Effects of immobilization and remobilization on the ankle joint in Wistar rats

Abstract

A sprained ankle is a common musculoskeletal sports injury and it is often treated by immobilization of the joint. Despite the beneficial effects of this therapeutic measure, the high prevalence of residual symptoms affects the quality of life, and remobilization of the joint can reverse this situation. The aim of this study was to analyze the effects of immobilization and remobilization on the ankle joint of Wistar rats. Eighteen male rats had their right hindlimb immobilized for 15 days, and were divided into the following groups: G1, immobilized; G2, remobilized freely for 14 days; and G3, remobilized by swimming and jumping in water for 14 days, performed on alternate days, with progression of time and a series of exercises. The contralateral limb was the control. After the experimental period, the ankle joints were processed for microscopic analysis. Histomorphometry did not show any significant differences between the control and immobilized/remobilized groups and members, in terms of number of chondrocytes and thickness of the articular cartilage of the tibia and talus. Morphological analysis of animals from G1 showed significant degenerative lesions in the talus, such as exposure of the subchondral bone, flocculation, and cracks between the anterior and mid-regions of the articular cartilage and the synovial membrane. Remobilization by therapeutic exercise in water led to recovery in the articular cartilage and synovial membrane of the ankle joint when compared with free remobilization, and it was shown to be an effective therapeutic measure in the recovery of the ankle joint.

Remobilization causes site‐specific cyst formation in immobilization‐induced knee cartilage degeneration in an immobilized rat model

“…Remobilization is one approach used to prevent or reduce this degeneration (Kunz et al. ). The articular cartilage consists of chondrocytes embedded in abundant extracellular matrix (ECM); this tissue is hypovascular and thus has the lowest potential for restoration.…”

“…Joint immobilization causes decreased mobility and functional impairment consequent to the degeneration of joint structures, such as articular cartilage, or restriction of the range of joint motion (ROM). Remobilization is one approach used to prevent or reduce this degeneration (Kunz et al 2014). The articular cartilage consists of chondrocytes embedded in abundant extracellular matrix (ECM); this tissue is hypovascular and thus has the lowest potential for restoration.…”

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

“…Moreover, according to Hui, McCarty, Masuda, Firestein, Sah 13 , the composition and function of synovial fluid are also altered in cases of joint injury or disease. These changes can result in reduced ability to lubricate the articular cartilage, which can contribute to its deterioration, as already described in the literature 12 . Free swimming 14,15 , swimming associated with electrical stimulation 16 and resistance exercises 17,18,19 have been investigated as therapeutic modalities in peripheral nerve lesions.…”

“…The morphological and morphometric analyses of the articular tissues were performed using a light microscope (Olympus ® ) and the visual fields of interest were photomicrographed using 20 and 40 lenses. The protocol for the measurement of the articular cartilage thickness and the number of chondrocytes was the same as used by Kunz, Coradini, Silva, Bertolini, Brancalhão, Ribeiro 12 , which defined the areas of interest as the regions of the anterior joint (P1), middle joint (P2) and posterior joint (P3). Apart from the morphometry, the morphological characteristics of the articular cartilage were also observed, such as the appearance of the articular surface and the presence of cracks, pannus, flocculation and cell clones, as well as the subchondral bone and the synovial membrane.…”

“…Common symptoms of these nervous injuries include dormancy, paresthesia, weakness and atrophy of the effector muscles, as well as the impairment of the normal functions and movements of the lower limbs, since this musculature affects the motricity of the joints 3, 4 , including the ankle, which is responsible for providing a stable base of support for the body, in addition to effectively propelling it during locomotion 5 . Thus, nerve lesions lead to the disuse of the limb and, as a consequence, there is a reduction in the mechanical stimulus necessary to maintain the morphological properties of the joint [6][7][8][9] , which can lead to rigidity of the joint capsule and consequent restriction in movement 10 , as well as atrophic changes in the articular cartilage with a reduction in its thickness and the number of chondrocytes 11,12 . Moreover, according to Hui, McCarty, Masuda, Firestein, Sah 13 , the composition and function of synovial fluid are also altered in cases of joint injury or disease.…”