Histopathological Analysis of PEEK Wear Particle Effects on the Synovial Tissue of Patients

Introduction. Increasing interest developed in the use of carbon-fiber-reinforced-poly-ether-ether-ketones (CFR-PEEK) as an alternative bearing material in knee arthroplasty. The effects of CFR-PEEK wear in in vitro and animal studies are controversially discussed, as there are no data available concerning human tissue. The aim of this study was to analyze human tissue containing CFR-PEEK as well as UHMWPE wear debris. The authors hypothesized no difference between the used biomaterials. Methods and Materials. In 10 patients during knee revision surgery of a rotating-hinge-knee-implant-design, synovial tissue samples were achieved (tibial inserts: UHMWPE;bushings and flanges: CFR-PEEK). One additional patient received revision surgery without any PEEK components as a control. The tissue was paraffin-embedded, sliced into 2 mu m thick sections, and stained with hematoxylin and eosin in a standard process. A modified panoptical staining was also done. Results. A "wear-type" reaction was seen in the testing and the control group. In all samples, the UHMWPE particles were scattered in the tissue or incorporated in giant cells. CFR-PEEK particles were seen as conglomerates and only could be found next to vessels. CFR-PEEK particles showed no giant-cell reactions. In conclusion, the hypothesis has to be rejected. UHMWPE and PEEK showed a different scatter-behavior in human synovial tissue

Composting strategy for developing cities: A case study of Beira, Mozambique

This article aims to provide a contribution to the value and possibility of using composting as a tool for the treatment and management of the organic fraction of urban solid waste in developing contexts \u2013 specifically, the city of Beira, Mozambique. The aforementioned process should be intended not as an exhaustive tool but rather as a useful form of treatment to be employed within an Integrated Waste Management Plan. The high and diversified presence of materials suitable for the specific treatment in question is ascertained while also highlighting the diversification of the users that can be involved. Mixing strategies are drawn up in order to provide indications for a correct composition of the matrix that is intended to be started as a process and, according to the quantities considered (according to a modular approach), the production that can derive from it. A technical proposal is then drawn up on the functional areas making up the plant in order to develop the process in question. In addition to promoting the composting process itself, the article aims to valorize its final product, the compost, which in certain specific contexts, such as the one considered, can be useful or even necessary

Clinical Study The Impact of Personality Traits on the Outcome of Total Knee Arthroplasty

Ten to twenty percent of patients with total knee arthroplasty (TKA) are dissatisfied with their clinical outcome. Aim of this study was to investigate the impact of personality traits on the subjective outcome of TKA. We investigated 80 patients with 86 computer navigated TKAs. We asked for patients satisfaction and divided patients into two groups (satisfied or dissatisfied). 12 personality traits were tested by the Freiburg Personality Inventory (FPI-R). Postoperative examination included Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and the Visual Analogue Scale (VAS). Radiologic investigation was done in all patients. 84% of our patients were satisfied, while 16% were not satisfied. The FPI-R showed statistical significant influence of four personality traits on patient satisfaction: life satisfaction ( = 0.006), performance orientation ( = 0.015), somatic distress ( = 0.001), and emotional stability ( = 0.002). All clinical scores (VAS, WOMAC, and KSS) showed significantly better results in the satisfied patient. Radiological examination showed optimal alignment of all TKAs. There were no complications requiring revision surgery. The results of our study show that personality traits may influence patients satisfaction and clinical outcome after TKA. Therefore patients personality traits may be a useful predictive factor for postoperative satisfaction after TKA

Composting Strategy for Developing Cities: A Case Study of Beira, Mozambique

This article aims to provide a contribution to the value and possibility of using composting as a tool for the treatment and management of the organic fraction of urban solid waste in developing contexts – specifically, the city of Beira, Mozambique. The aforementioned process should be intended not as an exhaustive tool but rather as a useful form of treatment to be employed within an Integrated Waste Management Plan. The high and diversified presence of materials suitable for the specific treatment in question is ascertained while also highlighting the diversification of the users that can be involved. Mixing strategies are drawn up in order to provide indications for a correct composition of the matrix that is intended to be started as a process and, according to the quantities considered (according to a modular approach), the production that can derive from it. A technical proposal is then drawn up on the functional areas making up the plant in order to develop the process in question. In addition to promoting the composting process itself, the article aims to valorize its final product, the compost, which in certain specific contexts, such as the one considered, can be useful or even necessary. © 2020 WIT Press

Mesenchymal stem cells, autoimmunity and rheumatoid arthritis

The vast majority of literature pertaining to mesenchymal stem cells (MSC) immunomodulation has focussed on bone marrow-derived MSC that are systemically infused to alleviate inflammatory conditions. Rheumatoid arthritis (RA) is the commonest autoimmune joint disease that has witnessed significant therapeutic advances in the past decade, but remains stubbornly difficult to treat in a subset of cases. Pre-clinical research has demonstrated that bone marrow, adipose, synovial and umbilical cord-derived MSC all suppress the functions of different immune cells thus raising the possibility of new therapies for autoimmune diseases including RA. Indeed, preliminary evidence for MSC efficacy has been reported in some cases of RA and systemic lupus erythromatosis. The potential use of bone marrow-MSC (BM-MSC) for RA therapy is emerging but the use of synovial MSC (S-MSC) to suppress the exaggerated immune response within the inflamed joints remains rudimentary. Synovial fibroblasts that are likely derived from S-MSCs, also give rise to a cell-cultured progeny termed fibroblast-like synoviocytes (FLS), which are key players in the perpetuation of joint inflammation and destruction. A better understanding of the link between these cells and their biology could be a key to developing novel MSC-based strategies for therapy. The review briefly focuses on BM-MSC and gives particular attention to joint niche synovial MSC and FLS with respect to immunoregulatory potential therapy roles