The development of gonarthrosis (GA) involves inflammatory processes; the role of reactive oxygen species (ROS) is being increasingly mentioned. The body is protected from oxidative damage by the antioxidative barrier with fundamental role being played by antioxidative enzymes, such as superoxide dismutase (SOD), catalase (CAT) and enzymes involved in glutathione transformations, particularly glutathione peroxidase (GPx). The methods of treatment of cartilage depend on the disease advancement, patient's reactions to pain, disease-related impairment in daily activities, as well as the age and overall health of the patient. Viscosupplementation involving intra-articular injection of agents that increase the viscosity of the articular fluid is aimed at reducing the friction between articular surfaces and thus at reducing pain and excessive wear of the remaining articular cartilage. The objective of the study was to examine whether intra-articular administration of a hyaluronic acid agent has any effect on the function of the knee and on the selected biochemical parameters of the articular fluid and blood in gonarthrosis, as well as to demonstrate of correlation or no correlation between the effects of viscosupplementation and administration of hyaluronic acid into a knee containing articular fluid or a "dry" knee.
The study group consisted of 22 gonarthrosis patients who received hyaluronic acid into the knee containing the articular fluid (group PS) as per the study protocol and 27 gonarthrosis patients who received hyaluronic acid into the "dry" knee (group PPI). The study lasted about 40 weeks and involved 10 visits at the study site. Hyaluronic acid was administered intra-articularly upon the first three visits held in one-week intervals, as well as on visit 4 (12 weeks after visit 3). The study knee was assessed clinically at all visits using the osteoarthritis WOMAC scale, visual assessment scale (0-10) for the assessment of pain intensity and HHS questionnaire for clinical assessment of the knee function. Blood for study-related analyses was collected at study start and 12 weeks after administration of the third dose of hyaluronic acid. The activity of superoxide dismutase (SOD) within the articular fluid and plasma and plasma levels of MDA were determined. Results Worse WOMAC-scale quality of life was observed in patients with osteoarthrosis and "dry" knee, mostly due to higher joint stiffness. Following viscosupplementation treatment, improvement in all tested WOMAC scores was observed in both groups, and no significant differences between groups was observed. The SOD activity and the MDA levels in plasma did not differ between the study groups, both before the study and after viscosupplementation. No statistically significant changes were observed in the biochemical parameters following viscosupplementation in both groups other than for reduced articular fluid MDA levels in the PS group.
Viscosupplementation with hyaluronic acid administration is an effective method of conservative treatment in patients with gonarthrosis. Its beneficial effect consists mostly of pain reduction and knee function improvement both in patients with articular fluid present within the knee joints as in patients with "dry" knee joints.