Articular cartilage (AC) plays an important role in the biomechanics of synovial joints. Its task is to enable smooth movement and transfer of mechanical loads with minimised friction. AC is characterised by unique mechanical properties resulting from its complex structure, in which the dominant components are type II collagen, proteoglycans and water. Healthy articular cartilage shows elasticity in compression, viscoelastic properties, and the ability to relax stresses under the influence of cyclic loads. In response to different loading modes, it shows anisotropic and non-uniform behaviour, which translates into its cushioning and protective function for the subchondral bone. Significant changes occur in the structure and mechanical properties of cartilage with age as a result of mechanical overload or degenerative diseases, such as osteoarthritis. This results in a deterioration of the cushioning and mechanical function, which leads to progressive degradation of joint tissues. Understanding the mechanical properties of AC is crucial for developing effective diagnostic methods. Analysis of changes in mechanical properties contributes to the early detection of pathological changes. The aim of this paper is to review the current state of knowledge regarding the structure and biomechanical properties of articular cartilage, and to analyse conventional and alternative diagnostic methods in the context of their suitability for assessing the state of AC, particularly in the early stages of degenerative processes.

The ageing population and the resulting number of physical and health problems are now a major social and economic challenge around the world. Osteoarthritis is a common disease among older people. It can affect any joint, but it most often affects the knee, hip, and hand joints. Osteoarthritis of the knee joint significantly affects everyday life, limiting daily activities. Patients affected by this disease face many ailments, such as pain, stiffness, and a reduced of range of joint motion. In order to implement quick and effective treatment and prevent the development of the disease, accurate and early diagnosis is important. This will contribute to prolonging the health of the joints. Available methods for diagnosing osteoarthritis include conventional radiography, MRI, and ultrasound, but these methods are not suitable for screening. Over the years, there have been proposals to use vibroarthrography as a new, cheap, and noninvasive screening method for cartilage damage. The paper reviews recent studies on vibroarthrography as a diagnostic method for knee osteoarthritis. The aim of the study is to organise the current knowledge regarding the diagnosis of osteoarthritis of the knee joint and vibroarthrography as a proposal for a new diagnostic method.

This paper focuses on the microstructure and tribological properties of novel hardfacing alloy based on Fe-C-Mn-B doped with Ni, Cr, and Si. The 4 mm-thick coating was deposited on the AISI 1045 carbon steel by the MIG-welding method using flux-cored wires in three passes. The transition zone thickness between the weld layers was ~80 μm, and the width of the substrate-coating interface was 5–10 μm. The following coating constituents were detected: coarser elongated M₂B borides, finer particles of Cr₇C₃ carbides, and an Fe-based matrix consisting of ferrite and austenite. The nanohardness of the matrix was ~5–6 GPa, carbides ~16–19 GPa, and borides 22–23 GPa. A high cooling rate during coating fabrication leads to the formation of a fine mesh of M₇C₃ carbides; borides grow in the direction of heat removal, from the substrate to the friction surface, while in the transition zone, carbides become coarser. The dry sliding friction tests using a tribometer in PoD configuration were carried out at contact pressure 4, 7, 10, and 15 MPa against the AISI 1045 carbon steel (water-quenched and low-tempered, 50–52 HRC). The leading wear phenomenon at 4 and 7 MPa is fatigue, and at 10 and 15 MPa it is oxidation and delamination.

Osteoarthritis (OA) is a severe and progressive joint disease that usually affects elderly people. The consequence of this disease in its advanced stage is the need for total knee arthroplasty (TKA). Over the years, there has been a constant increase in the number of TKA procedures, with a predicted increase to 1.26 million procedures by 2030. Diagnostics are based on conventional radiography, although advanced techniques such as radiostereometry, SPECT/CT and PET/CT, which enable early detection of micromigration, are gaining increasing recognition. Vibroarthrography (VAG) is a proposed supplement to diagnostics, enabling the assessment of the characteristics of vibrations and friction of joint surfaces, thus supporting the process of early detection of endoprosthesis instability. The combination of conventional and alternative diagnostic methods, including vibroarthrography, may improve the detection of early TKA loosening. This may also result in increased implant durability. The aim of this article is to review the current state of knowledge on the classification and analysis of endoprosthesis loosening mechanisms. In addition, classic and modern methods of detecting and monitoring loosening are discussed, with particular emphasis on vibroarthrography as a potential tool for early diagnosis.

Here determination of the level dimensions regularity of the multicomponent contamination zones (by heavy metals and petroleum products) of the soils adjacent to the municipal solid waste landfill. The dependences of the mercury, copper and zinc concentrations in the soil on the distance to the...

The work presents an innovative design of a vibrating machine for cleaning pollution with a pulsating immersed jet with solid particles and analytically obtained the dependence of the mass productivity of the machine on the design parameters of the machine and the modes of operation of the...