What is the optimal management of a patient needing surgical clearance for a knee replacement with VWF Ag and factor VIII between 40-50 and no bleeding history?  

This is a difficult question. I would make sure that the patients had adequate "stress tests" of their hemostatic system before concluding they have no bleeding history. For example, it is difficult to estimate the bleeding risk if somebody has never had surgery or pregnancy and has been on OCP sinc...