Inpatient Hospital Costs, Emergency Department Visits, and Readmissions for Revision Hip and Knee Arthroplasty.

BACKGROUND: Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) tremendously burden hospital resources. This study evaluated factors influencing perioperative costs, including emergency department (ED) visits, readmissions, and total costs-of-care within 90 days following revision surgery. METHODS: A retrospective analysis of 772 revision TKAs and THAs performed on 630 subjects at a single center between January 2007 and December 2019 was conducted. Cost data were available from January 2015 to December 2019 for 277 patients. Factors examined included comorbidities, demographic information, preoperative Anesthesia Society of Anesthesiologists score, implant selection, and operative indication using mixed-effects linear regression models. RESULTS: Among 772 revisions (425 THAs and 347 TKAs), 213 patients required an ED visit, and 90 required hospital readmission within 90 days. There were 22.6% of patients who underwent a second procedure after their initial revision. Liver disease was a significant predictor of ED readmission for THA patients (multivariable odds ratio [OR]: 3.473, P = .001), while aseptic loosening, osteolysis, or instability significantly reduced the odds of readmission for TKA patients (OR: 0.368, P = .014). In terms of ED visits, liver disease increased the odds for THA patients (OR: 1.845, P = .100), and aseptic loosening, osteolysis, or instability decreased the odds for TKA patients (OR: 0.223, P < .001). Increased age was associated with increased costs in both THA and TKA patients, with significant cost factors including congestive heart failure for TKA patients (OR: $7,308.17, P = .004) and kidney disease for THA patients. Revision surgeries took longer than primary ones, with TKA averaging 3.0 hours (1.6 times longer) and THA 2.8 hours (1.5 times longer). CONCLUSIONS: Liver disease increases ED readmission risk in revision THA, while aseptic loosening, osteolysis, or instability decreases it in revision TKA. Increased age and congestive heart failure are associated with increased costs. These findings inform postoperative care and resource allocation in revision arthroplasty. LEVEL OF EVIDENCE: Economic and Decision Analysis, Level IV.

Safety and Efficacy of Tranexamic Acid in Total Ankle Arthroplasty.

Tranexamic acid has been shown to significantly reduce blood loss in patients undergoing total knee arthroplasty and total hip arthroplasty. However, there is a paucity of data regarding its safety and efficacy in total ankle arthroplasty. The purpose of this study was to determine whether tranexamic acid use in patients with total ankle arthroplasty affects blood loss or overall complication rate. A retrospective chart review was conducted for 64 patients who underwent total ankle arthroplasty with (n = 32) and without (n = 32) intraoperative tranexamic acid from 2014 to 2023 at a single academic medical center. Recorded blood loss, pre-to-postoperative hemoglobin changes, hidden blood loss, and complication rates were recorded and compared. There was no statistically significant difference in recorded blood loss, total calculated blood loss, pre-to-postoperative hemoglobin difference, hidden blood loss, or overall complications between the groups (all, P > .05). A lower rate of wound complications was observed in the tranexamic acid group, but the difference between each group was not statistically significant (P > .05). Tranexamic acid did not decrease blood loss during total ankle arthroplasty, as measured in our study. Tranexamic acid was not associated with any increase in overall complications. Based on our findings, tranexamic acid may be a safe intervention in total ankle arthroplasty, but further studies are needed to better elucidate its clinical impact.Level of Evidence: Level 3.

Predictors of Success With Chronic Antibiotic Suppression for Prosthetic Joint Infections.

BACKGROUND: Management of recurrent prosthetic joint infection (PJI) after attempted surgical eradication remains a challenge. Chronic antibiotic suppression (CAS) is regarded as a reasonable treatment option for select patients with persistent infection or multiple comorbidities. The study seeks to compare cohorts who succeed and fail with CAS. METHODS: This retrospective cohort study assesses patients who were treated with CAS for a PJI. Patients were included if they had a culture-proven PJI and received chronic suppressive antibiotics. Failure of suppression was defined as reoperation after initiating CAS or death occurring as result of infection. A Cox proportional hazards multivariate regression model was used to estimate risk of reoperation as a function of risk factors related to patient comorbidities, surgical history, affected joint, and infecting organism. RESULTS: We identified 45 PJIs (31 knees, 14 hips) managed with CAS with a median follow-up of 50 (95% confidence interval [CI] 33.61-74.02) months. The overall success rate of managing PJI with CAS was 67% (30/45). Controlling for body mass index and Gram status of the organism, total hip arthroplasty patients were less likely than total knee arthroplasty patients to require reoperation (hazard ratio 0.18, 95% CI 0.01-0.96, P = .04). Patients with Gram-positive infections were less likely than those with a Gram-negative infections to require reoperation (hazard ratio 0.22, 95% CI 0.05-0.88, P = .03). Severe antibiotic side effects were rare. Patients who experienced multiple changes to their antibiotic regimen were more likely to fail with CAS. CONCLUSION: CAS is a reasonable strategy in patients with PJI who lack or refuse further surgical treatment options. Most hips and Gram-positive infections treated with CAS successfully avoided reoperation in this cohort.

Relative Efficacy of Intra-articular Injections in the Treatment of Knee Osteoarthritis: A Systematic Review and Network Meta-analysis.

BACKGROUND: In younger patients and those without severe degenerative changes, the efficacy of intra-articular (IA) injections as a nonoperative modality for treating symptomatic knee osteoarthritis (OA)-related pain while maintaining function has become a subject of increasing interest. PURPOSE: To assess and compare the efficacy of different IA injections used for the treatment of knee OA, including hyaluronic acid (HA), corticosteroids (CS), platelet-rich plasma (PRP), and plasma rich in growth factors (PRGF), with a minimum 6-month patient follow-up. STUDY DESIGN: Meta-analysis of randomized controlled trials; Level of evidence, 1. METHODS: A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the following databases: PubMed/MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Google Scholar. Mean or mean change from baseline and standard deviation for outcome scores regarding pain and function were recorded at the 6-month follow-up and converted to either a 0 to 100 visual analog scale score for pain or a 0 to 100 Western Ontario and McMaster Universities Osteoarthritis Index score for function. A frequentist network meta-analysis model was developed to compare the effects of HA, CS, PRP, PRGF, and placebo on patient-reported outcomes. RESULTS: All IA treatments except CS were found to result in a statistically significant improvement in outcomes when compared with placebo. PRP demonstrated a clinically meaningful difference in function-related improvement when compared with CS and placebo due to large effect sizes. Studies evaluating outcomes of PRGF reported significant improvement when compared with placebo due to large effect sizes, whereas a potential clinically significant difference was detected in the same comparison parameters in pain evaluation. With regard to improvements in pain, function, and both combined, PRP was found to possess the highest probability of efficacy, followed by PRGF, HA, CS, and placebo. CONCLUSION: PRP yielded improved outcomes when compared with PRGF, HA, CS, and placebo for the treatment of symptomatic knee OA at a minimum 6-month follow-up. Further investigations evaluating different IA and other nonoperative treatment options for patients with knee OA are warranted to better understand the true clinical efficacy and long-term outcomes of nonsurgical OA management.

Characterization of Chlamydomonas reinhardtii Core Histones by Top-Down Mass Spectrometry Reveals Unique Algae-Specific Variants and Post-Translational Modifications.

The unicellular microalga Chlamydomonas reinhardtii has played an instrumental role in the development of many new fields (bioproducts, biofuels, etc.) as well as the advancement of basic science (photosynthetic apparati, flagellar function, etc.). Chlamydomonas' versatility ultimately derives from the genes encoded in its genome and the way that the expression of these genes is regulated, which is largely influenced by a family of DNA binding proteins called histones. We characterize C. reinhardtii core histones, both variants and their post-translational modifications, by chromatographic separation, followed by top-down mass spectrometry (TDMS). Because TDMS has not been previously used to study Chlamydomonas proteins, we show rampant artifactual protein oxidation using established nuclei purification and histone extraction methods. After addressing oxidation, both histones H3 and H4 are found to each have a single polypeptide sequence that is minimally acetylated and methylated. Surprisingly, we uncover a novel monomethylation at lysine 79 on histone H4 present on all observed molecules. Histone H2B and H2A are found to have two and three variants, respectively, and both are minimally modified. This study provides an updated assessment of the core histone proteins in the green alga C. reinhardtii by top-down mass spectrometry and lays the foundation for further investigation of these essential proteins.