Antibiotic Prophylaxis Prior to Dental Procedures After Total Hip and Knee Arthroplasty Does Not Decrease the Risk of Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication after total hip and total knee arthroplasty (THA/TKA). While some guidelines no longer recommend routine use of prophylactic antibiotics for dental procedures, many surgeons continue to prescribe antibiotics for their THA/TKA patients. In a setting of increasing antibiotic resistance, it is important to reduce unnecessary antibiotic use. This study aims to evaluate antibiotics prior to dental procedures and the association between dental procedures and PJI. METHODS: We conducted a retrospective cohort study of patients who underwent THA/TKA between January 1, 2019 and December 31, 2020. The primary outcome was late-presenting PJI, occurring > 90 days after surgery. Patients were designated in the antibiotic group (2,000 mg of amoxicillin) or non-antibiotic group based on their surgeon's prophylaxis protocol. Dental-associated PJIs were considered if the patient had evidence of poor dentition or a recent dental procedure prior to the onset of PJI symptoms. RESULTS: There were 2,871 (26.4%) patients in the no antibiotics group and 8,023 (73.6%) patients in the antibiotics group. We found 27 (0.3%) late-presenting PJIs and 4 dental-associated PJIs. In the univariate and multivariable analyses, body mass index ≥-30 and revision surgery were the only variables that increased the odds of late-presenting PJI. All 4 dental-associated PJIs occurred in patients prescribed antibiotics. CONCLUSIONS: We found a low rate of late-presenting PJI. Routine antibiotics prior to dental procedures were not shown to affect the risk of late-presenting PJI. These findings suggest that routine antibiotic prophylaxis before dental procedures is not necessary after THA/TKA.

Staphylococcus epidermidis joint isolates: Whole-genome sequencing demonstrates evidence of hospital transmission and common antimicrobial resistance.

OBJECTIVE: We investigated genetic, epidemiologic, and environmental factors contributing to positive Staphylococcus epidermidis joint cultures. DESIGN: Retrospective cohort study with whole-genome sequencing (WGS). PATIENTS: We identified S. epidermidis isolates from hip or knee cultures in patients with 1 or more prior corresponding intra-articular procedure at our hospital. METHODS: WGS and single-nucleotide polymorphism-based clonality analyses were performed, including species identification, in silico multilocus sequence typing (MLST), phylogenomic analysis, and genotypic assessment of the prevalence of specific antibiotic resistance and virulence genes. Epidemiologic review was performed to compare cluster and noncluster cases. RESULTS: In total, 60 phenotypically distinct S. epidermidis isolates were identified. After removal of duplicates and impure samples, 48 isolates were used for the phylogenomic analysis, and 45 (93.7%) isolates were included in the clonality analysis. Notably, 5 S. epidermidis strains (10.4%) showed phenotypic susceptibility to oxacillin yet harbored mecA, and 3 (6.2%) strains showed phenotypic resistance despite not having mecA. Smr was found in all isolates, and mupA positivity was not observed. We also identified 6 clonal clusters from the clonality analysis, which accounted for 14 (31.1%) of the 45 S. epidermidis isolates. Our epidemiologic investigation revealed ties to common aspirations or operative procedures, although no specific common source was identified. CONCLUSIONS: Most S. epidermidis isolates from clinical joint samples are diverse in origin, but we identified an important subset of 31.1% that belonged to subclinical healthcare-associated clusters. Clusters appeared to resolve spontaneously over time, suggesting the benefit of routine hospital infection control and disinfection practices.

Venous Thromboembolism in Total Hip and Total Knee Arthroplasty.

Importance: The optimal pharmacologic thromboprophylaxis agent after total hip and total knee arthroplasty is uncertain and consensus is lacking. Quantifying the risk of postoperative venous thromboembolism (VTE) and bleeding and evaluating comparative effectiveness and safety of the thromboprophylaxis strategies can inform care. Objective: To quantify risk factors for postoperative VTE and bleeding and compare patient outcomes among pharmacological thromboprophylaxis agents used after total hip and knee arthroplasty. Design, Setting, and Participants: This retrospective cohort study used data from a large health care claims database. Participants included patients in the United States with hip or knee arthroplasty and continuous insurance enrollment 3 months prior to and following their surgical procedure. Patients were excluded if they received anticoagulation before surgery, received no postsurgical pharmacological thromboprophylaxis, or had multiple postsurgery thromboprophylactic agents. In a propensity-matched analysis, patients receiving a direct oral anticoagulant (DOAC) were matched with those receiving aspirin. Exposures: Aspirin, apixaban, rivaroxaban, enoxaparin, or warfarin. Main Outcomes and Measures: The primary outcome was 30-day cumulative incidence of postdischarge VTE. Other outcomes included postdischarge bleeding. Results: Among 29 264 patients included in the final cohort, 17 040 (58.2%) were female, 27 897 (95.2%) had inpatient admissions with median (IQR) length of stay of 2 (1-2) days, 10 948 (37.4%) underwent total hip arthroplasty, 18 316 (62.6%) underwent total knee arthroplasty; and median (IQR) age was 59 (55-63) years. At 30 days, cumulative incidence of VTE was 1.19% (95% CI, 1.06%-1.32%) and cumulative incidence of bleeding was 3.43% (95% CI, 3.22%-3.64%). In the multivariate analysis, leading risk factors associated with increased VTE risk included prior VTE history (odds ratio [OR], 5.94 [95% CI, 4.29-8.24]), a hereditary hypercoagulable state (OR, 2.64 [95% CI, 1.32-5.28]), knee arthroplasty (OR, 1.65 [95% CI, 1.29-2.10]), and male sex (OR, 1.34 [95% CI, 1.08-1.67]). In a propensity-matched cohort of 7844 DOAC-aspirin pairs, there was no significant difference in the risk of VTE in the first 30 days after the surgical procedure (OR, 1.14 [95% CI, 0.82-1.59]), but postoperative bleeding was more frequent in patients receiving DOACs (OR, 1.36 [95% CI, 1.13-1.62]). Conclusions and Relevance: In this cohort study of patients who underwent total hip or total knee arthroplasty, underlying patient risk factors, but not choice of aspirin or DOAC, were associated with postsurgical VTE. Postoperative bleeding rates were lower in patients prescribed aspirin. These results suggest that thromboprophylaxis strategies should be patient-centric and tailored to individual risk of thrombosis and bleeding.

Teaching transferable skills in teamwork, accountability, goal setting, writing, and problem-solving in a non-major microbiology lab: the unknown bacteria experiment redefined.

College to Career is a phrase that we often use to describe the skills and abilities that students should achieve while preparing for college and/or careers. To help prepare our students for their future careers, we developed a microbiology laboratory curriculum based on factors identified to improve college-to-career readiness. These factors include content knowledge, analyzing and interpreting data, accountability, goal setting, and teamwork. At the core of the design are inquiry and problem-based learning. This approach allows students to actively engage in the scientific process while collaborating with classmates and learning technical and transferable career skills. The curriculum includes microbiology laboratory skills, including plating, serial dilutions, and biochemical tests, with integrated opportunities for students to engage in critical thinking, analysis and interpretation of data, teamwork, goal setting, decision-making, and scientific writing.

Risk Factors for Surgical Site Complications After Outpatient Lumbar Spine Surgery.

Background: With the recent increase of minor lumbar spine surgeries being performed in the outpatient setting, there is a need for information on factors that contribute to post-operative complications for these surgeries. Patients and Methods: This was a prospective observational study examining risk factors for self-reported post-operative drainage in patients who underwent lumbar spine surgery. Patient surveys and the hospital's electronic medical records were used to collect data on patient demographic, patient lifestyle, and surgical variables. Univariable and multivariable analyses in addition to a random forest classifier were performed. Results: A total of 146 patients were enrolled in the study with 111 patients included in the final analysis. The average age and body mass index (BMI) of these patients was 66 and 27.8, respectively. None of the 146 patients in this study developed surgical site infection. Older age, no steroid use, no pet ownership, and spine surgery involving two or more levels were all found to be risk factors for wound drainage. Conclusions: This study evaluated lifestyle, environmental, and traditional risk factors for surgical site drainage that have not been explored cohesively related to outpatient orthopedic surgery. Consistent with the existing literature, outpatient spine surgery involving two or more levels was most strongly associated with surgical site drainage after surgery.

Erratum: Whole-genome sequencing to assess clonality in a series of prosthetic joint Staphylococcus epidermidis isolates - WITHDRAWAL.

[This corrects the article DOI: 10.1017/ash.2022.160.].

The diversity officer: Police officers' and black women civilians' epistemologies of race and racism in policing.

Diversifying police forces has been suggested to improve "police-minority relations" amidst national uprisings against police violence. Yet, little research investigates how police and black civilians-two groups invoked in discourse on "police-minority relations"-understand the function of diversity interventions. We draw on 100 in-depth interviews with 60 black women civilians and 40 police from various racial and ethnic backgrounds to explore how they understand the function of racial diversity in policing. Findings highlight discrepancies in how these two groups frame the utility of racial diversity in policing, revealing conflicting epistemologies of race and racism. Police draw on an epistemology of racial ignorance (Mills 1997, 2007, 2015) to selectively accommodate race-conscious critique while denying the history and power dynamics between the institution and minority communities. Conversely, black women civilians, grounded in a standpoint epistemology (Collins 1986, 2009), emphasize the historical roots of policing, along with collective memories and lived experiences to understand the relationship between the institution and minority communities. Through a comparative analysis of these frames, we theorize dominant/state-sponsored discourse on diversity and police-minority relations as form of racecraft (Fields and Fields 2012, 2014) that serves to legitimize negligible institutional change to policing in an era of renewed scrutiny of police racism.

Risk factors for surgical site infections in knee and hip arthroplasty patients.

We performed a retrospective cohort study to identify risk factors for surgical site infection (SSI) in patients with hip and knee arthroplasty in a high-volume orthopedic center with low overall SSI rates. Active smoking and revision arthroplasty both increased the risk for SSI. Former smokers were seen to have a lower SSI risk, demonstrating a potential benefit in implementing mandated smoking secession programs.

Siglec-6 is a target for chimeric antigen receptor T-cell treatment of chronic lymphocytic leukemia.

The only current curative treatment for chronic lymphocytic leukemia (CLL) is allogenic hematopoietic stem cell transplantation. Chimeric antigen receptor treatment targeting CD19 for CLL achieved some complete responses, suggesting the need for alternative or combinational therapies to achieve a more robust response. In this work, we evaluated CAR-T cells specific for Siglec-6, an antigen expressed in CLL, as a novel CAR-T cell treatment for CLL. We found that detection of SIGLEC6 mRNA and Siglec-6 protein is highly restricted to placenta and immune cells in other tissues and it is not expressed in hematopoietic stem cells. We generated CAR-T cells specific for Siglec-6 based on the sequence of the fully human anti-Siglec-6 antibody (JML1), which was identified in a CLL patient that was cured after allo-hematopoietic stem cell transplantation (alloHSCT), and observed that it specifically targeted CLL cells in vitro and in a xenograft mouse model. Interestingly, a short hinge region increased the activity of CAR-T cells to target cells expressing higher Siglec-6 levels but similarly targeted CLL cells expressing lower Siglec-6 levels in vitro and in vivo. Our results identify a novel CAR-T cell therapy for CLL and establish Siglec-6 as a possible target for immunotherapy.

Immunomodulatory effects of radiation: what is next for cancer therapy?

Despite its former reputation as being immunosuppressive, it has become evident that radiation therapy can enhance antitumor immune responses. This quality can be harnessed by utilizing radiation as an adjuvant to cancer immunotherapies. Most studies combine the standard radiation dose and regimens indicated for the given disease state, with novel cancer immunotherapies. It has become apparent that low-dose radiation, as well as doses within the hypofractionated range, can modulate tumor cells making them better targets for immune cell reactivity. Herein, we describe the range of phenotypic changes induced in tumor cells by radiation, and explore the diverse mechanisms of immunogenic modulation reported at these doses. We also review the impact of these doses on the immune cell function of cytotoxic cells in vivo and in vitro.