Co-authored by Edward Harvey M.D.

- Discussion:
    - symptomatic hip almost uniformly progresses to further collapse without treatment;
    - collapse rates approach greater than 85% in the symptomatic hips, even if first seen in the earliest stages; 
    - treatment plan for the asymptomatic AVN is controversial;
    - approx 30% of the silent hips will go on to collapse;
    - theoretically, a better outcome is achieved w/ early intervention;
    - better outcomes w/ early intervention, have been demonstrated w/ core decompression for very early stages of AVN

Natural history of nontraumatic avascular necrosis of the femoral head.

Deformities of the hip in adults who have sickle-cell disease and had avascular necrosis in childhood. A natural history of fifty-two patients.

The Natural History of Asymptomatic Osteonecrosis of the Femoral Head in Adults with Sickle Cell Disease.

Physical Therapy Alone Compared with Core Decompression and Physical Therapy for Femoral Head Osteonecrosis in Sickle Cell Disease. 

Fate of Untreated Asymptomatic Osteonecrosis of the Femoral Head