Osteonecrosis of the femoral head with subchondral collapse

[摘要] A 45-year-old woman with a history ofmultiple organ transplants presented witha 1-month history of anterior left hip painwith insidious onset. Although she was able toperform activities of daily living, she reportedincreasing diffi culty with weight-bearing activities. Physical examination of the left hip elicited pain on passive movement, particularly oninternal rotation. Plain radiography of the lefthip (Figure 1) revealed a subchondral radiolucent line in the femoral head, representingsubchondral collapse. This radiographic sign,referred to as the “crescent sign,” is seen in advanced stages of osteonecrosis of the femoralhead. Recognition of this subtle radiographicsign is important because it represents considerable subchondral necrosis and collapse, andindicates that further collapse is likely.

[学科分类] 卫生学