We hypothesized that inherited thrombophilia and hypofibrinolysis were risk factors for osteonecrosis of the femoral head.
We compared measures of thrombophilia and hypofibrinolysis in referred new adult patients with idiopathic osteonecrosis (n = 71)
or secondary osteonecrosis (n = 62) with the same measures in sex- and race-matched healthy control subjects. Heritable thrombophilic
Factor VIII and hypofibrinolytic Lp(a) were more frequently high in the 71 patients with idiopathic osteonecrosis than in
control subjects. High Factor VIII, Factor V Leiden heterozygosity, and resistance to activated protein C, all heritable thrombophilias,
were more frequently present in the 62 patients with secondary osteonecrosis than in control subjects. Our data suggest inherited
thrombophilia and hypofibrinolysis are risk factors for both idiopathic and secondary osteonecrosis of the head of the femur.
Level of Evidence: Level IV, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.
One or more of the authors (CJG) has received funding from the Jewish Hospital Medical Research Council.
Each author certifies that his or her institution has approved the human protocol for this investigation, that all investigations
were conducted in conformity with ethical principles of research, and that informed consent was obtained.