Aims: 

The arthritis syndrome embraces various joint disorders with distinct etiologies, ranging from osteoarthritis to rheumatoid arthritis and gout, and the consequences include pain and reduced joint motility. Classical clinical signs of arthritis such as rubor/redness and tumor/swelling are typical to joint inflammation and these reactions are originating from pathophysiological alterations in the microcirculation of the synovial membrane. In contrast, periosteal microcirculatory inflammatory reactions of the periosteum are usually non-infections in nature and mostly brought about by therapeutic interventions (tourniquet and free flap surgery). The consequences affect the major function of the periosteum including nutrition of the bones and mesenchymal osteoprogenitor cell production. In our microcirculatory studies, the pathological consequences of arthritis in the synovial membrane and the effects of ischemia-reperfusion (IR) in the periosteum were examined and characterized.

Methods: 

Fluorescence intravital videomicroscopy was used to visualize the tibial periosteal and the synovial microcirculation with a new method.

Results: 

Microcircirculatory impairment is characterized by increased polymorphonuclear leukocyte (PMN)-endothelial interactions, enhanced adhesion molecule expression and a reduction in microvascular perfusion in both tissue types. In carrageenan-kaolin-induced monoarthritis, interventions targeting the PMN-mediated reactions reduced knee volumes and were also associated with lower degree of nociceptive sensitivity of the limbs, suggesting a causative role of PMN-dependent reactions in the pathogenesis of knee inflammation. IR of the limbs evoked by tourniquet application was associated with remarkable degree of microcirculatory failure in the periosteum and a lesser extent of reactions in the synovium. Limb IR also brought about systemic inflammatory activation. Both local periosteal and systemic inflammatory complications of limb IR could effectively be modulated by estrogen treatment, colloid solutions and ischemic preconditioning of the limb.

Conclusion: 

Differences in ischemic sensitivity between the periosteum and synovium necessitate the application of tissue-specific therapeutic interventions targeting the microcirculation.

Support: 

TAMOP-4.2.1/B-09/1/KONV-2010-0005 and TAMOP-4.2.2-08/1-2008-0013