Table 1.

Differences between patients with idiopathic and secondary osteonecrosis and race- and sex-matched healthy normal control subjects for heritable thrombophilia and hypofibrinolysis

Variable	High factor VIII (greater than 150%)	High Lp(a) (35 mg/dL or greater)
Idiopathic osteonecrosis (n = 71; 46 men, 25 women)	19/71 (27%)	25/69 (36%)
Race- and sex-matched control subjects (n = 69; 44 men, 25 women)	3/66 (5%)	12/67 (18%)
p	0.0004	0.016

Variable	High factor VIII (greater than 150%)	Factor V Leiden heterozygosity	Resistance to activated protein C
Secondary osteonecrosis (n = 62; 32 men, 30 women)	16/62 (26%)	6/61 (10%)	8/51 (16%)
Race- and sex-matched control subjects (n = 62; 32 men, 30 women)	5/60 (8%)	0/61 (0%)	2/59 (3%)
p	0.011	0.028	0.042