Transferability of Buckingham Parameters for Short-Range Repulsion between Topological Atoms.

The repulsive part of the Buckingham potential, with parameters A and B, can be used to model deformation energies and steric energies. Both are calculated using the interacting quantum atom energy decomposition scheme where the latter is obtained from the former by a charge-transfer-based energy correction. These energies relate to short-range interactions, specifically the deformation of electron density and steric hindrance, respectively, when topological atoms approach each other. In this work, we calculate and fit the energies of carbonyl carbon, carbonyl oxygen, and, where possible, amine nitrogen atoms to the repulsive part of the Buckingham potential for 26 molecules. We find that while the steric energies of all atom pairs studied display exponential behavior with respect to distance, some deformation energy data do not. The obtained parameters are shown to be transferable by calculating root-mean-square errors of fitted potentials with respect to energy data of the same atom in, as far as possible, all other molecules from our data set. We observed that 36% and 10% of these errors were smaller than 4 kJ mol-1 for steric and deformation energy, respectively. Thus, we find that steric energy parameters are more transferable than deformation energy parameters. Finally, we speculate about the physical meaning of the A and B parameters and the implications of the strong exponential and exponential-linear piecewise relationships that we observe between them.

Who Benefits from Manipulation under Anesthesia Following Total Knee Arthroplasty?

Arthrofibrosis is a multifactorial process that results in decreased knee range of motion (ROM). Manipulation under anesthesia (MUA) is commonly regarded as the preferred initial treatment of arthrofibrosis following total knee arthroplasty (TKA). There have been no well-controlled studies demonstrating that MUA effectively increases ROM in patients who develop arthrofibrosis after TKA when compared with routine care. The purpose of this study was to determine whether MUA had any advantage over routine care in the treatment of patients who developed arthrofibrosis following TKA. The authors identified patients who underwent primary TKA at the authors' institution between 2010 and 2014 and had flexion ≤ 100 degrees at early follow-up. Knees were grouped based on how the arthrofibrosis was treated: those who underwent MUA and those who received routine care. Knee flexion was captured preoperatively (prior to TKA), at early follow-up (prior to MUA or routine care), and at 1-year follow up. Flexion change from early follow-up to 1 year was calculated. The average flexion at 1-year follow-up was not significantly different between the two groups (106.1 ± 11.7 degrees in the routine care group versus 106.3 ± 12.8 degrees in the MUA group). The MUA group had a greater proportion of patients with flexion gains > 20 degrees at final follow-up when compared with patients who underwent routine care (56% vs. 8%, p < 0.0001). This study demonstrates that patients with decreased ROM at early follow-up after primary TKA can expect greater ROM increase at 1-year follow-up if they undergo MUA compared with patients who undergo routine care. (Journal of Surgical Orthopaedic Advances 33(1):033-036, 2024).

Acute Kidney Injury After Total Hip and Knee Arthroplasty. What Is the Culprit?

Background: Acute kidney injury (AKI) is associated with increased complications after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to determine the risk factors for AKI after THA and TKA and evaluate if preoperative use of antihypertensive drugs is a risk factor for AKI. Methods: A retrospective review of 7406 primary TKAs and THAs (4532 hips and 2874 knees) from 2013 to 2019 was performed. The following preoperative variables were obtained from medical records: medications, chemistry 7 panel, Elixhauser comorbidities, and demographic factors. AKI was defined as an increase in serum creatinine by 26.4 µmol·L-1. Multivariate analysis was performed to identify the risk factors. Results: The overall incidence of postoperative AKI was 6.2% (n = 459). Risk factors for postoperative AKI were found to be: chronic kidney disease (odds ratio [OR] = 7.09; 95% confidence interval [CI]: 4.8-9.4), diabetes (OR: 5.03; 95% CI: 2.8-6.06), ≥3 antihypertensive drugs (OR: 4.2; 95% CI: 2.1-6.2), preoperative use of an angiotensin receptor blockers or angiotensin-converting enzyme inhibitors (OR: 3.8; 95% CI: 2.2-5.9), perioperative vancomycin (OR: 2.7; 95% CI: 1.8-4.6), and body mass index >40 kg/m2 (OR: 1.9; 95% CI: 1.3-3.06). Conclusions: We have identified several modifiable risk factors for AKI that can be optimized prior to an elective THA or TKA. The use of certain antihypertensive agents namely angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and multidrug antihypertensive regimens were found to significantly increase the risk of AKI. Therefore, perioperative management of patients undergoing joint replacement should include medical comanagement with a focus on careful management of antihypertensives.

A Baker's Dozen of Top Antimicrobial Stewardship Intervention Publications in 2022.

Keeping abreast of the antimicrobial stewardship-related articles published each year is challenging. The Southeastern Research Group Endeavor identified antimicrobial stewardship-related, peer-reviewed literature that detailed an actionable intervention during 2022. The top 13 publications were selected using a modified Delphi technique. These manuscripts were reviewed to highlight actionable interventions used by antimicrobial stewardship programs to capture potentially effective strategies for local implementation.

Socio-demographic and comorbid risk factors for poor prognosis in patients hospitalized with community-acquired bacterial pneumonia in southeastern US.

BACKGROUND: How socio-demographic characteristics and comorbidities affect bacterial community-acquired pneumonia (CAP) prognosis during/after hospitalization is important in disease management. OBJECTIVES: To identify predictors of medical intensive care unit (MICU) admission, length of hospital stay (LOS), in-hospital mortality, and bacterial CAP readmission in patients hospitalized with bacterial CAP. METHODS: ICD-9/10 codes were used to query electronic medical records to identify a cohort of patients hospitalized for bacterial CAP at a tertiary hospital in Southeastern US between 01/01/2013-12/31/2019. Adjusted accelerated failure time and modified Poisson regression models were used to examine predictors of MICU admission, LOS, in-hospital mortality, and 1-year readmission. RESULTS: There were 1956 adults hospitalized with bacterial CAP. Median (interquartile range) LOS was 11 days (6-23), and there were 26 % (513) MICU admission, 14 % (266) in-hospital mortality, and 6 % (117) 1-year readmission with recurrent CAP. MICU admission was associated with heart failure (RR 1.38; 95 % CI 1.17-1.62) and obesity (RR 1.26; 95 % CI 1.04-1.52). Longer LOS was associated with heart failure (adjusted time ratio[TR] 1.27;95 %CI 1.12-1.43), stroke (TR 1.90;95 %CI 1.54,2.35), type 2 diabetes (TR 1.20;95 %CI 1.07-1.36), obesity (TR 1.50;95 %CI 1.31-1.72), Black race (TR 1.17;95 %CI 1.04-1.31), and males (TR 1.24;95 %CI 1.10-1.39). In-hospital mortality was associated with stroke (RR 1.45;95 %CI 1.03-2.04) and age ≥65 years (RR 1.34;95 %CI 1.06-1.68). 1-year readmission was associated with COPD (RR 1.55;95 %CI 1.05-2.27) and underweight BMI (RR 1.74;95 %CI 1.04-2.90). CONCLUSIONS: Comorbidities and socio-demographic characteristics have varying impacts on bacterial CAP in-hospital prognosis and readmission. More studies are warranted to confirm these findings to develop comprehensive care plans and inform public health interventions.

Impact of Limiting Vancomycin Loading Doses in Patients With Methicillin-resistant Staphylococcus aureus Infections After Hospital Protocol Revision.

Background: Vancomycin loading doses are commonly used to quickly attain target serum concentrations; however, data supporting their effect on clinical patient outcomes is limited. In April 2020, our institution revised our pharmacist-driven vancomycin dosing protocol to reserve loading doses for hemodynamically unstable patients with suspected serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Prior to the protocol update, all patients treated with vancomycin at our institution received a weight-based loading dose. The purpose of this study is to assess clinical efficacy and safety outcomes related to the use of vancomycin loading doses. Methods: A retrospective, quasi-experimental study was performed to compare clinical outcomes in adult patients treated with vancomycin for laboratory-confirmed MRSA infections. Patients who received vancomycin therapy prior to our institution's vancomycin dosing protocol revisions (pre-intervention) were compared to patients who received vancomycin after the revisions (post-intervention). The primary outcome was all-cause, inpatient mortality. Secondary outcomes included persistent signs and symptoms of infection ≥5 days after vancomycin initiation, switch to alternative anti-MRSA therapy, and nephrotoxicity. Results: A total of 122 patients (63 pre-intervention patients and 59 post-intervention patients) were included. Receipt of a vancomycin loading dose did not impact the rate of inpatient mortality (4.76%vs 6.78%; OR 1.46, 95% CI [0.31, 6.79]). All secondary outcomes were similar between the two groups, including persistent signs and symptoms of infection, switch to alternative anti-MRSA therapy, and nephrotoxicity. Conclusions: Routine use of vancomycin loading doses is not associated with improved outcomes in hemodynamically stable patients with MRSA infections.

Model-Informed Precision Dosing Improves Outcomes in Patients Receiving Vancomycin for Gram-Positive Infections.

Background: Consensus guidelines for dosing and monitoring of vancomycin recommend collection of 2 serum concentrations to estimate an area under the curve/minimum inhibitory concentration ratio (AUC/MIC). Use of Bayesian software for AUC estimation and model-informed precision dosing (MIPD) enables pre-steady state therapeutic drug monitoring using a single serum concentration; however, data supporting this approach are limited. Methods: Adult patients with culture-proven gram-positive infections treated with vancomycin ≥72 hours receiving either trough-guided or AUC-guided therapy were included in this retrospective study. AUC-guided therapy was provided using MIPD and single-concentration monitoring. Treatment success, vancomycin-associated acute kidney injury (VA-AKI), and inpatient mortality were compared using a desirability of outcome ranking analysis. The most desirable outcome was survival with treatment success and no VA-AKI, and the least desirable outcome was death. Results: The study population (N = 300) was comprised of an equal number of patients receiving AUC-guided or trough-guided therapy. More patients experienced the most desirable outcome in the AUC-guided group compared to the trough-guided group (58.7% vs 46.7%, P = .037). Rates of VA-AKI were lower (21.3% vs 32.0%, P = .037) and median hospital length of stay was shorter (10 days [interquartile range {IQR}, 8-20] vs 12 days [IQR, 8-25]; P = .025) among patients receiving AUC-guided therapy. Conclusions: AUC-guided vancomycin therapy using MIPD and single-concentration monitoring improved outcomes in patients with culture-proven gram-positive infections. Safety was improved with reduced incidence of VA-AKI, and no concerns for reduced efficacy were observed. Moreover, MIPD allowed for earlier assessment of AUC target attainment and greater flexibility in the collection of serum vancomycin concentrations.

Application of the FFLUX Force Field to Molecular Crystals: A Study of Formamide.

In this work, we present the first application of the quantum chemical topology force field FFLUX to the solid state. FFLUX utilizes Gaussian process regression machine learning models trained on data from the interacting quantum atom partitioning scheme to predict atomic energies and flexible multipole moments that change with geometry. Here, the ambient (α) and high-pressure (ß) polymorphs of formamide are used as test systems and optimized using FFLUX. Optimizing the structures with increasing multipolar ranks indicates that the lattice parameters of the α phase differ by less than 5% to the experimental structure when multipole moments up to the quadrupole are used. These differences are found to be in line with the dispersion-corrected density functional theory. Lattice dynamics calculations are also found to be possible using FFLUX, yielding harmonic phonon spectra comparable to dispersion-corrected DFT while enabling larger supercells to be considered than is typically possible with first-principles calculations. These promising results indicate that FFLUX can be used to accurately determine properties of molecular solids that are difficult to access using DFT, including the structural dynamics, free energies, and properties at finite temperature.

Construction of a Gaussian Process Regression Model of Formamide for Use in Molecular Simulations.

FFLUX, a novel force field based on quantum chemical topology, can perform molecular dynamics simulations with flexible multipole moments that change with geometry. This is enabled by Gaussian process regression machine learning models, which accurately predict atomic energies and multipole moments up to the hexadecapole. We have constructed a model of the formamide monomer at the B3LYP/aug-cc-pVTZ level of theory capable of sub-kJ mol-1 accuracy, with the maximum prediction error for the molecule being 0.8 kJ mol-1. This model was used in FFLUX simulations along with Lennard-Jones parameters to successfully optimize the geometry of formamide dimers with errors smaller than 0.1 Šcompared to those obtained with D3-corrected B3LYP/aug-cc-pVTZ. Comparisons were also made to a force field constructed with static multipole moments and Lennard-Jones parameters. FFLUX recovers the expected energy ranking of dimers compared to the literature, and changes in C═O and C-N bond lengths associated with hydrogen bonding were found to be consistent with density functional theory.

Outcomes of Daptomycin Plus Ceftaroline Versus Alternative Therapy for Persistent Methicillin-resistant Staphylococcus aureus (MRSA) Bacteraemia.

OBJECTIVES: This study aimed to evaluate both efficacy and safety of combination therapy with daptomycin plus ceftaroline (DAP/CPT) versus alternative therapy in the treatment of persistent methicillin-resistant Staphylococcus aureus bacteraemia (MRSAB). METHODS: This retrospective, single-centre study investigated adult patients who underwent a change in antibiotic therapy for persistent MRSAB. Daptomycin plus ceftaroline was compared with alternative therapy after initial treatment with vancomycin or DAP monotherapy was modified. The primary outcome was in-hospital mortality, and several secondary efficacy and safety outcomes were evaluated. RESULTS: A total of 68 patients with persistent MRSAB had initial therapy switched to DAP/CPT (n = 43) or alternative therapy (n = 25). In-hospital mortality was similar with DAP/CPT versus alternative therapy (16.3% vs. 16%; P = 1.0). On average, the total duration of bacteraemia was numerically 1 day less in patients switched to DAP/CPT (11.4 days vs. 12.5 days; P = 0.5). Daptomycin plus ceftaroline was de-escalated in 81% of patients after receiving combination therapy for an average of 12.5 days. Secondary outcomes, including rates of adverse events and emergence of antimicrobial resistance, were similar between the two groups. CONCLUSIONS: Switching to DAP/CPT after approximately 1 week of persistent MRSA bacteraemia may result in similar clinical outcomes when compared with alternative therapy. Rates of adverse events and emergence of antimicrobial resistance were low without a statistically significant difference observed between DAP/CPT and alternative therapy. These findings, as well as the impact of earlier switch or prolonged treatment with the combination, require further investigation.

Which "weigh" to Go? Alternative Vancomycin Dosing Strategies in Obese Patients.

PurposeThis study aims to compare the performance of alternative weight-based vancomycin dosing strategies to traditional dosing in obese patients using area under the curve (AUC) monitoring. Methods: This retrospective study compared target attainment of an AUC between 400-600mcg*H/mL using alternative vancomycin dosing strategies. All patients received allometrically dosed vancomycin, with patient-specific AUCs calculated using 2 post-infusion steady-state vancomycin serum concentrations using the trapezoidal rule. Predicted AUCs were calculated using the following: 15 mg/kg total body weight (TBW), 15 mg/kg corrected body weight (CBW), and 12.5 mg/kg TBW. Predicted AUCs from the traditional 15 mg/kg TBW dosing were then compared to alternative dosing strategies using the predicted AUCs from 12.5 mg/kg TBW, 15 mg/kg CBW, and the actual AUCs calculated using allometrically scaled vancomycin dosing. The primary outcome was attainment of initial AUC within the target range of 400-600mcg*H/mL for each dosing method. Results: Eighty-four patients were included. When AUCs were compared to traditional 15 mg/kg dosing strategy, the CBW, 12.5 mg/kg, and allometric dosing strategies were significantly more likely to result in initial attainment of an AUC within a target range of 400-600 mcg*H/mL (P = 0.0003, 0.0135, and 0.0088, respectively). No significant differences were seen between each of the alternative dosing methods (P = 0.73). Conclusion: The 3 alternative vancomycin dosing strategies examined were all significantly more likely to achieve an initial AUC within the target range compared to traditional vancomycin dosing in obese patients. Clinicians should strongly consider one of these alternative dosing strategies for obese patients as opposed to traditional vancomycin dosing.

A Baker's Dozen of Top Antimicrobial Stewardship Intervention Publications in Non-Hospital Care Settings in 2021.

The scope of antimicrobial stewardship programs has expanded beyond the acute hospital setting. The need to optimize antimicrobial use in emergency departments, urgent, primary, and specialty care clinics, nursing homes, and long-term care facilities prompted the development of core elements of stewardship programs in these settings. Identifying the most innovative and well-designed stewardship literature in these novel stewardship areas can be challenging. The Southeastern Research Group Endeavor (SERGE-45) network evaluated antimicrobial stewardship-related, peer-reviewed literature published in 2021 that detailed actionable interventions specific to the nonhospital setting. The top 13 publications were summarized following identification using a modified Delphi technique. This article highlights the selected interventions and may serve as a key resource for expansion of antimicrobial stewardship programs beyond the acute hospital setting.

Are immediate postoperative X-Rays valuable in evaluating complications of primary total hip arthroplasty?

PURPOSE: This study aimed to investigate the complications of primary total hip arthroplasty based on immediate postoperative X-rays. The overall quality and cost of X-rays were assessed. METHODS: The institutional database was queried to identify all patients who underwent total hip arthroplasty in a single institution between January 1, 2018, and December 31, 2018. Immediate postoperative X-rays were reviewed to identify the complications such as periprosthetic fractures, dislocation, and fixation failure. The quality and cost of X-ray were assessed. The complications were categorized as "known" and "unknown" according to the intraoperative fluoroscopic results. RESULTS: A total of 518 total hip arthroplasties were included in this study. Based on intraoperative fluoroscopy, periprosthetic fractures were found in 10 (2%) THAs. Compared to the X-rays taken immediately after surgery, 9 periprosthetic fractures (recorded as "known") were found and 1 was not (recorded as "unknown"). There was no significant difference between intraoperative fluoroscopy and X-rays (P > 0.05). Of the 518 X-rays, 225 (43%) were of suboptimal quality. The cost of a single portable pelvic X-ray was $647. CONCLUSION: In total hip arthroplasty, X-rays taken immediately after surgery rarely reveal unknown complications. The X-rays are often of suboptimal quality, have minimal clinical utility, and are less cost-effective.

Evolving etiologies and rates of revision total knee arthroplasty: a 10-year institutional report.

BACKGROUND: The number of total knee arthroplasties (TKA) performed in the United States is projected to rise significantly, with a proportionate increase in the revision burden. Understanding the mechanism of failure in primary TKA is important as etiologies continue to evolve and reasons for revision change. The purpose of this study was to determine the reason for revision TKA at our institution among early and late failures and assess if the etiology has changed over a 10-year time-period. METHODS: We identified 258 revision TKAs performed at our institution between 2005 and 2014. Reasons for revision TKA were categorized according to diagnosis. We also conducted subgroup analysis for TKA revisions performed within two years of the primary TKA (early failures) and those performed after two years (late failures). Revision TKAs were also grouped by year of primary TKA (before and after 2000) and time period in which the revision TKA was performed (2005-2009 and 2010-2014). RESULTS: The most common reason for revision TKA was infection (29.3%), followed by aseptic loosening (19.7%), which together accounted for half of all revisions. Other indications for revision were instability (11.6%), osteolysis (10.4%), arthrofibrosis (8.1%), polyethylene (PE) wear (7.7%), malalignment/malposition (5.4%), patellar complication (3.1%), periprosthetic fracture (2.3%), pain (1.5%), and extensor mechanism deficiency (0.8%). Nearly half of early failures (47%) were due to infection. Osteolysis and PE wear made of a significantly higher proportion of revisions of TKAs performed prior to 2000 compared to index TKAs performed after 2000. CONCLUSION: At our institution, infection was the most common reason for revision TKA. Infection had a higher rate of early revisions. Proportion of TKAs revised for osteolysis and PE wear was higher for TKAs performed prior to 2000. Proportion of revision TKA for infection and instability were higher with TKAs performed after 2000.

Clinical risk factors for admission with Pseudomonas and multidrug-resistant Pseudomonas community-acquired pneumonia.

BACKGROUND: Microbial etiology for community-acquired pneumonia (CAP) is evolving with pathogens known for high CAP mortality e.g., Pseudomonas species. Chronic obstructive pulmonary disease (COPD) patients are at risk for hospitalization for CAP. Understanding regional patterns and risk factors for multidrug-resistant (MDR) Pseudomonas acquisition has implications for antimicrobial stewardship. OBJECTIVES: To evaluate the regional epidemiology of MDR Pseudomonas CAP and its association with COPD. METHODS: We queried the electronic medical records of the University of Alabama at Birmingham Healthcare System to identify patients hospitalized for CAP with Pseudomonas positive respiratory samples between 01/01/2013-12/31/2019. Log binomial regression models were used to examine associations between COPD diagnosis and risk of Pseudomonas/MDR Pseudomonas CAP. RESULTS: Cohort consisted of 913 culture positive CAP cases aged 59-year (IQR:48-68), 61% (560) male, 60% (547) white, 65% (580) current/past smokers, and 42% (384) COPD. Prevalence of Pseudomonas CAP in culture positive CAP was 18% (167), MDR Pseudomonas CAP in Pseudomonas CAP was 22% (36), and yearly incidence of MDR Pseudomonas CAP was stable (p = 0.169). COPD was associated with Pseudomonas CAP (RR 1.39; 95% CI 1.01, 1.91; p = 0.041) but not with MDR Pseudomonas CAP (0.71; 95% CI 0.35, 1.45; p = 0.349). Stroke (RR 2.64; 95% CI 1.51, 4.61; p = 0.0006) and use of supplemental oxygen (RR 2.31; 95% CI 1.30, 4.12; p = 0.005) were associated with MDR Pseudomonas CAP. CONCLUSION: Incidence of MDR Pseudomonas CAP was stable over time. COPD was associated with Pseudomonas CAP but not with MDR Pseudomonas CAP. Larger cohort studies are needed to confirm findings.

The impact of failed novel technology and technical errors on the revision burden in total hip arthroplasty: what percentage of revision hip arthroplasty was potentially avoidable?

BACKGROUND: Despite the high success rate of total hip arthroplasty (THA), new implant technologies continue to be developed. Although potentially useful, such novel developments may result in unintended consequences, leading to revision surgery, often prematurely. In several instances, new technology that appeared promising was later found to be inferior to existing technology and resulting in early revision surgery. Additionally, technical surgical errors may also lead to early revisions. Some have argued that revisions related to such phenomena are potentially avoidable. The present analysis investigates to what extent the contribution of "failed new technology" and "technical errors" contributes to the revision burden and to the need for premature revision arthroplasty. METHODS: We retrospectively analysed 432 revision THAs and categorised them as either "late revisions" based on survivorship of 10 years or "premature revisions". Among both cohorts, we determined what percentage of revisions were potentially avoidable and due to failed novel technologies and technical errors, and what percent were "unavoidable". RESULTS: Of the 432 revisions, 267 (62%) were considered premature and 38% were considered late. Of the premature revisions, 108 were considered potentially avoidable (81 failed novel technologies, 27 technical errors). CONCLUSIONS: Our data demonstrates that new technology and surgical techniques can result in premature failure of THA. Surgeons should take caution when incorporating new implant technology or surgical techniques into their practice.

How fluoroquinolone preauthorization affects third- and fourth-generation cephalosporin use and resistance in a large academic hospital.

OBJECTIVE: We observed an overall increase in the use of third- and fourth-generation cephalosporins after fluoroquinolone preauthorization was implemented. We examined the change in specific third- and fourth-generation cephalosporin use, and we sought to determine whether there was a consequent change in non-susceptibility of select Gram-negative bacterial isolates to these antibiotics. DESIGN: Retrospective quasi-experimental study. SETTING: Academic hospital. INTERVENTION: Fluoroquinolone preauthorization was implemented in the hospital in October 2005. We used interrupted time series (ITS) Poisson regression models to examine trends in monthly rates of ceftriaxone, ceftazidime, and cefepime use and trends in yearly rates of nonsusceptible isolates (NSIs) of select Gram-negative bacteria before (1998-2004) and after (2006-2016) fluoroquinolone preauthorization was implemented. RESULTS: Rates of use of ceftriaxone and cefepime increased after fluoroquinolone preauthorization was implemented (ceftriaxone RR, 1.002; 95% CI, 1.002-1.003; P < .0001; cefepime RR, 1.003; 95% CI, 1.001-1.004; P = .0006), but ceftazidime use continued to decline (RR, 0.991, 95% CI, 0.990-0.992; P < .0001). Rates of ceftazidime and cefepime NSIs of Pseudomonas aeruginosa (ceftazidime RR, 0.937; 95% CI, 0.910-0.965, P < .0001; cefepime RR, 0.937; 95% CI, 0.912-0.963; P < .0001) declined after fluoroquinolone preauthorization was implemented. Rates of ceftazidime and cefepime NSIs of Enterobacter cloacae (ceftazidime RR, 1.116; 95% CI, 1.078-1.154; P < .0001; cefepime RR, 1.198; 95% CI, 1.112-1.291; P < .0001) and cefepime NSI of Acinetobacter baumannii (RR, 1.169; 95% CI, 1.081-1.263; P < .0001) were increasing before fluoroquinolone preauthorization was implemented but became stable thereafter: E. cloacae (ceftazidime RR, 0.987; 95% CI, 0.948-1.028; P = .531; cefepime RR, 0.990; 95% CI, 0.962-1.018; P = .461) and A. baumannii (cefepime RR, 0.972; 95% CI, 0.939-1.006; P = .100). CONCLUSIONS: Fluoroquinolone preauthorization may increase use of unrestricted third- and fourth-generation cephalosporins; however, we did not observe increased antimicrobial resistance to these agents, especially among clinically important Gram-negative bacteria known for hospital-acquired infections.

A Baker's Dozen of Top Antimicrobial Stewardship Intervention Publications in 2020.

The number of articles related to antimicrobial stewardship published each year has increased significantly over the last decade. Keeping up with the literature, particularly the most innovative, well-designed, or applicable to one's own practice area, can be challenging. The Southeastern Research Group Endeavor (SERGE-45) network reviewed antimicrobial stewardship-related, peer-reviewed literature from 2020 that detailed actionable interventions. The top 13 publications were summarized following identification using a modified Delphi technique. This article highlights the selected interventions and may serve as a key resource for teaching and training, and to identify novel or optimized stewardship opportunities within one's institution.

Aspirin used for venous thromboembolism prophylaxis in total hip arthroplasty decreases heterotopic ossification.

BACKGROUND: Heterotopic ossification (HO) is a known complication of total hip arthroplasty (THA) that can lead to persistent pain, stiffness, nerve impingement, and instability. Aspirin (ASA) has become an increasingly popular method of venous thromboembolism (VTE) prophylaxis, given its availability, ease of use, and relative safety. Although indomethacin has been commonly used for HO prophylaxis, we wanted to determine whether ASA, given the similar mechanism of action, may be effective in reducing the risk of HO in routine unilateral, primary THA when already being used for VTE prophylaxis. METHODS: The postoperative radiographs of 222 consecutive patients undergoing unilateral, primary THA with cementless fixation were evaluated for HO formation using the Brooker classification immediately before and after surgeon protocol shifted to routine utilization of ASA as VTE prophylaxis in low-risk patients. RESULTS: HO was detected in 13 of 99 (13.1%) THAs prescribed ASA for VTE prophylaxis (11 grade I, 1 grade II, 1 grade III) compared with 38 of 123 (30.9%) THAs prescribed non-ASA chemoprophylaxis (26 grade I, 7 grade II, 4 grade III, 1 grade IV). Significantly more THAs in the non-ASA cohort developed HO (P < .01). There was no significant difference in the distribution of HO severity between cohorts (P = .61). CONCLUSIONS: ASA may be effective as monotherapy for both VTE and HO reduction in low-risk patients undergoing unilateral primary arthroplasty with cementless fixation.

Osteochondritis Dissecans Lesion Location Is Highly Concordant With Mechanical Axis Deviation.

BACKGROUND: The cause of osteochondritis dissecans (OCD) is unknown. PURPOSE: To determine if mechanical axis deviation correlates with OCD lesion location in the knee, if degree of mechanical axis deviation correlates with size of OCD lesion, and if the deformity was primarily in the distal femur or proximal tibia. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We identified 61 knees that underwent osteochondral allograft (OCA) transplantation for femoral condyle OCD lesions and used preoperative lower extremity alignment radiographs to measure lower extremity mechanical axis, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and hip-knee-ankle angle. Lesion location and area were retrieved from operative records. RESULTS: The location of the OCD lesion was the medial femoral condyle (MFC) for 37 knees and lateral femoral condyle (LFC) for 24 knees. Among knees with MFC lesions, alignment was varus in 25 (68%). Conversely, knees with LFC lesions had valgus alignment in 16 (67%). The mLFDA was significantly more valgus in the LFC group. mMPTA was not different between MFC and LFC groups. There was no significant correlation between degree of mechanical axis deviation and lesion size. CONCLUSION: In this cohort, two-thirds of patients with symptomatic OCD lesions had associated mechanical axis deviation. Lesion location correlated with mechanical axis deviation (LFC lesions were associated with a deformity in the distal femur). Degree of deformity was not correlated with lesion size. Mechanical axis deviation may play a role in OCD pathogenesis. These data do not allow analysis of the role of mechanical axis deviation in causation or prognosis of OCD lesions, but surgeons treating OCD should be aware of this common association.