The induction of ischemic osteonecrosis in immature pigs produces IL-6 in articular cartilage through a hif-1-dependent pathway, and IL-6 produced by hypoxic articular chondrocytes further stimulates the inflammatory cytokine response in synoviocytes, leading to the development of hip synovitis after osteonecrosis. Here, HIF1A is linked to osteonecrosis.