The Impact of Culture Negativity on the Outcomes of Revision Total Knee Arthroplasty for Chronic PJI.

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of two-stage revision of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p = 0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p = 0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p = 0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from first to second stage was significantly shorter in the CN cohort (p = 0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

The Impact of Hospital Exposures Prior to Total Knee Arthroplasty on Postoperative Outcomes.

Background: Total knee arthroplasty (TKA) procedures are expected to grow exponentially in the upcoming years, highlighting the importance of identifying preoperative risk factors that predispose patients to poor outcomes. The present study sought to determine if preoperative healthcare events (PHEs) influenced outcomes following TKA. Methods: This was a retrospective review of all patients who underwent TKA at a single institution from June 2011 to April 2022. Patients who had a PHE within 90 days of surgery, defined as an emergency department visit or hospital admission, were compared to patients with no history of PHE. Patients who underwent revision, nonelective, and/or bilateral TKA were excluded. Chi-squared analysis and independent sample t-tests were used to determine significant differences between demographic variables. All significant covariates were included in binary logistic regressions used to predict discharge disposition, 90-day readmission, and 1-year revision. Results: Of the 10,869 patients who underwent TKA, 265 had ≥1 PHE. Patients who had a PHE were significantly more likely to require facility discharge (odds ratio [OR]: 1.662; P = .001) than patients who did not have a PHE. Any PHE predisposed patients to significantly higher 90-day readmission rates (OR: 2.173; P = .002). Patients with ≥2 PHEs were at a significantly higher risk of 1-year revision (OR: 5.870; P = .004) compared to patients without a PHE. Conclusions: Our results demonstrate that PHEs put patients at significantly greater risk of facility discharge, 90-day readmission, and 1-year revision. Moving forward, consideration of elective surgery scheduling in the context of a recent PHE may lead to improved postoperative outcomes. Level III Evidence: Retrospective Cohort Study.

Ambulatory status after revision total hip arthroplasty in elective versus fracture indications.

INTRODUCTION: To improve revision total hip arthroplasty (rTHA) prognosis and postoperative management, a better understanding of how non-elective and elective indications influence clinical outcomes is needed. We sought to compare ambulatory status, complication rates, and implant survival rates in patients who underwent aseptic rTHA for periprosthetic fracture or elective indications. MATERIALS AND METHODS: This retrospective study examined all aseptic rTHA patients with a minimum follow-up of two years at a single tertiary referral center. Patients were divided into two groups: fracture rTHA (F-rTHA) if the patient had a periprosthetic femoral or acetabular fracture, and elective rTHA (E-rTHA) if the patient underwent rTHA for other aseptic indications. Multivariate regression was performed for clinical outcomes to adjust for baseline characteristics, and Kaplan-Meier analysis was performed to assess implant survival. RESULTS: A total of 324 patients (F-rTHA: 67, E-rTHA: 257) were included. In the F-rTHA cohort, 57 (85.0%) and 10 (15.0%) had femoral and acetabular periprosthetic fractures, respectively. F-rTHA patients were more likely to be discharged to skilled nursing (40.3% vs. 22.2%, p = 0.049) and acute rehabilitation facilities (19.4% vs. 7.8%, p = 0.004). F-rTHA patients had higher 90-day readmission rates (26.9% vs. 16.0%, p = 0.033). Ambulatory status at three months postoperatively significantly differed (p = 0.004); F-rTHA patients were more likely to use a walker (44.6% vs. 18.8%) and less likely to ambulate independently (19.6% vs. 28.6%) or with a cane (28.6% vs. 41.1%). These differences did not persist at one and two years postoperatively. Freedom from all-cause re-revision (77.6% vs. 74.7%, p = 0.912) and re-revision due to PJI (88.1% vs. 91.9%, p = 0.206) were similar at five-year follow-up. CONCLUSIONS: Compared to rTHA performed for elective aseptic indications, fracture rTHA patients had poorer early functional outcomes, with greater need for ambulatory aids and non-home discharge. However, these differences did not persist long term and did not portend increased infection or re-revision rates.

Evaluating the interactive effects of artificial light at night and background color on tadpole crypsis, background adaptation efficacy, and growth.

Artificial light at night (ALAN) is a global pollutant of rising concern. While alterations to natural day-night cycles caused by ALAN can affect a variety of traits, the broader fitness and ecological implications of these ALAN-induced shifts remain unclear. This study evaluated the interactive effects of ALAN and background color on traits that have important implications for predator-prey interactions and fitness: crypsis, background adaptation efficacy, and growth. Using three amphibian species as our models, we discovered that: (1) Exposure to ALAN reduced the ability for some species to match their backgrounds (background adaptation efficacy), (2) Crypsis and background adaptation efficacy were enhanced when tadpoles were exposed to dark backgrounds only, emphasizing the importance of environmental context when evaluating the effects of ALAN, (3) ALAN and background color have a combined effect on a common metric of fitness (growth), and (4) Effects of ALAN were not generalizable across amphibian species, supporting calls for more studies that utilize a diversity of species. Notably, to our knowledge, we found the first evidence that ALAN can diminish background adaptation efficacy in an amphibian species (American toad tadpoles). Collectively, our study joins others in highlighting the complex effects of ALAN on wildlife and underscores the challenges of generalizing ALAN's effect across species, emphasizing the need for a greater diversity of species and approaches used in ALAN research.

The morphological effects of artificial light at night on amphibian predators and prey are masked at the community level.

Artificial light at night (ALAN) is a pervasive pollutant that influences wildlife at both the individual and community level. In this study, we tested the individual-level effects of ALAN on three species of tadpole prey and their newt predators by measuring prey pigmentation and predator and prey mass. Then we evaluated whether the individual-level effects of ALAN on pigmentation and mass had cascading community-level effects by assessing the outcome of predator-prey interactions. We found that spring peepers exposed to ALAN were significantly darker than those reared under control conditions. Additionally, wood frogs reared in ALAN conditions were significantly smaller than those reared in control conditions. In contrast, Eastern newts collected earlier in the spring that were exposed to ALAN were significantly larger than controls while those collected later in the spring were not affected by ALAN, suggesting phenological differences in the effect of ALAN. To understand how changes in pigmentation and size due to ALAN influence predation rates, we ran predation assays in both ALAN-polluted and ALAN-free outdoor environments. After the predation assay, the size disparity in wood frogs reared in ALAN was eliminated such that there was no longer a treatment difference in wood frog size, likely due to size-selective predation. This demonstrates the beneficial nature of predators' selective pressure on prey populations. Lastly, despite individual-level effects of ALAN on pigmentation and mass, we did not detect cascading community-level effects on predation rates. Overall, this study highlights important species-level distinctions in the effects of ALAN. It also emphasizes the need to incorporate ecological complexity to understand the net impact of ALAN.