Lateral ankle ligament reconstruction using the anterior half of the peroneus longus tendon.

PURPOSE: The purpose of this study was to assess the results of a novel surgical technique for the treatment of chronic lateral ankle instability with attenuated or deficient ligamentous tissue that the modified Broström procedure could not be performed. A lateral ankle ligament reconstruction using the anterior half of the peroneus longus tendon has been performed. METHODS: Thirty-four consecutive patients treated with lateral ankle ligament reconstruction using anterior half of the peroneus longus tendon were enrolled. Median age at surgery was 24 years (range 19-46 years). The clinical and radiologic outcomes were evaluated preoperatively and at a median of 21 months (range 12-51 months) follow-up. RESULTS: The Karlsson-Peterson ankle score significantly improved from 58.2 ± 10.9 points preoperatively to 83.9 ± 7.0 points at the last follow-up. Mechanical stability was achieved. The mean talar tilt angle significantly improved from 15.7° ± 3.5° preoperatively to 4.6° ± 1.7° at the last follow-up, and the mean anterior talar translation significantly improved from 7.3 ± 2.6 mm preoperatively to 4.1 ± 1.7 mm at the last follow-up. Fifteen patients (52%) were very satisfied with the results, nine patients (31%) were satisfied, four patients (14%) were fair, and one patient (3%) was dissatisfied with the results. CONCLUSIONS: Lateral ankle ligament reconstruction using the anterior half of the peroneus longus tendon can be a surgical option for chronic lateral ankle instability with attenuated or deficient ligaments. LEVEL OF EVIDENCE: Case-series, Level IV.

Effect of preculture and loading on expression of matrix molecules, matrix metalloproteinases, and cytokines by expanded osteoarthritic chondrocytes.

OBJECTIVE: One of the pathologic changes that occurs during osteoarthritis (OA) is the degeneration of the pericellular matrix (PCM). Since the PCM is likely to be involved in mechanotransduction, this study was undertaken to investigate the effects of PCM-like matrix accumulation in zonal OA chondrocytes and their influence on chondrocyte response to compression. METHODS: Superficial and middle/deep zone chondrocytes from macroscopically normal cartilage of OA knees were expanded and encapsulated in alginate gels. The effects of compression (short-term or long-term) and preculture on chondrocyte expression of various matrix molecules, cytokines, and matrix metalloproteinases (MMPs) were assessed. Additionally, nonexpanded chondrocytes were encapsulated in alginate and cultured in the presence or absence of transforming growth factor ß1 (TGFß1) and dexamethasone and analyzed following short-term compression experiments. RESULTS: Expanded OA chondrocytes (superficial and middle/deep zone) that were precultured for 2 weeks under free-swelling conditions prior to dynamic compression responded more sensitively to loading and had increased matrix accumulation, increased interleukin-1ß (IL-1ß) and IL-4 levels, and decreased levels of MMP-2 (in the middle/deep zone) compared to the nonloaded controls. Compression also decreased MMP-3 and MMP-13 levels even without preculture. Nonexpanded chondrocytes did not respond to compression, but differences in gene expression were found depending on the zone of harvest, time in culture, and medium composition. CONCLUSION: Our findings demonstrate that with predeposited PCM-like matrix, compressive stimulation can enhance matrix protein accumulation in expanded OA chondrocytes. Investigations into how PCM or other matrix components differentially affect this balance under mechanical loading may provide invaluable insight into OA pathogenesis and the use of expanded cells in tissue engineering and regenerative medicine-based applications.

Arthroscopic ankle arthrodesis with intra-articular distraction.

Arthroscopic ankle arthrodesis has shown high rates of union comparable to those with open arthrodesis but with substantially less postoperative morbidity, shorter operative times, less blood loss, and shorter hospital stays. To easily perform arthroscopic resection of the articular cartilage, sufficient distraction of the joint is necessary to insert the arthroscope and instruments. However, sometimes, standard noninvasive ankle distraction will not be sufficient in post-traumatic ankle arthritis, with the development of arthrofibrosis and joint contracture after severe ankle trauma. In the present report, we describe a technique to distract the ankle joint by inserting a 4.6-mm stainless steel cannula with a blunt trocar inside the joint. The cannula allowed sufficient intra-articular distraction, and, at the same time, a 4.0-mm arthroscope can be inserted through the cannula to view the joint. Screws can be inserted to fix the joint under fluoroscopic guidance without changing the patient's position or removing the noninvasive distraction device and leg holder, which are often necessary during standard arthroscopic arthrodesis with noninvasive distraction.

Top Ten Tips Palliative Care Clinicians Should Know About Caring for Patients Under Guardianships.

Palliative care clinicians often help facilitate coordination of care, complex serious illness, and end-of-life medical decision-making. However, the clinical and legal issues related to guardianship can complicate the decision-making process, care delivery, outcomes, and the role of the palliative care clinician. Adult patients who have a guardian have been found by a court to be unable to make some or all decisions for themselves. Providing care for patients under guardianship is where medicine overlaps with legal rights. It is crucial to be familiar with the patients' rights and the guardians' responsibilities to clarify medical decision-making processes and identify necessary authorities. This article uses an interprofessional approach to leverage the expertise of physicians, nurses, lawyers, and guardians and to guide palliative care clinicians to optimally support patients under guardianship.

Ankle arthroscopy in a hanging position combined with hindfoot endoscopy for the treatment of concurrent anterior and posterior impingement syndrome of the ankle.

The purpose of the present study was to evaluate the results of arthroscopic and endoscopic treatment of concurrent anterior and posterior ankle impingement with the patient in a prone position. From May 2009 to September 2010, 22 patients with simultaneously combined anterior and posterior ankle impingements underwent ankle arthroscopy in a prone position. Noninvasive ankle distraction was achieved by hanging the affected ankle on a shoulder-holding traction frame, followed by hindfoot endoscopy. The mean age at surgery was 22.6 (range 20 to 46) years. The mean follow-up duration was 15.4 (range 12 to 29) months. The American Orthopaedic Foot and Ankle Society scores and Foot Function Index were checked preoperatively and at the final follow-up visit. The mean American Orthopaedic Foot and Ankle Society score increased from 62.6 preoperatively to 86.0 at the final follow-up visit (p < .05). The Foot Function Index improved from 45.8 to 17.2 (p < .05). Of the 22 patients, 18 were very satisfied or satisfied with the results, 2 rated their results as fair, and 2 were dissatisfied. No complications related to ankle distraction in a hanging position occurred. Ankle arthroscopy with the patient in a prone position with the ankle hung on a shoulder-holding traction frame combined with hindfoot endoscopy provided a useful method for treating anterior and posterior ankle impingement that does not require changing the patient's position from supine to prone.

Control of on-off or off-on fluorescent and optical [Cu²âº] and [Hg²âº] responses via formal Me/H substitution in fully characterized thienyl "scorpionate"-like BODIPY systems.

One 8-phenyl and two 8-mesityl-substituted "scorpionate"-like BODIPY-type species of the formula [3,4,4-tris(5-R-(2-thienyl))-8-(2,4,6-R'-phenyl)-4-bora-3a,4a-diaza-s-indacene (R = H, R' = H, 3a; R, = H, R' = Me, 2a; R, = Me, R' = Me, 2b)] have been synthesized and fully characterized. Importantly, differences in their solution (MeCN) optical Cu(2+) and Hg(2+) probing capacity via SSS-chelation were investigated. Compounds 2a-3a were prepared from the requisite 8-substituted BODIPY complexes. They were characterized first by complete (1)H, (11)B and (13)C NMR spectroscopic assignments (CD(3)Cl or CD(3)C(O)CD(3)); the molecular structures of 2a and 3a were determined by X-ray crystallography. Compounds 2a-3a were studied by UV-vis and fluorescence spectroscopy [Φ(F) = 0.27 ± 0.013 (2a); 0.024 ± 0.0016 (2b); 0.0034 ± 0.00047 (3a)]. Importantly, low [Cu(2+)] with 3a (<3.0 × 10(-5) M) gave rise to an increase of fluorescence intensity (off-on; 6.3-fold), whereas with 2a it decreased (on-off). When [Hg(2+)] (<3.0 × 10(-5) M) was added to 2b, the λ(em,max) value increased (off-on; 3.2-fold), and for 2a, it decreased (on-off). The association constant (K(a)) for Hg(2+)·2a was determined to be 3120 ± 307 M(-1). An approximate stoichiometric 1:1 binding determined by Job plot analysis is in line with successful DFT modeling of SSS-Cu(2+) binding for this system type. (1)H NMR spectroscopy also revealed tentative sets of product complex peaks. These simple differences caused by formal ligand Me-group incorporation are the first for any related fluorophores, to the best of our knowledge.

Nanoparticles for drug delivery in Parkinson's disease.

Although effective symptomatic treatments for Parkinson's disease (PD) have been available for some time, efficient and well-controlled drug delivery to the brain has proven to be challenging. The emergence of nanotechnology has created new opportunities not only for improving the pharmacokinetics of conventional therapies but also for developing novel treatment approaches and disease modifying therapies. Several exciting strategies including drug carrier nanoparticles targeting specific intracellular pathways and structural reconformation of tangled proteins as well as introducing reprogramming genes have already shown promise and are likely to deliver more tailored approaches to the treatment of PD in the future. This paper reviews the role of nanoparticles in PD including a discussion of both their composition and functional capacity as well as their potential to deliver better therapeutic agents.

Coombs-negative hemolytic anemia in a male with COVID-19.

This case illustrates the need to consider SARS-CoV-2 infection as a catalyst for Coombs-negative hemolytic anemia as well as the potential for IVIG to serve as an effective treatment for the condition.

Invisibilizing politics: Accepting and legitimating ignorance in environmental sciences.

Although sociologists have explored how political and economic factors influence the formation of ignorance in science and technology, we know little about how scientists comply with external controls by abandoning their prior research and leaving scientific innovations incomplete. Most research in science and technology studies (STS) on ignorance has relied on structural and historical analyses, lacking in situ studies in scientific laboratories. Drawing on ethnographic research, this article examines the habitus of ignorance as a mechanism of the social production of ignorance. Scientists have a set of dispositions that establish practical contexts enabling them to ignore particular scientific content. Leaders of the organization repeatedly legitimate the abandonment of unfinished projects, while ordinary laboratory scientists internalize the normalized view that the scientific field is inherently opportunistic and that unfunded research should be left undone. A cycle of legitimation and acceptance of ignorance by actors at distinctive positions within the organization provides a mechanism of social control of scientific knowledge. As the mechanism is habitually self-governed by the rules of the game of current scientific institutions, the result is an indirect, although deeply subjugating, invisible and consolidating form of political and economic domination of the scientific field.

Optical effects of S-oxidation and M(n+) binding in meso-thienyl dipyrrin systems and of stepwise bromination of 4,4-difluoro-8-(2,5-dibromo-3-thienyl)-4-bora-3a,4a-diaza-s-indacene.

We report 16 novel species and 8 molecular structures in studying how meso-thienyl-substituted dipyrrole oxidation, bromination, and metal ion binding impart optical changes, as monitored by UV-vis absorption/emission spectroscopy. Treatment of 4,4-difluoro-8-(3-benzothienyl)-4-bora-3a,4a-diaza-s-indacene (varphi(F) = 0.19) with m-CPBA gives selective S-dioxidation (varphi(F) = 0.006). Results of titrations of transition metal- and "scorpionate"-like dipyrrin species varied under room temperature treatment of m-CPBA. Ni-(thienyl-dipyrrin)(n) (n = 2) degraded significantly in the presence of m-CPBA, whereas related species (M = Cu, Fe, Co; n = 2, 3) were inert. meso-Thienyl group properties were revealed through the use of 3,4,4-triphenyl-8-(thienyl)-4-bora-3a,4a-diaza-s-indacene; Cu(2+) addition resulted in smooth absorption decreases which were modeled to support 1:1 substrate:M(2+) binding; for Hg(2+) 1:2 substrate:M(2+) binding was found. Treatment of 4,4-difluoro-8-(2,5-dibromo-3-thienyl)-4-bora-3a,4a-diaza-s-indacene with Br(2) gave red-shifted UV-vis absorption band features that grow with increasing dipyrrin bromination. Structures of the di- and tetra-substituted bromination products were obtained.

A Novel 3D Cultured Model for Studying Early Changes in Age-Related Macular Degeneration.

Various in vitro culture systems have been used to investigate the pathogenesis of age-related macular degeneration (AMD). However, many still rely on oversimplified monolayer culture models. AMD is a complex disease, associated with the pathological changes to multiple structural components such as the Bruch's membrane, retinal pigment epithelium (RPE), and choroidal endothelial cells. This study aims to construct a novel 3D coculture model using the polycaprolactone (PCL)-gelatin electrospun scaffold, with human RPE cells (hRPE) and primate choroidal cells (RF-6A). Results from this study show that PCL-gelatin scaffolds have a highly porous ultrastructure that supports the attachment, proliferation, differentiation, and migration of the hRPEs and choroidal endothelial cells. It is also demonstrated that the PCL-gelatin 3D coculture model may be useful in exploring the molecular interplay between the hPRE and the choroidal endothelial cells, and their effects on growth factor modulation, which may be important in the pathogenesis of AMD.

Reinforcement of hydrogels using three-dimensionally printed microfibres.

Despite intensive research, hydrogels currently available for tissue repair in the musculoskeletal system are unable to meet the mechanical, as well as the biological, requirements for successful outcomes. Here we reinforce soft hydrogels with highly organized, high-porosity microfibre networks that are 3D-printed with a technique termed as melt electrospinning writing. We show that the stiffness of the gel/scaffold composites increases synergistically (up to 54-fold), compared with hydrogels or microfibre scaffolds alone. Modelling affirms that reinforcement with defined microscale structures is applicable to numerous hydrogels. The stiffness and elasticity of the composites approach that of articular cartilage tissue. Human chondrocytes embedded in the composites are viable, retain their round morphology and are responsive to an in vitro physiological loading regime in terms of gene expression and matrix production. The current approach of reinforcing hydrogels with 3D-printed microfibres offers a fundament for producing tissue constructs with biological and mechanical compatibility.

Perspectives in multiphasic osteochondral tissue engineering.

Critical-sized osteochondral defects are clinically challenging, with limited treatment options available. By engineering osteochondral grafts using a patient's own cells and osteochondral scaffolds designed to facilitate cartilage and bone regeneration, osteochondral defects may be treated with less complications and better long-term clinical outcomes. Scaffolds can influence the development and structure of the engineered tissue, and there is an increased awareness that osteochondral tissue engineering concepts need to take the in vivo complexities into account in order to increase the likelihood of successful osteochondral tissue repair. The developing trend in osteochondral tissue engineering is the utilization of multiphasic scaffolds to recapitulate the multiphasic nature of the native tissue. Cartilage and bone have different structural, mechanical, and biochemical microenvironments. By designing osteochondral scaffolds with tissue-specific architecture, it may be possible to enhance osteochondral repair within shorter timeframe. While there are promising in vivo outcomes using multiphasic approaches, functional regeneration of osteochondral constructs still remains a challenge. In this review, we provide an overview of in vivo osteochondral repair studies that have taken place in the past three years, and define areas which needs improvement in future studies.

Multiphasic construct studied in an ectopic osteochondral defect model.

In vivo osteochondral defect models predominantly consist of small animals, such as rabbits. Although they have an advantage of low cost and manageability, their joints are smaller and more easily healed compared with larger animals or humans. We hypothesized that osteochondral cores from large animals can be implanted subcutaneously in rats to create an ectopic osteochondral defect model for routine and high-throughput screening of multiphasic scaffold designs and/or tissue-engineered constructs (TECs). Bovine osteochondral plugs with 4 mm diameter osteochondral defect were fitted with novel multiphasic osteochondral grafts composed of chondrocyte-seeded alginate gels and osteoblast-seeded polycaprolactone scaffolds, prior to being implanted in rats subcutaneously with bone morphogenic protein-7. After 12 weeks of in vivo implantation, histological and micro-computed tomography analyses demonstrated that TECs are susceptible to mineralization. Additionally, there was limited bone formation in the scaffold. These results suggest that the current model requires optimization to facilitate robust bone regeneration and vascular infiltration into the defect site. Taken together, this study provides a proof-of-concept for a high-throughput osteochondral defect model. With further optimization, the presented hybrid in vivo model may address the growing need for a cost-effective way to screen osteochondral repair strategies before moving to large animal preclinical trials.