ABFAS Boards – Rearfoot and Forefoot Practice Test

Prolonged bleeding time reflects a defect in primary hemostasis, where the platelet plug fails to form properly at sites of injury. The most classic condition causing this type of defect is von Willebrand disease, in which deficient or dysfunctional von Willebrand factor impairs platelet adhesion to exposed subendothelium via the GPIb receptor. This delays plug formation and lengthens bleeding time.

Vitamin K deficiency mainly disrupts the coagulation cascade, prolonging PT (and sometimes PTT) but not bleeding time. Aplastic anemia or severe thrombocytopenia can extend bleeding time due to low platelet numbers, but the hallmark, most characteristic association, is the impaired platelet adhesion seen in von Willebrand disease.