Table 1 Preoperative stages of the 71 hips classified according to the Steinberg's classification system.
Stage | Characteristics | Number of Hips |
|---|---|---|
0 | Normal radiographs, bone scan, and MR images | 0 |
I | Normal radiographs, abnormal bone scan, and MR images | Â |
   A: mild | < 15% of head involvement | 0 |
   B: moderate | 15% to 30% | 2 |
   C: severe | > 30% | 1 |
II | Abnormal radiograph | Â |
   A: mild | < 15% of head involvement | 1 |
   B: moderate | 15% to 30% | 3 |
   C: severe | > 30% | 24 |
III | Subchondral collapse producing a crescent sign | Â |
   A: mild | < 15% of articular surface | 0 |
   B: moderate | Crescent beneath 15% to 30% | 1 |
   C: severe | Crescent beneath > 30% | 2 |
IV | Â | Â |
   A: mild | < 15% of surface collapsed and depression is < 2 mm | 2 |
   B: moderate | 15% to 30% collapsed or 2 to 4 mm depression | 8 |
   C: severe | > 30% collapsed or > 4 mm depression | 24 |
V | Joint narrowing with or without acetabular involvement | Â |
   A, B, or C | Average of femoral head involvement, as determined in Stage an d estimated acetabular involvement | 3 |
VI | Advanced degenerative changes | 0 |