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Journal of Anatomy Aug 2018The infrapatellar pad, a fibro-adipose tissue with peculiar microscopic and mechanical features, is gaining wide attention in the field of rheumatological research. The... (Review)
Review
The infrapatellar pad, a fibro-adipose tissue with peculiar microscopic and mechanical features, is gaining wide attention in the field of rheumatological research. The purpose of this descriptive review is to summarize the most recent published evidence on the anatomic, physiologic and biomechanical inter-relationship between the infrapatellar fat pad and the knee synovial membrane. As an extrasynovial tissue, the infrapatellar fat pad does not directly interact with the articular cartilage; based on its location in close contact with the synovial membrane, and due to the metabolic properties of adipose tissue, it may influence the behavior of the synovial membrane. In fact, considering evidence of macroscopic and microscopic anatomy, the infrapatellar fat pad is the site of insertion of the infrapatellar and medial synovial plicae. Also biochemically, there is much evidence highlighting the interaction among these two structures; in the case of inflammation, the mutual interplay is ascribable to the release of pro-inflammatory mediators stimulating the proliferation of inflammatory cells and promoting tissue modifications in both. All these assumptions could support the emerging idea that the infrapatellar fat pad and the synovial membrane may be considered a morpho-functional unit.
Topics: Adipose Tissue; Humans; Knee Joint; Synovial Membrane
PubMed: 29761471
DOI: 10.1111/joa.12820 -
Clinical Rheumatology Jul 2021Synovial biopsy techniques have developed and widely expanded over the past few years, in particular due to the development of ultrasound-guided procedures. This article... (Review)
Review
Synovial biopsy techniques have developed and widely expanded over the past few years, in particular due to the development of ultrasound-guided procedures. This article reviews the different techniques, clinical applications, and the latest advances in translational research as well as current challenges and perspectives. The first part focuses on different techniques available for biopsy, along with their feasibility, success rate, tolerance, and training requirements. In the second part, clinical applications are described. Data on diagnostic performances are reported, especially regarding septic arthritis. Translational research applications are described and explained in the final part, from the early histological studies and the first description of pathotype to more recent technologies involving -omics. Latest developments involving single-cell RNA sequence analysis have allowed the discovery of new cell subpopulations with remarkable roles in RA pathophysiology. These studies pave the ground for the discovery of new therapeutic targets and the implementation of personalized therapy in RA. Key Point •This review provides an overview of synovial biopsy techinques and applications especially in clinical and translational research.
Topics: Arthritis, Infectious; Biopsy; Humans; Synovial Membrane; Synovitis; Ultrasonography
PubMed: 33274415
DOI: 10.1007/s10067-020-05512-7 -
Frontiers in Immunology 2022Rheumatoid arthritis (RA) is a systemic autoimmune disease during which fibroblast-like synoviocytes (FLS) contribute to both joint inflammation and destruction. FLS... (Review)
Review
Rheumatoid arthritis (RA) is a systemic autoimmune disease during which fibroblast-like synoviocytes (FLS) contribute to both joint inflammation and destruction. FLS represent the core component of the synovial membrane. Following inflammation of this membrane, an effusion of cell-rich synovial fluid (SF) fills the joint cavity. Unlikely, SF has been shown to contain fibroblasts with some shared phenotypic traits with the synovial membrane FLS. These cells are called SF-FLS and their origin is still unclear. They are either brought into the synovium migration through blood vessels, or they could originate within the synovium and exist in projections of the synovial membrane. SF-FLS function and phenotype are poorly documented compared to recently well-characterized synovial membrane FLS subsets. Furthermore, no study has yet reported a SF-FLS single-cell profiling analysis. This review will discuss the origin and cellular characteristics of SF-FLS in patients with RA. In addition, recent advances on the involvement of SF-FLS in the pathogenesis of RA will be summarized. Current knowledge on possible relationships between SF-FLS and other types of fibroblasts, including synovial membrane FLS, circulating fibrocytes, and pre- inflammatory mesenchymal (PRIME) cells will also be addressed. Finally, recent therapeutic strategies employed to specifically target SF-FLS in RA will be discussed.
Topics: Arthritis, Rheumatoid; Fibroblasts; Humans; Inflammation; Synovial Fluid; Synoviocytes
PubMed: 35990693
DOI: 10.3389/fimmu.2022.942417 -
Cells Jun 2020An improved understanding of fundamental physiological principles and progressive pathophysiological processes in human articular joints (e.g., shoulders, knees, elbows)... (Review)
Review
An improved understanding of fundamental physiological principles and progressive pathophysiological processes in human articular joints (e.g., shoulders, knees, elbows) requires detailed investigations of two principal cell types: synovial fibroblasts and chondrocytes. Our studies, done in the past 8-10 years, have used electrophysiological, Ca imaging, single molecule monitoring, immunocytochemical, and molecular methods to investigate regulation of the resting membrane potential (E) and intracellular Ca levels in human chondrocytes maintained in 2-D culture. Insights from these published papers are as follows: (1) Chondrocyte preparations express a number of different ion channels that can regulate their E. (2) Understanding the basis for E requires knowledge of a) the presence or absence of ligand (ATP/histamine) stimulation and b) the extraordinary ionic composition and ionic strength of synovial fluid. (3) In our chondrocyte preparations, at least two types of Ca-activated K channels are expressed and can significantly hyperpolarize E. (4) Accounting for changes in E can provide insights into the functional roles of the ligand-dependent Ca influx through store-operated Ca channels. Some of the findings are illustrated in this review. Our summary diagram suggests that, in chondrocytes, the K and Ca channels are linked in a positive feedback loop that can augment Ca influx and therefore regulate lubricant and cytokine secretion and gene transcription.
Topics: Animals; Calcium; Chondrocytes; Humans; Membrane Potentials; Potassium; Synovial Fluid
PubMed: 32610485
DOI: 10.3390/cells9071577 -
Knee Surgery, Sports Traumatology,... Jul 2021To analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with subacromial impingement syndrome and compare them with samples...
PURPOSE
To analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with subacromial impingement syndrome and compare them with samples from male patients with post-traumatic recurrent shoulder instability, to detect increased inflammatory activity that might be present inside the humeroscapular joint.
METHODS
Twenty male patients scheduled for surgery for either subacromial decompression or Bankart reconstruction were included. Four biopsies from each patient were obtained during surgery from the capsule and the subscapularis tendon. Each specimen was analyzed for TNF-α, IL-6, CD-3 and CD-72. Multiplex fluorescence immunohistochemistry was performed on histological samples from the capsule and tendon to demonstrate the level of inflammatory markers. Fluorescence microscope images were acquired using an automated scanning system. On each slide, the number of pixels was registered and used in the analyses.
RESULTS
The subacromial impingement syndrome group comprised eight patients, median age 53 (45-74) years, while the instability group 12, median age 27 (22-48) years (p < 0.00001). The amount of IL-6 and TNF-α was significantly higher in the subscapularis tendon of the patients with subacromial impingement syndrome compared with instability patients (p = 0.0015 and p = 0.0008 respectively). In the capsular samples, significantly higher amount of TNF-α and CD-72 was found in patients with subacromial impingement syndrome compared with instability patients (p < 0.0001 for both). On the other hand, the amount of CD-3 was significantly higher in the instability group (p = 0.0013).
CONCLUSIONS
This study provides evidence that an extended inflammatory process is present, not only in the subacromial bursa but also in the glenohumeral joint in patients with subacromial impingement syndrome.
LEVEL OF EVIDENCE
Level III.
CLINICAL RELEVANCE
To develop a treatment targeted towards intra-articular inflammatory cytokines appears appealing.
Topics: Aged; Biomarkers; Biopsy; Bursa, Synovial; Cytokines; Decompression, Surgical; Humans; Inflammation; Interleukin-6; Joint Capsule; Joint Instability; Male; Middle Aged; Plastic Surgery Procedures; Rotator Cuff; Shoulder; Shoulder Impingement Syndrome; Shoulder Joint; Tendons; Tumor Necrosis Factor-alpha
PubMed: 32356046
DOI: 10.1007/s00167-020-05992-9 -
Cells Mar 2022In cancers and other complex diseases, the fusion of two genes can lead to the production of chimeric RNAs, which are associated with disease development. Several...
In cancers and other complex diseases, the fusion of two genes can lead to the production of chimeric RNAs, which are associated with disease development. Several recurrent chimeric RNAs are expressed in different cancers and are thus used for clinical cancer diagnosis. Rheumatoid arthritis (RA) is an immune-mediated joint disorder resulting in synovial inflammation and joint destruction. Despite advances in therapy, many patients do not respond to treatment and present persistent inflammation. Understanding the landscape of chimeric RNA expression in RA patients could provide a better insight into RA pathogenesis, which might provide better treatment strategies and tailored therapies. Accordingly, we analyzed the publicly available RNA-seq data of synovium tissue from 151 RA patients and 28 healthy controls and were able to identify 37 recurrent chimeric RNAs found to be expressed in at least 3 RA samples. Furthermore, the parental genes of these 37 recurrent chimeric RNAs were found to be differentially expressed and enriched in immune-related processes, such as adaptive immune response and the positive regulation of B-cell activation. Interestingly, the appearance of 5 coding and 23 non-coding chimeric RNAs might be associated with regulating their parental gene expression, leading to the generation of dysfunctional immune responses, such as inflammation and bone destruction. Therefore, in this paper, we present the first study to demonstrate the novel chimeric RNAs that are highly expressed and functional in RA.
Topics: Arthritis, Rheumatoid; Humans; Inflammation; RNA; Synovial Membrane
PubMed: 35406656
DOI: 10.3390/cells11071092 -
The British Journal of Radiology 2016Ultrasound-guided needle biopsy of synovium is an increasingly performed procedure with a high diagnostic yield. In this review, we discuss the normal synovium, as well... (Review)
Review
Ultrasound-guided needle biopsy of synovium is an increasingly performed procedure with a high diagnostic yield. In this review, we discuss the normal synovium, as well as the indications, technique, tissue handling and clinical applications of ultrasound-guided synovial biopsy.
Topics: Humans; Image-Guided Biopsy; Synovial Membrane; Ultrasonography, Interventional
PubMed: 26581578
DOI: 10.1259/bjr.20150363 -
International Journal of Environmental... Jul 2021Osteoarthritis (OA) of the glenohumeral (GH) joint is a common cause of shoulder pain, resulting in considerable invalidity. Unfortunately, the study of its pathogenesis...
Arthroscopic Tenotomy of the Long Head of the Biceps Tendon and Section of the Anterior Joint Capsule Produce Moderate Osteoarthritic Changes in an Experimental Sheep Model.
Osteoarthritis (OA) of the glenohumeral (GH) joint is a common cause of shoulder pain, resulting in considerable invalidity. Unfortunately, the study of its pathogenesis is challenging. Models of OA are necessary to identify specific targets for therapy and to be able to interfere with the development and evolution of OA. This study aims to assess the effect of an arthroscopic tenotomy of the long head of the biceps tendon (LHBT) and section of the anterior glenohumeral joint capsule on the ovine glenohumeral joint. In addition, the authors aim to validate and evaluate the reliability of a modified semi-quantitative MRI score to assess joint degeneration in a sheep's shoulder. Eight skeletally mature sheep received an arthroscopic tenotomy of the LHBT and section of the anterior joint capsule and were euthanized four months after surgery. All animals tolerated the surgery well, and no complication was recorded for six weeks. Moderate degenerative changes to the ovine shoulder joint were found on MRI and histological evaluation. The arthroscopic tenotomy of the LHBT and the anterior glenohumeral joint capsule section caused moderate degenerative changes to the ovine shoulder joint.
Topics: Animals; Joint Capsule; Reproducibility of Results; Rotator Cuff Injuries; Sheep; Shoulder Joint; Tendons; Tenotomy
PubMed: 34299937
DOI: 10.3390/ijerph18147471 -
Knee Surgery, Sports Traumatology,... Dec 2023The purpose of this in vitro study was to investigate whether or not hyaluronic acid supplementation improves knee joint friction during osteoarthritis progression under...
PURPOSE
The purpose of this in vitro study was to investigate whether or not hyaluronic acid supplementation improves knee joint friction during osteoarthritis progression under gait-like loading conditions.
METHODS
Twelve human cadaveric knee joints were equally divided into mild and moderate osteoarthritic groups. After initial conservative preparation, a passive pendulum setup was used to test the whole joints under gait-like conditions before and after hyaluronic acid supplementation. The friction-related damping properties given by the coefficient of friction µ and the damping coefficient c (in kg m/s) were calculated from the decaying flexion-extension motion of the knee. Subsequently, tibial and femoral cartilage and meniscus samples were extracted from the joints and tested in an established dynamic pin-on-plate tribometer using synthetic synovial fluid followed by synthetic synovial fluid supplemented with hyaluronic acid as lubricant. Friction was quantified by calculating the coefficient of friction.
RESULTS
In the pendulum tests, the moderate OA group indicated significantly lower c values (p < 0.05) under stance phase conditions and significantly lower µ (p = 0.01) values under swing phase conditions. No degeneration-related statistical differences were found for µ or c. Friction was not significantly different (p > 0.05) with regard to mild and moderate osteoarthritis in the pin-on-plate tests. Additionally, hyaluronic acid did not affect friction in both, the pendulum (p > 0.05) and pin-on-plate friction tests (p > 0.05).
CONCLUSION
The results of this in vitro study suggested that the friction of cadaveric knee joint tissues does not increase with progressing degeneration. Moreover, hyaluronic acid viscosupplementation does not lead to an initial decrease in knee joint friction.
Topics: Humans; Hyaluronic Acid; Cartilage, Articular; Friction; Knee Joint; Osteoarthritis; Synovial Fluid; Cadaver
PubMed: 37843587
DOI: 10.1007/s00167-023-07602-w -
Antimicrobial Agents and Chemotherapy Mar 2021The objectives of this study were to evaluate the population pharmacokinetics of prophylactic cefazolin (CFZ) from its serum and hip joint capsule concentrations in...
The objectives of this study were to evaluate the population pharmacokinetics of prophylactic cefazolin (CFZ) from its serum and hip joint capsule concentrations in patients undergoing total hip arthroplasty and to establish the pharmacodynamic target concentration exceeding the MIC for designing an effective dosing regimen for serum and the hip joint capsule. We analyzed 249 serum samples and 125 hip joint capsule samples from 125 individuals using a nonlinear mixed-effects model. The pharmacodynamic index target value obtained from our results indicates the probability of maintaining CFZ trough and hip joint capsule concentrations exceeding the MIC of 1 mg/liter to account for methicillin-susceptible (MSSA). We estimated the population pharmacokinetics using a two-compartment model. The estimated population pharmacokinetic parameters were as follows: clearance (CL) (liters/h) = 1.46 × (creatinine clearance [CL] [ml/min]/77), volume of distribution of the central compartment (V) (liters) = 7.5, central-hip joint capsule compartment clearance (Q) (liters/h) = 3.38, and volume of distribution in the hip joint capsule compartment (V) (liters) = 36.1. The probability of achieving concentrations exceeding the MIC for MSSA was approximately 100% for serum and 100% for the hip joint capsule at 3 h after the initial dose. Our findings suggest that population-based parameters are useful for evaluating CFZ pharmacokinetics and that individual dosages should be determined based on the dosage regimen that achieves and maintains adequate tissue CFZ concentration.
Topics: Anti-Bacterial Agents; Arthroplasty, Replacement, Hip; Cefazolin; Humans; Joint Capsule; Microbial Sensitivity Tests; Staphylococcus aureus
PubMed: 33526489
DOI: 10.1128/AAC.02114-20