Arthrodesis as Salvage for Failed Metacarpophalangeal Arthroplasty.

BACKGROUND: Surgical management of failed metacarpophalangeal (MCP) arthroplasties includes revision arthroplasty and arthrodesis. The purpose of this study was to review the indications and outcomes of arthrodesis as a salvage procedure for failed MCP arthroplasties. METHODS: This was a retrospective cohort study of all patients undergoing salvage MCP arthrodesis at a single institution from 1990 to 2020. Patient charts were reviewed for patient demographics, indication for salvage, surgical technique, revision rate, and time to radiographic union. Patient-reported outcomes, including the Michigan Hand Outcomes Questionnaire and an MCP-specific questionnaire detailing pain, functional, appearance, and patient satisfaction, were also collected. RESULTS: Eleven digits in 9 patients (6 women, 3 men, median age of 66) with median 36-month follow-up were included. The majority (91%) of patients also had concomitant soft tissue deformities, including joint contractures, extension lag, and collateral ligament insufficiency. The overall revision rate following arthrodesis was 45% with 3 digits requiring one revision each, and 2 digits undergoing 3 revisions. The overall union rate was 91% with median time to union of 4 months from most recent arthrodesis. Patient-reported outcomes obtained from 4 patients demonstrated improvements in pain and function. CONCLUSION: Despite a high revision rate of 45%, salvage MCP arthrodesis following arthroplasty has a high eventual union rate of 91% and is associated with improved pain and function based on 4 patients' experiences. Arthrodesis as a salvage procedure for failed MCP arthroplasties should be considered in patients with persistent joint instability and functionally limiting soft tissue deformities.

Neurophysiological Oscillatory Mechanisms Underlying the Effect of Mirror Visual Feedback-Induced Illusion of Hand Movements on Nociception and Cortical Activation.

Mirror Visual Feedback (MVF)-induced illusion of hand movements produces beneficial effects in patients with chronic pain. However, neurophysiological mechanisms underlying these effects are poorly known. In this preliminary study, we test the novel hypothesis that such an MVF-induced movement illusion may exert its effects by changing the activity in midline cortical areas associated with pain processing. Electrical stimuli with individually fixed intensity were applied to the left hand of healthy adults to produce painful and non-painful sensations during unilateral right-hand movements with such an MVF illusion and right and bilateral hand movements without MVF. During these events, electroencephalographic (EEG) activity was recorded from 64 scalp electrodes. Event-related desynchronization (ERD) of EEG alpha rhythms (8-12 Hz) indexed the neurophysiological oscillatory mechanisms inducing cortical activation. Compared to the painful sensations, the non-painful sensations were specifically characterized by (1) lower alpha ERD estimated in the cortical midline, angular gyrus, and lateral parietal regions during the experimental condition with MVF and (2) higher alpha ERD estimated in the lateral prefrontal and parietal regions during the control conditions without MVF. These preliminary results suggest that the MVF-induced movement illusion may affect nociception and neurophysiological oscillatory mechanisms, reducing the activation in cortical limbic and default mode regions.

Morphology of the scaphotrapeziotrapezoid joint: A multi-domain statistical shape modeling approach.

The scaphotrapeziotrapezoid (STT) joint is involved in load transmission between the wrist and thumb. A quantitative description of baseline STT joint morphometrics is needed to capture the variation of normal anatomy as well as to guide staging of osteoarthritis. Statistical shape modeling (SSM) techniques quantify variations in three-dimensional shapes and relative positions. The objectives of this study are to describe the morphology of the STT joint using a multi-domain SSM. We asked: (1) What are the dominant modes of variation that impact bone and articulation morphology at the STT joint, and (2) what are the morphometrics of SSM-generated STT joints? Thirty adult participants were recruited to a computed tomography study of normal wrist imaging and biomechanics. Segmentations of the carpus were converted to three-dimensional triangular surface meshes. A multi-domain, particle-based entropy system SSM was used to quantify variation in carpal bone shape and position as well as articulation morphology. Articular surface areas and interosseous proximity distributions were calculated between mesh vertex pairs on adjacent bones within distance (2.0 mm) and surface-normal angular (35°) thresholds. In the SSM, the first five modes of variation captured 76.2% of shape variation and contributed to factors such as bone scale, articular geometries, and carpal tilt. Median interosseous proximities-a proxy for joint space-were 1.39 mm (scaphotrapezium), 1.42 mm (scaphotrapezoid), and 0.61 mm (trapeziotrapezoid). This study quantifies morphological and articular variations at the STT joint, presenting a range of normative anatomy. The range of estimated interosseous proximities may guide interpretation of imaging-derived STT joint space.

Psychosocial dimensions of vaccine hesitancy: A systematic review.

Despite widely recognised effectiveness against the spread of COVID-19, vaccine hesitancy persists. This systematic literature review aimed to clarify the definition and the operationalisation of the term 'vaccine hesitancy' and disclose the various psychosocial factors underlying this phenomenon. The results of studies conducted in European countries and in the United States after the vaccines became available were taken into account. The review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analyses statement. Twelve studies met the inclusion criteria and were reviewed. efinitions and measures of vaccine hesitancy differed across the studies, limiting their comparison. Nonetheless, by drawing on theoretical frameworks, we were able to identify several psychosocial variables in determining vaccine hesitancy. Our findings point to the need for a transdisciplinary approach to understanding the antecedents of vaccine hesitancy. A better understanding of the phenomenon may help to develop interventions and social policies to address a complex challenge such as vaccination hesitancy.

Identification of Innovative Folate Inhibitors Leveraging the Amino Dihydrotriazine Motif from Cycloguanil for Their Potential as Anti-Trypanosoma brucei Agents.

Folate enzymes, namely, dihydrofolate reductase (DHFR) and pteridine reductase (PTR1) are acknowledged targets for the development of antiparasitic agents against Trypanosomiasis and Leishmaniasis. Based on the amino dihydrotriazine motif of the drug Cycloguanil (Cyc), a known inhibitor of both folate enzymes, we have identified two novel series of inhibitors, the 2-amino triazino benzimidazoles (1) and 2-guanidino benzimidazoles (2), as their open ring analogues. Enzymatic screening was carried out against PTR1, DHFR, and thymidylate synthase (TS). The crystal structures of TbDHFR and TbPTR1 in complex with selected compounds experienced in both cases a substrate-like binding mode and allowed the rationalization of the main chemical features supporting the inhibitor ability to target folate enzymes. Biological evaluation of both series was performed against T. brucei and L. infantum and the toxicity against THP-1 human macrophages. Notably, the 5,6-dimethyl-2-guanidinobenzimidazole 2g resulted to be the most potent (Ki = 9 nM) and highly selective TbDHFR inhibitor, 6000-fold over TbPTR1 and 394-fold over hDHFR. The 5,6-dimethyl tricyclic analogue 1g, despite showing a lower potency and selectivity profile than 2g, shared a comparable antiparasitic activity against T. brucei in the low micromolar domain. The dichloro-substituted 2-guanidino benzimidazoles 2c and 2d revealed their potent and broad-spectrum antitrypanosomatid activity affecting the growth of T. brucei and L. infantum parasites. Therefore, both chemotypes could represent promising templates that could be valorized for further drug development.

Exposure to gallium arsenide nanoparticles in a research facility: a case study using molecular beam epitaxy.

We evaluated GaAs nanoparticle-concentrations in the air and on skin and surfaces in a research facility that produces thin films, and to monitored As in the urine of exposed worker. The survey was over a working week using a multi-level approach. Airborne personal monitoring was implemented using a miniature diffusion size classifier (DiSCMini) and IOM sampler. Environmental monitoring was conducted using the SKC Sioutas Cascade Impactor to evaluate dimensions and nature of particles collected. Surfaces contamination were assessed analyzing As and Ga in ghost wipes. Skin contamination was monitored using tape strips. As and Ga were analyzed in urines collected every day at the beginning and end of the shift. The greatest airborne exposure occurred during the cutting operations of the GaAs Sample (88883 np/cm3). The highest levels of contamination were found inside the hood (As max = 1418 ng/cm2) and on the laboratory floor (As max = 251 ng/cm2). The average concentration on the worker's skin at the end of the work shift (3.36 ng/cm2) was more than 14 times higher than before the start of the shift. In weekly urinary biomonitoring an average As concentration of 19.5 µg/L, which was above the Società Italiana Valori di Riferimento (SIVR) reference limit for the non-occupational population (2.0 - 15 µg/L), but below the ACGIH limit (30 µg/L). Overall, airborne monitoring, surface sampling, skin sampling, and biomonitoring of worker confirmed the exposure to As of workers. Systematic cleaning operations, hood implementation and correct PPE management are needed to improve worker protection.

Investigation Into the Effects of Intra-Articular Steroid on Post-Traumatic Osteoarthritis in Distal Radius Fractures: A Randomized Controlled Pilot Study.

PURPOSE: The aim of this prospective, randomized, controlled, double-blinded pilot study was to determine the rates of post-traumatic osteoarthritis and assess joint space width in the presence or absence of a single intra-articular injection of corticosteroid after an acute, intra-articular distal radius fracture (DRF). METHODS: Forty patients received a single, intra-articular, radiocarpal joint injection of 4 mg of dexamethasone (DEX) (n = 19) or normal saline placebo (n = 21) within 2 weeks of a surgically or nonsurgically treated intra-articular DRF. The primary outcome measure was minimum radiocarpal joint space width (mJSW) on noncontrast computed tomography scans at 2 years postinjection. Secondary outcomes were obtained at 3 months, 6 months, 1 year, and 2 years postinjection and included Disabilities of the Arm, Shoulder, and Hand; Michigan Hand Questionnaire; Patient-Rated Wrist Evaluation; wrist range of motion; and grip strength. RESULTS: At 2-year follow-up, there was no difference in mean mJSW between the DEX group (2.2 mm; standard deviation, 0.6; range, 1.4-3.2) and the placebo group (2.3 mm; standard deviation, 0.7; range, 0.9-3.9). Further, there were no differences in any secondary outcome measures at any postinjection follow-up interval. CONCLUSIONS: Radiocarpal joint injection of corticosteroid within 2 weeks of an intra-articular DRF does not appear to affect the development of post-traumatic osteoarthritis within 2 years follow-up in a small pilot cohort. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

State-of-the-art Review on the Antiparasitic Activity of Benzimidazolebased Derivatives: Facing Malaria, Leishmaniasis, and Trypanosomiasis.

Protozoan parasites represent a significant risk for public health worldwide, afflicting particularly people in more vulnerable categories and cause large morbidity and heavy economic impact. Traditional drugs are limited by their toxicity, low efficacy, route of administration, and cost, reflecting their low priority in global health management. Moreover, the drug resistance phenomenon threatens the positive therapy outcome. This scenario claims the need of addressing more adequate therapies. Among the diverse strategies implemented, the medicinal chemistry efforts have also focused their attention on the benzimidazole nucleus as a promising pharmacophore for the generation of new drug candidates. Hence, the present review provides a global insight into recent progress in benzimidazole-based derivatives drug discovery against important protozoan diseases, such as malaria, leishmaniasis and trypanosomiasis. The more relevant chemical features and structure-activity relationship studies of these molecules are discussed for the purpose of paving the way towards the development of more viable drugs for the treatment of these parasitic infections.

What Plastic Surgeons Should Know about Small-Joint Arthroplasty: Is This for Your Practice?

SUMMARY: This article reviews the state of the art for arthroplasty of the metacarpophalangeal and proximal interphalangeal joints. Arthritis that affects these joints can result in significant pain and compromised function. The authors review indications for arthroplasty for each joint, types of implants to consider, technical considerations, patient expectations, and outcomes and complications.

Total Wrist Arthroplasty: An International Perspective.

Concerns about implant durability and technical difficulty continue to make total wrist arthroplasties a specialized procedure with a narrow scope of indications. As a result, more routinely performed total or partial wrist arthrodesis continues to maintain popularity over arthroplasty. However, wrist motion preservation is undoubtedly preferable for patients and current literature is trending to more favorable outcomes for total wrist arthroplasties. In the setting of the evolving role of wrist arthroplasties in clinical practice, it is important to focus on providing hand surgeons a practical approach to incorporating total wrist arthroplasty into the treatment toolbox available to them when treating patients with painful wrist arthritis.