Why does prolonged immobilization of a joint, such as after casting a fractured limb, increase the risk of osteoarthritis despite reduced mechanical loading?

💡 Explanation

Prolonged immobilization alters chondrocyte metabolism because the lack of joint loading reduces the convective transport of nutrients and waste products within the cartilage matrix. Therefore, chondrocytes experience metabolic stress, increasing osteoarthritis risk, rather than the alternative outcomes mediated by angiogenesis or synovial fluid.

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