Can osteonecrosis of the femoral head be recurrent?

Three patients with osteonecrosis of the femoral head in whom the extent of necrosis increased by repeated episodes of osteonecrosis are described. In all cases the evidence of two attacks of osteonecrosis was detected clearly on magnetic resonance images. The significance of the recurrent attacks of osteonecrosis is not clear and the detectable incidence of the recurrence seems to be low. The authors propose the possibility that the osteonecrosis may be the result of multiple episodes of necrosis.