http://orthoinfo.aaos.org/topic.cfm?topic=A00216 Osteonecrosis of the Hip Osteonecrosis of the Hip AAOS: Osteonecrosis of the Hip American Academy of Orthopaedic Surgeons AAOS: Osteonecrosis de cadera Osteonecrosis of the hip Osteonecrosis of the hip