Association of Thrombophilic Factors in Pathogenesis of Osteonecrosis of Femoral Head in Indian Population.

PURPOSE

Role of heritable blood clotting disorders, both thrombophilias and hypofibrinolysis in causing avascular necrosis (AVN) of femoral head have been studied in regions like Europe and U.S.A. This study was done to investigate the role of heritable thrombophilias in ethnic Indian population.

MATERIALS AND METHODS

A case control study of 150 patients (100 cases and 50 age and sex matched controls) of Indian Ethnicity with clinico-radiographically documented idiopathic AVN of femoral head was done after ethics committee approval. DNA was extracted from the blood and PCR analysis was used to study heritable thrombophilic gene mutation (G1691A Factor V Leiden). Enzyme-linked immunosorbent assay (ELISA)-based assays, were utilized to measure antigen levels of protein C, antithrombin III levels and protein S.

RESULTS

Nine cases out of 100 showed deficiency of Protein C (9%) while no control showed deficiency of Protein C ( value: 0.028-significant, Odds ratio: 9.791) Ten cases showed deficiency of Protein S (10%) in study population as compared to one case (2%) in control population ( value: 0.038-significant, Odds ratio: 5.44). ATIII deficiency was more prevalent in control group i.e. 22% compared to 11% in study group. Factor V mutation was present in 3% cases as compared to one (2%) in control group. ( value is 0.393-not significant).

CONCLUSION

Difference in thrombophilic mutations in various populations indicates possible effect of ethnicity on genetic profile in the development of AVN. This risk stratification will enable in near future early diagnosis and possible role of antithrombotics in disease prevention.