Potential aetiological factors concerning the development of osteonecrosisof the femoral head

Background The aetiology and pathogenesis of non-traumatic osteonecrosis (O N) of the femoral head have not been fully elucidated. The present study wa s conducted to evaluate the possible correlation of relevant haematological and biochemical factors with the development of ON. Patients and methods Our investigation consisted of measurement of haematol ogical indices and assessment of the biochemical and lipid profile of a stu dy population of 68 patients with non-traumatic ON of the femoral head and 36 healthy controls. The disease was considered idiopathic in 17 and second ary in 51 patients. Results There were no statistically significant differences in the paramete rs measured among the idiopathic ON, secondary ON and control groups, excep t for globulins alpha 1, alpha 2 and beta, which were significantly increas ed in both patient groups, and apolipoprotein B (Apo B), which was increase d in patients with idiopathic disease compared with the control group. Both patient groups presented increased von Willebrand factor (VWF) and lipopro tein (a) [Lp(a)] levels and decreased protein C and S concentrations, but w ithout statistical significance. However, both patient groups exhibited a g reater proportion of abnormal values of any of these parameters, in 58.9% o f the idiopathic and in 62.7% of the secondary ON patients, compared with 8 .3% of the controls. Conclusion Our study underlines the potential association of abnormal value s of protein C, protein S, VWF and Lp(a) with ON. To our knowledge this is the first reported association of VWF with the disease. The majority of bot h idiopathic and secondary ON patients in our series exhibits a thrombotic potential that adds further support to the postulation that intravascular c oagulation is a major pathogenetic mechanism leading to the disease.