Risks Following Total Knee Arthroplasty in Patients Who Have Antiphospholipid Syndrome.

BACKGROUND: Antiphospholipid syndrome (APS) is recognized as a thrombophilic autoimmune condition characterized by a tendency to develop venous thromboembolism. Total knee arthroplasty (TKA) is a prevalent procedure in patients who have advanced knee arthritis. Notably, TKA is unequivocally considered a thrombotic risk factor. However, outcomes of APS patients after TKA are still poorly documented in literature. The purpose of this study was to evaluate APS as a potential risk factor for complications after TKA. METHODS: Using the PearlDiver Mariner database from 2010 to 2022, APS patients undergoing primary TKA were identified and compared to 10:1 matched control based on age, sex, and relevant comorbidities. A total of 7,478 patients undergoing primary TKA were analyzed, of which 683 had APS. Multivariable logistic regression analyses were done for medical complications up to 90 days and surgical complications including revision up to 2 years. Ninety-day emergency department visit and inpatient readmission were also documented. RESULTS: Within 90 days after TKA, patients who have APS exhibited higher rates of cerebrovascular accident (adjusted odds ratio 2.04, 95% confidence interval 1.12 to 3.57; P = .014) and deep vein thrombosis (adjusted odds ratio 2.87, 95% confidence interval 1.99 to 4.06; P < .001) as compared to matched controls. No difference in surgical or nonthrombotic medical complications was observed between 2 cohorts. CONCLUSIONS: There were significantly higher rates of stroke and deep vein thrombosis in APS patients. Our study did not find statistical differences in other surgical complications or readmissions between the 2 groups. Orthopaedic surgeons should consider appropriate prophylaxis of thrombosis in this patient population undergoing TKA perioperatively.

Hydrogen Peroxide Generation of Copper/Ascorbate Formulations on Cotton: Effect on Antibacterial and Fibroblast Activity for Wound Healing Application.

Greige cotton (unbleached cotton) is an intact plant fiber that retains much of the outer cotton fiber layers. These layers contain pectin, peroxidases, and trace metals that are associated with hydrogen peroxide (H2O2) generation during cotton fiber development. When greige cotton is subjected to a nonwoven hydroentanglement process, components of the outer cotton fiber layers are retained. When hydrated, this fabric can generate H2O2 (5⁻50 micromolar). This range has been characterized as inducing accelerated wound healing associated with enhanced cell signaling and the proliferation of cells vital to wound restoration. On the other hand, H2O2 levels above 50 micromolar have been associated with bacteriostatic activity. Here, we report the preparation and hydrogen peroxide activity of copper/ascorbate formulations, both as adsorbed and in situ synthesized analogs on cotton. The cooper/ascorbate-cotton formulations were designed with the goal of modulating hydrogen peroxide levels within functional ranges beneficial to wound healing. The cotton/copper formulation analogs were prepared on nonwoven unbleached cotton and characterized with cotton impregnation titers of 3⁻14 mg copper per gram of cotton. The copper/ascorbate cotton analog formulations were characterized spectroscopically, and the copper titer was quantified with ICP analysis and probed for peroxide production through assessment with Amplex Red. All analogs demonstrated antibacterial activity. Notably, the treatment of unbleached cotton with low levels of ascorbate (~2 mg/g cotton) resulted in a 99 percent reduction in Klebsiella pneumoniae and Staphylococcus aureus. In situ synthesized copper/ascorbate nanoparticles retained activity and did not leach out upon prolonged suspension in an aqueous environment. An assessment of H2O2 effects on fibroblast proliferation are discussed in light of the copper/cotton analogs and wound healing.

Designing cellulosic and nanocellulosic sensors for interface with a protease sequestrant wound-dressing prototype: Implications of material selection for dressing and protease sensor design.

Interfacing nanocellulosic-based biosensors with chronic wound dressings for protease point of care diagnostics combines functional material properties of high specific surface area, appropriate surface charge, and hydrophilicity with biocompatibility to the wound environment. Combining a protease sensor with a dressing is consistent with the concept of an intelligent dressing, which has been a goal of wound-dressing design for more than a quarter century. We present here biosensors with a nanocellulosic transducer surface (nanocrystals, nanocellulose composites, and nanocellulosic aerogels) immobilized with a fluorescent elastase tripeptide or tetrapeptide biomolecule, which has selectivity and affinity for human neutrophil elastase present in chronic wound fluid. The specific surface area of the materials correlates with a greater loading of the elastase peptide substrate. Nitrogen adsorption and mercury intrusion studies revealed gas permeable systems with different porosities (28-98%) and pore sizes (2-50 nm, 210 µm) respectively, which influence water vapor transmission rates. A correlation between zeta potential values and the degree of protease sequestration imply that the greater the negative surface charge of the nanomaterials, the greater the sequestration of positively charged neutrophil proteases. The biosensors gave detection sensitivities of 0.015-0.13 units/ml, which are at detectable human neutrophil elastase levels present in chronic wound fluid. Thus, the physical and interactive biochemical properties of the nano-based biosensors are suitable for interfacing with protease sequestrant prototype wound dressings. A discussion of the relevance of protease sensors and cellulose nanomaterials to current chronic wound dressing design and technology is included.