Stage
Clinical Features
Radiographs
Early
0
Preclinical
0
0
I
Preradiographic
+
0
II Precollapse
+
Diffuse Porosis, Sclerosis, Cysts
Transition:
Flattening, Cresent Sign
III Collapse
++
Broken Contour of Head Certain
Sequestrum, Joint Space Normal
IV
Osteoarthritis
+++
Flattened Contour Decreased Joint Space
Collapse of Head
------------------------------
Idiopathic Bone Necrosis of the Femoral Head; Early Diagnosis and Rx;
R.P. Ficat
JBJS, Br ed. Vol. 67 B. No 1. Jan 1985;