Table 1 Relationship between hip lesion type and progression of femoral head collapse. Collapse rate and extent were higher for osteonecrosis of type C than for osteonecrosis of types A or B
Collapse distance (mm) | Type | Total | |||
|---|---|---|---|---|---|
A | B | C1 | C2 | ||
0 | 5 | 4 | 4 | 5 | 18(58%) |
0–3 | 0 | 2 | 2 | 3 | 7(23%) |
3–5 | 0 | 0 | 3 | 1 | 4(13%) |
5≦ | 0 | 0 | 1 | 1 | 2(6%) |
Collapsed hip | 0/5 | 2/6 | 6/10 | 5/10 | 13/31 |
Collapse rate (%) | 0% | 33% | 60% | 50% | (42%) |