Cefadroxil-Induced Infection Following Total Knee Arthroplasty.

Perioperative infection prophylaxis is a fundamental element of total knee arthroplasty (TKA). There has been a recent trend toward the use of extended postoperative oral antibiotics in high-risk patients. We describe a case report of a patient who underwent a primary TKA and subsequently developed  colitis after an extended course of postoperative prophylactic oral cefadroxil.

Head-Neck Taper Corrosion in Metal-on-Polyethylene Total Hip Arthroplasty: Risk Factors, Clinical Evaluation, and Treatment of Adverse Local Tissue Reactions.

Adverse local tissue reaction (ALTR) associated with mechanically assisted crevice corrosion of metal-on-polyethylene (MoP) head-neck modular total hip arthroplasty (THA), similarly observed in the metal-on-metal bearing, is a growing concern in MoP THA patients. Given the complex pathogenesis as well as variable clinical presentation, the diagnosis can be challenging. This article focuses on providing surgeons with an evidence-based update on (1) implant, surgical, and patient risk factors associated with ALTRs; (2) clinical systematic evaluation; and (3) surgical management options for ALTRs in MoP THA patients based on the currently available evidence.

Outcome of Dual Mobility Constructs for Adverse Local Tissue Reaction Associated Abductor Deficiency in Revision Total Hip Arthroplasty.

Background: Treatment of adverse local tissue reaction (ALTR) is challenging owing to high complications and poor outcomes after a revision surgery. As dislocation is the most common cause of reoperation, it is often necessary to use advanced articulations such as dual mobility. This study aims to evaluate the outcome and complication rates after revision surgery with dual mobility constructs, compared to constrained and conventional articulations in the setting of significant abductor deficiency due to ALTR.

The impact of early-life shocks on adult welfare in Brazil: Questions of measurement and timing.

Recent literature provides evidence that income shocks early in life can have long-run consequences on adult welfare. Rural Brazil frequently suffers from rainfall variations that negatively impact vulnerable households, who often lack the means for coping with these events. This paper evaluates how early-life rainfall shocks influence adult health and socioeconomic outcomes in Brazil.

Relationship of the Posterior Condylar Line and the Transepicondylar Axis: A CT-Based Evaluation.

Posterior condylar referencing, a common method for determining femoral axial orientation during total knee arthroplasty (TKA), relies upon an assumed consistent relationship between the posterior condylar line (PCL) and the transepicondylar axis (TEA) of 3 degrees rotation. A total of 3,010 computed tomography (CT) scans and three-dimension (3D)-reconstructions for presurgical creation of patient-matched TKA instrumentation were analyzed. Demographic data and five anthropometric measurements (hip-knee angle [HKA], distal femoral angle [DFA], proximal tibial angle [PTA], tibial slope [TS], and PCL-TEA relationship) were recorded for each scan.

Preoperative Opioid Use Negatively Affects Patient-reported Outcomes After Primary Total Hip Arthroplasty.

Background: Opioid use is a public health crisis in the United States and an area of increased focus in orthopaedic surgery. The aim of this study is to investigate whether preoperative opioid use had any effect on patient-reported outcome measures (PROMs) before and after total hip arthroplasty (THA).

Methods: A total of 389 patients with THA with both preoperative and postoperative PROMs were reviewed: (1) 76 patients with preoperative opioid use (24%) and (2) 237 patients without preoperative opioid use (76%).

Receptiveness to advice, cognitive ability, and technology adoption.

We construct a model of technology adoption with agents differing on two dimensions: their cognitive ability and their receptiveness to advice. While cognitive ability unambiguously speeds adoption, receptiveness to advice may speed adoption for individuals with low cognitive ability, but slow adoption for individuals with high cognitive ability. We conduct economic experiments measuring US farmers' cognitive ability and receptiveness to advice and examine how these characteristics impact their speed of adoption of genetically modified (GM) corn seeds.

Early diagnosis of septic arthritis in immunocompromised patients.

Objectives: Septic arthritis results in rapid joint destruction if not properly diagnosed and treated. A work up for septic arthritis includes a peripheral white blood cell count, inflammatory markers, and a joint aspiration. In the general population, the interpretation of these labs has been well-defined by prior studies.

Differences in Post-Operative Outcome Between Conversion and Primary Total Hip Arthroplasty.

Background: The demand for conversion of prior hip surgery to total hip arthroplasty (conversion THA) is likely to increase as a function of increasing US hip fracture burden in addition to its application in managing other conditions. Thus, outcome analysis is warranted to better inform value-based reimbursement schemes in the era of bundled payments.

Methods: Via Current Procedural Terminology codes, the National Surgical Quality Improvement Project data files were queried for all patients who underwent primary THA and conversion of previous hip surgery to THA from 2005 to 2014.

The Lawrence D. Dorr Surgical Techniques & Technologies Award: Differences in Postoperative Outcomes Between Total Hip Arthroplasty for Fracture vs Osteoarthritis.

Background: Hip fracture is an increasingly common expanded indication for total hip arthroplasty (THA) and warrants outcome analysis so as to best inform risk assessment models, public reporting of outcome, and value-based reimbursement schemes.

Methods: The National Surgical Quality Improvement Program data file from 2011 to 2014 was used to identify all patients undergoing THA via current procedural terminology code 27130. Propensity score matching in a 1:5 fashion was used to compare 2 cohorts: THA for osteoarthritis and THA for fracture.

The Impact of Metabolic Syndrome on 30-Day Complications Following Total Joint Arthroplasty.

Background: The arthroplasty population increasingly presents with comorbid conditions linked to elevated risk of postsurgical complications. Current quality improvement initiatives require providers to more accurately assess and manage risk presurgically. In this investigation, we assess the effect of metabolic syndrome (MetS), as well as the effect of body mass index (BMI) within MetS, on the risk of complication following hip and knee arthroplasty.

Improving outcomes in total knee arthroplasty-do navigation or customized implants have a role?

Modern total knee arthroplasty is effective at treating the pain and disability associated with osteoarthritis. The number of total knee replacements done in the USA continues to increase. Despite the great care taken during all of these procedures, some patients remain dissatisfied with their outcome.

Isoleucine as a possible bridge between exogenous delivery and terrestrial enhancement of homochirality.

We report a highly enantioselective oligomerization of isoleucine stereomers in the salt-induced peptide formation reaction under plausibly prebiotic earth conditions. Up to 6.5-fold superiority in reactivity of L-isoleucine was observed, compared to its D-enantiomer, after 14 evaporation cycles in the presence of Cu(2+) and NaCl.

Ambient measurements of 2,2,4-trimethyl, 1,3-pentanediol monoisobutyrate in Southern California.

2,2,4-trimethyl, 1,3-pentanediol monoisobutyrate (TPM) is a widely used solvent found in water-based coatings. Ambient measurements of TPM are reported here for the first time. Although this compound has been previously measured in indoor air, this study illustrates successful detection and quantification of TPM in ambient air at three locations in Southern California: Pico Rivera, Azusa, and Riverside.

Effect of metal Ions (Ni²⁺, Cu²⁺ and Zn²⁺) and water coordination on the structure of L-phenylalanine, L-tyrosine, L-tryptophan and their zwitterionic forms.

Methods of quantum chemistry have been applied to double-charged complexes involving the transition metals Ni(2+), Cu(2+) and Zn(2+) with the aromatic amino acids (AAA) phenylalanine, tyrosine and tryptophan. The effect of hydration on the relative stability and geometry of the individual species studied has been evaluated within the supermolecule approach. The interaction enthalpies, entropies and Gibbs energies of nine complexes Phe•M, Tyr•M, Trp•M, (M = Ni(2+), Cu(2+) and Zn(2+)) were determined at the Becke3LYP density functional level of theory.

Selective adsorption and chiral amplification of amino acids in vermiculite clay-implications for the origin of biochirality.

Smectite clays are hydrated layer silicates that, like micas, occur naturally in abundance. Importantly, they have readily modifiable interlayer spaces that provide excellent sites for nanochemistry. Vermiculite is one such smectite clay and in the presence of small chain-length alkyl-NH(3)Cl ions forms sensitive, 1-D ordered model clay systems with expandable nano-pore inter-layer regions.

Effect of metal ions (Li+, Na+, K+, Mg2+, Ca2+, Ni2+, Cu2+ and Zn2+) and water coordination on the structure and properties of L-histidine and zwitterionic L-histidine.

Interactions between metal ions and amino acids are common both in solution and in the gas phase. The effect of metal ions and water on the structure of L-histidine is examined. The effect of metal ions (Li+, Na+, K+, Mg2+, Ca2+, Ni2+, Cu2+ and Zn2+) and water on structures of His·M(H2O)m, m=0.

Arginine in the salt-induced peptide formation reaction: enantioselectivity facilitated by glycine, L- and D-histidine.

The salt-induced peptide formation reaction has been proposed as a conceivable preliminary to the prebiotic evolution of peptides. In the present paper, the behaviour of arginine is reported for this reaction together with a discussion of the catalytic effects of glycine, and L- and D-histidine. Importantly, the behaviour of the two histidine enantiomers is different.

Catalytic effects of histidine enantiomers and glycine on the formation of dileucine and dimethionine in the salt-induced peptide formation reaction.

The salt-induced peptide formation (SIPF) reaction takes place readily under mild reaction conditions and proceeds via a copper complex. Its ease of reaction and the universality for prebiotic scenarios add weights to the arguments in favour of the importance of peptide and proteins in the tug of war with the RNA world hypothesis. In addition, the SIPF reaction has a preference for L-form amino acids in dipeptide formation, casting light on the puzzle of biohomochirality, especially for the amino acids with aliphatic side chains.

The catalytic effect of L- and D-histidine on alanine and lysine peptide formation.

A starting phase of chemical evolution on our ancient Earth around 4 billion years ago was the formation of amino acids and their combination to peptides and proteins. The salt-induced peptide formation (SIPF) reaction has been shown to be appropriate for this condensation reaction under moderate and plausible primitive Earth conditions, forming short peptides from amino acids in aqueous solution containing sodium chloride and Cu(II) ions. In this paper we report results about the formation of dialanine and dilysine from their monomers in this reaction.

Effect of metal ions (Li+, Na+, K+, Mg2+, Ca2+, Ni2+, Cu2+, and Zn2+) and water coordination on the structure and properties of L-arginine and zwitterionic L-arginine.

Interactions between metal ions and amino acids are common both in solution and in the gas phase. The effect of metal ions and water on the structure of L-arginine is examined. The effects of metal ions (Li(+), Na(+), K(+), Mg(2+), Ca(2+), Ni(2+), Cu(2+), and Zn(2+)) and water on structures of Arg x M(H2O)m , m = 0, 1 complexes have been determined theoretically by employing the density functional theories (DFT) and using extended basis sets.

Methionine peptide formation under primordial earth conditions.

According to recent research on the origin of life it seems more and more likely that amino acids and peptides were among the first biomolecules formed on earth and that a peptide/protein world was thus a key starting point in evolution towards life. Salt-induced Peptide Formation (SIPF) has repeatedly been shown to be the most universal and plausible peptide-forming reaction currently known under prebiotic conditions and forms peptides from amino acids with the help of copper ions and sodium chloride. In this paper we present experimental results for salt-induced peptide formation from methionine.