Herein, intimate organic-inorganic primary interactions arising from the superchaotropic nature of the {Mo154} lead to versatile nanoscopic hybrid C8G1-{Mo154} aggregates including crystalline discrete assemblies, smectic lamellar liquid crystals, and large uni- or multilamellar vesicles where the large torus {Mo154} acts a trans-membrane component.

Gunshot Trauma Patients Have Higher Risk of PTSD Compared With Blunt Trauma and Elective Populations: A Retrospective Comparative Study of Outpatient Orthopaedic Care.

BACKGROUND: Posttraumatic stress disorder (PTSD) has been extensively studied in patients who have experienced natural disasters or military conflict, but there remains a substantial gap in knowledge about the prevalence of PTSD after civilian orthopaedic trauma, especially as related to firearms. Gun violence is endemic in the United States, especially in urban centers, and the mental impact is often minimized during the treatment of physical injuries. QUESTIONS/PURPOSES: (1) Do patients who experience gunshot wound (GSW) trauma have higher PTSD screening scores compared with patients with blunt or other trauma (for example, motor vehicle and motorcycle accidents or stab wounds) and those with elective conditions (for example, arthritis, tendinitis, or nerve compression)? (2) Are PTSD scores correlated with pain scores in patients with GSW trauma, those with non-GSW trauma, and patients with elective orthopaedic symptoms? METHODS: We performed a retrospective study of adults older than 18 years of age presenting to an orthopaedic clinic over an 8-month period between August 2021 and May 2022. All patients presenting to the clinic were approached for inclusion (2034 patients), and 630 new or postoperative patients answered study surveys as part of routine care. Patients were divided into three cohorts based on the orthopaedic condition with which they presented, whether gunshot trauma, blunt trauma, or elective orthopaedic symptoms. Overall, the results from 415 patients were analyzed, including 212 patients with elective orthopaedic symptoms, 157 patients with non-GSW trauma, and 46 patients with GSW trauma. Clinical data including demographic information were collected at the time of appointment and abstracted along with results from the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, short screening questionnaire, which uses a 7-item scale scored from 0 to 7 (with higher scores representing worse symptoms), and from the numeric rating scale for pain (range 0 to 10). Both questionnaires were routinely administered by medical assistants at patient intake. The proportions of patients completing PTSD scoring were 45% (95) in the elective group, 74% (116) in the group with non-GSW trauma, and 85% (39) in the group with GSW trauma (p = 0.01). We compared the PTSD scores across the three groups and then dichotomized the scores as a negative versus positive screening result at a value of ≥ 4 with further comparative analysis. The correlation between pain and PTSD scores was also evaluated. RESULTS: Patients with GSW trauma had higher mean ± SD PTSD scores compared with those who had non-GSW trauma (4.87 ± 4.05 versus 1.75 ± 2.72, mean difference 3.21 [95% CI 1.99 to 4.26]; p < 0.001) and those who presented with elective conditions (4.87 ± 4.05 versus 0.49 ± 1.04, mean difference 4.38 [95% CI 3.50 to 5.26]; p < 0.001). When dichotomized for positive or negative PTSD screening results, patients with GSW trauma had a higher risk of having PTSD (64% [25 of 39]) compared with patients with non-GSW trauma (27% [31 of 116], relative risk 2.40 [95% CI 1.64 to 3.51]; p < 0.001) and compared with patients with elective conditions (4% [4 of 95], relative risk 15.22 [95% CI 5.67 to 40.87]; p < 0.001). Pain scores were correlated with PTSD scores only for patients with non-GSW trauma (ρ = 0.37; p < 0.0001). No correlation with pain scores was present for patients with GSW (ρ = 0.24; p = 0.16) or patients with elective conditions (ρ = -0.04; p = 0.75). CONCLUSION: In an orthopaedic clinic population, the prevalence of positive screening for PTSD was highest in the population sustaining gunshot trauma as compared with blunt or other trauma and elective orthopaedic conditions. Interestingly, pain scores correlated with PTSD screening only in the patients with non-GSW trauma. These differences suggest a substantial difference in the populations at risk of PTSD after trauma. Overall, the psychological impacts of gun trauma are poorly understood. The next step would be to prospectively study the differences and timelines of PTSD screening in patients with GSW trauma in comparison with patients with blunt or other trauma to better define the treatment needs in this population. LEVEL OF EVIDENCE: Level III, prognostic study.

Orthopaedic Sports Medicine Randomized Controlled Trials Infrequently Report on the Social Determinants of Health Factors of Their Patient Cohorts.

PURPOSE: To describe the prevalence of randomized controlled trials (RCTs) in orthopaedic sports medicine-related journals reporting on the social determinants of health (SDOH) of their patient cohorts, including factors receiving less attention, such as education level, employment status, insurance status, and socioeconomic status. METHODS: The PubMed/MEDLINE database was used to search for RCTs between 2020 and 2022 from 3 high-impact orthopaedic sports medicine-related journals: American Journal of Sports Medicine, Arthroscopy, and Journal of Shoulder and Elbow Surgery. The following information was extracted from each article: age, sex/gender, body mass index, year published, corresponding author country, and self-reported SDOH factors (race, ethnicity, education level, employment status, insurance status, and socioeconomic status). RESULTS: A total of 189 articles were analyzed. Articles originated from 34 different countries, with the United States (n = 66) producing the greatest number of articles. Overall, age (n = 186; 98.4%) and sex/gender (n = 184; 97.4%) were the factors most commonly reported, followed by body mass index (n = 112; 59.3%), race (n = 17; 9.0%), ethnicity (n = 10; 5.3%), employment status (n = 9; 4.8%), insurance status (n = 7; 3.7%), and education level (n = 5; 2.6%). Socioeconomic status was not reported in any of the articles analyzed. Articles from the United States report on SDOH factors more frequently than international articles, most notably race (24.2% vs 0.8%, respectively) and ethnicity (15.2% and 0%, respectively). CONCLUSIONS: RCTs from 3 high-impact orthopaedic sports medicine journals infrequently report on SDOH. CLINICAL RELEVANCE: Better understanding patient SDOH factors in RCTs is important to help orthopaedic surgeons and other practitioners best apply study results to their patients, as well as help researchers and our field ensure that research is being done transparently with relevance to as many patients as possible.

Traumaplasty: When and How to Perform Acute Arthroplasty for Fractures Around the Hip in the Elderly Patient.

Acute fractures around the hip are prevalent injuries associated with potentially devastating outcomes. The growing utilization of arthroplasty for femoral neck fractures in the elderly is likely a result of improvements in reoperation rates and postoperative function. Compared to hemiarthroplasty, total hip arthroplasty is associated with a slight functional benefit that is unlikely noticeable for many patients, as well as minimal differences in complications and patient reported outcome measures. However, the evidence supporting cement use in femoral stem fixation is robust. Multiple high power randomized controlled trial-based studies indicate cement fixation brings more predictable outcomes and fewer reoperations. In the setting of acute acetabular fracture, total hip arthroplasty is a favorable approach for elderly patients and fracture patterns associated with increased risk of revision after open reduction and internal fixation. Variations in patient characteristics and fracture patterns demand careful consideration whenever selecting the optimal treatment. In fracture patient populations, comanagement is an important consideration when seeking to reduce complications and promote cost-effective quality care.

Systematic Review of Gender and Sex Terminology Use in Arthroplasty Research: There Is Room for Improvement.

BACKGROUND: There is increasing appreciation of the distinction between gender and sex as well as the importance of accurately reporting these constructs. Given recent attention regarding transgender and gender nonconforming (TGNC) and intersex identities, it is more necessary than ever to understand how to describe these identities in research. This study sought to investigate the use of gender- and sex-based terminology in arthroplasty research. METHODS: The 5 leading orthopaedic journals publishing arthroplasty research were reviewed to identify the first twenty primary clinical research articles on an arthroplasty topic published after January 1, 2022. Use of gender- or sex-based terminology, whether use was discriminate, and whether stratification or adjustment based on gender or sex was performed, were recorded. RESULTS: There were 98 of 100 articles that measured a construct of gender or sex. Of these, 15 articles used gender-based terminology, 45 used sex-based terminology, and 38 used a combination of gender- and sex-based terminology. Of the 38 articles using a combination of terminology, none did so discriminately. All articles presented gender and sex as binary variables, and 2 attempted to explicitly define how gender or sex were defined. Of the 98 articles, 31 used these variables for statistical adjustments, though only 6 reported stratified results. CONCLUSIONS: Arthroplasty articles infrequently describe how gender or sex was measured, and frequently use this terminology interchangeably. Additionally, these articles rarely offer more than 2 options for capturing variation in sex and gender. Future research should be more precise in the treatment of these variables to improve the quality of results and ensure findings are patient-centered and inclusive.

Reuse of Surgical Masks During the COVID-19 Shortage: Association with the Incidence of Surgical Site Infections.

The association between the reuse of surgical masks (SMs) for multiple procedures and rates of surgical site infections (SSIs) is unclear. Hence, the purpose of this study was to determine whether a policy mandating the reuse of SMs was associated with increased SSI incidence. It was hypothesized the rate of SSIs would be significantly greater during the postimplementation period compared with the preimplementation period. Retrospective chart review of patients who underwent orthopaedic and general surgery during the 60 days before and after policy implementation was performed. Focus was on consecutive procedures performed by the same surgeon on the same day. An assessment of SSI risk factors suggested the postimplementation group was at higher risk. However, the daily use of a single SM across multiple procedures was not associated with a clinically significant increase in SSIs. Because future pandemics and public health crises may be accompanied by similar shortages, it may be possible to reuse masks in these situations without concern for increased SSI. (Journal of Surgical Orthopaedic Advances 33(2):097-102, 2024).

A multi-institutional study of short-term mortality in COVID-positive patients undergoing hip fracture surgery: is survival better than expected?

PURPOSE: Early reports of 30-day mortality in COVID-positive patients with hip fracture were often over 30% and were higher than historical rates of 10% in pre-COVID studies. We conducted a multi-institutional retrospective cohort study to determine whether the incidence of 30-day mortality and complications in COVID-positive patients undergoing hip fracture surgery is as high as initially reported. METHODS: A retrospective chart review was performed at 11 level I trauma centers from January 1, 2020 to May 1, 2022. Patients 50 years or older undergoing hip fracture surgery with a positive COVID test at the time of surgery were included. The primary outcome measurements were the incidence of 30-day mortality and complications. Post-operative outcomes were reported using proportions with 95% confidence interval (C.I.). RESULTS: Forty patients with a median age of 71.5 years (interquartile range, 50-87 years) met the criteria. Within 30-days, four patients (10%; 95% C.I. 3-24%) died, four developed pneumonia, three developed thromboembolism, and three remained intubated post-operatively. Increased age was a statistically significant predictor of 30-day mortality (p = 0.01), with all deaths occurring in patients over 80 years. CONCLUSION: In this multi-institutional analysis of COVID-positive patients undergoing hip fracture surgery, 30-day mortality was 10%. The 95% C.I. did not include 30%, suggesting that survival may be better than initially reported. While COVID-positive patients with hip fractures have high short-term mortality, the clinical situation may not be as dire as initially described, which may reflect initial publication bias, selection bias introduced by testing, or other issues. LEVELS OF EVIDENCE: Therapeutic Level III.

Retrograde intramedullary nailing of the femur: identifying the true anatomic axis for the ideal start point.

PURPOSE: Retrograde femoral intramedullary nailing (IMN) is commonly used to treat distal femur fractures. There is variability in the literature regarding the ideal starting point for retrograde femoral IMN in the coronal plane. The objective of this study was to identify the ideal starting point, based on radiographs, relative to the intercondylar notch in the placement of a retrograde femoral IMN. METHODS: A consecutive series of 48 patients with anteroposterior long-leg radiographs prior to elective knee arthroplasty from 2017 to 2021 were used to determine the femoral anatomic axis. The anatomic center of the isthmus was identified and marked. Another point 3 cm distal from the isthmus was marked in the center of the femoral canal. A line was drawn connecting the points and extended longitudinally through the distal femur. The distance from the center of the intercondylar notch to the point where the anatomic axis of the femur intersected the distal femur was measured. RESULTS: On radiographic review, the distance from the intercondylar notch to where the femoral anatomic axis intersects the distal femur was normally distributed with an average distance of 4.1 mm (SD, 1.7 mm) medial to the intercondylar notch. CONCLUSION: The ideal start point, based on radiographs, for retrograde femoral intramedullary nailing is approximately 4.1 mm medial to the intercondylar notch. Medialization of the starting point for retrograde intramedullary nailing in the coronal plane aligns with the anatomic axis. These results support the integration of templating into preoperative planning prior to retrograde IMN of the femur, with the knowledge that, on average, the ideal start point will be slightly medial. Further investigation via anatomic studies is required to determine whether a medial start point is safe and efficacious in patients with distal femur fractures treated with retrograde IMNs.

The Practice Patterns of American Association of Hip and Knee Surgeons for the Management of Chronic Periprosthetic Joint Infection After Total Knee Arthroplasty.

BACKGROUND: The management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) has considerable variation. In order to better capture current preferences for the management of PJI, this study sought to poll the current members of American Association of Hip and Knee Surgeons (AAHKS) first to characterize the distribution of practice patterns. METHODS: There were 32 questions in an online survey distributed to members of AAHKS. The questions were multiple choice regarding the management of PJI for TKA. There were 844 out of 2,752 members who completed the survey (response rate of 31%). RESULTS: Most of the members were in private practice (50%) compared to 28% being in an academic setting. On average, members were performing between 6 to 20 PJI cases per year. Two-stage exchange arthroplasty was performed in over 75% of the cases with either a cruciate retaining (CR) or posterior stabilized (PS) primary femoral component used in over 50% of the cases and 62% using an all-polyethylene tibial implant. Most of the members were using vancomycin and tobramycin. Typically, 2 to 3 grams of antibiotics were added per bag of cement regardless of the cement type. When indicated, amphotericin was the most often-used antifungal. Post-operative management had major variability with range of motion, brace use, and weight-bearing restrictions. CONCLUSION: There was variability in the responses from the members of AAHKS, but there was a preference toward performing a two-stage exchange arthroplasty with an articulating spacer using a metal femoral component and an all-polyethylene liner.

Predicting Postoperative Anemia and Blood Transfusion Following Total Knee Arthroplasty.

BACKGROUND: While transfusion and clinically relevant anemia after elective primary total knee arthroplasty (TKA) are uncommon, there remains a question of who needs postoperative hemoglobin monitoring, especially in the setting of increasing incidence of outpatient TKA. The purpose of this study was to create predictive models for postoperative anemia and blood transfusion to guide clinical decision-making. METHODS: The records of consecutive TKA patients were reviewed from February 2016 to December 2020 at a single institution. Two multivariable logistic regression models, for postoperative anemia (hemoglobin < 10 g/dL) and allogeneic blood transfusion included 8 variables: age, sex, body mass index, preoperative hemoglobin level, tranexamic acid total dose, American Society of Anesthesiologists level, operative time, and drain use. Model performance was assessed using accuracy, area under the curve (AUC), sensitivity, and specificity. RESULTS: The records of 14,901 patients were included in this study. Patients had a mean (± standard deviation) age of 67.9 ± 9.2 years and mean body mass index of 31.3 ± 6.5 kg/m2. The postoperative anemia model had an accuracy of 88% (95% confidence interval [CI], 87%-89%) and AUC of 0.88 (95% CI, 0.87-0.89). The blood transfusion model had an accuracy of 97% (95% CI, 96%-97%) and AUC of 0.90 (95% CI, 0.87-0.93). CONCLUSION: The postoperative anemia and blood transfusion model accurately predicted each outcome. Patients with less than a 5% probability of postoperative anemia may not benefit from a complete blood count at postoperative day 1. Application of these criteria may save the healthcare system hundreds of millions of dollars. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Postoperative mortality in the COVID-positive hip fracture patient, a systematic review and meta-analysis.

PURPOSE: The extent to which concomitant COVID-19 infection increases short-term mortality following hip fracture is not fully understood. A systemic review and meta-analysis of COVID-19 positive hip fracture patients (CPHFPs) undergoing surgery was conducted to explore the association of COVID-19 with short-term mortality. METHODS: Review of the literature identified reports of short-term 30-day postoperative mortality in CPHFPs. For studies including a contemporary control group of COVID-19 negative patients, odds ratios of the association between COVID-19 infection and short-term mortality were calculated. Short-term mortality and the association between COVID-19 infection and short-term mortality were meta-analyzed and stratified by hospital screening type using random effects models. RESULTS: Seventeen reports were identified. The short-term mortality in CPHFPs was 34% (95% C.I., 30-39%). Short-term mortality differed slightly across studies that screened all patients, 30% (95% C.I., 22-39%), compared to studies that conditionally screened patients, 36% (95% C.I., 31-42%), (P = 0.22). The association between COVID-19 infection and short-term mortality produced an odds ratio of 7.16 (95% C.I., 4.99-10.27), and this was lower for studies that screened all patients, 4.08 (95% C.I., 2.31-7.22), compared to studies that conditionally screened patients, 8.32 (95% C.I., 5.68-12.18), (P = 0.04). CONCLUSION: CPHFPs have a short-term mortality rate of 34%. The odds ratio of short-term mortality was significantly higher in studies that screened patients conditionally than in studies that screened all hip fracture patients. This suggests mortality prognostication should consider how COVID-19 infection was identified as asymptomatic patients may fare slightly better.

Comparison of post-op opioid use and pain between short and long cephalomedullary nails in elderly intertrochanteric fractures.

PURPOSE: It remains unknown if cephalomedullary nail (CMN) length has an impact on pain and opioid use following fixation. Given the lack of level I evidence favoring a specific CMN length to prevent adverse surgical outcomes, we investigated if CMN length impacts acute postoperative pain and opioid use. The authors hypothesize that the use of longer CMNs results in increased pain scores and morphine milligram equivalents (MME) intake during the 0-24 h (h) and 24-36 h postoperative period. METHODS: A retrospective chart review was performed from 2010 to 2020 of patients ≥ 65 years-old who underwent CMN for IT fractures and fractures with subtrochanteric extension (STE). We compared patients who received short and long CMNs using numeric rating scale (NRS) pain scores and MME intake at 0-24 h and 24-36 h postoperatively. RESULTS: 330 patients receiving short (n = 155) and long (n = 175) CMNs met criteria. CMN length was found to not be associated with higher pain scores in the early postoperative phase. However, patients with long CMNs received higher MME from 0-24 h (25.4% estimated mean increase, p value = 0.02) and 24-36 h (22.3% estimated mean increase, p value = 0.04) postoperatively, even after adjusting for covariates, gender, and age. CONCLUSION: Patients with long CMNs received greater MME postoperatively. Additionally, differences in pain and MME were not significantly different between patients with and without STE, suggesting our findings were not influenced by this pattern. These results suggest longer CMNs are associated with higher acute postoperative opioid intake among patients with IT fractures. LEVEL OF EVIDENCE: Therapeutic level III.

Cross-sectional examination of ultra-processed food consumption and adverse mental health symptoms.

OBJECTIVE: To explore whether individuals who consume higher amounts of ultra-processed food (UPF) have more adverse mental health symptoms. DESIGN: Using a cross-sectional design, we measured the consumption of UPF as a percentage of total energy intake in kilo-calories using the NOVA food classification system. We explored whether individuals who consume higher amounts of UPF were more likely to report mild depression, more mentally unhealthy days and more anxious days per month using multivariable analyses adjusting for potential confounding variables. SETTING: Representative sample from the United States National Health and Nutrition Examination Survey between 2007 and 2012. PARTICIPANTS: 10 359 adults aged 18+ without a history of cocaine, methamphetamine or heroin use. RESULTS: After adjusting for covariates, individuals with the highest level of UPF consumption were significantly more likely to report at least mild depression (OR: 1·81; 95 % CI1·09, 3·02), more mentally unhealthy (risk ratio (RR): 1·22; 95 % CI 1·18, 1·25) and more anxious days per month (RR: 1·19; 95 % CI 1·16, 1·23). They were also significantly less likely to report zero mentally unhealthy (OR: 0·60; 95 % CI 0·41, 0·88) or anxious days (OR: 0·65; 95 % CI 0·47, 0·90). CONCLUSIONS: Individuals reporting higher intakes of UPF were significantly more likely to report mild depression, more mentally unhealthy and more anxious days and less likely to report zero mentally unhealthy or anxious days. These data add important information to a growing body of evidence concerning the potential adverse effects of UPF consumption on mental health.

Clinical Outcomes Following Distal Femur Replacement for Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis.

BACKGROUND: Management of periprosthetic distal femur fractures (PDFFs) is often complicated by poor bone quality and limited bone stock making fixation attempts challenging and prone to failure. Distal femoral replacement (DFR) is being used to treat such injuries although outcome data are mostly from small case series. We sought to systematically review the literature on DFR for PDFF to summarize their outcomes. METHODS: PubMed, MEDLINE (EBSCO), and Cochrane Central Database were searched to identify reports of PDFFs treated with DFR. Articles reporting on 5 or more knees were systematically reviewed for clinical function, complications, and mortality. Random effects meta-analysis was used to create summary estimates and publication bias also assessed. RESULTS: Of 287 identified and screened articles, 15 were included, 14 retrospective, reporting on 352 knees. Following DFR, 87% (95% confidence interval [CI] 71-95) of patients were able to ambulate. The mean postoperative Knee Society Score was 80 (95% CI 77-84). The risk of periprosthetic joint infection was 4.3% (95% CI 2.2-8.2). One-year postoperative mortality rate was 10% (95% CI 6-18). There was some evidence of publication bias with a trend toward smaller studies reporting lower infection risk and mortality. CONCLUSION: DFR for PDFFs is associated with high functional outcomes and a relatively modest risk of infection. The periprosthetic joint infection and 1-year mortality rates reported here should be considered lower bounds estimates due to publication bias and loss to follow-up. Further investigation of long-term outcomes following DFR for PDFFs is warranted though short-term functional outcomes are promising.

Self-Reported Health of Severely Obese US Adults With Osteoarthritis.

BACKGROUND: Severe obesity is associated with complications following arthroplasty, leading surgeons to increasingly counsel patients regarding weight loss. For patients seeking arthroplasty, learning that severe obesity may be a relative contraindication to surgery can create a challenging clinical interaction. We sought to describe the self-reported health of United States (US) adults who had severe obesity and osteoarthritis (OA) to better understand patient perspectives. METHODS: The National Health and Nutrition Examination Survey, a nationally representative sample of the US population, was used to identify adult participants who had a body mass index (BMI) over 35 and an OA diagnosis. In total, 889 participants representing a US population of 9,604,722 were included. Self-reported health was dichotomized as poor to fair versus good to excellent. Analyses were weighted to produce national estimates. Associations between obesity severity and patient characteristics with self-reported health were assessed. RESULTS: Of US adults with a BMI over 35 and OA diagnosis, 64% rated their health as good or better. For adults who had a BMI over 45, 55% still reported their health as good or better. The strongest predictors of self-reported health were measures of physical functioning. Only 37% of participants who had much difficulty walking a quarter mile rated their health as good or better compared to 86% without difficulty (P < .001). CONCLUSION: Approximately two-thirds of patients who have severe obesity and OA do not perceive their health as compromised and consider decreased physical function as the primary driver of decreased health. This suggests that counseling about the association between obesity and overall health may improve shared decision making and that patient satisfaction metrics may be difficult to interpret in these clinical situations.

Magnetic Resonance Imaging Synovial Classification Is Associated With Revision Indication and Polyethylene Insert Damage.

BACKGROUND: Patients with total knee arthroplasty (TKA) stiffness are commonly presumed to have arthrofibrosis though no specific test exists. In patients undergoing revision TKA, we asked the following question: (1) Do patients who are revised for stiffness display a synovial reaction on MRI that is different than patients revised for other reasons? (2) Do these patients have a different magnitude of polyethylene insert damage than patients revised for other reasons? and (3) Is the MRI synovial classification associated with polyethylene insert damage? METHODS: Patients undergoing revision TKA for stiffness had a preoperative MRI performed, and the synovium was classified on MRI in a blinded fashion as arthrofibrosis, focal scarring, polymeric reaction, infection, or abnormal. At surgery, the polyethylene inserts were removed, and graded by 2 reviewers for total surface damage. RESULTS: Revision indication and MRI synovial classification were associated (P < .0001), with a greater proportion of patients assigned an MRI classification of arthrofibrosis revised for arthrofibrosis and a greater proportion of patients assigned a polymeric classification revised for aseptic loosening. Patients assigned an MRI synovial classification of polymeric had the greatest damage to the tibial insert (P < .0001), and patients revised for the clinical indication of aseptic loosening had the greatest damage to the tibial insert (P < .0001). CONCLUSION: Synovial grading on MRI is strongly associated with revision indication and polyethylene insert damage. In patients with stiffness in the absence of another complication, MRI can be a helpful diagnostic adjuvant in confirming the diagnosis of stiffness.

Host-Guest Complexation Between Cyclodextrins and Hybrid Hexavanadates: What are the Driving Forces?

Host-guest complexes between native cyclodextrins (α-, ß- and γ-CD) and hybrid Lindqvist-type polyoxovanadates (POVs) [V6 O13 ((OCH2 )3 C-R)2 ]2- with R = CH2 CH3 , NO2 , CH2 OH and NH(BOC) (BOC = N-tert-butoxycarbonyl) were studied in aqueous solution. Six crystal structures determined by single-crystal X-ray diffraction analysis revealed the nature of the functional R group strongly influences the host-guest conformation and also the crystal packing. In all systems isolated in the solid-state, the organic groups R are embedded within the cyclodextrin cavities, involving only a few weak supramolecular contacts. The interaction between hybrid POVs and the macrocyclic organic hosts have been deeply studied in solution using ITC, cyclic voltammetry and NMR methods (1D 1 H NMR, and 2D DOSY, and ROESY). This set of complementary techniques provides clear insights about the strength of interactions and the binding host-guest modes occurring in aqueous solution, highlighting a dramatic influence of the functional group R on the supramolecular properties of the hexavanadate polyoxoanions (association constant K1:1 vary from 0 to 2 000 M-1 ) while isolated functional organic groups exhibit only very weak intrinsic affinity with CDs. Electrochemical and calorimetric investigations suggest that the driving force of the host-guest association involving larger CDs (ß- and γ-CD) is mainly related to the chaotropic effect. In contrast, the hydrophobic effect supported by weak attractive forces appears as the main contributor for the formation of α-CD-containing host-guest complexes. In any cases, the origin of driving forces is clearly related to the ability of the macrocyclic host to desolvate the exposed moieties of the hybrid POVs.

Redox-Responsive Host-Guest Association between γ-Cyclodextrin and Mixed-Metal Keggin-Type Polyoxometalates.

The complexation of Keggin-type polyoxometalates (POMs) with γ-cyclodextrin (γ-CD) leads to supramolecular inclusion assemblies in aqueous solution driven by a chaotropic effect. The strength of the interaction between γ-CD and oxidized or one-electron reduced POMs in a series of molybdenum and vanadium monosubstituted phospho- and silico-tungstates, [XW11MO40]n- Keggin-type anions where X = P or Si and M = MoV/VI or VIV/V, has been evaluated by isothermal titration calorimetry (ITC), NMR spectroscopy, and cyclic voltammetry. Such a study reveals that the host-guest binding constant K1:1 increases strongly with the decrease of the global ionic charge of the POM unit. There is an almost one magnitude order of variation in K1:1 per charge unit, where K1:1 falls down from about 105 M-1 to values close to zero as ionic charge varies from 3- to 6-. Such POMs with molybdenum and vanadium addenda offer the possibility of tuning the host-guest association strength by the simple addition/removal of one electron to POMs, opening a new avenue for the design of smart materials through redox stimuli.

"Dying is Not a Fear": Teen and Parent Perspectives on Messaging to Prevent Crystal Meth Use Among Teens in Rural North Idaho.

Crystal methamphetamine ("meth") use is on the rise in the USA, having devastating effects on individuals and communities. Innovative prevention strategies are therefore critical. Through an exploratory qualitative study, we examined the perspectives and experiences of teenagers and parents around meth prevention messaging formats and strategies. Teens and adults were recruited through middle and high schools, libraries, local sporting events, and word of mouth in three communities in North Idaho, May-September 2016. Guided by the theoretical framework of the Extended Parallel Process Model, we conducted focus groups and small group interviews (three teen; two adults). Using a deductive content analytic approach, we developed teen- and adult-specific codebooks, analyzed the transcripts with NVivo 12-Plus, and identified themes. Teens and adults were all acutely aware of meth use in their communities, personally knowing people who were addicted to meth, and all understood the oral ("meth mouth") and physical ("crank bugs") consequences of meth use. Three primary themes were identified, which focused on the effects of, addiction to, and messaging around crystal meth use. For teens and adults, images illustrating the effects of meth were least effective if they appeared unrealistic or comical. Teens resonated most with messages focusing on pain and vanity (bad teeth and breath), and there was consensus that showing teens images simulating changes in their appearance over time as a result of meth use in a clinical setting would be an effective prevention strategy. Teens and adults who had exposure to meth addiction in North Idaho felt that prevention messages focused on meth are imperative, given its high prevalence and deleterious effects. Future work will entail developing and testing a communication-based meth prevention strategy along with tailored messaging that can be used with teens in dental settings.

Intraoperative Complications and Early Return to the Operating Room in Total Hip Arthroplasty Performed Through the Direct Anterior and Posterior Approaches. An Institutional Experience of Surgeons After Their Learning Curve.

BACKGROUND: Proponents of the direct anterior approach (DAA) for total hip arthroplasty (THA) claim a faster recovery, whereas critics claim an increased risk of early femoral complications. This study analyzed intraoperative and postoperative complications requiring reoperation within one year after THA through the DAA and posterior approach (PA). METHODS: A total of 2348 elective, unilateral DAA THAs in patients with osteoarthritis performed between 2016 and 2019 were matched 1:1 for age (±5 years), gender, body mass index (±5), and femoral fixation with 2348 patients who underwent PA THA during the same period. Mixed-effects logistic regression was used. Odds ratios were reported for the occurrence of intraoperative femoral fracture, postoperative femoral fracture, infection, dislocation, and other etiologies requiring reoperation within one year. RESULTS: Intraoperative femoral fracture occurred in 12 DAA (0.5%) and 14 PA (0.6%) patients. Twenty-five patients (1.06%) in the DAA and 28 (1.19%) in the PA group underwent reoperation within the first year. Reoperations were due to periprosthetic fracture (40%), infection (28%), dislocation (23%), and other (9%). Regression analysis revealed no difference in intraoperative femoral fracture (odds ratio (OR): 0.86, 95% confidence interval (CI): 0.40-1.86, P = .69), postoperative femoral fracture (OR: 1.10, 95% CI: 0.47-2.60, P = .83), infection (OR: 1.50, 95% CI: 0.53-5.23, P = .44), or reoperation within one year for other reasons (OR: 1.50, 95% CI: 0.25-9.00, P = .65). DAA had fewer dislocations requiring reoperation (OR: 0.20, 95% CI: 0.04-0.91, P = .02). CONCLUSION: This comparative study did not find differences in intraoperative or postoperative fracture or infection between DAA and PA. DAA was associated with a lower likelihood of reoperation for dislocation within one year of surgery.