Resistance exercise recovers the structure of cartilage and synovial membrane of the ankle joint of rats after sciatic compression

Aim: to determine the effects of sciatic compression and treatment with resistance exercise on the morphology of the ankle joint of Wistar rats. Methods: 32 male rats, aged 10 ± 1 week, weighing 376±22 grams were divided into the following four groups (n=8/group): CG (control), LG (lesion), EG (exercise) and LEG (lesion and exercise). Three days after sciatic compression, the animals in the EG and LEG were submitted to resistance exercise by climbing stairs (five days/week) for three weeks and a load of 100 grams was added. The exercise was carried out in two sets of ten consecutive ascents of the steps. The ankle joint tissues were analyzed for their morphometry and morphology using light microscopy. Results: Regarding the number of chondrocytes, the LG and EG had more cells in the anterior articular cartilage in the tibia (62 and 43%) and in the talus (57 and 45%) when compared to the CG. In the LEG there was a 25% and 26% reduction of chondrocytes in the anterior cartilage in the tibia and talus when compared to the LG. Changes were observed in the tibia and talus in the LG, with the presence of flocculation, invagination of the subchondral bone, discontinuity of tidemark and pannus covering the subchondral bone in the talus, as well as changes in the synovial membrane. These alterations were minimized in the articular cartilage and synovial membrane in the LEG. Conclusions: exercise restores the tissue morphology of ankle joint in Wistar rats after sciatic compression.