The innate immune system consists of functionally specialized "modules" that are activated in response to a particular set of stimuli via sensors located on the surface or inside the tissue cells. These cells screen tissues for a wide range of exogenous and endogenous danger/damage-induced signals with the aim to reject or tolerate them and maintain tissue integrity. In this line of thinking, inflammation evolved as an adaptive tool for restoring tissue homeostasis. A number of diseases are mediated by a maladaptation of the innate immune response, perpetuating chronic inflammation and tissue damage. Here, we review recent evidence on the cross talk between innate immune sensors and development of rheumatoid arthritis, osteoarthritis, and aseptic loosening of total joint replacements. In relation to the latter topic, there is a growing body of evidence that aseptic loosening and periprosthetic osteolysis results from long-term maladaptation of periprosthetic tissues to the presence of by-products continuously released from an artificial joint.

• MeSH
• Lectins, C-Type metabolism   MeSH
• Humans MeSH
• Osteoarthritis immunology   physiopathology   MeSH
• Osteolysis physiopathology   MeSH
• Immunity, Innate physiology   MeSH
• Joint Prosthesis adverse effects   MeSH
• Receptor for Advanced Glycation End Products MeSH
• Receptors, Cytoplasmic and Nuclear metabolism   MeSH
• Receptors, Immunologic metabolism   MeSH
• Arthritis, Rheumatoid immunology   physiopathology   MeSH
• Nod Signaling Adaptor Proteins metabolism   MeSH
• Toll-Like Receptors metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Lectins, C-Type MeSH
• Receptor for Advanced Glycation End Products MeSH
• Receptors, Cytoplasmic and Nuclear MeSH
• Receptors, Immunologic MeSH
• Nod Signaling Adaptor Proteins MeSH
• Toll-Like Receptors MeSH

BACKGROUND: At present time the number of implantations of joint replacements as well as their revisions increases. Higher demands are required on the quality and longevity of implants. The aim of this work was to determine the degree of oxidative degradation and the amount of free/residual radicals in selected ultra-high molecular weight polyethylene (UHMWPE) components of the joint replacements and demonstrate that the measured values are closely connected with quality and lifetime of the polymer components. METHODS: We tested both new (4 samples) and explanted (4 samples) UHMWPE polymers for total joint replacements. The samples were characterized by infrared spectroscopy (IR), electron spin resonance (ESR) and microhardness (MH) test. The IR measurements yielded the values of oxidation index and trans-vinylene index. The ESR measurements gave the free radicals concentration. RESULTS: In the group of new polyethylene components, we found oxidation index values ranging from 0.00-0.03 to 0.24. The trans-vinylene index values ranged from 0.044 to 0.080. The value of free radical concentration was zero in virgin and also in sample of Beznoska Company and non-zero in the other samples. In the group of explanted components, the measured values were associated with their history, micromechanical properties and performance in vivo. CONCLUSIONS: We demonstrated that measuring of oxidative damage may help the orthopaedic surgeon in estimating the quality of UHMWPE replacement component and thus radically to avoid early joint replacement failure due to worse polyethylene quality.

• MeSH
• Biocompatible Materials chemistry   MeSH
• Electron Spin Resonance Spectroscopy MeSH
• Crystallization MeSH
• Hip Prosthesis * MeSH
• Humans MeSH
• Oxidation-Reduction MeSH
• Polyethylenes chemistry   MeSH
• Knee Prosthesis * MeSH
• Reoperation MeSH
• Prosthesis Failure MeSH
• Spectrophotometry, Infrared MeSH
• Materials Testing MeSH
• Hardness MeSH
• Free Radicals analysis   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Biocompatible Materials MeSH
• Polyethylenes MeSH
• ultra-high molecular weight polyethylene MeSH Browser
• Free Radicals MeSH

Wear debris, of deferent sizes, shapes and quantities, generated in artificial hip and knees is largely confined to the bone and joint interface. This debris interacts with periprosthetic tissue and may cause aseptic loosening. The purpose of this review is to summarize and collate findings of the recent demonstrations on debris characterization and their biological response that influences the occurrence in implant migration. A systematic review of peer-reviewed literature is performed, based on inclusion and exclusion criteria addressing mainly debris isolation, characterization, and biologic responses. Results show that debris characterization largely depends on their appropriate and accurate isolation protocol. The particles are found to be non-uniform in size and non-homogeneously distributed into the periprosthetic tissues. In addition, the sizes, shapes, and volumes of the particles are influenced by the types of joints, bearing geometry, material combination, and lubricant. Phagocytosis of wear debris is size dependent; high doses of submicron-sized particles induce significant level of secretion of bone resorbing factors. However, articles on wear debris from engineered surfaces (patterned and coated) are lacking. The findings suggest considering debris morphology as an important parameter to evaluate joint simulator and newly developed implant materials.

• Keywords
• biological response, isolation, morphology, nano-toxicity, wear debris,
• Publication type
• Journal Article MeSH
• Review MeSH