Dual Antibiotic Therapy with Vancomycin and Cefazolin for Surgical Prophylaxis in Total Knee Arthroplasty

Background: Perioperative administration of intravenous antibiotics is a routine part of total knee arthroplasty.  Antibiotic selection is a matter of controversy, and the potential risks and benefits associated with each antibiotic selection need to be considered.  The objective of this study is to examine the effects of routine dual antibiotic prophylaxis with both cefazolin and vancomycin on infection and renal failure after primary total knee arthroplasty (TKA) compared with cefazolin alone. Methods: We performed a retrospective review of primary TKA patients for two years before and two years after routine dual antibiotic prophylaxis was implemented at our institution. 1502 patients were included (567 cefazolin-only and 935 dual prophylaxis).   Results: 2 patients (0.4%) in the cefazolin-only group had a deep surgical site infection, compared with 13 patients (1.4%) in the dual prophylaxis group (p=0.06). 46 patients (8.1%) in the cefazolin-only group had postoperative renal failure, compared with 36 patients (3.9%) in the dual prophylaxis group (p=0.0006). Discussion and Conclusion: Our results did not support the routine use of vancomycin in primary total joint arthroplasty to decrease periprosthetic joint infection. However, we also did not see any clear harm due to renal failure in the routine use of dual antibiotic prophylaxis

Retrieval analysis of a failed synthetic mesh extensor mechanism reconstruction after total knee arthroplasty

Extensor mechanism disruption after total knee arthroplasty is a relatively rare but potentially devastating complication. One technique to address this problem involves reconstruction with synthetic mesh. Although there are reports of successful clinical outcomes using this technique, we are not aware of any histological analyses of removed mesh grafts. This case report of a failed mesh reconstruction includes a retrieval analysis demonstrating robust host soft-tissue incorporation into the mesh graft and supports the rationale for continued use of this off-label technique. This case report also highlights the need for careful operative technique when performing these procedures to increase the chance of a successful outcome. Keywords: Extensor mechanism disruption, Total knee arthroplasty, Synthetic mes

Total Joint Arthroplasty Patient Demographics Before and After Coronavirus Disease 2019 Elective Surgery Restrictions

Background: In 2020, the coronavirus disease 2019 (COVID-19) pandemic caused the cessation of nonemergent total joint arthroplasty (TJA, referring to total hip and total knee arthroplasty) operations between mid-March and April 2020. The purpose of this study is to analyze the effects and potential disparities in access to care due to the COVID-19 restrictions. Methods: A database was used to examine the demographics of patients undergoing TJA from May to December 2019 (pre-COVID-19) and from May to December 2020 (post-COVID-19 restrictions). Categorical covariates were summarized by reporting counts and percentages and compared using Fisher exact tests. Continuous covariates were summarized by reporting means and standard deviations. Two-sample t-tests were used for continuous covariates. The equality of TJA counts by year was tested using a test of proportions. Results: There were more TJA procedures performed during the post-COVID-19 period in 2020 than in the pre-COVID-19 period (1151 vs 882, P < .001). There was an increase in the relative percentage of THAs vs TKAs performed in 2020 vs 2019 (26.9% vs 18.8%, P < .001) and an increase in patients with Medicaid with a decrease in private insurance (P = .043). The average length of stay was shorter in 2020 with a greater percentage of TJAs performed outpatient (P < .001). There were no differences in patient sex, race, body mass index, smoking status, or age between the 2 periods. Conclusions: A relative increase in THA procedures, an increase in patients with Medicaid and decrease in private insurance, and a a decreased length of stay were seen after COVID-19 restrictions. These trends may reflect pandemic-related changes in insurance status as well as the growing shift to same-day discharge

Regulatory T cells in skin are uniquely poised to suppress profibrotic immune responses

At the center of fibrosing diseases is the aberrant activation of tissue fibroblasts. The cellular and molecular mechanisms of how the immune system augments fibroblast activation have been described; however, little is known about how the immune system controls fibroblast function in tissues. Here, we identify regulatory T cells (Tregs) as important regulators of fibroblast activation in skin. Bulk cell and single-cell analysis of Tregs in murine skin and lungs revealed that Tregs in skin are transcriptionally distinct and skewed toward T helper 2 (TH2) differentiation. When compared with Tregs in lung, skin Tregs preferentially expressed high levels of GATA3, the master TH2 transcription factor. Genes regulated by GATA3 were highly enriched in skin "TH2 Treg" subsets. In functional experiments, Treg depletion resulted in a preferential increase in TH2 cytokine production in skin. Both acute depletion and chronic reduction of Tregs resulted in spontaneous skin fibroblast activation, profibrotic gene expression, and dermal fibrosis, all of which were exacerbated in a bleomycin-induced murine model of skin sclerosis. Lineage-specific deletion of Gata3 in Tregs resulted in an exacerbation of TH2 cytokine secretion that was preferential to skin, resulting in enhanced fibroblast activation and dermal fibrosis. Together, we demonstrate that Tregs play a critical role in regulating fibroblast activation in skin and do so by expressing a unique tissue-restricted transcriptional program that is mediated, at least in part, by GATA3

Incidence of Rapidly Progressive Osteoarthritis Following Intra-articular Hip Corticosteroid Injection: A Systematic Review and Meta-Analysis

Background: The American Academy of Orthopedic Surgery recommends intra-articular corticosteroid injections (CSIs) for managing hip osteoarthritis (OA) based on short-term, prospective studies. Recent retrospective studies have raised concerns that CSIs may lead to rapidly progressive OA (RPOA). We sought to systematically review the literature of CSIs for hip OA to estimate the incidence of RPOA. Methods: MEDLINE, Embase, and Cochrane Library were searched to identify original research of hip OA patients receiving CSIs. Overall, 27 articles involving 5831 patients published from 1988 to 2022 were included. Study design, patient characteristics, CSI details, follow-up, and cases of RPOA were recorded. Studies were classified by their ability to detect RPOA based on follow-up. Random effects meta-analysis was used to calculate the incidence of RPOA for studies able to detect RPOA. Results: The meta-analytic estimate of RPOA incidence was 6% (95% confidence interval, 3%-9%) based on 10 articles classified as able to detect RPOA. RPOA definitions varied from progression of OA within 6 months to the presence of destructive changes. These studies were subject to bias from excluding patients with missing post-CSI radiographs. The remaining 17 articles were classified as unable to detect RPOA, including all of the studies cited in the American Academy of Orthopedic Surgery recommendation. Conclusions: The incidence of RPOA after CSIs remains unknown due to variation in definitions and follow-up. While RPOA following CSIs may be 6%, many cases are not severe, and this may reflect selection bias. Further research is needed to understand whether clinically significant RPOA is incident enough to limit CSI use

Clinicopathologic predictors of renal outcomes in light chain cast nephropathy: a multicenter retrospective study

Light chain cast nephropathy (LCCN) in multiple myeloma often leads to severe and poorly reversible acute kidney injury. Severe renal impairment influences the allocation of chemotherapy and its tolerability; it also affects patient survival. Whether renal biopsy findings add to the clinical assessment in predicting renal and patient outcomes in LCCN is uncertain. We retrospectively reviewed clinical presentation, chemotherapy regimens, hematologic response, and renal and patient outcomes in 178 patients with biopsy-proven LCCN from 10 centers in Europe and North America. A detailed pathology review, including assessment of the extent of cast formation, was performed to study correlations with initial presentation and outcomes. Patients presented with a mean estimated glomerular filtration rate (eGFR) of 13 +/- 11 mL/min/1.73 m(2), and 82% had stage 3 acute kidney injury. The mean number of casts was 3.2/mm(2) in the cortex. Tubulointerstitial lesions were frequent: acute tubular injury (94%), tubulitis (82%), tubular rupture (62%), giant cell reaction (60%), and cortical and medullary inflammation (95% and 75%, respectively). Medullary inflammation, giant cell reaction, and the extent of cast formation correlated with eGFR value at LCCN diagnosis. During a median follow-up of 22 months, mean eGFR increased to 43 +/- 30 mL/min/1.73 m(2). Age, beta(2)-microglobulin, best hematologic response, number of cortical casts per squaremillimeter, and degree of interstitial fibrosis/tubular atrophy (IFTA) were independently associated with a higher eGFR during follow-up. This eGFR value correlated with overall survival, independently of the hematologic response. This study shows that extent of cast formation and IFTA in LCCN predicts the quality of renal response, which, in turn, is associated with overall survival