Dual Antibacterial Properties of Copper-Coated Nanotextured Stainless Steel.

Bacterial adhesion to stainless steel, an alloy commonly used in shared settings, numerous medical devices, and food and beverage sectors, can give rise to serious infections, ultimately leading to morbidity, mortality, and significant healthcare expenses. In this study, Cu-coated nanotextured stainless steel (nSS) fabrication have been demonstrated using electrochemical technique and its potential as an antibiotic-free biocidal surface against Gram-positive and negative bacteria. As nanotexture and Cu combine for dual methods of killing, this material should not contribute to drug-resistant bacteria as antibiotic use does. This approach involves applying a Cu coating on nanotextured stainless steel, resulting in an antibacterial activity within 30 min. Comprehensive characterization of the surface revealing that the Cu coating consists of metallic Cu and oxidized states (Cu2+ and Cu+), has been performed by this study. Cu-coated nSS induces a remarkable reduction of 97% in Gram-negative Escherichia coli and 99% Gram-positive Staphylococcus epidermidis bacteria. This material has potential to be used to create effective, scalable, and sustainable solutions to prevent bacterial infections caused by surface contamination without contributing to antibiotic resistance.

Synovial fluid monocyte-to-lymphocyte ratio in knee osteoarthritis patients predicts patient response to conservative treatment: a retrospective cohort study.

BACKGROUND: Biomarkers that predict the treatment response in patients with knee osteoarthritis are scarce. This study aimed to investigate the potential role of synovial fluid cell counts and their ratios as biomarkers of primary knee osteoarthritis. METHODS: This retrospective study investigated 96 consecutive knee osteoarthritis patients with knee effusion who underwent joint fluid aspiration analysis and received concomitant intra-articular corticosteroid injections and blood tests. The monocyte-to-lymphocyte ratio (MLR) and neutrophil-to-lymphocyte ratio (NLR) were calculated. After 6 months of treatment, patients were divided into two groups: the responder group showing symptom resolution, defined by a visual analog scale (VAS) score of ≤ 3, without additional treatment, and the non-responder group showing residual symptoms, defined by a VAS score of > 3 and requiring further intervention, such as additional medication, repeated injections, or surgical treatment. Unpaired t-tests and univariate and multivariate logistic regression analyses were conducted between the two groups to predict treatment response after conservative treatment. The predictive value was calculated using the area under the receiver operating characteristic curve, and the optimal cutoff value was determined. RESULTS: Synovial fluid MLR was significantly higher in the non-responder group compared to the responder group (1.86 ± 1.64 vs. 1.11 ± 1.37, respectively; p = 0.02). After accounting for confounding variables, odds ratio of non-responder due to increased MLR were 1.63 (95% confidence interval: 1.11-2.39). The optimal MLR cutoff value for predicting patient response to conservative treatment was 0.941. CONCLUSIONS: MLR may be a potential biomarker for predicting the response to conservative treatment in patients with primary knee osteoarthritis.

Controlled posterior condylar milling technique for unicompartmental knee arthroplasty minimises tibia resection during gap balancing: Short-term clinical results.

PURPOSE: The purpose of this study was to demonstrate the clinical utility of controlled posterior condylar milling (CPCM) in gap balancing while minimally resecting the tibia during fixed-bearing unicompartmental knee arthroplasty (UKA). METHODS: This study is a retrospective cohort study. Patients who underwent medial UKA for isolated medial compartment osteoarthritis with a minimum follow-up of 2 years were included. The patients were divided into two groups: the conventional group (n = 56) and the CPCM group (n = 66). In the CPCM group, the proximal tibia was resected at the level of the distal end of the subchondral bone. If the flexion gap was tighter than extension, the posterior condyle was additionally milled to adjust gap tightness. Standing knee X-ray and scanogram were used to evaluate alignment and tibia resection amount. Range of motion (ROM) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) scores were used to evaluate clinical outcomes. RESULTS: The CPCM group showed significantly smaller tibia resection (3.6 ± 1.9 mm) compared to the conventional group (5.2 ± 2.7 mm) (p < 0.001). Postoperative ROM (133.0 ± 8.3°, 135.2 ± 7.2°, n.s.) and WOMAC (19.3 ± 13.6, 23.6 ± 17.7, n.s.) were not significantly different between the two groups. Postoperative periprosthetic fractures occurred in two patients in conventional group, while the CPCM group had no periprosthetic fractures. CONCLUSION: The CPCM technique may be a simple and useful intraoperative technique that can achieve minimal tibia resection and promising clinical outcomes while easily adjusting gap tightness between flexion and extension during medial fixed-bearing UKA. LEVEL OF EVIDENCE: Level III.

Fixed-Bearing Unicompartmental Knee Arthroplasty in Tibia Vara Knees Results in Joint Surface Malalignment and Varus Joint Line Obliquity, but Does Not Affect Functional Outcomes at Greater Than 5 Years Follow-Up.

BACKGROUND: This study aimed to investigate the clinical outcomes of fixed-bearing medial unicompartmental knee arthroplasty (UKA) for tibia vara knees and the associated changes in joint space malalignment (JSM) and joint line obliquity (JLO). METHODS: We retrospectively analyzed a consecutive group of 100 patients who underwent fixed-bearing medial UKA with a preoperative medial proximal tibia angle (MPTA) ≥86° (n = 50) and MPTA <86° (n = 50) and who had a minimum 5-year follow-up. Radiological parameters, including the hip-knee-ankle angle, MPTA, and the postoperative JSM and JLO, were measured. Functional evaluation was performed using the range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index score. RESULTS: The MPTA <86° group showed significantly higher postoperative JLO (91.8 versus 90.4°, respectively; P = .002) and JSM (6.1 versus 4.2°, respectively; P = .026) compared to the MPTA ≥86° group. Functional outcomes, including range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index scores, were not significantly different between the 2 groups. CONCLUSIONS: Fixed-bearing medial UKA is a safe and effective surgical option for patients who have tibia vara knees, as an increase in JLO and JSM postoperatively does not have a clinically relevant impact, even after a minimum 5-year follow-up.

ISCOMs/MPLA-Adjuvanted SDAD Protein Nanoparticles Induce Improved Mucosal Immune Responses and Cross-Protection in Mice.

The epidemics caused by the influenza virus are a serious threat to public health and the economy. Adding appropriate adjuvants to improve immunogenicity and finding effective mucosal vaccines to combat respiratory infection at the portal of virus entry are important strategies to boost protection. In this study, a novel type of core/shell protein nanoparticle consisting of influenza nucleoprotein (NP) as the core and NA1-M2e or NA2-M2e fusion proteins as the coating antigens by SDAD hetero-bifunctional crosslinking is exploited. Immune-stimulating complexes (ISCOMs)/monophosphoryl lipid A (MPLA) adjuvants further boost the NP/NA-M2e SDAD protein nanoparticle-induced immune responses when administered intramuscularly. The ISCOMs/MPLA-adjuvanted protein nanoparticles are delivered through the intranasal route to validate the application as mucosal vaccines. ISCOMs/MPLA-adjuvanted nanoparticles induce significantly strengthened antigen-specific antibody responses, cytokine-secreting splenocytes in the systemic compartment, and higher levels of antigen-specific IgA and IgG in the local mucosa. Meanwhile, significantly expanded lung resident memory (RM) T and B cells (TRM /BRM ) and alveolar macrophages population are observed in ISCOMs/MPLA-adjuvanted nanoparticle-immunized mice with a 100% survival rate after homogeneous and heterogeneous H3N2 viral challenges. Taken together, ISCOMs/MPLA-adjuvanted protein nanoparticles could improve strong systemic and mucosal immune responses conferring protection in different immunization routes.

Chemical and biological conjugation strategies for the development of multivalent protein vaccine nanoparticles.

The development of subunit vaccine platforms has been of considerable interest due to their good safety profile and ability to be adapted to new antigens, compared to other vaccine typess. Nevertheless, subunit vaccines often lack sufficient immunogenicity to fully protect against infectious diseases. A wide variety of subunit vaccines have been developed to enhance antigen immunogenicity by increasing antigen multivalency, as well as stability and delivery properties, via presentation of antigens on protein nanoparticles. Increasing multivalency can be an effective approach to provide a potent humoral immune response by more strongly engaging and clustering B cell receptors (BCRs) to induce activation, as well as increased uptake by antigen presenting cells and their subsequent T cell activation. Proper orientation of antigen on protein nanoparticles is also considered a crucial factor for enhanced BCR engagement and subsequent immune responses. Therefore, various strategies have been reported to decorate highly repetitive surfaces of protein nanoparticle scaffolds with multiple copies of antigens, arrange antigens in proper orientation, or combinations thereof. In this review, we describe different chemical bioconjugation methods, approaches for genetic fusion of recombinant antigens, biological affinity tags, and enzymatic conjugation methods to effectively present antigens on the surface of protein nanoparticle vaccine scaffolds.

Retro Diels-Alder-triggered self-assembly of a polymerizable macrocyclic diacetylene.

A new triggered self-assembly method, which utilizes retro Diels-Alder (rDA)-promoted self-assembly of a macrocyclic diacetylene, was developed. The steric bulk present in a Diels-Alder (DA) adduct was released by a thermally promoted rDA reaction, resulting in the generation of a linear diacetylene that readily self-assembles to form a supramolecular polymer. The maleimide-containing blue-colored polydiacetylene, which was generated by UV irradiation, was utilized as a thiol specific colorimetric sensor.

Outcomes of Arthroscopic All-Inside Repair Are Improved Compared to Transtibial Pull-Out Repair of Medial Meniscus Posterior Root Tears.

PURPOSE: The purpose of the present study was to compare the clinical outcomes of patients who underwent an all-inside repair (with a bony trough) versus transtibial pull-out repair in medial meniscus posterior root tears (MMPRTs). METHODS: We retrospectively investigated consecutive patients who underwent MMPRT repairs in nonacute tears in age over 40 from November 2015 to June 2019. All patients were divided into a transtibial pull-out repair group and an all-inside repair group. Different surgical techniques were used during different time frames. All patients were followed-up for a minimum of 2 years. The data collected included the International Knee Documentation Committee (IKDC) Subjective, Lysholm, and Tegner activity scores. Magnetic resonance imaging (MRI) was performed at the 1-year follow-up to assess meniscus extrusion, signal intensity, and healing. RESULTS: The final cohort consisted of 28 patients in the all-inside repair group and 16 in the transtibial pull-out repair group. In the all-inside repair group, the IKDC Subjective, Lysholm, and Tegner scores improved significantly at the 2-year follow-up. In the transtibial pull-out repair group, the IKDC Subjective, Lysholm, and Tegner scores did not improve significantly at the 2-year follow-up. Postoperative extrusion ratio increased in both groups, and patient-reported outcomes at follow-up did not differ between the two groups The change in the extrusion ratio was significantly less in the all-inside repair group (P = .009), as was the postoperative meniscus signal (P = .011). Postoperative MRI revealed significantly better healing in the all-inside group (P = .041). CONCLUSION: All-inside repair improved the functional outcome scores. Radiologically, all-inside repair was better than transtibial pull-out repair. All-inside repair may be a viable MMPRT treatment option. LEVEL OF EVIDENCE: III, retrospective cohort study.

Reprint of: Outcomes of Arthroscopic All-Inside Repair Are Improved Compared to Transtibial Pull-Out Repair of Medial Meniscus Posterior Root Tears.

PURPOSE: The purpose of the present study was to compare the clinical outcomes of patients who underwent an all-inside repair (with a bony trough) versus transtibial pull-out repair in medial meniscus posterior root tears (MMPRTs). METHODS: We retrospectively investigated consecutive patients who underwent MMPRT repairs in nonacute tears in age over 40 from November 2015 to June 2019. All patients were divided into a transtibial pull-out repair group and an all-inside repair group. Different surgical techniques were used during different time frames. All patients were followed-up for a minimum of 2 years. The data collected included the International Knee Documentation Committee (IKDC) Subjective, Lysholm, and Tegner activity scores. Magnetic resonance imaging (MRI) was performed at the 1-year follow-up to assess meniscus extrusion, signal intensity, and healing. RESULTS: The final cohort consisted of 28 patients in the all-inside repair group and 16 in the transtibial pull-out repair group. In the all-inside repair group, the IKDC Subjective, Lysholm, and Tegner scores improved significantly at the 2-year follow-up. In the transtibial pull-out repair group, the IKDC Subjective, Lysholm, and Tegner scores did not improve significantly at the 2-year follow-up. Postoperative extrusion ratio increased in both groups, and patient-reported outcomes at follow-up did not differ between the two groups The change in the extrusion ratio was significantly less in the all-inside repair group (P = .009), as was the postoperative meniscus signal (P = .011). Postoperative MRI revealed significantly better healing in the all-inside group (P = .041). CONCLUSION: All-inside repair improved the functional outcome scores. Radiologically, all-inside repair was better than transtibial pull-out repair. All-inside repair may be a viable MMPRT treatment option. LEVEL OF EVIDENCE: III, retrospective cohort study.

Lateral Retinacular Release During Medial Unicompartmental Knee Arthroplasty in the Presence of Patello-Femoral Joint Arthritis Relieves Patello-Femoral Joint Pressure and Improves Associated Symptoms.

BACKGROUND: This study evaluated the effects of concomitant lateral patellar retinacular release (LPRR) during medial unicompartmental knee arthroplasty (UKA). METHODS: We retrospectively analyzed 100 patients who had patello-femoral joint (PFJ) arthritis who underwent medial UKA with (n = 50) and without (n = 50) LPRR who had ≥2 years follow-up. Radiological parameters associated with lateral retinacular tightness, including patellar tilt angle (PTA), lateral patello-femoral angle (LPFA), and congruence angle, were measured. Functional evaluation was performed using the Knee Society Pain Score, Knee Society Function Score (KSFS), Kujala Score, and the Western Ontario McMaster Universities Osteoarthritis Index score. Intraoperative patello-femoral pressure evaluation was performed on 10 knees to evaluate the pressure changes before and after LPRR. Mann-Whitney U-tests were used for statistical analyses. RESULTS: Demographic data did not differ between the LPRR(+) and LPRR(-) groups. A decrease in PTA and an increase in LPFA were observed in the LPRR(+) group compared to those in the LPRR(-) group (PTA; -0.54 versus -1.74, P = .002, LPFA; 0.51 versus 2.01, P = .010). The LPRR(+) group showed significantly better KSFS and Kujala scores than the LPRR(-) group (KSFS: 90 versus 80, P = .017; Kujala score: 86 versus 79, P = .009). Intraoperative patello-femoral pressure analysis showed a 22.6% reduction in the PFJ contact pressure and an 18.7% reduction in PFJ peak pressure after LPRR. (P = .0015, P < .0001, respectively) CONCLUSION: A LPRR during UKA may be a simple and useful adjunct procedure to relieve PFJ symptoms with concomitant PFJOA.

Regulator of RNase E activity modulates the pathogenicity of Salmonella Typhimurium.

RNase E-mediated RNA processing and degradation are involved in bacterial adaptation to environmental changes. The RraA regulatory protein, which is highly conserved in γ-proteobacteria, differentially modulates RNase E activity. Recent studies have revealed the association of Salmonella enterica serovar Typhimurium RNase E (STRNase E) with bacterial pathogenicity; however, the molecular mechanisms are unknown. Here, we show that the expression levels of STRraA, a protein regulator of STRNase E activity, affect S. Typhimurium pathogenicity. RNA-sequencing and RT-PCR analyses indicated positive effects of STRraA levels on the abundance of mRNA species from class II flagellar operons. Primer extension analysis further identified STRraA-regulated STRNase E cleavage in the 5' untranslated region of fliDST mRNA. The cleavage affected the stability of this polycistronic mRNA, suggesting that STRraA protects fliDST mRNA from STRNase E cleavage, leading to enhanced flagellar assembly. Accordingly, STRraA positively regulated flagellar assembly and motility. In addition, STrraA-deleted cells showed decreased invasion ability and cytotoxicity in infection of human cervical epithelial carcinoma cells and reduced mortality in a mouse infection model compared to wild-type cells. These results support an active role of STRraA in RNase E-mediated modulation of pathogenesis in S. Typhimurium.

Investigating the cognitive capacity constraints of an ICU care team using a systems engineering approach.

BACKGROUND: ICU operational conditions may contribute to cognitive overload and negatively impact on clinical decision making. We aimed to develop a quantitative model to investigate the association between the operational conditions and the quantity of medication orders as a measurable indicator of the multidisciplinary care team's cognitive capacity. METHODS: The temporal data of patients at one medical ICU (MICU) of Mayo Clinic in Rochester, MN between February 2016 to March 2018 was used. This dataset includes a total of 4822 unique patients admitted to the MICU and a total of 6240 MICU admissions. Guided by the Systems Engineering Initiative for Patient Safety model, quantifiable measures attainable from electronic medical records were identified and a conceptual framework of distributed cognition in ICU was developed. Univariate piecewise Poisson regression models were built to investigate the relationship between system-level workload indicators, including patient census and patient characteristics (severity of illness, new admission, and mortality risk) and the quantity of medication orders, as the output of the care team's decision making. RESULTS: Comparing the coefficients of different line segments obtained from the regression models using a generalized F-test, we identified that, when the ICU was more than 50% occupied (patient census > 18), the number of medication orders per patient per hour was significantly reduced (average = 0.74; standard deviation (SD) = 0.56 vs. average = 0.65; SD = 0.48; p < 0.001). The reduction was more pronounced (average = 0.81; SD = 0.59 vs. average = 0.63; SD = 0.47; p < 0.001), and the breakpoint shifted to a lower patient census (16 patients) when at a higher presence of severely-ill patients requiring invasive mechanical ventilation during their stay, which might be encountered in an ICU treating patients with COVID-19. CONCLUSIONS: Our model suggests that ICU operational factors, such as admission rates and patient severity of illness may impact the critical care team's cognitive function and result in changes in the production of medication orders. The results of this analysis heighten the importance of increasing situational awareness of the care team to detect and react to changing circumstances in the ICU that may contribute to cognitive overload.

The efficacy of intraarticular viscosupplementation after arthroscopic partial meniscectomy: a randomized controlled trial.

BACKGROUND: This study aimed to evaluate the efficacy of viscosupplementation after arthroscopic partial meniscectomy. METHOD: A randomized controlled trial of 47 patients who underwent arthroscopic partial meniscectomy was conducted between March 2020 and March 2021. Patients were randomized into two groups: a viscosupplementation group (n = 23) and a control group (n = 24). A single-dose intraarticular hyaluronic acid injection was used as viscosupplementation. The 100 mm visual analogue scale (VAS) for pain assessment was measured at baseline and at 1 day, 2 weeks, 6 weeks, and 3 months post-surgery. The International Knee Documentation Committee (IKDC), Tegner, Lysholm, and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores and range of motion (ROM) of the knee were measured at baseline, 2 weeks, 6 weeks, and 3 months. RESULTS: The 100 mm VAS score for pain was significantly lower in the viscosupplementation group at 2 weeks post-surgery (27.5 mm vs. 40.7 mm, P = 0.047). ROM was significantly greater in the viscosupplementation group than in the control group at 2 weeks (131.5° vs. 121.0°, P = 0.044) post-surgery. No significant differences were observed in the IKDC or in the Tegner, Lysholm, and WOMAC scores between the two groups. CONCLUSIONS: Viscosupplementation after arthroscopic partial meniscectomy significantly reduced pain at 2 weeks post-surgery and improved ROM of the knee at 2 weeks post-surgery. There might be some benefits in terms of pain and functional recovery of viscosupplementation after arthroscopic surgery. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. TRIAL REGISTRATION: This randomized controlled trial was registered at cris.nih.go.kr # KCT0004921 .

Health Effects Associated With Humidifier Disinfectant Use: A Systematic Review for Exploration.

BACKGROUND: It has been 10 years since the outbreak of lung disease caused by humidifier disinfectants in Korea, but the health effects have not yet been summarized. Therefore, this study aims to systematically examine the health effects of humidifier disinfectants that have been discovered so far. METHODS: All literature with humidifier disinfectants and their representative components as the main words were collected based on the web, including PubMed, Research Information Sharing Service, and government publication reports. A total of 902 studies were searched, of which 196 were selected. They were divided into four groups: published human studies (group 1), published animal and cytotoxicology studies (group 2), technical reports (group 3), and gray literature (group 4). RESULTS: Out of the 196 studies, 97 (49.5%) were published in peer-reviewed journals as original research. Group 1 consisted of 49 articles (50.5%), while group 2 consisted of 48 articles (49.5%). Overall, respiratory diseases such as humidifier disinfectant associated lung injury, interstitial lung disease, and asthma have a clear correlation, but other effects such as liver, heart, thymus, thyroid, fetal growth, metabolic abnormalities, and eyes are observed in toxicological experimental studies, but have not yet been identified in epidemiologic studies. CONCLUSION: The current level of evidence does not completely rule out the effects of humidifier disinfectants on extrapulmonary disease. Based on the toxicological evidence so far, it is required to monitor the population of humidifier disinfectant exposure continuously to see if similar damage occurs.

Influences of pregravid liver enzyme levels on the development of gestational diabetes mellitus.

BACKGROUND & AIMS: Elevated liver enzymes are associated with later development of type 2 diabetes mellitus. The objective of this study was to assess the association between prepregnancy liver enzyme levels and subsequent risk of gestational diabetes mellitus. METHODS: Data from a total of 236,109 women who participated in the National Health Screening Examination between 2011 and 2015 was analysed. Multivariate logistic regression analyses were performed to estimate the risk of developing gestational diabetes mellitus in relation to pregravid liver enzyme levels. Subgroup analyses were performed according to pregravid obesity and metabolic syndrome (MetS). RESULTS: Approximately 5.7% and 1.1% of women developed gestational diabetes mellitus with and without insulin treatment requirement respectively. Pregravid gamma-glutamyl transferase and alanine aminotransferase levels with greater than or equal to the 4th quartile were associated with significantly increased risks of gestational diabetes mellitus requiring insulin treatment in women with obesity and with MetS, (odds ratios [ORs] with 6.228 and 9.505, respectively, P < .001 for both). In women without obesity and without MetS, the risks of gestational diabetes mellitus requiring insulin treatment were also significant (ORs with 2.837 and 3.029, respectively, P < .001 for both). The elevated pregravid liver enzymes were associated with gestational diabetes mellitus without insulin treatment requirement, but minimally. CONCLUSIONS/INTERPRETATION: The elevated pregravid liver enzyme levels were significantly associated with the subsequent risk of gestational diabetes mellitus, especially gestational diabetes mellitus requiring insulin treatment, not only in women with obesity or MetS, but also in women without obesity or MetS.

The Causal Relationship Between Portal Usage and Self-Efficacious Health Information-Seeking Behaviors: Secondary Analysis of the Health Information National Trends Survey Data.

BACKGROUND: Patient portals have drawn much attention, as they are considered an important tool for health providers in facilitating patient engagement. However, little is known about whether the intensive use of patient portals contributes to improved management of patients' health in terms of their confidence in acquiring health information and exercising self-care. There is a lack of randomized trials with these outcomes measured both pre- and postadoption of patient portals. OBJECTIVE: The aim of this study was to examine the causal relationship between the usage of patient portals and patients' self-efficacy toward obtaining health information and performing self-care. METHODS: This study was a secondary data analysis that used data from a US national survey, the National Cancer Institute's Health Information National Trends Survey 5 Cycle 1. Patient portal usage frequency was used to define the treatment. Survey items measuring self-efficacy on a Likert-type scale were selected as the main outcomes, including patients' confidence in obtaining health information and performing self-care. To establish causality using survey data, we adopted the instrumental variables method. To determine the direction of the causal relationship in the presence of high-dimensional confounders, we further proposed a novel testing framework that employs conditional independence tests in a directed acyclic graph. The average causal effect was measured using the two-stage least squares regression method. RESULTS: We showed that frequently using patient portals improves patients' confidence in obtaining health information. The estimand of the weighted average causal effect was 0.14 (95% CI 0.06-0.23; P<.001). This means that when increasing the portal usage intensity, for instance, from 1-2 times to 3-5 times per year, the expected average increase in confidence level measured on a Likert-type scale would be 0.14. However, we could not conclusively determine the causal effect between patient portal usage and patients' confidence in exercising self-care. CONCLUSIONS: The results support the use of patient portals and encourage better support and education to patients. The proposed statistical method can be used to exploit the potential of national survey data for causal inference studies.

The amount of displacement can determine non-operative treatment in posterior cruciate ligament avulsion fracture.

PURPOSE: It is generally agreed that surgical treatment is warranted for acute posterior cruciate ligament (PCL) avulsion fracture with displacement. However, the amount of displacement that warrants surgical treatment has not been defined. The purpose of this study was to determine the optimal cut-off value for displacement of posterior cruciate ligament avulsion fracture in determining non-operative treatment and to compare the results of non-operative treatment in acute isolated PCL avulsion fractures with non-operative treatment of acute PCL injury. METHODS: Between 2007 and 2017, 30 consecutive patients with acute isolated PCL avulsion fractures and 70 consecutive patients with acute isolated PCL injuries, all of whom underwent non-operative treatment (cast immobilization with > 2 years of follow-up) were retrospectively analyzed. Clinical scores including the International Knee Documentation Committee subjective score, Lysholm score, and Tegner activity score, as well as side-to-side differences on stress radiographs, were compared between the PCL avulsion fracture and PCL injury groups at the final follow-up. The failure rates of non-operative treatment were also compared. The predictive value of the amount of fracture displacement for successful non-operative treatment was calculated using area under the receiver operating characteristic curve (AUROC). The optimal cut-off of the amount of fracture displacement to determine non-operative treatment was based on the maximal sum of sensitivity and specificity. RESULTS: The two groups exhibited comparable clinical scores and mean side-to-side differences on stress radiographs. There were 5 (16.6%) failures of non-operative treatment in the PCL avulsion fracture group and 19 (27.1%) failures in the PCL injury group. (n.s) There was a significant positive correlation between the amount of initial avulsion fracture displacement and side-to-side difference in posterior stress radiographs at final follow up (P < 0.001). The optimal cut-off value for the amount of fracture displacement in PCL avulsion fracture to predict failure of non-operative treatment was 6.7 mm (AUROC = 1.0). CONCLUSION: The outcomes of non-operative treatment of acute isolated PCL avulsion fractures were comparable to those of patients with acute isolated PCL injuries. Acute PCL avulsion injuries with displacement of less than 6.7 mm should be considered for non-operative treatment. LEVEL OF EVIDENCE: IV.

Comparable clinical and radiological outcomes between anatomical and high femoral tunnels in posterior cruciate ligament reconstruction.

PURPOSE: To compare clinical and radiological outcomes and failure rates between anatomical and high femoral tunnels in remnant-preserving single-bundle posterior cruciate ligament (PCL) reconstruction. METHODS: 63 patients who underwent remnant-preserving single-bundle PCL reconstruction between 2011 and 2018 with a minimum 2-year follow-up were retrospectively reviewed. Patients were divided into two groups according to the femoral tunnel position: group A (33 patients with anatomical femoral tunnel) and group H (30 patients with high femoral tunnels). The femoral tunnel was positioned at the center (group A) or upper margin (group H) of the remnant anterolateral bundle. The position of the femoral tunnel was evaluated using the grid method on three-dimensional computed tomography. Clinical and radiological outcomes and failure rates were compared between the groups at the 2-year follow-up. RESULTS: The position of the femoral tunnel was significantly high in group H than in group A (87.4% ± 4.2% versus 76.1% ± 3.7%, p < 0.001). Clinical outcomes were not significantly different between the two groups in terms of the clinical scores (International Knee Documentation Committee subjective, Lysholm, and Tegner activity scores), range of motion, and posterior drawer test. Radiological outcomes also showed no intergroup differences in the side-to-side differences of posterior tibial translation and osteoarthritis progression. Side-to-side difference on the Telos stress radiograph was 5.2 ± 2.9 mm in group A and 5.2 ± 2.7 mm in group H (n.s.). There were four failures in group A (12.1%) and one in group H (3.3%). The differences between the groups were not statistically significant. CONCLUSION: The clinical and radiological outcomes and failure rates of the high femoral tunnels were comparable with those of the anatomical femoral tunnels at the 2-year follow-up after remnant-preserving single-bundle PCL reconstruction. The findings of this study suggest that high femoral tunnels can be considered an alternative in remnant-preserving single-bundle PCL reconstruction. LEVEL OF EVIDENCE: III.

Optimal dose of topical tranexamic acid considering efficacy and safety in total knee arthroplasty: a randomized controlled study.

PURPOSE: This study aimed to evaluate the optimal dosage of topical tranexamic acid (TXA) considering the efficacy and safety for controlling bleeding after total knee arthroplasty (TKA). METHODS: This prospective randomized double-blinded placebo-controlled comparative study included 325 patients scheduled to undergo TKA, who were randomly assigned to five groups based on the topical TXA injection (n = 65 per group): control; group 1, 0.5 g TXA; group 2, 1.0 g TXA; group 3, 2.0 g TXA; and group 4, 3.0 g TXA. The primary outcome was decrease in postoperative hemoglobin levels. The secondary outcomes were blood loss calculated using Good's method, drainage volume, frequency of transfusion, and range of motion (ROM). Plasma TXA levels and complications were also evaluated. RESULTS: Significant differences were noted in the decrease in hemoglobin levels between the control group and groups 2 (p = 0.0027), 3 (p = 0.005), and 4 (p = 0.001). No significant differences were shown among the experimental groups. Significant differences in total blood loss and frequency of transfusion were noted between the control group and groups 2 (p = 0.004, 0.002, respectively), 3 (p = 0.007, 0.001, respectively), and 4 (p = 0.001, 0.009, respectively) without showing significant differences among the experimental groups. With respect to drainage volume, no significant differences were observed among the groups. The serum TXA levels increased proportionally with the applied dose of topical TXA immediately and at 3 and 6 h postoperatively. Symptomatic deep vein thrombosis or pulmonary embolism was not observed in any group. Other complications related to TXA administration were not detected. CONCLUSION: Topical application of 1.0 g or more of TXA shows significant bleeding control without a dose-response relationship. Blood TXA levels increase with the TXA dose following topical TXA application. Therefore, to prevent overdosing and reduce potential complications with ensuring the effectiveness, 1.0 g of TXA is recommended as a topical application. LEVEL OF EVIDENCE: I.

Elastic pneumatic tourniquet cuff can reduce postoperative thigh pain after total knee arthroplasty: a prospective randomized trial.

BACKGROUND: Tourniquet use is associated with complications such as thigh pain, skin problems, and deep vein thrombosis (DVT). This prospective study aimed to evaluate the efficacy and safety of the pneumatic tourniquet system using an elastic cuff and limb occlusion pressure (LOP) in total knee arthroplasty (TKA). The hypothesis of this study was that an elastic cuff tourniquet would result in less postoperative thigh pain after TKA. METHODS: This prospective randomized controlled trial involved a total of 98 patients who underwent primary TKA. They were randomized into two groups: tourniquet system using an elastic cuff and LOP group (Group E) and tourniquet system using a conventional-cuff and LOP group (Group C). Outcomes including postoperative thigh pain assessed using a visual analog scale (VAS), serum muscle enzymes, recommended tourniquet pressure (RTP), bloodlessness of surgical field, surgical time, incidence of DVT, and the frequency of rescue analgesic use after surgery, were compared between groups. RESULTS: Patients in Group E experienced significantly less thigh pain compared to those in Group C on postoperative day 4 (P = 0.01) and day 7 (P = 0.04). The difference between RTP and systolic blood pressure was significantly lower in Group E (P = 0.045). One case of thigh DVT was found in Group E, while no such cases were found in Group C. One and two cases of poor bloodless surgical fields were observed in Group E and Group C, respectively. There was no significant difference in surgical time, levels of serum muscle enzymes, and the frequency of rescue analgesic use between the two groups. CONCLUSIONS: The pneumatic tourniquet system using an elastic cuff and LOP reduced early postoperative thigh pain more effectively than did the tourniquet system using a conventional cuff and LOP. TRIAL REGISTRATION: # KCT0003149 . Registered August 17, 2018 - Retrospectively registered.