Table 3.
Relationship between risk-score levels and estimated hip survival/failure event with bone grafting for ONFHs
| Risk-score level | Hips (n) | Failure event |
Estimate survival time |
Estimated cumulative survival rate |
Estimated annual hazard of failure rate |
|---|---|---|---|---|---|
| (n, %) | (means, M) | mean (95% CI) | mean (95% CI) | ||
| Low risk (≤4.0) | 409 | 32 (7.8%) | 184.9 | 93.4% (91.4% – 95.5%) | 0.5% (0.3% – 0.6%) |
| Medium risk (4.5 – 5.5) | 215 | 36 (16.7%) | 178.5 | 87.3% (84.1% – 90.6%) | 1.0% (0.7% – 1.3%) |
| High risk (6.0 – 6.5) | 301 | 82 (27.2%) | 154.8 | 81.4% (78.5% – 84.3%) | 1.7% (1.4% – 2.0%) |
| Ultra-high risk (≥ 7.0) | 254 | 116 (46.1%) | 117.4 | 71.3% (67.8% – 74.8%) | 3.9% (3.3% – 4.5%) |
| Overall | 1179 | 267 (22.6%) | 165.5 | 79.2% (77.1% – 81.3%) | 1.9% (1.7% – 2.1%) |
Results of Kaplan-Meier survival analysis; there were significant differences between each score level (p < 0.01).