Disuse Atrophy of the Articular Cartilage and Its Relationship to Osteoarthritis

Abstract

Mechanical stress, especially loading, is essential for the histological and functional maintenance of articular cartilage. However, in clinical practice, treatments for several diseases are accompanied by bed rest, and there are opportunities to reduce the loading on the lower limbs. Immobility and inactivity have been reported to cause disuse histological changes in both the skeletal muscle and the bone. Similarly, many researchers in basic and clinical studies reported that the unloading environment induces the disuse histological changes in the articular cartilage, and in 2019, “disuse atrophy in articular cartilage” was proposed. The histological changes were mainly due to the thinning of the cartilage and the decrease of the matrix staining intensity.
Also, in 2019, our research group reported that the unloading environment for 4 weeks induced these histological changes of the cartilage in the medial tibiofemoral joint using the hindlimb suspension rat model. In this review, the findings on articular cartilage, loading, and osteoarthritis that our research group has been working on were reviewed, and also results of the ongoing research were introduced.