Use of hyaluronic acid associated with triamcinolone acetonide or ozone gas in the treatment of induced osteoarthritis in rabbits

Purpose: To evaluate the effects of the intra-articular application of hyaluronic acid associated with triamcinolone acetonide, and ozone gas in the treatment of induced osteoarthritis in rabbit’s stifles.Methods: Twenty-one Norfolk rabbits were submitted to cranial cruciate ligament transection of the left stifle. After six weeks of the surgery, the rabbits were randomized assigned into three groups: G1 (control) – saline solution (0.9%); G2 – hyaluronic acid associated with triamcinolone; G3 – ozone gas, submitted to three intra-articular applications every seven days. Results: Significant differences occurred: osteophytes at medial femoral condyle (G2 > G1, G2 > G3) on radiography exam; thickening of the medial condyle (G1 > G3, G2 > G3) on ultrasound exam; osteophytes at lateral tibial condyle (G2 > G1, G2 > G3), and medial femoral condyle (G1 > G2, G3 > G1) on computed tomography. Histologically, mean values of chondrocytes in the femur and tibia in G3 and G2 were statistically lower. Conclusions: The intra-articular injection of hyaluronic acid associated with triamcinolone accentuated degenerative joint disease by imaging and macroscopic evaluations, and by histological findings, this treatment and the ozone gas treatment showed similar effects and were inferior to the saline solution (0.9%).

Hyaluronic acid in tobacco-exposed rats. Inflammatory reaction, and duration of effect

Purpose:To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats.Methods:Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE.Results:This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39).Conclusions:This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.(AU)