Table 2.

Risk factors of avascular necrosis (AVN): results of univariate and multivariate analyses to determine significance

Risk factors	Univariate p-value	Odds ratio	95 % CI	Multivariate p-value	Odds ratio	95 % CI
Male gender	0.011	16.6	1.92–142.58	0.027	16.2	1.38–190.76
Age at diagnosis	0.28	1.0	0.97–1.13
Bilateral	0.06	0.3	0.11–1.05	0.027	0.2	0.03–0.82
Left side	0.85	0.9	0.36–2.33
Age >6 months at CR	0.66	0.8	0.29–2.16
Ossific nucleus present at CR	0.16	0.5	0.21–1.31
Bracing before CR	0.28	0.6	0.22–1.55
Traction before CR	0.018	3.5	1.23–9.66	0.019	5.8	1.34–25.43
Adductor tenotomy	0.11	2.7	0.81–9.04	0.37	2.2	0.39–12.70
Hip abduction angle	0.87	1.0	0.97–1.04
Hip abduction angle ≥50°	0.57	1.4	0.47–4.08

CR closed reduction, CI confidence interval, Bracing Pavlik harness/hip abduction orthosis

Variables included in the multivariate model if univariate p-value <0.15 [34]