Table 4 The univariate analysis of the risk factors related to the incidence of AVN of the femoral head after CR
| Â | non-AVN | AVN | P |
|---|---|---|---|
Number of patients (n) | 66 | 6 | Â |
Age at initial CR (Mo) | 15.97 ± 4.67 | 12.98 ± 45.04 | 0.141 |
Sex (n) | Â | Â | 1 |
 Male | 9 | 1 |  |
 Female | 57 | 5 |  |
Laterality (n) | Â | Â | 0.936 |
 Unilateral DDH | 48 | 5 |  |
 Bilateral DDH | 18 | 1 |  |
Percutaneous adductor tenotomy (n) | Â | Â | 0.308 |
 Yes | 24 | 4 |  |
 No | 42 | 2 |  |
Seniority of orthopedists (n) | Â | Â | 0.086 |
 ≤ 15 years | 25 | 0 |  |
 > 15 years | 41 | 6 |  |
Presence of femoral ossific nucleus (n) | Â | Â | 1 |
 Yes | 10 | 1 |  |
 No | 56 | 5 |  |
IHDI grade (n) | Â | Â | 0.703 |
 II | 23 | 2 |  |
 III | 23 | 3 |  |
 IV | 20 | 1 |  |
MI after CR | 31.83 ± 3.40 | 26.55 ± 4.64 | 0.008 |
AI at the initial CR (°) | 35.80 ± 6.60 | 37.33 ± 5.48 | 0.582 |