Posterior Tibial Slope Measurements of the Medial and Lateral Plateaus Vary Widely Between Magnetic Resonance Imaging and Computed Tomography.

Purpose: To compare posterior tibial slope (PTS) measurements of the medial tibial plateau (MTP) and lateral tibial plateau (LTP) on magnetic resonance imaging (MRI) versus computed tomography (CT) to determine the agreement of measurement between imaging modalities.

Methods: Patients aged 15 to 65 years with concurrent MRI and CT imaging were initially included. Knees with significant arthrosis (Kellgren-Lawrence grade >2), proximal tibia fracture, or artifact obscuring visualization were excluded.

Outcomes of isolated medial tibial plateau fractures by fracture morphology.

Purpose: To identify a cohort of isolated medial tibial plateau fractures treated with surgical fixation and to categorize them by Moore and Wahlquist classifications in order to determine the rate of complications with each fracture morphology and the predictive value of each classification system. We hypothesized there would be high rates of neurovascular injury, compartment syndrome, and complications overall with a higher incidence of neurovascular injury in Moore type III rim avulsion fractures and Wahlquist type C fractures that enter the plateau lateral to the tibial spines.

Methods: Patients who presented to six Level I trauma centers between 2010 and 2021 who underwent surgical fixation for isolated medial tibial plateau fractures were retrospectively reviewed.

Early Complication Rates Are Equivalent Between Isolated Cartilage Restoration and Concomitant Cartilage Restoration and Osteotomy of the Knee.

Objective: Realignment osteotomy performed concomitantly with cartilage restoration typically requires early restricted weightbearing and can add significant morbidity, potentially leading to an increased risk of early perioperative complications. The purpose of this study was to compare the 30-day complication rates after isolated cartilage restoration (ICR) versus concomitant cartilage restoration and osteotomy (CRO) using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

Design: NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing ICR (autologous chondrocyte implantation, osteochondral autograft transfer, or osteochondral allograft transplantation) and CRO (with concomitant high tibial osteotomy, distal femoral osteotomy, and/or tibial tubercle osteotomy).

Outcomes of Arthroscopic Lysis of Adhesions for the Treatment of Postoperative Knee Arthrofibrosis: A Systematic Review.

Background: Postoperative knee arthrofibrosis is a common and potentially detrimental complication affecting knee function and gait. Several cohort studies have reported good outcomes after arthroscopic lysis of adhesions (LOA) with manipulation under anesthesia (MUA).

Purpose: To review the literature assessing the efficacy and complications of arthroscopic LOA and MUA for postoperative arthrofibrosis of the knee and evaluate whether any relevant subgroups are associated with different clinical presentation and outcomes.

Osteochondral Allografts in Knee Surgery: Narrative Review of Evidence to Date.

Knee articular cartilage defects can result in significant pain and loss of function in active patients. Osteochondral allograft (OCA) transplantation offers a single-stage solution to address large chondral and osteochondral defects by resurfacing focal cartilage defects with mature hyaline cartilage. To date, OCA transplantation of the knee has demonstrated excellent clinical outcomes and long-term survivorship.

The dual degree orthopedic surgeon: A survey of the trends, motivations, and perceived value of the master of business administration degree.

Orthopedic surgeons are obtaining Master of Business Administration (MBA) degrees at an increasing rate. This study aimed to identify the motivations, trends, and perceived value of the MBA degree for these dual degree surgeons. A total of 157 orthopedic surgeons with both MD and MBA degrees were surveyed with a 19-item questionnaire to identify surgeons' motivations for obtaining an MBA degree and the perceived value of the degree.

Platelet-Rich Plasma Is an Equal Alternative to Surgery in the Treatment of Type 1 Medial Epicondylitis.

Background: Medial epicondylitis (ME) is characterized as an overuse injury resulting in pathological alterations of the common flexor tendon at the elbow. Platelet-rich plasma (PRP) has recently become of interest in the treatment of musculoskeletal conditions as an alternative to operative management.

Purpose: To compare the outcomes of recalcitrant type 1 ME after treatment with either PRP or surgery.

Double-Row Repair for Recalcitrant Medial Epicondylitis.

Background: Various techniques have been described for surgical treatment of recalcitrant medial epicondylitis (ME). No single technique has yet to be proven the most effective.

Purpose: To evaluate the clinical outcomes of a double-row repair for ME.

A perpetual switching system in pulmonary capillaries.

Of the 300 billion capillaries in the human lung, a small fraction meet normal oxygen requirements at rest, with the remainder forming a large reserve. The maximum oxygen demands of the acute stress response require that the reserve capillaries are rapidly recruited. To remain primed for emergencies, the normal cardiac output must be parceled throughout the capillary bed to maintain low opening pressures.

Occlusion Outside the Norm: A Unique Case of the Pulseless, Well-Perfused Hand Following Closed Humeral Shaft Fracture.

Transient arterial injury is a common complication encountered in the management of pediatric supracondylar humerus fractures, often presenting as a pulseless hand that appears well perfused, also known as the "pink, pulseless hand." Arterial injuries in pediatric humeral shaft fractures, on the other hand, are exceedingly rare, especially in closed fractures. The authors report a rare case of a humeral shaft fracture presenting as a pink, pulseless hand.

Synchronized electromechanical integration recording of cardiomyocytes.

Cardiac issues are always one of major health problems that attract wide attention by the public. It is urgent to explore a preclinical strategy to efficiently prevent the life-threatening arrhythmias by precisely assessing the cardiac excitation-contraction behavior. Conventional label-free asynchronous strategies are difficult to synchronously record and precisely match the excitation and contraction signals in vitro, while label-based strategies generally present pharmacological adverse effects and phototoxicity that significantly interfere the natural excitation and contraction signals.

Frequency-Dependent Multi-Well Cardiotoxicity Screening Enabled by Optogenetic Stimulation.

Side effects on cardiac ion channels causing lethal arrhythmias are one major reason for drug withdrawals from the market. Field potential (FP) recording from cardiomyocytes, is a well-suited tool to assess such cardiotoxic effects of drug candidates in preclinical drug development, but it is currently limited to the spontaneous beating of the cardiomyocytes and manual analysis. Herein, we present a novel optogenetic cardiotoxicity screening system suited for the parallel automated frequency-dependent analysis of drug effects on FP recorded from human-induced pluripotent stem cell-derived cardiomyocytes.

An impedance-based approach using human iPSC-derived cardiomyocytes significantly improves in vitro prediction of in vivo cardiotox liabilities.

Current in vitro approaches to cardiac safety testing typically focus on mechanistic ion channel testing to predict in vivo proarrhythmic potential. Outside of the Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative, structural and functional cardiotoxicity related to chronic dosing effects are of great concern as these effects can impact compound attrition. Development and implementation of an in vitro cardiotoxicity screening platform that effectively identifies these liabilities early in the discovery process should reduce costly attrition and decrease preclinical development time.

[Progressive multifocal leukoencephalopathy following azathioprine and steroid treatment of pulmonary sarcoid disease].

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system following reactivation of the John-Cunningham-Virus (JVC) in an immunocompromised host. This rare condition is characterized by rapid progressing neurologic symptoms often leading to death. In the following, we report on a rapid evolving deterioration of mental status due to PML in an 53-year-old man during treatment of pulmonary sarcoid disease using azathioprine and steroids.

Impaired compensation to femoral artery ligation in diet-induced obese mice is primarily mediated via suppression of collateral growth by Nox2 and p47phox.

The present study was undertaken to establish the role of NADPH oxidase (Nox) in impaired vascular compensation to arterial occlusion that occurs in the presence of risk factors associated with oxidative stress. Diet-induced obese (DIO) mice characterized by multiple comorbidities including diabetes and hyperlipidemia were used as a preclinical model. Arterial occlusion was induced by distal femoral artery ligation in lean and DIO mice.

Nitric oxide and the cardiovascular system.

Nitric oxide (NO) generated by endothelial cells to relax vascular smooth muscle is one of the most intensely studied molecules in the past 25 years. Much of what is known about NO regulation of NO is based on blockade of its generation and analysis of changes in vascular regulation. This approach has been useful to demonstrate the importance of NO in large scale forms of regulation but provides less information on the nuances of NO regulation.

Minimized cell usage for stem cell-derived and primary cells on an automated patch clamp system.

Introduction: Chip-based automated patch clamp systems are widely used in drug development and safety pharmacology, allowing for high quality, high throughput screening at standardized experimental conditions. The merits of automation generally come at the cost of large amounts of cells needed, since cells are not targeted individually, but randomly positioned onto the chip aperture from cells in suspension. While cell usage is of little concern when using standard cell lines such as CHO or HEK cells, it becomes a crucial constraint with cells of limited availability, such as primary or otherwise rare and expensive cells, like induced pluripotent stem (IPS) cell-derived cardiomyocytes or neurons.

Differentiation and selection of hepatocyte precursors in suspension spheroid culture of transgenic murine embryonic stem cells.

Embryonic stem cell-derived hepatocyte precursor cells represent a promising model for clinical transplantations to diseased livers, as well as for establishment of in vitro systems for drug metabolism and toxicology investigations. This study aimed to establish an in vitro culture system for scalable generation of hepatic progenitor cells. We used stable transgenic clones of murine embryonic stem cells possessing a reporter/selection vector, in which the enhanced green fluorescent protein- and puromycin N-acetyltransferase-coding genes are driven by a common alpha-fetoprotein gene promoter.

Is the real in vivo nitric oxide concentration pico or nano molar? Influence of electrode size on unstirred layers and NO consumption.

Objective: There is a debate if the [NO] required to influence vascular smooth muscle is below 50 nM or much higher. Electrodes with 30 μm and larger diameter report [NO] below 50 nM, whereas those with diameters of <10-12 μm report hundreds of nM. This study examined how size of electrodes influenced [NO] measurement due to NO consumption and unstirred layer issues.

Rapid and slow nitric oxide responses during conducted vasodilation in the in vivo intestine and brain cortex microvasculatures.

Conduction of arteriolar vasodilation is initiated by activation of nitric oxide (NO) mechanisms, but dependent on conduction of hyperpolarization. Most studies have used brief (<1 second) activation of the initial vasodilation to evaluate the fast conduction processes. However, most arteriolar mechanisms involving NO production persist for minutes.

Nitric oxide formation by lymphatic bulb and valves is a major regulatory component of lymphatic pumping.

Microscopic lymphatics produce nitric oxide (NO) during contraction as flow shear activates the endothelial cells. The valve leaflets and bulbous valve housing contain a large amount of endothelial nitric oxide synthase (eNOS) due both to many endothelial cells and increased expression of eNOS. Direct NO measurements indicate the valve area has a 30-50% higher NO concentration ([NO]) than tubular regions although both regions generate equivalent relative increases in [NO] with each contraction.

Dynamic monitoring of beating periodicity of stem cell-derived cardiomyocytes as a predictive tool for preclinical safety assessment.

Background And Purpose: Cardiac toxicity is a major concern in drug development and it is imperative that clinical candidates are thoroughly tested for adverse effects earlier in the drug discovery process. In this report, we investigate the utility of an impedance-based microelectronic detection system in conjunction with mouse embryonic stem cell-derived cardiomyocytes for assessment of compound risk in the drug discovery process.

Experimental Approach: Beating of cardiomyocytes was measured by a recently developed microelectronic-based system using impedance readouts.