Search Results (5)

Background/Objectives: Streptococcus intermedius, a member of the Streptococcus anginosus group, is characterized by a marked propensity for abscess formation but only rarely causes native-joint septic arthritis. Involvement of the acromioclavicular (AC) joint is particularly uncommon. We describe a case of native AC joint septic arthritis due to S. intermedius in a patient with multiple predisposing factors and highlight diagnostic and management considerations. Methods: We report the clinical course of a 72-year-old man with poorly controlled type 2 diabetes mellitus who presented with progressive right shoulder pain, erythema, and swelling following recurrent minor skin abrasions from a newly adopted dog. Initial management for presumed inflammatory shoulder pathology included brief systemic corticosteroids and an ultrasound-guided intra-articular ketorolac injection. Magnetic resonance imaging (MRI) was performed after symptom progression. The patient underwent operative irrigation and debridement with collection of synovial fluid and deep tissue cultures. Blood cultures and transthoracic echocardiography were obtained to evaluate for systemic involvement. Results: MRI demonstrated multiloculated periarticular abscesses and osteolysis centered on the AC joint. Operative cultures yielded high colony counts of S. intermedius from synovial fluid and deep tissues. Blood cultures and echocardiography were negative. The patient required multiple operative debridements with irrigation, adjunctive local antibiotic therapy, and prolonged targeted β-lactam treatment. Clinical and radiographic improvement was achieved following surgical source control and antimicrobial therapy. Conclusions: Native AC joint septic arthritis due to S. intermedius is rare. Older age, uncontrolled diabetes, recent intra-articular intervention, and possible zoonotic inoculation from canine wound licking may represent contributory risk factors. Early imaging, prompt surgical source control, and guideline-concordant antimicrobial therapy are essential when bone and soft tissue involvement is present. Full article

Meniscal preservation is increasingly recognized as a critical determinant of long-term knee joint health, yet successful repair remains challenging due to the meniscus’s limited intrinsic healing capacity. The adult meniscus is characterized by restricted vascularity, low cellularity, a dense extracellular matrix, complex biomechanical loading, and a hostile post-injury intra-articular inflammatory environment—factors that collectively impair meniscus healing, particularly in the avascular zones. Over the past several decades, a wide range of biologic augmentation strategies have been explored to overcome these barriers, including synovial abrasion, fibrin clot implantation, marrow stimulation, platelet-derived biologics, cell-based therapies, scaffold coverage, and emerging biologic and biophysical interventions. This review summarizes the biological basis of meniscal healing, critically evaluates current and emerging biologic augmentation techniques, and integrates these approaches within a unified framework of vascular, cellular, matrix, biomechanical, and immunologic targets. Understanding and modulating the cellular and molecular mechanisms governing meniscal degeneration and repair may enable the development of more effective, mechanism-driven strategies to improve healing outcomes and reduce the risk of post-traumatic osteoarthritis. Full article

In articular joint implants, polymeric inserts are usually exploited for on-contact sliding surfaces to guarantee low friction and wear, a high load-bearing capacity, impact strength and stiffness, and biocompatibility. Surface micro-structuring can drastically reduce friction and wear by promoting hydrostatic friction due to synovial fluid. Ultra-High Molecular Weight Polyethylene (UHMWPE) is a suitable material for these applications due to its strong chemical resistance, excellent resistance to stress, cracking, abrasion, and wear, and self-lubricating property. However, surface micro-texturing of UHMWPE is hardly achievable with the currently available processes. The present study investigates UHMWPE’s micro-textured surface replication capability via injection molding, comparing the results with the more easily processable High-Density Polyethylene (HDPE). Four different micro-texture cavities were designed and fabricated on a steel mold by micro-EDM milling, and used for the experimental campaign. Complete samples were fabricated with both materials. Then, the mold and samples were geometrically characterized, considering the dimensions of the features and the texture layout. The replication analysis showed that HDPE samples present geometrical errors that span from 1% to 9% resulting in an average error of 4.3%. In comparison, the UHMWPE samples display a higher variability, although still acceptable, with percentage errors ranging from 2% to 31% and an average error of 11.4%. Full article

Menisci are crucial structures for knee homeostasis. After a meniscal lesion, the golden rule, now, is to save as much meniscus as possible; only the meniscus tissue that is identified as unrepairable should be excised, and meniscal sutures find more and more indications. Several different methods have been proposed to improve meniscal healing. They include very basic techniques, such as needling, abrasion, trephination and gluing, or more complex methods, such as synovial flaps, meniscal wrapping or the application of fibrin clots. Basic research of meniscal substitutes has also become very active in the last decades. The aim of this literature review is to analyze possible therapeutic and surgical options that go beyond traditional meniscal surgery: from scaffolds, which are made of different kind of polymers, such as natural, synthetic or hydrogel components, to new technologies, such as 3-D printing construct or hybrid biomaterials made of scaffolds and specific cells. These recent advances show that there is great interest in the development of new materials for meniscal reconstruction and that, with the development of new biomaterials, there will be the possibility of better management of meniscal injuries Full article

The microstructuring of surfaces is a highly researched field that is aimed at enhancing the tribological behavior of sliding surfaces such as artificial joints, which are subject to wear. Lubrication of the joint interface plays a key role in the wear process, although the mechanisms of lubrication are quite complex. In order to improve the lubrication, the surfaces of the articulating components can be modified by pulsed femtosecond-laser microstructuring. Through microstructuring, the apparent dynamic viscosity of the synovial fluid between the artificial joint can be increased due to its non-Newtonian properties. This may lead to better hydrodynamic lubrication and, therefore, reduced particle abrasion. Femtosecond laser-induced microstructures were investigated in a modified rheometer setup featuring a reduced gap size in order to reproduce and measure the interface between fluid and implant surface more accurately. As a test fluid, a synovial fluid substitute was used. The study has shown that an increase in the viscosity of the synovial fluid substitute can be achieved by microstructuring. Compared to a smooth implant surface, the apparent viscosity of the synovial fluid substitute increased by over 30% when ring-shaped microstructures of 100 µm diameter with an aspect ratio of 0.66 were implemented. Full article