Metabolic dysregulation accelerates injury-induced joint degeneration, driven by local inflammation; an in vivo rat study

Evidence is growing for the existence of an obesity-related phenotype of osteoarthritis in which low-grade inflammation and a disturbed metabolic profile play a role. The contribution of an obesity-induced metabolic dysbalance to the progression of the features of osteoarthritis upon mechanically induced cartilage damage was studied in a rat in...

Radiographic progression of knee osteoarthritis is associated with MRI abnormalities in both the patellofemoral and tibiofemoral joint

Objective: To investigate patterns of MRI abnormalities in the patellofemoral (PFJ) and tibiofemoral joint (TFJ) and their association with radiographic progression, using hypothesis free analyses. Design: 205 patients from the GARP study with symptomatic OA at multiple sites (mean age 60 years, 80% woman, median BMI 26 kg/m2), underwent knee...

Evolution of synovitis in osteoarthritic knees and its association with clinical features

Objective: To investigate the course of synovitis on contrast-enhanced magnetic resonance images (CE-MRI) in osteoarthritic knees over 2 years, and its association with pain and cartilage deterioration. Design: Consecutive patients (n = 39, mean age 61 years, 79% woman, median (range) body mass index (BMI) 29 (24-48) kg/mm2) with clinical...

Inflammatory Cells in Patients with Endstage Knee Osteoarthritis: A Comparison between the Synovium and the Infrapatellar Fat Pad

Objective: To get a better understanding of inflammatory pathways active in the osteoarthritic (OA) joint, we characterized and compared inflammatory cells in the synovium and the infrapatellar fat pad (IFP) of patients with knee OA. Methods: Infiltrating immune cells were characterized by flow cytometry in 76 patients with knee OA (mean age 63...

Association of pain in knee osteoarthritis with distinct patterns of synovitis

Objective To determine possible patterns of synovitis on contrast-enhanced magnetic resonance imaging (CE-MRI) and its relation to pain and severity in patients with radiographic knee osteoarthritis (OA). Methods In total, 86 patients (mean age 62 years, 66% women, median body mass index 29 kg/m2) with symptomatic knee OA (Kellgren/Lawrence...

Degree of synovitis on MRI by comprehensive whole knee semi-quantitative scoring method correlates with histologic and macroscopic features of synovial tissue inflammation in knee osteoarthritis

Objective: To evaluate the association between synovitis on contrast enhanced (CE) MRI with microscopic and macroscopic features of synovial tissue inflammation. Method: Forty-one patients (mean age 60 years, 61% women) with symptomatic radiographic knee OA were studied: twenty underwent arthroscopy (macroscopic features were scored (0-4),...

Synovial inflammation, immune cells and their cytokines in osteoarthritis: A review

Objective: Although osteoarthritis (OA) is considered a non-inflammatory condition, it is widely accepted that synovial inflammation is a feature of OA. However, the role of immune cells and their cytokines in OA is largely unknown. This narrative systematic review summarizes the knowledge of inflammatory properties, immune cells and their...

Elevation of cartilage AGEs does not accelerate initiation of canine experimental osteoarthritis upon mild surgical damage

Osteoarthritis is a highly prevalent disease, age being the main risk factor. The age-related accumulation of advanced-glycation-endproducts (AGEs) adversely affects the mechanical and biochemical properties of cartilage. The hypothesis that accumulation of cartilage AGEs in combination with surgically induced damage predisposes to the...

Degeneration, inflammation, regeneration, and pain/disability in dogs following destabilization or articular cartilage grooving of the stifle joint

Objective: The most used model for joint instability is the canine anterior cruciate ligament transection (ACLT)-model. The ACLT-model can be extended with a medial meniscectomy (MX) (i.e., ACLT-MX-model) to avoid unintentional, and with that variable, meniscal damage. The present study compares the ACLT-MX-model with the more recently...

Erosive arthritis in a patient with pycnodysostosis: An experiment of nature

Objective. The excellent poster painter Henri de Toulouse-Lautrec is the most famous patient with cathepsin K-deficient pycnodysostosis. Cathepsin K is believed to play a major role in osteoclast-driven bone resorption. In this study we explored the role of cathepsin K in bone resorption in a patient with a cathepsin K mutation causing...

The canine 'groove' model, compared with the ACLT model of osteoarthritis

Objective: The frequently used anterior cruciate ligament transection (ACLT) model of osteoarthritis (OA) in the dog, makes use of a permanent trigger (joint instability) for inducing degenerative changes. The present study evaluates a canine model of degenerative cartilage damage, mimicking OA, which is induced without making use of permanent...

Steady progression of osteoarthritic features in the canine groove model

Objective: Recently we described a canine model of osteoarthritis (OA), the groove model with features of OA at 10 weeks after induction, identical to those seen in the canine anterior cruciate ligament transection (ACLT) model. This new model depends on cartilage damage accompanied by transient intensified loading of the affected joint. The...

Blood-induced joint damage: A canine in vivo study

Objective. To investigate the direct and indirect (via synovial inflammation) effects of intraarticular bleeding on cartilage in vivo. Methods. Right knees of 14 beagle dogs were injected with autologous blood on days 0 and 2. Cartilage matrix proteoglycan turnover, collagen damage, and synovial inflammation of these knees, including the...