When a child suddenly refuses to put weight on one leg, or when an adult develops an unexplained deep ache in the hip that appeared without obvious cause, the experience is disorienting. Transient synovitis — an acute inflammation of the synovial membrane lining the hip joint — is the most common cause of acute hip pain in children between three and twelve years old, and it also affects…

Receiving a diagnosis of avascular necrosis (AVN) of the hip—also known as osteonecrosis of the femoral head—can feel like a sudden and silent betrayal by your own body. The primary bone in your hip joint, starved of blood, begins to suffer micro-fractures, initiating a cascade that can lead to joint collapse and severe osteoarthritis.