Effects of equine joint injury on boundary lubrication of articular cartilage by synovial fluid: Role of hyaluronan

Objective. Hemophilic arthropathy is characterized by recurrent bleeding episodes in patients with hemophilia leading to irreversible joint degeneration. The involvement of CX3CL1 (fractalkine) and its receptor CX3CR1 was observed in the pathogenesis of numerous arthritis-associated diseases. Taking this into account, we have presented a study investigating the role of the CX3CL1/CX3XR1 axis in the course of hemophilic arthropathy, including the CX3CL1-dependent expression of CD56+, CD68+, and CD31+ cells along with evaluation of articular cartilage and synovial membrane morphology. Methods. The study was carried out using cases (n=20) of end-stage hemophilic arthropathy with a severe type of hemophilia A and control cases (n=20) diagnosed with osteoarthritis. The biofluids including blood serum and synovial fluid were obtained intraoperatively for the evaluation of CX3CL1 using the ELISA test. Tissue specimens including articular cartilage and synovial membrane were similarly collected during surgery and stained immunohistologically using selected antibodies including anti-CX3CR1, anti-CD56, anti-CD68, and anti-CD31. Additionally, the analysis included the assessment of articular cartilage, synovial membrane, and blood vessel morphology. Results. In our study, we have documented increased average concentration of CX3CL1 in the blood serum of the study group (7.16±0.53 ng/ml) compared to the control group (5.85±0.70 ng/ml) without statistically significant difference in synovial fluid concentration at the same time. We have observed an increased macrophage presence with more marked proliferation and fibrosis of the synovial membrane in the study group. Remaining results such as expression of CX3CR1 presence of NK cells and larger surface area of blood vessels within the synovial membrane were noted also without statistical significance. Conclusions. This study has demonstrated collective CX3CL1/CX3CR1 axis involvement in hemophilic arthropathy pathogenesis introducing new interesting diagnostics and a therapeutic target.

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Subchondral bone remodelling in osteoarthritis

EFORT Open Reviews ◽

10.1302/2058-5241.4.180102 ◽

2019 ◽

Vol 4 (6) ◽

pp. 221-229 ◽

Cited By ~ 8

Author(s):

Simon Donell

Keyword(s):

Bone Marrow ◽

Articular Cartilage ◽

Synovial Fluid ◽

Subchondral Bone ◽

Bone Cells ◽

Bone Remodelling ◽

Delayed Union ◽

Osteophyte Formation ◽

Subchondral Sclerosis

Subchondral bone remodelling is an integral part of osteoarthritis and involves the development of subchondral sclerosis seen on plain imaging, along with osteophyte formation. The development of these changes is due to persistent abnormal mechanical stresses which create a cellular and biomolecular response to microfractures in the subchondral bone and osteochondral junction. An early sign is bone marrow lesions seen on MRI scanning. Healing can occur at this stage by correcting the abnormal loads. Persistence leads to what is thought to be a delayed union or nonunion response by the bone. Microfractures of the osteochondral junction, coupled with articular cartilage fissuring and loss, allows synovial fluid to penetrate the subchondral bone along with cytokines and other molecules reacting with the bone cells to increase the pathological effects. This review gives an overview of the current thoughts on subchondral bone remodelling in osteoarthritis that is aimed at orthopaedic surgeons to help in the understanding of the pathogenesis of osteoarthritis and the role of surgical management. Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180102

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MICROSCOPIC TRIBOLOGICAL ANALYSIS OF THE KNEE JOINT

Tribologia ◽

10.5604/01.3001.0010.6249 ◽

2018 ◽

Vol 273 (3) ◽

pp. 147-154

Author(s):

Anna M. RYNIEWICZ ◽

Andrzej RYNIEWICZ ◽

Anna PUKALUK ◽

Paweł PAŁKA

Keyword(s):

Articular Cartilage ◽

Synovial Fluid ◽

Knee Joint ◽

Superficial Layer ◽

Ground Substance ◽

Atomic Force ◽

Electron Microscopes ◽

Tribological Analysis ◽

Scanning Electron Microscopes

The aim of the conducted research was the evaluation of the topography and the structure of the superficial layer of meniscus and articular cartilage. These are surfaces that optimise the friction and lubrication process in the knee joint. The animal samples of the menisci and the articular cartilage were examined. The research was performed using scanning electron microscopes and an atomic force microscope. The structure of the surface of meniscus and articular cartilage is very regular. The collagenous fibres, which are embedded in the ground substance, are parallel to the surface. The undulation of the surface was observed. In the area of the anterior horn on tibia side of both menisci as well as in the anterior area of tibial plateau, the concavity and convexity pattern is evident. The observed cavities enable the accumulation of the synovial fluid. The synovial fluid plays the role of the lubricant in the knee joint, and its presence is highly desired during the load transmission.

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Biomarkers in the serum, synovial fluid and articular cartilage show promising utility in patients with femoroacetabular impingement: a systematic review

Journal of ISAKOS Joint Disorders & Orthopaedic Sports Medicine ◽

10.1136/jisakos-2017-000165 ◽

2017 ◽

Vol 3 (3) ◽

pp. 167-176 ◽

Cited By ~ 1

Author(s):

Jeffrey Kay ◽

Muzammil Memon ◽

Vito Z Zou ◽

Andrew Duong ◽

Nicole Simunovic ◽

...

Keyword(s):

Systematic Review ◽

Articular Cartilage ◽

Synovial Fluid ◽

Femoroacetabular Impingement ◽

Matrix Protein ◽

Potential Role ◽

Cartilage Damage ◽

Cost Effective ◽

Level Of Evidence

ImportanceBiomarkers have promising potential to provide a cost-effective tool to identify patients with femoroacetabular impingement (FAI) who are most at risk and who may benefit most from early joint preservation surgery.ObjectiveTo assess the potential role of biomarkers in the diagnosis and prognosis of FAI.Evidence reviewThree databases (PubMed, Ovid (MEDLINE) and Embase) were searched on 20 August 2017 from database inception, and two reviewers independently and in duplicate screened the resulting literature. Methodological quality of all included papers was assessed using the Methodological Index for Non-Randomized Studies criteria. The results are presented in a narrative summary fashion using descriptive statistics including means, proportions and ranges.FindingsSeven studies (one retrospective laboratory series and six controlled laboratory studies) were identified including a total of 227 patients. The mean age of the patients was 41.6 years (range: 13–80), with a mean follow-up period of 29.9 months (SD=3.2). Markers of articular cartilage breakdown, including cartilage oligomeric matrix protein (COMP) and fibronectin–aggrecan complex (FAC), were identified in high concentrations in the serum and synovial fluid of patients with FAI, respectively. Moreover, mRNA expression of catabolic cytokines in the articular cartilage of patients with FAI has been reported.Conclusions and relevanceAlthough not yet used in clinical settings, several biomarkers of articular cartilage damage have been identified in the serum, synovial fluid and articular cartilage of patients with FAI. These findings provide promising insight into the potential role of biomarkers in guiding clinical practice and assisting with patient selection and preoperative counselling in patients with FAI and should be evaluated further.Level of evidenceIV, systematic review of level III and IV studies.

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Paper 12: Modes of Lubrication in Human Joints

Proceedings of the Institution of Mechanical Engineers Conference Proceedings ◽

10.1243/pime_conf_1966_181_206_02 ◽

1966 ◽

Vol 181 (10) ◽

pp. 45-54 ◽

Cited By ~ 22

Author(s):

D. Dowson

Keyword(s):

Articular Cartilage ◽

Synovial Fluid ◽

Boundary Lubrication ◽

Bearing Material ◽

Modes Of Operation ◽

Basic Properties ◽

Lubrication Regimes ◽

Basic Characteristics ◽

Human Joints ◽

Lubrication Conditions

The various lubrication regimes encountered in engineering are listed and the basic characteristics of each regime described. This survey covers hydrodynamic, elastohydrodynamic, mixed, and boundary lubrication conditions. The geometric, kinematic, and loading conditions in human joints are examined, and the basic properties of synovial fluid and articular cartilage, as the lubricant and bearing material respectively, noted. An assessment of the hydrodynamic, boundary, weeping, and elastohydrodynamic modes of operation which have been proposed as explanations of the performance of human joints is presented.

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